Shell farm manual : a booklet devoted to varied phases of mechanised farming with comprehensive information for "The Man on the Land"

A booklet devoted to varied phases of mechanised farming with comprehensive information for "The Man on the Land.”

INTRODUCTION

For many years the major problem in farm mechanisation has been how to change from the horse to horsepower — the development and perfection of the tractor and the modification of horse-drawn equipment to tractor power. The basic factor in this transformation has been the perfection of the economical heavy-duty high compression engine; the source of the farmer’s power and his greatest friend or enemy according to how he treats it.

Rubber-tyred wheels especially designed for manoeuvrability allowed the tractor to assume the ease of operation now so common an experience with motorists. Greater speeds, ease of handling and flexibility of use became the factors upon which the farmer based his profits.

Following the adaptation of rubber came the application of hydraulic controls with power aids, which enabled the tractor, once a substitute for the horse, to perform all manner of agricultural work. As a stationary engine, the tractor’s power output can be transmitted to operate a variety of smaller mechanisms, ranging from water pumps to orchard sprays.

Tractor and agricultural implement maintenance is now a considerable item on any power farm and a well equipped repair-shop is a necessity. Replacement parts, mechanical failures and breakdowns all cost money. In addition, repairs use valuable time for while a tractor or implement is lying idle the farmer may very easily lose many times its worth in loss or damage to his crops.

The Shell Company has always taken a lively interest in the field of agriculture and Shell Technical Service knows that year after year depreciation and machine repairs can cut the farmer’s profits, unless he gets the maximum of useful work from his equipment. With this knowledge and the desire to assist in correct lubrication where it applies to power farming, the Shell Company of Australia offers its vast technical and research facilities to the “man on the land.”

Kerosine Operated Appliances Laying-out for Ploughing -Lubrication Recommendations -Maintenance Check-up Chart -Poisonous Plants - - -

The engineer’s measure of a tractor’s capacity is its drawbar horse-power. This horse-power, however, bears no relation to the work a horse can do on a farm; that is, one cannot assume that a 10 horse-power tractor will do the work of ten horses. And so, although a farmer will recognise that a tractor of 1? h.p. is fifty per cent, more powerful than one of 10 h.p., he will very likely not know how much to expect from either of them in a day’s work, when pulling, say, a plough or a cultivator. For this reason another kind of measure is commonly adopted for use on the farm. Usually, instead of specifying the h.p., the number of furrows the tractor should plough at once is followed instead. However, this measure is not exact, because the pull required by a given plough will vary with soil, working conditions, and the speed of the work. Generally accepted standards are:—

Land : Australian light and medium farm land is ploughed with a shallow working plough equipped with a small mouldboard. Depths range up to four inches, and ploughs are built to twelve furrows, cutting 6, 7, or 8-inch wide furrows. These are sometimes referred to as skim ploughs, and are not to be confused with the British or American type of skim coulter, where a slice of the sod is cut off and laid beneath the main sod; this is accomplished by a small cutting share fixed above the main share.

For the light soil type of plough referred to above approximately 4 rated drawbar horsepower would be necessary for each furrow. Heavy soils with a depth of furrow up to 10 inches and 16 inches in width would require 8 to 10 drawbar horsepower for each furrow.

Thus, in comparing tractor rated drawbar horse-power to animal horse-power, it may be assumed that a relationship of 2i mechanical drawbar horse-power will be equivalent to one animal horse-power.

MAINTENANCE CHECK-UP CHART

Complete instructions for the maintenance of the. tractor are given in the maker’s handbook, which will naturally differ in detail according to the make. The general principles, however, are the same for all tractors, and they are best practised in accordance with an effective check on running hours. Because of greasy hands on the part of the operator, the necessary details are often omitted from the log book at the appropriate time.

A simple device (Fig. 1), which is easy to attach to the tractor, and at the same time laughs at greasy hands, is an “Hour Indicator.” This device is simply a board mounted conveniently on the tractor clearly showing the hours to 100. At the end of a bout, a nail or stud is placed in the hole opposite the appropriate hour; by this arrangement the operator can see at a glance when the next servicing period falls due. The indicator in no way should take the place of the log book, because through careful recording of running details several benefits result, mainly:—

DAILY—EVERY 8 HOURS

CROSS

To the man on the land every avenue for making money and saving money is an avenue worth investigating. Cross Kerosine is just such an avenue—because every drop of*Cross does a powerful good job. It vaporises completely. Every drop is turned from precious fuel to positive power—and there is no waste. On Cross your tractor responds better, does a bigger job, uses less fuel and, because of its higher quality, your engine needs less servicing. For power that is so important use Cross Power Kerosine—for perfect lubrication of every moving part use Shell lubricants. You'll be repaid time and again. For supplies get in touch with your local Shell Depot or Agent. „

OPERATION TROUBLES

SPARK IGNITION TRACTORS

The following is a list of the more common faults which occasionally occur in tractors, together with the methods by which the operator can locate the trouble in the least possible time:

Ignition switch not turned on No fuel in tank or carburettor Fuel feed lines blocked Fuel pump defective Battery discharged Battery Cables corroded or loose

Exhaust pipe clogged Carburettor mixture incorrect Air cleaner obstructed Choke incorrectly adjusted Air Vent in fuel tank blocked Throttle not opening fully Fuel lines or carburettor jets blocked

’Water pump defective Oil level dangerously low Exhaust or muffler obstructed Smoky Exhaust:

Mixture too rich Engine overloaded Dirty spark plugs, cracked or otherwise faulty Restricted exhaust or muffler Blue Smoke—

Air Cleaner oil level too high Air Cleaner oil too light Piston rings worn, sticking Crankcase oil level too high. Defective Ignition:

Wrong type, old, cracked, dirty or poorly set spark plugs. Broken, loose or improperly connected wiring Distributor cup cracked or con' tacts dirty

Breaker points pitted, dirty or improperly gapped Breaker arm sticking Magneto not timed correctly

Backfiring -— Misfiring Valves sticking Carburettor mixture too lean Foreign matter in carburettor Air leaks around intake mani' fold

Engine not warmed up Red hot carbon deposits in combustion chamber Ignition timing excessively re' tarded Knocking:

Excessive carbon in cylinders Loose piston pin, connecting rod, camshaft, or crankshaft bearings

Oil pump strainer clogged, or pump not functioning Oil gauge faulty Leaks in oil lines

Carburettor adjustment too rich Clogged fuel strainer Faulty fuel pump Jet size incorrect Jets worn or clogged Excessive idling or idling speed too high

Crankcase oil level too high Oil pressure too high Crankcase breather clogged Oil grade too light or oil diluted

Bearings loose or worn Crankshaft oil seals faulty. Gaskets, oil seals, or external oil lines leak

DIESEL ENGINE TROUBLES

There are two items of prime importance upon which the satisfactory performance of the high speed diesel engine depends.

The first item depends very largely upon pistons, piston rings, and valves, together with their operating mechanism, whilst the second item largely depends upon the injectors and their operating mechanism.

Below are given a series of troubles, which may be experienced by operators, together with a few of the possible causes and suggested remedies:—

1. ENGINE WILL NOT START

Note: Exhaust smoke is caused by incomplete combustion of fuel and/or burning of excess engine oil in the combustion chamber or exhaust manifold.

An accumulation of engine oil in the combustion chamber will cause a blue smoke when the engine is started. If this smoke does not disappear eventually, but increases with engine speed and decreases with load, it is an indication that excessive engine oil is passing by the piston rings, due possibly to stuck or worn rings and pistons.

White smoke is vaporised but unburnt fuel. If it continues after the engine is running, it indicates that one or more cylinders are misfiring.

Brown or black smoke is the visible concentration of excess amounts of unburned carbon particles. Combustion is never absolutely complete, but in the cases of good combustion the concentration of carbon particles is so small that the exhaust is barely visible.

4. FUEL PUMP

If this item is suspected of being faulty, it should not be tampered with unless proper equipment and specially trained personnel are available to rectify the trouble.

Provided that clean fuel is supplied to the pump and it is not tampered with, it should give trouble-free operation for at least 100,000 miles. It is recommended, however, that apart from usual maintenance, the pump should be removed from the engine when the vehicle is in dock for overhaul when it can be sent to the local agent for the necessary check up.

5. INJECTORS

The first symptoms of injector trouble usually fall into one or more of the following headings:—

SHELL AUTOMOTIVE ENGINE OILS AND SPECIALISED LUBRICANTS

ENGINE OILS

Shell Premium Quality Motor Oils. These are top quality additive type engine oils recommended for use in all types of petrol engines.

Silver Shell Special SAE 10 Triple Shell SAE 50 Silver Shell SAE 20 Golden Shell SAE 60

Shell Talpa Oils. These are 'Straight Mineral’ type diesel engine lubricants complying with the specifications of various English manufacturers. Available in SAE 20, 30, 40 and 50 viscosity ratings, and frequently recommended for industrial engines.

Shell Rotella Oils. These are 'Heavy Duty’ type diesel engine lubricants meeting U.S. Army Specification 2-104B, possessing outstanding wear resistance and engine cleanliness properties. Available in SAE 20, 30, 40, and 50 viscosity ratings.

Shell Rimula Oil. A “superior” Diesel Engine Lubricant for EXTREME conditions. Available in S.A.E. 30 viscosity rating only.

Shell Rotella Oil will demonstrate its superior qualities to a maximum when used in a new or newly-overhauled engine; when introduced into an engine which has been operated for some time since overhaul, it will reduce further engine wear and will show some removal of deposits laid down by previous oils. Therefore, when introducing Shell Rotella Oil into an engine which has been operated on oils other than heavy duty, the following procedure should be followed:—

3. Depending upon the prevailing conditions of clean liness, the initial charge of Shell Rotella Oil should be drained at approximately one-third to one-half normal drain period.

4. Thereafter use the correct grade of Shell Rotella Oil and return to normal maintenance procedure.

SHELL GEAR OILS

Shell Spirax 90EP and 140EP are all purpose extreme pressure gear oils conforming to the requirements of all vehicle and gear manufacturers’ specifications including U.S. Army Specification 2-105B.

Shell Spirax C is a high quality SAE 140 lightly compounded gear oil not containing E.P. additives.

Shell Dentax. These are high viscosity-index straight mineral gear oils available in SAE 90, 140 and 250 viscosity ratings.

SHELL SPECIALITY GREASES

AUTOMOTIVE HYDRAULIC EQUIPMENT

Where a compounded oil is necessary, use Shell Trochus Oil J31 or Shell Oil G9170. Where a straight mineral oil is approved use the appropriate Shell Motor Oil grade according

TURAL LUBRICANTS

For use in sheep shearing machines, reapers and binders, as a heavy milking machine oil, and as a general medium bodied machine bearing lubricant.

A similar but heavier oil for use in chaff cutters, grain cutters, wheat graders, etc.

A medium bodied oil for lubrication of windmills (exposed gears), ploughs, harvesters, etc.

Without lubrication the life of a tractor could be measured in minutes, the forces generated in the engine alone would cause its own destruction so quickly that it would not be worth the time and expense of manufacture. The motion of all engine parts is accompanied by frictional wear, and friction as we know it, is the resistance that exists between two bodies in contact which tends to prevent their motion on each other. Although metal surfaces appear quite smooth to the naked eye, under magnification their irregularities are plainly visible. These minute irregularities cause the metal to adhere in contact thus resulting in the destruction or tearing-off of the projecting particles, a process which is known as “wear.”

The tractor’s actual value can only be assessed from its capacity for work and its general usefulness. Work, however, means motion and motion means friction, and as previously explained friction promotes wear— all factors which materially contribute towards the shortness of the tractor’s working life. The basic requirement of a lubricant is that it should reduce friction by preventing direct contact of moving surfaces, and a good oil when so used will reduce the rate of wear. It is now an established fact that the care and regularity with which correct lubricants are applied, is the most important item in determining the life of the tractor once it has left the manufacturer.

The engine in your tractor is first and foremost a heat engine, the liquid fuel is converted into heat energy by burning, and this heat energy is used to do the work of moving the tractor along. However, no more than about 25% of this energy is transmitted to the rear wheels, the remainder is lost by radiation from the engine and by the flow of hot gases through the exhaust, and in overcoming internal friction in the engine and transmission. The most efficient automotive engine . designed to date has a thermal efficiency of about 25%, i.e., it uses only 25% and wastes 75% of the heat energy of the fuel it consumes (Fig. 2).

This flow of waste heat is a major problem in engine design. Unless it can be put to useful work, heat exerts its energy destructively on every part of the engine, and the problem is to conduct it away from the engine to the outside air as rapidly as possible. Correct lubrication, however, largely prevents overheating.

Once used in the automotive engine, oil is no longer the clear, Viscous liquid poured from a spotless container. It becomes a part of the engine itself. Inanimate though it may appear alone, once placed in an engine it becomes a life-giving fluid, just as essential to and as much a part of the engine life as a crankshaft or piston. The value of engine oil is represented by its ability to protect the engine, yet paradoxically, it is eventually made worthless by the same engine to which it gives life.

Automotive engine oil is required to perform four separate and distinct functions in the lubrication of an engine; it must cool, lubricate, seal and scavenge. Simple functions, these, if they could be performed separately in an engine. Simple too, if a separate oil could be used for each task, but automotive engine oil is called upon to perform all of these duties in the same place and at the same time.

Firstly, to cool oil must stay thin and to seal it must stay thick; to lubricate it must stay clean; and to scavenge it must get dirty. An engine oil that can fulfil these varying requirements and not eventually be damaged in fulfilling them cannot be produced under the existing natural laws as man knows them. The successful performance of these tasks requires that a single oil embody many diametrically-opposed characteristics, and so far as it has been scientifically possible Shell Research has developed automotive engine oils which efficiently perform these tasks.

HOW AN ENGINE OIL COOLS

Cooling is usually associated in thought with a cold substance such as ice, which we know can absorb heat. But such a cooling agent is always eventually destroyed by continuously absorbing heat, because, by itself, ice cannot discharge this heat as fast as it is absorbed, except by melting. Similarly, motor oil in an engine is a coolant which continually absorbs, transfers and dissipates heat, but unless this heat is absorbed from the oil as fast as it enters the oil must be destroyed. In acting as a continuous transfer medium, the oil absorbs heat from the engine bearing, cylinders and other parts, then carries and transfers the heat to the sump or some other part of the engine'which is cooler (at a lower temperature) than the oil itself. For the oil to transmit heat away from vital engine parts it must be free flowing. Free and rapid flow of oil aids cooling because the layer of oil in contact with metal surfaces is being continuously changed, and for this reason to secure the best cooling action, it is essential that a large quantity of oil circulates rapidly over the heated surfaces.

Upon the viscosity or thickness of the oil depends its degree of flow. A large quantity of rapidly-flowing light oil in the crankcase, will give better cooling results than the same quantity of heavy oil which will not flow as rapidly. Oils are not ideal coolants because they are viscous in nature; hence, they do not have the quick-flowing action of water or similar lighter fluids. Heavier oils (higher S.A.E. grades) do not have the cooling properties of lighter oils, simply because they do not flow as fast under the same temperature conditions. Further, lighter oils will penetrate into closer clearances, thus reaching greater surface areas from which to carry away heat.

HOW AN ENGINE OIL LUBRICATES

Perhaps one of the best methods of describing the simple act of lubricating is to divide the actual act into three parts. First, the ability of the oil to make a surface slippery; second, its ability to adhere to the surface; and, third, its ability to maintain a film between rubbing surfaces.

In order to make a surface slippery, oil molecules are believed to roll or slide over each other, and this can best be visualised by thinking of the molecules as tiny pliable balls which, when enough are present, roll, and slide about like raindrops on a greasy surface.

In order to adhere to a metal surface, an oil must spread readily over and cling to the metal. Certain liquids possess varying abilities for adhering to metal surfaces. For example, kerosine will cling to metal quite effectively, whereas mercury tends to form globules when in contact with a metal surface and thus does not adhere readily. From the foregoing it would seem that a light oil with the same clinging or adhesive abilities of kerosine would lubricate well. This, however, is not correct, because in an engine the surfaces to be lubricated are often so hot that such an oil would vaporise as fast as it touched the hot metal surfaces. Obviously, then, it is desirable for an oil to have adhesive qualities and a high boiling point so that it will penetrate between and cling to the closely-fitted hot metal surfaces.

In order to maintain a film between two surfaces in motion, it is acknowledged that an oil must have film strength. To state it another way, once a film of oil is established between two surfaces, the resistance of the oil to the rupture of that film is its film strength. Oil besides possessing adhesive powers also has forces of cohesion, which means that the oil molecules will cling together, and thus maintain an unbroken film under pressure or against the shearing action which occurs between surfaces moving over each other at high speed.

HOW AN OIL SEALS

Sealing is required of an engine oil in order to prevent gas leakage past the pistons, a condition usually known as “blowby.” There is always some gas leakage even in a new engine under ideal conditions, due to the fact that two metal surfaces are never perfect. Therefore, the high spots on one piece of metal strike the high spots on the other, and, as a result, they will not fit perfectly together. Further, to allow for the unequal expansion of the pistons and cylinders as the engine becomes heated, and to provide space for an oil film, there must always be a clearance space between the pistons and the cylinder walls, and between the rings and their grooves. An oil film can effectively fill these clearances thereby creating a seal. The function of engine oil as a sealing medium is perhaps the most easily understood of its four tasks. As might be expected, the more viscous an oil is, the better it will seal. However, the high temperatures which are present on the cylinder walls and pistons tend to reduce the body or viscosity of the oil and, therefore, its ability to seal.

In the task of sealing alone, an oil which does not thin out readily at high temperatures is preferable. In this function, however, oil can only be considered as a portion of the problem, because badly worn cylinders and piston rings will offset the chances of any oil preventing a blowby. The design, materials and workmanship of the piston rings and cylinder walls play an important part in the sealing problem. With the closely fitted parts of modern engines a light oil may be used because it will do an effective sealing job and have additional advantages from a cooling standpoint. As the engine becomes worn, it may be necessary to use a heavier oil in order to seal effectively; but in a new engine the use of too heavy an oil increases the rate of wear, for such an oil cannot penetrate closer clearances and, therefore, will not do as good a lubricating job as the lighter oil.

HOW AN OIL SCAVENGES

In order to scavenge effectively, oil must act somewhat as a cleanser. It must wash the interior of an engine much as water does when used in washing dishes. Just as dish water becomes discoloured in use, the scavenging action of oil results in its natural discolouration. Dirt, carbon and waste products are constantly being picked up and carried in suspension by the oil.

Discolouration in reality is the tendency of light-coloured oils to turn dark quickly, because the oil is carrying on its work of scavenging effectively. An oil which has a dark colour originally will not show the same amount of dirt as will a light-coloured oil, for the same simple reason that a dark coloured shirt does not look dirty as quickly as a white one. Then, too, an oil which does not scavenge well, but leaves the dirt and carbon deposited on the interior of the engine, instead of carrying it to the crankcase as it should, may quite easily remain in apparently good condition insofar as coloured appearance is concerned.

Lighter oils, that is oils of lower viscosity, have better scavenging properties than heavy oils, just as flushing oil is a better washing agent than grease. Kerosine would be an excellent scavenging medium, but here again a single function must be balanced by the requirements of the other functions of lubricating, cooling and sealing.

Good filters are able to remove the solid contaminants from the oil, thus keeping it in condition to continue its work of scavenging. Unfortunately, however, the liquid filth, such as partially-burned fuel, combinations of water and unburned fuel will chemically combine with the oil, and naturally, thereafter cannot be filtered. Any engine oil which contains the dissolved impurities from an engine, as a result of its acting as an engine scavenger, its exposure to flame, and the chemical changes created by these actions, will eventually become so saturated with impurities that it carries more harmful contaminants into the engine’s working parts than it carries away.

Only technical skill, first-class production facilities and a background of extensive research into petroleum chemistry such as Shell possesses, can ensure the provision of these necessary qualities in a lubricating oil; the methods and tests employed are complicated and no simple striking demonstration of their success is possible, because it is very difficult to reproduce conditions in the combustion chamber outside the engine. Shell have been in the past, and will continue to be, a reliable source of intelligent advice and guidance to the layman in the selection of oils for specific purposes, Shell has leadership in lubrication and Shell is your best guarantee.

Deakin University is not endorsed by or affiliated by the Shell Company of Australia

SHELL SERVES THE PRIMARY PRODUCER

Cattle or corn, wool or wheat. . . . Shell makes the primary producer's work more profitable. Shell chemists and scientists never let up in the search for ways to improve existing products and to evolve special products for new needs.

For all standard needs you will find Shell's regular brands exactly suited, economically priced, and consistently reliable. If you discover a new need, please write or telephone your local Shell Depot or Agent, and the Shell laboratories will be most interested to help. Shell brands of general interest include : •—

YOU CAN BE SURE OF

TRACTOR LUBRICATION

The modern tractor is a costly unit of machinery, and it is expected to work efficiently throughout the year. Without correct lubrication, however, heavy repair bills will be inevitable and operating profits will gradually disappear.

In order to appreciate the need for correct lubrication, it is necessary to consider what is actually happening inside the engine when the tractor is hard at work. The engine is operating at a governed speed with the loads constantly changing. The speed of the pistons changes from time to time and the bearings likewise carry a varying load; the valves and camshaft remain under constant load, whilst the transmission is subject to many changes according to the type of soil or conditions of operation. All these parts must be lubricated adequately and efficiently. The oil is their sole protection against the grinding wear which hard work, high temperatures, and foreign matter, such as dust, impose continually upon them.

On a cold morning the correct grade of lubricating oil in an engine will enable the operator to start without difficulty, and the oil will be readily pumped to all parts requiring lubrication. In a short time the engine will reach a normal working temperature, and a corresponding rise in oil temperature can be observed. The oil will be slightly thinner and will register a lower oil pressure reading than when starting up from cold. The difference in oil pressure reading is therefore normal, but when a distinct drop is noticed in the pressure this may be taken as a warning of impending mechanical trouble or that contamination has occurred as a result of unburnt fuel mixing with the oil and thinning it out.

This dilution of the oil occurs in every engine irrespective of the fuel used, and unless the oil is changed at specified intervals, considerable damage may result. Some manufacturers advise that a certain quantity of oil must be drawn off at the end of a fixed number of running hours. This is because the addition of clean oil assists in raising the lubricating value and makes the sump oil slightly more viscous. Contamination, however, still goes on, and we find that field dust, carbon and water collect and gradually change the character of the lubricant with the result that on observing the dipstick it will be found that the oil has blackened and will appear to be quite thin.

Experience has proven that the rate of contamination is not necessarily progressive, but the total amount of foreign matter that can be determined by chemical analysis clearly proves that the sump oil must be rejected at a set period, dependent upon its design and its operating conditions. Dust with which tractors are frequently covered is one of the biggest enemies to lubrication, because dust and oil form an excellent grinding paste.

Carefully designed air cleaners, which prevent dust from entering the engine are a standard fitting, and in the majority of cases they are known as the “oil bath” type. They should be cleaned and serviced with oil frequently, and regular attention should be given them to ensure that they are functioning correctly, particularly when operating under dusty conditions. From the fuel aspect, attention is no less important because a dirty air cleaner restricts the air flow to the engine, and thereby results in a rich mixture and excessive consumption. Water found in oil may, in most cases, be traced to condensation. If a large quantity is present it suggests that a dirty container has been used for topping-up, or a mechanical fault requires attention, possibly a defective cylinder head gasket. The presence of water is, of course, most undesirable, and the constant pumping and churning within the crankcase will produce an emulsion which heat and carbon will eventually turn into a sludge.

Breathing devices fitted to the crankcase provide correct ventilation, but if dust and foreign matter are allowed to restrict the flow of air, condensation is inevitable. Crankcase ventilation can be likened to travelling in a closed-in car on a cold, wet day. The windows soon steam up and your vision is blurred, but immediately a window is lowered the circulation of air is restored and the steam gradually disappears.

In general, tractors operating on kerosine require a slightly more viscous lubricant than should be used in a diesel or petrol engined model. Kerosine being less volatile than motor spirit tends to accumulate in the crankcase if not completely vaporised and burnt. This has the effect of thinning the lubricant, and the use of a slightly heavier oil counteracts this to some extent.

The word “bearing” has many meanings, but when applied to mechanical engineering it describes any machine part that supports a load. In operation any surface that moves over the surface of another object, without the aid of lubrication develops a condition known as solid friction. No engine or machine can operate without moving the surface of one part over the surface of another, and no surface can pass over another without creating friction. Power must be used to overcome this friction because friction is the force that resists the movement of one surface over another. Therefore, if friction reduces the amount of work a machine can do, it is obvious that if lubrication reduces friction, the better the lubrication the more efficiently the machine will operate.

At some point in every moving part of a machine there is a friction point which bears the load at that spot. It has already been mentioned that friction exists in every moving bearing and that friction absorbs power and that it can only be overcome by substituting fluid friction for solid friction. Thus machine bearings are usually classified in two main groups, namely: (1) Plain-Type Bearings, and (2) Anti Friction Type Bearings. In plain-type bearings, one body slides over the surface of another while with anti-friction bearings the surfaces are separated by balls or rollers, and rolling friction is developed.

PLAIN TYPE BEARINGS :

These types of bearings are those which have sliding contact between their surfaces and they may be grouped under three main headings:—

(3) Thrust bearings, or those which restrict or support the longitudinal motion of a revolving shaft.

Reference to the illustration (Fig. 3) explains pictorially the exact function of plain-type bearings although it must be remembered that each of these main groups, in actual machine practice, are sub-divided into different types, although their function remains basically the same.

PLAIN BEARING LUBRICATION :

An important factor in plain bearings is that proper clearances must be maintained in relation to the speeds and loads under which the bearings are operated. The clearance must allow for the expansion and contraction changes and provide sufficient space for the lubricant to enter and maintain its protective film. The necessity of providing space for the lubricant is of major importance. Too small a clearance will not allow a sufficient supply of lubricant to form a film to cushion the load. The degree of clearance between the journal and the bearing surface controls to a large extent the viscosity of the oil to be used. Small bearing-clearances normally require the use of a light oil, whereas larger clearances require a heavier lubricant. Excessive clearances promote “slapping” or “knocking” of the journal against the bearing, which results in the rupture of the oil film and subsequent metal to metal contact.

ANTI FRICTION BEARINGS :

All anti'friction type bearings are those which have rolling contact between their surfaces. Ancient history provides many instances wherein the use of this type of bearing was employed to move heavy loads to save the manual energy normally required to shift objects subject to solid friction.

The everyday names “ball” and “roller” are obtained from the shape of the bearing itself. Except in special cases ball and roller bearings consist of two rings or races, a set of rollers or balls and a cage. The cage separates the rolling elements and spaces them evenly around the circumference of the races and because of the cage, a bearing is a self- ' contained unit which makes for easy handling.

Bearings are classified according to the manner in which they support a load. By this method, ball and roller bearings are known as “radial” or “annular” and “thrust” types. In the “radial” or “annular” the load is carried in a manner described by the names themselves, which actually mean “round.” Thus the load carried surrounds the outer ring of the bearing. The “thrust” type bearing supports a load moving parallel to the axis of the shaft upon which the bearing is mounted (Fig. 4)

The main difference between ball and roller type bearings lies in the fact that ball bearings (Fig. 5), carry their load at any one instant on two diametrically opposed tiny “spots” of contact. The roller bearing (Fig. 6), on the othe hand, carries its load at any particular inst.nt on two fine “lines” of contact also opposite each other on the roller. Since the FIG. 5 area of contact in both cases is very small, it Spot contact .should be obvious that the ball or roller must

be made of a material which will not distort under loading, thus increasing the area of contact by “flattening-out.” For this reason, ball and roller bearing parts are made from hardened steels and precision workmanship is required in their machining if the area of contact is to be kept at a minimum, and the anti-friction properties to a maximum.

BALL BEARINGS :

In theory the balls in ball bearings are perfectly spherical in shape. Their varied application however, makes it necessary that they be arranged in many different types of assemblies. By changing the race construction they can be built to accommodate radial loads, or thrust loads, or a combination of both. In some cases they are assembled in multiple rows in one bearing unit. By simply changing their site and number or the construction of the races, cages and separators, a ball bearing can be made to accommodate almost any antifriction load.

ROLLER BEARINGS :

This type of anti-friction bearing is divided into two groups, namely — straight roller bearings and tapered roller bearings. The straight roller bearing may be either a solid roller or the hollow type. The latter is often referred to as a “flexible” roller bearing because its structure enables the roller to accommodate itself to slight irregularities in the surfaces of the parts with which it is in contact.

The tapered roller bearing is a solid roller, and its shape approximates that of a cone. Generally, tapered roller bearings are used where a certain amount of thrust as well as radial load must be supported, and where it is desirable to eliminate a separate thrust hearing unit. A good example of the use of a tapered roller bearing is in the front wheel assembly of a wheeled tractor.

No bearing gives an unlimited length of service and, like any other machine element, can be damaged and made unserviceable for various reasons. If the bearing is exposed to moisture or dirt, it may be rendered unusable through rust or abrasive wear. However, if it is protected, well lubricated and carefully handled, all causes of damage are eliminated except fatigue of the bearing itself. The usual bearing failures which result from fatigue are:—

It is important to learn to identify the various kinds of bearing failures because it is only by studying the appearances of the failed bearing that some guide is provided for locating the cause.

Flaking may be identified in the early stages by a small bruise on the race surface; as it progresses the mark takes on an eroded appearance which may become a scraggy scar over the entire raceway. Flaking can be an indication that the useful life of the bearing is coming to an end. There are other reasons for flaking, such as incorrect shape of the shaft or the bearing housing, faulty mounting or that edge loading on the rollers has occurred.

Cracking: Crack formations are many and varied and are generally the result of a heavy load of short duration, overloading the bearing to a degree where faults develop. They are easily recognisable and indicate that the bearing ring is yielding under loading thus bringing out any errors due to a hard to detect fault in manufacture.

Cavitation and Pitting: When foreign matter enters a bearing and is pressed between the rolling elements and the rings, indentations occur in the raceways. Heavy or impact loads can cause cavities at the points of ball or roller contact and in some cases, also where the bearing is subject to vibration. Cavity faults are easily distinguished by the distinct dents which develop within the bearing ring.

Smearing: Smearing is a variety of seizing in its early state caused by two surfaces sliding one upon the other. The more common cause of this type of fault is due to the bearing being filled with a hardened lubricant which retards the roller action. Lubricating grease that is too thick or oil of a heavy viscosity can produce a braking effect powerful enough to make the rollers slide on the track when they pass from the unloaded to the loaded sone. Smearing is most likely to occur when the machine is first started up, and before it reaches normal operating temperature. Although this condition does not affect the machine when normal running is reached, it does speedily reduce the lifetime of the bearing. To assist this condition it is important to lubricate bearings strictly in accordance with the makers’ instructions. Smearing in appearance resembles the marks left on metal when it is rubbed in a circular motion with an abrasive material such as steel wool.

Creep: Wear may develop through the inner ring of the bearing creeping upon its shaft. This may be due to too loose a fit at mounting or through some other mechanical condition. A bearing subject to creep is naturally not rigid on its shaft and excessive wear will develop in the bearing ring, on the shaft and to the bearing housing. This condition calls for a skilled mechanic to trace the cause and effect repairs.

Corrosion: Or rust formation in bearings is the result of the entry of either water or moisture from humid surroundings. Prevention against rust is achieved with the use of the correct lubricant and the avoidance of handling or exposing bearings to moisture-laden air.

Cage Failure: Cages for balls and rollers are sensitive to poor or improper lubrication. Wear develops where the cage contacts the rolling element and the rings and where the lack of lubrication is evident, cage failure will result. In all cases if the bearing is well and efficiently lubricated, cage failure will seldom, if ever, occur.

Anti-Friction Bearing Lubrication: Under different conditions, either lubricating oil or grease may be used for ball or roller bearing lubrication. The type of lubricant depends largely upon the design of the equipment in which the bearing is used. In machines where lubricating oil may be readily supplied to the bearing, the ability of fluid lubricant to dissipate heat more readily than semi-fluid or solid lubricants such as greases, makes this method of bearing lubrication an ideal one. However, in practice, where full automatic lubrication is difficult or impracticable, or where a minimum of attention can be given to those parts during operation, such as during a ploughing bout, the use of grease lubrication in the bearings is the most practical method. The texture of greases used in anti-friction bearings should never be of the long fibre or stringy type. Experience has shown that such long fibre or stringy type greases are not satisfactory in this type of bearing.

To secure the maximum life and full service from pneumatic tyres, they should be kept inflated to specified pressures. Air pressures should be checked every two weeks and they should not be allowed to drop below the manufacturers' recommendations. Where possible, when checking tyre pressures, use a special low-pressure gauge with one pound graduations.

UNDER INFLATION

This condition is indicated by flexing of the tyre sidewall which eventually breaks the cord fabric. When buckling occurs, the air pressure should be increased to a point where the sidewalls remain smooth while the tractor is being operated. Under inflation may also cause the tyre to slip on the rim resulting in the valve stem being torn from the tube.

OVER INFLATION

When a tyre is over inflated, the load is carried in the middle of the tread surface leaving the tyre shoulders with little or no load, this causes excessive wear of the tread. Over inflation reduces the area of ground contact which results in a loss of traction and subsequent excessive slippage. The tyre is under great tension, which causes a weakening of the cord body and-a probability of tread cutting. Because-of the-hardness of the tyre and its loss of shock-absorbing ability the beading is strained and the tyre’s life is considerably shortened.

PRESERVING THE TYRE'S LIFE

When new tractors are despatched from the manufacturer all tyres are given a high pressure to prevent bouncing and scuffing during transit. Therefore, it is important to check and perhaps lower the tyres’ pressure before putting the tractor to work. However, care should be exercised to avoid lowering the pressure below the maker’s limit. When ploughing it is advantageous to the tyre and work as well, to increase the furrow wheel tyre four pounds. This increase will offset the load transferrred to the furrow wheel tyre by the tilted position of the tractor. When the tractor is left in the hot sun for a time, cover the tyres with bags and if it is not intended to be used for a lengthy period, jack up the wheels to relieve the tyres from strain. Wipe off all oil or grease that may have contacted the rubber and for this reason do not spray the floor of the tractor shed with old sump oil. It may keep the dust down, but it will also destroy the rubber surface rapidly. After using the tractor for spraying work flush off any chemicals on the tyres with water.

TYRE TRACTION

The draw-bar pull or traction exerted by a tractor tyre is in direct proportion to the load carried by the tyre. The amount of draw-bar pull, in pounds, is determined by the type of soil in which the tyre is working.

Increasing the actual tyre size by replacing it with a larger size does not greatly increase the draw-bar pull. The result however would be that the larger tyre size will carry greater loading and in consequence great draw-bar pull can be gained by adding more wheel loading. For every 2 lbs. extra weight added, approximately 1 lb. more draw-bar pull up to the power output of the engine may be obtained in relationship to the carrying capacity of the tyres.

THREE QUARTERS INFLATION

The use of water ballast to increase the draw-bar pull and “tractive efficiency” of tyres has a very distinct advantage over the practice of increasing wheel loading, by the use of weights. With weight wheel loading the additional weight is borne by the axle and tyre, whereas with partial water inflation the weight is in the tyre where it will give the best results. Actually for every gallon of water used the wheel and tyre weight is increased by 10 lbs. and the draw-bar pull by approximately 5 lbs.

The full inflation of tractor tyres with water is not recommended by some manufacturers because with this practice the tyres are made solid which results in a loss of shock-absorbing ability. The common practice is to fill tyres three-quarters or 75% of their capacity with FIG. 7 water (Fig. 7). The quantity of water re quired is gauged when filling the tyre, by setting the wheel with the valve in “top dead-centre” position. When the water commences to flow from the valve level of its own accord, then the level has been exceeded. The remaining quarter or 25% of air left in the tyre should be brought to correct pressure. Thus with a combination of water and air, traction is increased while the tyre retains its cushioning quality. Water inflation does not affect the life or performance of rubber inner tubes and providing a tractor with partly water inflated tyres is not operated before the tyres are brought to correct air pressure, no detrimental effects to the tyres result from the use of

WATER BALLAST INFLATION CHART

During very cold weather, which occurs throughout the country in winter months, there is a possibility of water in tractor tyres freezing. An efficient anti-freeze solution can be made by adding 1 lb. of Calcium Chloride for every gallon of water. By way of caution, remember to put Calcium Chloride in water (not water on Calcium Chloride) in an open container and allow the solution to cool.

LOAD AND INFLATION CHARTS

When mounted implements are used on tractors, loads may be increased up to 20% with no increase in air pressure.

FULL INFLATION

Although it has been a recognised practice for some years to fill tractor tyres three quarters full, a new development now makes possible tyres 100 per cent, filled with water. It is in no way suggested that the new method outmodes the former, but the performances claimed make interesting reading. It was found that by filling tractor tyres completely with water after evacuating all air, some unexpected improvements resulted. The extra liquid added to the tyre by this method is on the average about 25%. The resulting increased weight means better traction with a reduction in slippage between the tyre and the soil and it is claimed 100 per cent, water filling enables more work to be done with a given amount of fuel. Slippage causes friction and by reducing friction energy is saved and diverted to useful work.

Although water is considered incompressible, in actual tests it was found that there was no decrease in the tyres strength, and resistance to exterior damage remained the same. Another advantage claimed is that once a tyre has been filled 100 per cent, to the correct pressure, no loss of pressure will occur unless there is a leakage due to a puncture or a defective valve. This means that the operator where his tyres are fully water inflated does not have the responsibility of constantly checking the air-pressure and re-inflating them when necessary. Water filling cannot be achieved by the usual methods, and a special pump is required to effect 100 per cent, filling. Information concerning the pumps, together with its application should be sought from the local garage or tractor dealer.

TRACTOR HITCH ADJUSTMENT

No set rule can be given to cover the directions for hitching implements to a tractor, but a knowledge of the principles involved will enable the tractor owner to couple his implements correctly.

Although many farmers have from time to time observed a high fuel consumption, together with difficulty in managing their tractors, never once has it occurred to them to look to the hitch to correct their troubles. More often than not the tractor or its engine received the blame for high fuel consumption or difficult manoeuvrability.

It has often puzzled tractor owners why some tractors con' sume more fuel than others of a similar make under the same conditions of soil and loading. The reason for this variance in performances when conditions are identical can in nearly every case be traced to the hitch.

Field tests have proved that improper hitching can increase draught to such a degree that fuel consumption climbs by over 25%. Added to this increased operating cost, excessive wheel bearing wear occurs, together with rapid deterioration in plough bottom parts.

Simply described, the perfect hitch is a straight line from the point of load on the implement to the point of pull on the tractor, both vertically and horizontally.

The centre of load on a plough is located at a point one-fourth of the width of cut of one bottom, measured to the left of the centre of cut at the point of share and mouldboard, when ploughing approximately seven inches deep. The point or centre of pull on the tractor is approximately three inches ahead of the rear axle, at a point midway between the wheels.

HORIZONTAL SETTING :

In a tractor with two drive wheels connected by the orthodox differential, approximately equal pull is exerted by both wheels Friction in the differential gearing however causes one wheel to pull slightly more than the other, but its effect can usually be discounted.

To illustrate how the hitch may be worked out, let us assume that a two bottom 12 inch plough cutting 24 inches, is coupled to a general purpose tractor with a tread adjustment of 56 to 88 inches.

One-half of the total cut is 12 inches, that is, the centre of cut, one-fourth the width of one bottom (3 inches) measured to the left, brings the point of load to 15 inches from the furrow wall. With the tractor wheels in their narrowest setting, in this instance 56 inches, the distance between tyres (using 10-inch tyres) and measuring from the centre of each tyre is 46 inches. The point of pull therefore is at the centre of the 46 inch width between tyres or 23 inches from the furrow wall. As the point of load is 15 inches from the furrow wall there is a difference of 8 inches, which must be necessarily offset by adjusting the hitch on the cross-bar to the land (Fig. 8). Usually modern ploughs are designed to handle up to an 8-inch variation from the straight line, and in this case a difference of 8 inches is within the limit, although with the use of wider bottomed ploughs the shift will not be excessive.

With the hitching of larger ploughs of three or more bottoms, the tractor tread can be widened to permit horizontal hitching by following the procedure outlined. Example: A three bottom 14 inch plough has a centre of draught 24 J inches from the furrow wall, thus both tractor wheels should be set out 1J inches to attain the proper line of draught.

VERTICAL SETTING

All normal draw-bar loads transfer weight from the front to the rear axle. Similarly the amount of weight transferred is increased as the hitch is raised higher. Thus a reasonably high hitch is required for a rear wheel drive tractor because the increased weight on the rear wheels improves traction and only sufficient weight is needed at the front to make for easy steering. With tracklaying tractors, however, traction is improved by a low hitch because efficient performance demands an equal distribution of weight on the tracks.

Usually the commonest error in vertical hitch adjustment is in having the hitch crossbar adjusted too high, which causes the plough to run on its “nose” through excessive weight on the front wheels; this results in heavier draught and excessive wear on the points of the shares. Further, when the hitch is too high on the plough, it is correspondingly low on the tractor causing wheel slippage with a loss of traction and power wastage. ,

Adjusting the hitch crossbar too high on the tractor and too low on the plough results in an upward pull on the front of the plough, thus reducing the weight on the front wheels, and placing too much weight on the rear wheel, this may cause the land wheel to slip when the clutch is engaged. Likewise a low hitch on the plough throws greater weight on the rear driving wheels of the tractor, which naturally makes the tractor difficult to handle.

The correct vertical hitch adjustment can best be determined by ensuring that the hitch crossbar on the plough falls on a straight line drawn from the tractor drawbar to the point of load on the plough (Fig. 9).

There are many patent hitches with automatic releases for ploughs which are not designed for jumping obstacles, but where frequent obstructions are likely to be encountered, the stump-jump implement should be used. With most other implements the important principle to bear in mind is that the implements be so hitched that the natural line of travel of the implement is parallel to the line of draught of the tractor.

When two or more implements are coupled to run parallel with each other, care should be taken that the load on either side should be as equal as possible. Any increase to one side tends to throw the tractor to that particular side and this must necessarily be counteracted by the steering wheel which means that power is being wasted by unnecessary friction to the detriment of the tractor. Attention must also be paid to vertical adjustment, this being particularly necessary with those implements which work in the ground and are provided with travelling wheels.

MULTIPLE HITCHES:

So that the full power of a large tractor may be utilised to its greatest advantage, it is generally desirable to pull two or more implements. The benefits from multiple hitching are:—

(a) One man can handle more implements, thus accomplishing a greater volume of work.

(b) A tractor operates most economically in relation to the amount of work-output when operating near capacity. Additional implements increase the load when a single implement is not a full load.

(c) Smaller implements hitched to a tractor are generally handled easier on uneven ground than is a large single implement.

Generally the requirements of a multiple hitch are such that it must be strong enough to transmit the pull of the tractor, and it must allow the attached implements to turn without interference. If the hitch is wide, it should have joints or some other provision for flexibility on uneven ground, and it should be constructed in such a manner that it may be quickly dismantled for transportation, bearing in mind such obstructions as gates, bridges and the like. The hitch should be easily adapted to different types of implements, and where it is mounted on wheels, it is important that wheels of ample size and tyre width be used so as not to increase the draught of the multiple unit. The hitch member should be attached to the axle so that the pull from the tractor drawbar to the centre of resistance of the load does not cause a downward pressure on the wheel.

With tractor ploughing many circumstances must be considered in deciding just what method is best suited for a particular field with a particular outfit. There is no set method however which can be considered best for all types and sizes of field.

Methods of laying out fields for tractor ploughing fall into two classes: (a) Those in which the bottoms are lifted in crossing the ends; (b) and those in which they are not. The advantages of methods of the first group are that short turns are eliminated, except in some cases at the beginning and ending of the lands, and that a higher quality of ploughing is possible at the corners or turns. The advantages of group (b) are that little or no time is lost in travelling with the bottoms out of the ground, and that the numbers of dead furrows and back furrows are considerably less.

The more time spent in turning or running with the bottoms lifted, the less acreage ploughed in a day; however, the making of short turns is awkward with some tractors, particularly the larger models, and the operator often has difficulty in lining-up the tractor in the correct position for starting the furrows after this type of turn has been made. Although short turns should be avoided with large tractors, it should be remembered that the loss of time and fuel due to long idle runs across the ends of the field is just as serious with all types of tractors. The time lost in making loop turns in starting and finishing a large number of lands is less with a tractor equipped with brakes, which assist considerably in making short turns. This should be borne in mind in deciding on the most desirable size and number of lands. From the viewpoint of time lost in idle running, the size of the tractor should be considered only in respect of the difficulty in making short turns.

In deciding on the method to use, the ease of handling the tractor and plough is not always the most important point to consider. In areas of heavy rainfall, it may be best to make narrow lands with frequent deadfurrows and backfurrows as an aid to drainage; in dry areas the reverse may be necessary. In other cases the contour of the land will in itself determine the method to be followed.

If a field is sufficiently rectangular and level so that contouring need not be considered, the choice of method will usually depend on how short a turn can be made with the tractor and plough and how undesirable the additional back and dead-furrows are. If it is decided to use the method in which the bottoms are out of the ground in crossing the end of the field, it must be decided into how many lands the area should be divided for the best results, the width of the headlands for turning and the proposed positions for setting the guide stakes or markers.

WIDTH AND NUMBER OF LANDS

The wider the lands are made, the fewer will be the dead-furrows and backfurrows, but the greater will be the time consumed in idle running across the ends.

Consider a field 40 rods wide ploughed in this manner, one land at a time, each land being of 132 feet. If the tractor is pulling a three bottom 14 inch plough, it would take approximately 38 trips across the field to plough out each land. Disregarding extra distances the tractor must cover in swinging out of the furrow and back in again, and in making the short or figure eight turns in starting a backfurrow land or finishing a deadfurrow are ignored, the average length of travel across the ends — that is, the average distance in a straight line from the point where the bottoms are lifted out of the ground to the next point of entry — is one-half the width of the land, or 66 feet. This makes 2,508 feet, or practically half a mile for each land, and almost 2\ miles of idle running in ploughing the whole area.

If the field were laid out in 11 lands, each of 60 feet wide, the non-productive travel at the ends would be reduced to approximately 1 mile, but this reduction would be greatly offset by the increased number of figure eight turns necessary in starting the extra lands, and also the probability of the plough running at less than its full width of cut for a considerable distance in finishing the extra number of lands. If the field were laid out in only three lands the travel across the ends would be increased to approximately 4 miles, but there would be only two deadfurrows to finish out with the possibility of the plough not cutting its full width.

The increased time required to make difficult turns at each backfurrow or deadfurrow, which must of course be added to the time to travel these straight-line distances, will reduce the advantage of the narrow lands to a certain degree. However, a tractor pulling a three bottom plough and possessing a short turning radius, which makes turning fairly quickly, will plough a 40 rod width field laid out in five lands in approximately an hour less than a field laid out in three lands.

The dimensions of the field will in most cases determine whether the time saving in making narrow lands offsets the disadvantages of the extra deadfurrows and backfurrows and the difficulty of making short turns. The best width under average conditions appears to be about 100 feet for a two or three bottom plough. If the field has no irregularities, its entire width should be measured and divided into lands of approximately equal width.

PLOUGHING THE HEADLANDS

Before commencing the headland, it is advisable to note which direction was previously taken, so that ploughing is not always carried out towards the fence or boundary, otherwise a build-up of soil will result. It is easier to commence at the boundary and work towards the main body of the ploughing, which leaves the least unploughed strip, but consideration should be given to the general condition of the field and when necessary ploughing should commence from the original headland furrow.

The width of the headland will depend largely on the total length of the tractor and plough, and the turning radius of the tractor. Plenty of room should always be left for easy turning and to provide correct alignment so that the tractor may be headed in at the beginning of the furrows. The wider the headland, the less possibility of going over the same ground repeatedly during turns, thus packing the soil tightly.

Headlands of 15 to 25 feet wide are most suitable when smaller tractors are used. With a large tractor pulling more than one unit no less than 75 to 100 feet wide may be necessary. Generally a distance equal to one and a half times the total length of the plough and implement will give ample room for turning.

If a paddock is fenced on all sides, a border equal in width to the headlands may be left on each side. It is then possible to finish the area neatly by ploughing around the entire field.

A pocket with an obstruction requires tractor to be backed repeatedly to boundary. This should be done before ploughing the headland.

ACREAGE TIME TABLE

This table indicates the approximate number of acres that can be worked in a 10-hour day. These figures are supported by a rule among agricultural engineers that if you multiply the actual cutting width of your implement (in feet) by the rate of travel (in miles per hour) you will obtain the approximate number of acres you can work in a 10-hour day. Time for normal stops and headland turning is taken into account.

It has been said that the primary producer holds a fortune on his land, but it may also be asked whether he can hold that land long enough to realise the fortune. Profitable farming depends upon soil quality as well as total acres, and good soil is the result of careful planning and wise farming. To-day any farmer can build himself a richer living through using farming methods that do not call for special farm equipment or complicated preparation.

Throughout Australia, acres of once-productive land have become utter wasteland. Waste conditions have resulted from mis-management, lack of knowledge, and the failure to observe soil-saving practices. This situation is one that exists and can exist in many of the nation’s best productive areas. Even more alarming is that the condition of soil wastage never improves of its own accord — it grows worse and worse as inch after inch of topsoil is washed or blown away. These are the stages of erosion that ultimately result in desolation.

Prevention is possible and it is a fact that in countries where land is not plentiful the science of soil conservation has always been the fundamental principle of successful farming. Although preventative measures are governed by local conditions, the practices of soil saving can be grouped broadly under three headings, namely: Contour Farming, Pasture Improvement and Terracing.

CONTOUR FARMING:

Many farmers are well aware of the continued loss of topsoil on their own farms, but they have hesitated to adopt soil saving practices because they believed that such a course involved an entirely new type of farming with new equipment. Conservation farming need not be avoided because of this, for practically all equipment used in “straight row” farming is suitable for conservation work.

The first step in contour farming is the laying of contour guide lines which run across the slope at a uniform level. After laying, all tillage operations are carried out parallel to the lines, making each harrow mark or plough furrow a miniature terrace to retain as much water as possible in the soil and retard the run-off of the remainder.

Contour guide lines may be laid out with simple home-made equipment, one suggested here (Fig. 13) is made from an ordinary spirit level mounted on a staff and fitted with a small mirror for sighting the bubble. Without a mirror it would take an above average-in-height man to see the bubble at dead centre without disturbing the balance. In addition to the level a sighting pole is required. The pole may be simply a stake cut square at the base and made exactly the same height as the upper edge or sighting line of the level.

Accuracy is quite important in the construction of the level, and the pole for the contour lines can be no more accur- FIG. 13

A contour or horizontal line across a hillside is determined by sighting with the level from the proposed starting point to the sighting pole, which is held approximately 100 feet distant (the maxi' mum distance). The man handling the sighting pole moves up and down the the level falls directly on the top of the sight pole. Both of these spots are then staked and the process repeated around the entire contour of the hill (Fig. 14).

When selecting the first contour guide line on a hillside, the usual practice is to go to the highest point in the paddock ?.nd then walk directly down the slope from this point to a distance approximately 100 feet (See Fig. 15). On long gentle slopes the first contour line may be 150 feet or more from the top of the hillside.

After the first contour guide line is established the number of lines is limited only by the area into which lines of 100 or 150 feet can be placed. The greatest difficulty in contour farming arises when lines are spaced too far apart, so remember that on steep or irregular hills the distance between guide

White guide lines follow true contour. Black lines show modified curve followed in tillage operations.

PRE-FLQUGHING PREPARATIONS :

With the necessary contour guide lines staked or marked out they are permanently marked by ploughing a back furrow along each line. Sharp turns in the contour lines are rounded out as the furrows are made. To make this line more prominent, the first furrow is turned uphill and the second rolled down on top of it. This will make a ridge which is easily followed during cultivating and planting, a double ploughing each way will form a permanent guide bank which will remain easy to follow.

It is a good practice to permanently locate contour guide lines by markers placed on the fence. These markers simplify the process of locating and following guide lines during succeeding seasons. If care is used, contour guide lines should last for several years, but when doubt exists, the line should be redetermined and re-run before planting row crops again (Fig. 16).

Contour cultivation ridges thrown up to act as gu^;de lines. (Soil Conservation Board, Victoria, photo.)

CONTOUR PLOUGHING:

There are two generally accepted systems of contour ploughing. The first is to continue driving around the back furrows or guide banks (originally contour guide lines) until the ploughed land extends halfway up or down to the next guide line at the narrowest point in the area between lines. Then the process is repeated around the succeeding guide lines. Finally, any angular or odd areas in between the two finished lands are ploughed out. This places the dead furrow halfway between the contour lines and it thus follows closely the true contour of the land (Fig. IV).

The second method is to plough around each back furrow until the ploughed land extends from one back furrow a quarter of the distance to the next. This is repeated around succeeding back furrows, leaving a full width land to be finished between the two ploughed areas.

CONTOUR ROW CROPS:

When planting row crops on the contour, the rows should run parallel to the first contour guide line — up to the top of the slope, and half the distance down to the second guide line at the narrowest point between the two. Planting is then

commenced again at the second contour line, and continued up towards the first and halfway down towards the third. This method places point rows approximately in the centre of the area between the contour lines (See Fig. 18). This ensures that short or point rows are grouped where they can be handled without extra driving. The procedure is followed for each successive contour of the hillside.

For more permanent planting on the contour such as for orchards, each row can best be on a true contour thus eliminating the “point rows.” In this form of lay-out, variations in horizontal spacing are taken up in each row.

THE ECONOMY OF CONTOURING

The famous explorers Blaxland, Lawson and Wentworth brought prosperity to the infant colony of N.S.W. by discovering the rich farming land beyond the Blue Mountains. These men succeeded where many others had failed, and the secret of their success lay in the action of following the land’s natural contours. To-day the railway and the road follow closely their original track. What was once to these men the easiest way of crossing mountains, still remains the swiftest and most economical method.

The principle remains the same in tractor farming — no one goes over a hill if going around it achieves the same result. Tests conducted in America have proved that contour ploughing as opposed to straight ploughing over the hilltop reduced fuel consumption 10% on a 7J% slope. In addition, the operator ploughing on the contour and semi-level plane travelled at higher speed, although this is not always desirable, and ploughed 12% more land. This is obvious when one realises that contour ploughing eliminates labouring pulls by the tractor over the last few yards of a hill and reduces brake wear on steep declines.

From records kept by 135 farmers in the State of Illinois, U.S.A., over a four-year period, man labour cost per crop acre for contour farming averaged £3/13/9 as against £4/0/4 ordinary farming. Similarly power and machinery costs averaged £2/9/6 on contoured fields against £2/11/1 on others. The impression that contour farming and terracing will banish the evil of soil erosion is not entirely correct. To a great extent, these practices do counteract the ravages of wind and water, but to be most effective the principles of contour farming should be looked upon as the mechanical aids to enable the farmer to hold his soil, when combined with other methods of intelligent land use, including reasonable rotations, use of trash and pasture development.

The combination of these methods will ensure a high standard of soil fertility. Keeping the soil rich in humus increases its moisture holding capacity, thus making it possible to keep the rainfall in the soil where it is most needed.

GRASSED WATERWAYS

While contour cultivated ground is designed to absorb as much water as possible, some run off can be expected. This excess water must be led safely off the area with the least possible disturbance to soil surface.

Grassed waterways provide a safe means for carrying run-off water from contoured or terraced land. The compact sod of grassed waterways resists the scouring action which is common on loose surfaces. This method of protecting the soil prevents the formation of runnels or sharp gullies which, besides being

difficult to cross with farm machinery, are also the fore-runners of deep erosion. .

A grassed waterway is generally located at the most suitable position in the paddock to take the water from the greatest number of terraces, and at the same time offer as little obstruction to the efficient working of the area. It does not necessarily follow the natural drainage line, but does ultimately lead to it. It must be level across and of sufficient width to take the water led to it, without excessive depth. It should not be constructed along the line of filled-in scours. A good grass cover must always be maintained, therefore a grassed waterway is best fenced out from the rest of the paddock.

After grass cover has been effectively established, the terraces or graded banks can be constructed and led to the waterway. To reverse this order leads to erosion along the waterway and added cost in maintenance.

Many farmers contour their land first and construct the waterways later, this is done because the contoured surface

reduces the amount of run-off thus giving the protective sod of the waterway a chance to establish itself.

When a water channel has been reshaped resembling a shallow “U” (Fig. 20), the loose dirt is packed firmly by rolling it crosswise with a soil packer or roller. A heavily weighted disc-harrow with the gangs set straight may be used for this step. The waterway should then be heavily fertilised and seeded down with a good permanent grass mixture. A cover crop of cereal rye or oats is often desirable, particularly as it produces a good straw mulch and will hold the soil until the permanent sod is established. In dry areas a straw mulch may be spread instead of, or in addition to, the cover crop to hold the soil while the permanent grass is establishing itself. The seed bed is best left rough to retard washing or blowing action, but it should be prepared well enough to promote a quick uniform “catch” of grass.

The edges of prepared grassed waterways are bordered with low banks to prevent the formation of ditches where the sod joins the cultivated land. A waterway should always be so wide as to handle the heaviest run-off. Never should the waterway be less than twelve feet in width since this will allow the grass to be mowed and handled with regular haying equipment, keeping down weeds and providing a crop from the land in the waterway. A general indication is to allow two feet of waterway for every acre drained, but of course this will vary with local conditions. If the waterway is too narrow, overflow following heavy rains will invade the ploughed land and form ditches on each side of the grassed waterway.

KEEP WHAT YOU HAVE :

Maintaining grassed waterways is largely a matter of continued care and commonsense. Tillage tools must be lifted when crossing a waterway, otherwise the grass area will be destroyed. The gangs of implements, such as the disc harrow, are either straightened so they roll free when crossing waterways, or the paddock worked in sections to avoid crossing sodded areas. Additional to lifting implements in crossing, parallel ploughing to the waterways must be avoided; neither should the waterway be used as a paddock road as furrows or wheel tracks leading down a slope readily become ditches.

TERRACING

Terraces or graded banks provide a valuable means of checking erosion and retaining the maximum amount of moisture in the soil where its presence can be most effective. It is a measure adopted in cultivation paddocks with slopes up to about 8%. If terracing is a partial solution to the problem of erosion on your particular farm, ordinary implements such as the mouldboard or disc plough can effectively handle the job.

One of the conditions necessary in constructing a terrace is that the soil must be in a workable condition. On most soils this means sufficiently dry and firm enough to ensure ease of ploughing. With sticky soils the operation is best attempted in the late summer or early autumn when the ground is fairly dry yet not too hard to penetrate.

The area to be ploughed should be fairly free of vegetation since any debris will make loose soil difficult to work. If a

disc plough is used, clogged soil can be handled better than with a mouldboard plough, but an excess of weeds, stalks or grass must be avoided because it will weaken the terrace ridge and may ultimately cause it to fail.

Generally a broad base terrace has a shallow water channel approximately 15 to 20 feet wide and 15 inches deep, with a correspondingly wide gently-curved terrace ridge on the lower side. When constructed with a plough the terrace is usually of the island type with a foundation of solid unploughed soil beneath the actual ridge.

As with contour ploughing, it is necessary in terracing to have the lines marking the location of each terrace, carefully laid out to give the correct amount of continuous fall in the terrace channel, or in drier areas, to give a level channel designed to hold the rainfall on the slope. Both types call for careful surveying, and it is hardly likely that a sufficient degree of accuracy will be achieved by the use of home-made levelling equipment. Therefore, if terracing is necessary, it is desirable to obtain the assistance of the Soil Conservation Service of your State. When the area has been surveyed, and staked out with each line of stakes showing the centre of each terrace waterway, the paddock is ready for terracing with an ordinary plough disc or mouldboard pull type or tractor mounted.

CONSTRUCTION OF A TERRACE:

The first furrow is turned downhill, with the plough running just above the line of stakes. When the first run across the paddock is completed, the stakes are moved separately straight down the slope for a uniform distance of 8 to 12 feet, depend' ing on the width of terrace ridge desired. This restaking is gauged by means of a length of rope or board, since it is important to keep the width uniform.

On the return run across the paddock ploughing is done just below the new line of stakes, thereby throwing the dirt uphill and forming an “island” of uniform width between the two sets of furrows. Care should be takeri in driving the tractor to keep these furrows parallel.

If the terrace is being built with an ordinary pull-type 2 bottom 14 inch plough, two more rounds are ploughed, around the island (Fig. 22). If other types of ploughs are used, ploughing is continued until a strip of land seven feet wide is ploughed on each side of the “island.” On the first rounds the plough is run at a uniform depth of four inches, but on the final round the plough is adjusted to make the furrow on the upper side of the “island” very shallow. This avoids a sudden step'off from the unploughed land above. On the return half of the round on the lower side of the “island” the plough is operated at the full depth of four inches.

At the start of the next round, round 4, if a two bottom 14-inch plough is being used, the operator now begins to throw the ploughed soil on the upper side of the “island” further towards the centre to form the actual terrace ridge. This is done by starting again at the inside edge of the 7 ft. wave of ploughed soil and reploughing this same ground, running the plough so that on the first round the soil is moved 8 to 12 inches nearer to the centre of the “island.” The plough is run deep enough so that a thin slice of the firm earth beneath is turned with the loose soil to make the plough scour.

upper side of the “island” (rounds 4, 5 and 6, if a two bottom plough is used), the ploughed land on the lower side is widened out to 14 feet. On the last strip along the lower edge of this side, the plough is set so that the final furrow is very shallow, thus eliminating a ditch below the terrace ridge.

On the next round the operator starts to replough the upper “wave” of soil while on the same run he begins to replough the 14 foot lower “wave” running the plough so as to make the soil move a few inches nearer the centre of the “island.” No attempt should be made to move the lower “wave” any distance uphill. It is simply reploughed to heap the soil higher along the edge of the “island.” Ploughing is continued until the ploughed earth from upper and lower sides meet to a rounded terrace ridge. The water channel will at this stage have the desired dimensions, since the open furrow above

the terrace ridge will have been widened each time the upper “wave” has been reploughed.

If a nine-foot “island” was formed, at first approximately 27 rounds would be necessary to complete the terrace with a two bottom, 14 inch plough. However, degree of slope, rate of speed or work and condition of the soil will need to be considered in determining the number of rounds required to complete the terrace.

At this stage the upper 7 foot “wave” of soil will have been reploughed eight times (since the first ploughing) and the lower 14 foot “wave” reploughed three times. Three return trips across the field are left as extras to be used in smoothing up the lower side of the ridge and in filling any ditch left at the lower edge where the terrace joins the unploughed land. If the soil becomes too loose before the terrace is completed it is best “firmed” with a heavily-weighted disc-harrow with the gangs set straight or with a field packer. Some contend that where soil is very dry, good results are obtained by partially building the terrace and then allowing a light rain to soak and pack the soil so that ploughing may be continued without difficulty.

When terraces are completed, the paddock is ready for cropping. Terrace ridges are used as contour guide lines, with all planting and tillage operations carried on parallel to the well-defined terraces. Terrace waterways or channels should be heavily fertilised as compensation for the top soil removed in building the terrace.

Broad base terraces may be permanently maintained by the careful placing of back and dead furrows whenever ploughing is done. As often as necessary back-furrows are located on the top of the terrace ridge and dead furrows left in the centre of the water channel.

STEEP HILLSIDES :

When building terraces on slopes of six per cent, or more, a sound practice is to use a two-way plough so that all furrows

may be turned in the same direction irrespective of the direction of the tractor. A two-way plough makes it possible to turn the furrows uphill in ordinary tillage work. This will counteract the downward movement of the soil by erosion and also lays heavy sod so that rainfall naturally runs down under the furrow slices rather than having a direct run-oif as if the furrows were tiles on a roof. Another and important advantage in turning furrows uphill on a steep slope is that it allows the upper wheels of the tractor to run in the furrow giving easier steering and greater safety.

FODDER CONSERVATION

Pastures supply the bulk of food for cattle and sheep, and without it dairying, beef production, fat-lamb raising and wool growing would be unprofitable. Pasture growth is seasonal and, therefore, does not supply a continuous source of nutritious fodder throughout the entire year. This naturally demands a regular and sufficient supply of foodstuffs in all seasons, and fodder may best be acquired by conservation from the farm itself, instead of the expensive practice of buying it as required.

The quantity of fodder needed depends greatly on seasonal conditions, but generally each dairy cow requires 2 tons of hay or from 5 to 8 tons of silage yearly, and half of this quantity for each beef animal. Sheep usually need 2 cwt. of hay or from 5 to 8 cwt. of silage. It will be found in practice that these requirements are somewhat in excess, but this will allow a surplus reserve to accumulate for use during drought periods.

Hay is far more commonly used for fodder conservation than silage, mainly because it has the advantage of requiring less labour to make and later feed out, and it can be readily transported or marketed. Silage on the other hand is very heavy to handle — approximately four times the weight of silage needs to be handled to supply the same nutritious quantity as hay. Silage, however, is the most satisfactory way of preserving succulent fodder for future use. For dairying purposes it is far superior to hay, and if properly made, should keep indefinitely. With silage there is no risk of fire, so common with haystacks, and there is not the same temptation to sell when fodder prices rise in time of drought.

THE PRINCIPLE OF SILAGE:

When a mass of herbage is thrown together and packed down, a very rapid rise of temperature takes place, 140 deg.-170 deg. F. being reached. This rise in temperature is a sure indication of chemical action, which under these circumstances, is known as oxidation. The rise is also the outward sign of the important changes taking place within the plant cells, the main change being that materials like starch and sugar are being changed and lost. This loss is unavoidable, and similar losses take place in making and stacking hay.

Close packing and pressure reduce the amount of oxygen in the herbage to a minimum, thus reducing the life of the plant cells and the amount of heat generated. But it must be remembered that, if individual cells are alive after the oxygen is exhausted, they may for a short time extract oxygen from the material with which they are surrounded, thus causing some degree of fermentation. Ultimately, final bacterial action is. terminated by lack of oxygen and the action of heat.

From the foregoing, an important practical point is evident from the knowledge of the right time to cut the plants and the need for quick transportation to the silo. If the material is cut at too advanced a stage or allowed to dry off or wilt before being transferred to the silo, the vital energy of the plant cells will be reduced, thus preventing the necessary rise of temperature to kill the bacteria, in consequence of which, inferior silage is likely to result from undesirable bacteriological action.

In addition to the percentage of loss already referred to, there is another loss due to mould, which invariably forms on the surface of the silage. These moulds belong to a class of organisms which can only develop when they are in contact with atmospheric oxygen, thus they are noticeable on the top or sides when the material has shrunk away from the silo walls. Mould will not penetrate to any depth if the material has been well and closely packed, because there is no free oxygen present in the lower layers to assist mould growth. In packing, the material should be well pressed down, particularly along the sides, otherwise mould streaks may develop right through the silage, causing excessive waste.

On smaller farms the most economical method of making silage is to cut the grass with a mower and sweep direct into a silage pit. The pit is simply a hole in the ground,

well drained and preferably on the side of a slope, with provision made for backing in a truck when lifting out. The pit should be about 6 feet deep and the pasture should be piled up almost 6 feet above ground level, so that the silage will not be below ground level when it settles. If it is to be kept for more than a season, the silage should be covered with 1 foot of earth.

Well-made silage should retain the original green colour of the foliage, but there is always a tendency towards brown tints, the more particularly with leguminous plants. This dark colour generally implies over-oxidation and excessively high temperatures. With silage there is always a very distinctive odour and, if the silage has been well made, it will not be offensive. The offensive odour of some forms of silage is due to decomposition of nitrogenous matter. This is particularly noticeable with lucerne, which, on this account, is not suitable for silage. If it is necessary to use silage, it should be mixed with some cereal crop, such as wheat, oats, sorghum or maize. When extracting matter from a silo or pit, it should be taken off in layers, no deep vertical cuts being made, although the latter is the easier method. A good cereal hay crop makes ideal silage, but there are numerous other factors which must be considered. Cereals, peas, maize, sorghum, millets, Soudan grass and like crops are suitable for ensilage, but lucerne is best turned into hay.

The most suitable stage at which to cut plants for silage is shortly after the blossoming of the plants, for at this stage they are carrying the greatest quantity of food material. For cereals such as oats, wheat, maize, etc., it is advisable to cut when the grain is still in the milky stage. With vetches, peas and the like, when the pods have been formed and the crop is still fresh and green. As crops are apt to ripen off very quickly, it is better to start operations a little before the correct time than to be too late.

HAY-MAKING :

Hay is ready to cart when moisture cannot be squeezed out by twisting a small bunch in the hands. Hay stacked at this stage is tough and palatable, with little loss of clover leaves and other nutritious portions.

If hay is to be kept for any length of time it should be stacked on dry foundations under cover or else in large stacks which are thatched or covered with tarpaulins. The size of stack necessary can be assessed from the quantity of hay in the paddock. It takes from 350 to 600 cubic feet of loose pasture hay to weigh a ton in a freshly-built stack. A large freshly-built stack of good quality, loose hay will go about 350 cubic ft. to the ton. Stacks built on a rectangular base 10 feet by 20 feet, and 9 feet to the eaves, with fairly vertical sides and steep top to shed the rain, hold 6 to 8 tons of hay. If taken 12 ft. to the eaves they hold 9 to 12 tons, and if taken 15 ft., 13^ to 18 tons. If the sides spread, more hay will be built into them. After twelve months the stacks will have settled, and then 300 to 400 cubic ft. of hay will weigh 1 ton.

Baled pasture hay varies greatly with the dryness and quality of the hay, and the pressure used in baling. Approximately 200 to 250 cubic feet of well-pressed hay weighs 1 ton. Where pick-up bales are used to bale direct from the windrow it is necessary to press the bales lightly at 250 cubic feet to the ton. If pressed too tightly the moisture content may ruin the hay. Hay with 25 per cent, moisture may be stacked loose or pressed lightly.

Dew on the windrows increases the moisture content of the hay and for that reason it is inadvisable to press direct from the windrow too early in the morning following a dew.

PASTURES

The necessity for replenishing the soil after taking off a crop has been recognised from the very earliest times, and early Roman documents show that the regular manuring of fields was a definite practice in their husbandry, yet at the present time numerous pastures in Australia are continually carrying stock without any attempt being made to replenish the essential constituents of the soil which are being removed by the stock. The result of this practice is making itself felt by the deterioration of pasture lands and the consequent reduction in carrying capacity.

The following figures enable one to form some definite conception of the amount of essential matter which is being removed from the soil by stock. In Victoria the average amount of stock slaughtered annually would amount to approximately 3,000,000 sheep and 280,000 cattle; now the average phosphoric acid content in the carcase of a sheep is 1\ lbs. and in an ox 15 lbs. This means that 5,223 tons of phosphoric acid are being removed from the soil of this State annually. In addition to this, a further 6,000 tons of phosphoric acid are removed from the soil by pigs, wool and dairy products, making an annual total of 11,223 tons. Besides this loss of phosphoric acid there are natural losses of lime and nitrates. In England experiments have shown that on a rainfall of 28 inches the loss of carbonate of lime by leaching is over 6 cwt. per acre. These astounding figures provide unequivocal proof of the necessity of manuring pasture lands.

As pastoralists pursue their vocation with the object of making as great a profit as possible, the costs of production have to be carefully considered, and every item affecting production must be carefully studied to achieve the best results at the smallest costs. The scientific investigations of the Agricultural Departments and Colleges in Europe, Australia and New Zealand have made available a considerable amount of knowledge, which is at the disposal of the primary producer to use and profit by.

THE EFFECT OF TOP-DRESSED PASTURES ON STOCK:

It has been observed that cattle will invariably show a decided preference for top-dressed pastures and thrive better on them. This preference is evidently due to the higher food content, especially phosphate of lime, which is vitally necessary in substantial quantities for the proper development of bone and body tissue in young stock. On one estate some years ago the owners found they could not breed sheep successfully. Later on, after cropping the land for a couple of years, the carrying capacity of the land was practically doubled, and not only could lambs be reared successfully, but they could be fattened. There are numerous areas in Australia where dry sheep thrive on native pasture, but cannot rear lambs. This is due to deficiency in phosphate and can be rectified by suitable topdressing with superphosphate. In certain areas stock are notoriously predisposed to disease, and this is invariably traceable to the lack of certain constituents in the food caused by the deficiency of the phosphatic and lime contents of the soil.

Dairy cows need liberal supplies of phosphate of lime for milk production, as every gallon of milk produced contains the equivalent of 1^ oz. of phosphoric acid. If the animal cannot acquire the necessary minerals from her fodder, she will commence drawing on her own system for the deficiency and seek to replenish it by unnatural forms of food. The calves, as soon as they can forage for themselves, also need large quantities of lime and phosphates to develop frame and tissue; if there is a dearth of these items in the pasture, their growth will be retarded and in extreme cases the bones are imperfect.

RESULTS OF DEPARTMENTAL TESTS:

For some time past in Europe the top-dressing of pastures has been fairly commonly practised, and in Australia an extensive series of tests have proved that top-dressing will do more to increase the stock-carrying capacity of grass lands than anything else. These tests have shown that the best results are to be obtained in the higher rainfall districts, and compared with any other fertiliser, superphosphate gives the best results per £1 expenditure. The fact that the best results have been obtained in the higher rainfall areas does not mean that topdressing will not prove profitable in the drier areas, and it will be advisable therefore, for those situated in the drier areas, to carry out experiments in their localities in conjunction with information and advice received from the local Agricultural Department. Soil, moisture, and temperature are the three main factors governing the growth of plant life, and it is therefore necessary to record the available information under these headings.

TRACE ELEMENTS:

In recent years plant physiologists have discovered that other elements were necessary for the growth of crops besides those already known. Of the latter, about ten elements were essential, seven of which the soil supplied, namely: Phosphorus, Potassium, Calcium, Magnesium, Nitrogen, Iron and Sulphur. The additional elements are needed only in very small amounts and for that reason they are known as “Minor” or “Trace” elements. ,

The main “Trace elements” now known to be beneficial to crop and stock growth are: Copper, Zinc, Cobalt and Molybdenum, and each of these soil elements occurs in widely separated areas throughout Australia. Where there is a deficiency of one or more, the best cannot be expected from crops grown in such soil or stock grated upon its pastures.

A deficiency of copper is often commonplace in sandy and gravelly soils of certain types, and its effect is quite noticeable on the growth of pasture plants. Where a deficiency exists for any lengthy period of time in the feed of cattle, “falling disease” is likely to result. Signs of copper deficiency in full-grown sheep are “steely wool,” anaemia and excessive scouring. “Steely wool” may occur when pastures are deficient in a mild degree, and Copper licks or drenches should be used as supplements where a deficiency is known to exist.

ZINC :

Generally the results of tests conducted in Western Australia on Zinc deficiencies showed that agricultural crops were not lacking greatly in this “Minor Element.” However, some evidence of deficiencies was revealed in Subterranean Clover and cereals in certain light soil areas. The tests showed that for best results under certain soil conditions a combination of Zinc and Copper is necessary.

In areas where the presence of Zinc in the soil is doubtful, particularly on alkaline grey soils, the growth of Subterranean Clover has been noticeably improved by the addition of Zinc Sulphate to the Superphosphate during seeding down.

COBALT:

A reddish-grey coloured metal similar in many respects to nickel, is contained in an iron ore known as limonite. Cobalt is the medicinal part of limonite, and is used for the treatment of stock as a prevention and cure of “wasting-disease.” So far as it is known at present Cobalt deficiency does not affect plants, although it is known that the Cobalt content of plant matter varies according to soil conditions.

The treatment of stock suspected to be suffering from or subject to “wasting disease” as a result of Cobalt deficiency, is direct in the feed and not through pastures. Hay may be. treated with a Cobalt solution made-up of one ounce concentrated solution mixed with \ to 1 gallon of water, and sprayed over each ton of hay as it is placed in the stack. Actually one ounce of Cobalt Chloride is sufficient to maintain in good health 200 sheep or 40 cattle for a period of one year. Ten pounds of hay treated with the above solution contains a daily dose of Cobalt. As an alternative method licks or drenches containing Cobalt can be used quite effectively to control the disease.

MOLYBDENUM :

The ironstone soils in the Adelaide Hills in South Australia became noted some years ago for their unsuitability for growing Subterranean Clover, despite the liberal use of fertilisers. In certain areas Subterranean Clover was grown successfully on ash beds and upon examination these beds revealed traces of Molybdenum.

This “Minor Element” is a metal as are Cobalt, Zinc and Copper, and its effect on plant growth has been rather remarkable. On old pastures which had received generous dressings of superphosphate for some years previously, excellent results were obtained with the use of Molybdenum applied on its own during the first year. With newly-cleared areas, however, large quantities of phosphate are necessary.

SOIL AND ITS EFFECT ON PASTURES :

In the course of evolution and as a natural result of the law of “survival of the fittest,” plants have adapted themselves to the conditions governing their life and growth. On the poorer soils and in drought areas the less hardy plants die out, leaving those most capable of enduring these conditions. A little observation and consideration, therefore, of the plants and grasses in a pasture afford a very good indication of the state of the pasture. The clovers and trefoils are very sensitive to the phosphatic content of the soil, and respond very quickly to topdressing with superphosphate. On the contrary, when a pasture is being continually denuded of the phosphate in the soil, there will come a time when there is only enough phosphate to carry one plant in an area which formerly carried two, in consequence the weaker plant will die, leaving a bare patch, which may or may not be filled by some other plant of low phosphoric requirements, or some useless weed. Thus, when good pastures with clovers and English grasses slowly begin to revert to native grasses, flat weeds, dandelions and bracken, it is a strong indication that top-dressing with phosphate is necessary. In pastures which have never been sown with clovers and English grasses, the decline in fertility is indicated by increasing tuftness and bare patches.

The average results of experiments tend to show that with a good rainfall the application of 1 cwt. of superphosphate to the acre tends to increase the grass yield by about 50 per cent., while 2 cwt. gives an increase of about 100 per cent, during the year of application. The effect of the phosphate is not exhausted in one year, and an application of 2 cwt. may produce beneficial results for five years, but it is advisable to renew the dressing more frequently than this.

A little study of the distribution, after application, of phosphates in the soil, will provide a guide to the pastoralist in conducting experiments on his own pastures. A series of experiments conducted in South Australia showed that, after topdressing, by far the greatest proportion of the phosphates remained in the top two inches of the soil, a very small proportion being leached down to the lower layers. With lime, however, there is a much stronger tendency for the lime to be leached into the lower layers of the soil. The plants themselves also tend to raise the phosphates from the lower layers and re-deposit it on the surface when they decay. With a top-dressing of lime and superphosphate applied at separate times, it was found that the phosphoric acid tended to penetrate the lower layers of the soil to a greater extent.

POISONOUS PLANTS

INTRODUCTION :

Every country possesses plants which carry some principle poisonous to stock, and Australia has its own share. What is the purpose of such poisonous plants in the scheme of nature is perhaps difficult to determine, unless it be given for the protection of the plants themselves, to preserve them from predatory animals or insects, so that they may occupy their proper place in the scheme of the balance of nature. There are certain plants which are poisonous only during certain stages of their growth; for instance, some of the hybrid Sorghums which are grown for fodder are quite dangerous during the early stages of growth of the plant, while, after flowering, or used as ensilage, they are quite safe. Then again, there is the condition of the stock to be considered. If sheep or cows are in a weak or half-starved condition, a good feed of some of the most nourishing of clovers will set up stomach conditions similar to poisoning. Then some plants carry poison in their flowers, others in the bark or in the fruits or seeds.

Thus many flowers of the genus Lomatia, a white flowered race of plants related to the Grevillea, carry prussic acid, a rank poison, in their floral organs, which is responsible for the death of very many insects, and which would certainly kill stock were they to browse on these blossoms. Then there is the beautiful and large flowered Amaryllid, of Queensland, known as Crinum pestilentis, which gives off so rank an odour as to cause vomiting and stomach sickness to humans, as well as to stock. Another aspect of poison plants is the growing of certain plants as ornamentals in gardens, which occasionally spread to pastures. Thus, the Lily of the Valley, the Autumn Crocus, the common Jessamine, the Cape Plumbago, the Laburnum, Daphne, Daffodil, Ranunculus, Anemone, Columbine, Iris, Primula, and many other flowering garden plants are all classed as poison plants, containing in many cases, severe poison principles.

Again, some plants are attacked by certain fungi which are poisonous, while the plants certainly are good fodder. Where the wheat and oats are attacked by rust, smut, or bunt, these diseased portions are poisonous and should not be fed to stock. Neither should lucerne which is affected with lucerne spot or rust. Rye grass and other grasses are often attacked by Ergot, which appears as a prominent and enlarged seed in the seed head, and always black or purplish-black in colour. This, again, is a rank poison.

INTRODUCED POISON PLANTS:

A prickly shrub up to three feet in height, leaves much den-tated, carrying yellow spines, as well as on the stems. Flowers purplish, one inch across; fruit, green first, then afterwards yellow, sometimes variegated, one inch in diameter. Action: —Definite stomach poisoning with vomiting; poison, an alkaloid.

A shrub up to six feet high, leaves small, composed of green leaflet, silky when young; bears an abundance of yellow peashaped flowers. The leaves are slightly poisonous, especially if stock are not well nourished.

A grass, not unlike English Rye grass when young, sending up heads also like this grass, but with seeds wider apart, each of the seed heads having a bristle on the end. Grain quite small. The seed heads and seed are poisonous, and care should be exercised by cultivation, to keep this plant out of wheat fields.

A tall shrub with large hand-like leaves, having large red flower and seed heads, bluntly spiny all over. Seeds like a large bean, marbled white and brown or black. Leaves and seeds are poisonous, carrying an albuminoid known as Ricinin; this causes a thickening of the blood, and stomach purging.

The common name, as used in Africa, should be “Cape Tulp.” A bulb, having leaves often two feet long, narrow and much veined. Flower stems up to two feet high, with several yellow or apricot red coloured Iris-like flowers an inch across. The plant in flower is very decorative. Small bulbils often form on stem near the base. It is exceedingly poisonous to stock of all kinds, causing excessive interna! inflammation of the mucous membrane.

The plant has very large, somewhat long leaves, quite as large as those of the cabbage. They form a large rosette on the ground often three feet across. The flower stems are tall, up to six feet in height, carrying numerous pink, purplish or white bell-shaped flowers an inch long. The poisonous principle is very bitter, and stock only eat the plant when other foliage is absent.

A spreading plant, with parsley-like ferny leaves, known as the Carrot or Parsley Fern. The leaves are rich green; flower stems a foot or more in height, with many small white clustered flowers in flat bunches or umbels. It is a deadly poisonous plant, both for stock and humans. Children have died very quickly after having eaten the leaves. The poisonous alkaloid is more abundant in the seeds, but it is found in the leaves and stem as well. Strangely, goats seem to be immune from the poison of this plant.

Nearly all species of Lobelia are poisonous. They thrive and are very green in summer, even when other plants, including grass, are quite dry. They usually grow spread out flat on the ground, covering an area a foot or so in diameter, with small leaves, and small flowers blue or of blue shades of colour. The herbs are very acrid, often having a milky juice, which is very poisonous.

A robust plant, up to four feet in height, having variegated green and white leaves, the leaves and plant being very prickly. Flowers, two to three inches in diameter, petals delicate and thin, flowering in summer, from very pale cream to yellow in colour. Along the sea coast the colour is usually yellow; inland it is often pale cream. Seeds and plant quite poisonous, the juice being yellow, possessing narcotic, acrid and purgative properties.

A tall shrub, up to ten feet, growing very freely in the warm or dry districts. It flowers abundantly all through the summer and autumn. The decorative pink, red, cream or white flowers make it a very desirable shrub for gardens and plantations. It is mentioned here because of the poisonous character of the flowers.

A strong-growing succulent climber, grown in gardens, having thick, shining, fleshy leaves, and somewhat fragrant white flower clusters, in a tail-like growth. The plant produces many tubers in the soil, and also along the course of the strong stems. Stock feed on the tubers as well as on the foliage.

The well-known Scarlet Pimpernel, although in Australia the flowers are more commonly deep blue in colour. A somewhat trailing or spreading plant, with succulent stems and small, soft leaves; an annual plant which ripens its seeds in a few weeks. When in the seed stage, the seed vessels appear in great numbers like small, round, green or yellowish berries. It is dangerous in chaff or hay. The poison is a stomach one, and sheep are often affected.

A small, weak, rich, bright green annual, often seen in gardens, having small green flowers. The plant grows from a single stem, spreading out six or eight inches high. The sap is very sticky, milky in colour. Seeds remain dormant in the soil for years. Its poisonous properties are debatable; authorities differ regarding this.

A strong-growing plant, three or four feet in height, with narrow, rich green leaves and small greenish flowers. The seeds are wrinkled and as large as peas. It has a white, milky sap. It is somewhat poisonous, acting as an emetic and a purgative.

This is a native plant, included here to keep all of the class together. This is a flat, prostrate growing plant, spreading over the soil, having very small leaves of a greyish tinge, sometimes tinted purplish. Flowers and seeds are quite insignificant. Often grows in claypans and crab holes. Summer travelling sheep eat it greedily, and thus it causes stomach poisoning.

A slender-growing plant, with long narrow leaves, growing upwards of five feet in height. Flowers very small and white; the green seed pods are apparently, but not really prickly, and considerably resemble the shape of a swan. When the seeds are ripe the pods burst open, disclosing a mass of kapok-like hairs. The plant has milky juice. Vomiting is the result when animals feed on the plant, stomach injury and irritation occurring.

A strong, sturdy-branching plant, two or more feet high, with large, irregularly-toothed leaves, and white or purple, large, five-pointed, trumpet-shaped flowers. The seed pod is an inch and a half long and broad, globular and very prickly. Seeds many, and brown or black. It is highly poisonous, containing a dangerous alkaloid. It is very bitter and stock rarely eat it.

A strong plant, up to three feet in height, small leaves, rankly smelling, with small white flowers. Later come small berries in clusters, at first green, and finally purplish black. The plant and berries are poisonous to stock, especially when the berries are green. When they are ripe, they are occasionally eaten and made into jam. Burbank raised a large berried form of this weed and called it the “Wonderberry.” .

This deadly nightshade is fortunately very rare in Australia It is a spreading, large-leaved plant, with large, dirty purplish flowers and small yellowish berries. It causes paralysis and staggering after eating, and is, as its name shows, deadly poisonous.

A trailing melon-like plant, spreading over many feet, carrying small, round, melon-like fruits; common in warm districts. It is reputed to be poisonous, and possibly it is so, but very often the poisoning effect is caused by the ill-health of the stock.

NATIVE POISON PLANTS :

These two low-growing, herbaceous-like plants grow north of the Murray in Eastern Australia, and are named after the Darling River, where they commonly grow. They grow up to three feet, with small, roundish leaflets, and clusters of small pea-shaped flowers, white, pink or purplish in colour. Later come several seed pods, which, when green, “pop” upon pressure. The latter species is more hairy than the former. The stems die down after seeding, new shoots taking their place. The poison acts on the muscles, causing paralysis of the limbs, starvation and emaciation quickly follow.

Variously called Indigo, Wild Lilac and Hairy Indigo. The foliage is much like that of the Darling Pea, only that the stems of the Indigo plants, which grow up to six feet in height, are perennial, while those of the Darling Pea die right down after seeding. The flower clusters carry many small purplish or white flowers, the seed pods being hard and flat. The poisonous action of the plant is slow.

This is a race of plants which is common in Central, Western and Northern Australia, but rare in the East, one species only being known in Queensland and New South Wales. In West Australia, the various species are known as York, Blind, Heart, Rock, Desert, Berry, Prickly, Box, or Bloom Poison. Occasionally the plants are called Wallflower Poison, on account of the colour of the flowers. There are three dozen or more species growing from low to very tall shrubs. The flowers,

carried in clusters, are pea-shaped, and usually are brownish, reddish brown, or yellow brown in colour, generally in wallflower shades. The pods of many species are very swollen or inflated. Many species also have hard, and sometimes spiny or prickly leaves. All of the plants are dangerous, and many are highly poisonous, and are much dreaded by stock owners. Interestingly, many of the plants, while very poisonous in the green stage, are reported to be quite innocuous when dry.

A bulbous plant, almost evergreen, with a tuft of succulent, thickish, deep green, onion-like leaves, a foot or more long. The flower stem is taller than the leaves, bearing a dozen or two of bright yellow, six-petalled, starry flowers, about an inch in diameter. It is common all over the Commonwealth, except in the West. Scouring of stock is the result of feeding on this plant, death very rarely occurring. There is a smaller growing species known as the Leek Lily, very similar in appearance, except that the stamens are bearded. The flowers are only about half the size of the former; the poisoning action is similar.

This is a tall shrub or small tree with large green, round and pointed leaves like those of the poplar, and often six inches long. The very small green flowers are carried on a long spike about three inches in length; the fruits, when ripe, are bluish grey, two joined together. When the leaves are fading in Spring, they turn red or reddish purple. The plant is common in New South Wales and Queensland. Blood poisoning is the result when stock browse on the foliage.

This is a leafless, cane-like, twining and climbing plant, twining its masses of fleshy stems often into a shapeless mass of growth. Clusters of small white flowers are borne at the joints; while the seed pods are often three inches long, having seeds with tufts of silky white hairs. It is common in the warmer parts of all States except Victoria and Tasmania. It has a very milky sap. Head and body swelling are the first symptoms of the poisoning; subsequently staggering and death follow.

A low-growing plant, up to two feet high, usually of grey stems and foliage, one to two inches long, with a dense spike an inch or two long of rich red or brick-red showy flowers; the flowers have a cluster of hairy leaves at their base. It is common in North Queensland. It is a very bad, poisonous weed for sheep, and one of the most poisonous of herbs.

Scrub poison trees, crooked in growth, often found in scrub and on rivers and coasts in the tropics. The leaves are small, round and thick, yellowish green; the sap is milky and very poisonous. Flowers are insignificant, greenish and red, followed by small green berries. Stock browse on the foliage, which is very poisonous.

The Zamia Palms are dreaded by stock owners in West Australia, as, after feeding on the foliage, cattle become paralysed, especially in their hind-quarters. The “Palms” are very decorative, often with a twelve-foot'high stem. The long fronds are rigid, shining green, up to ten feet long, with thin, stiff, narrow leaflets. They produce large cones often ten inches long, composed of flat scales, having, when ripe, large bright scarlet seeds. In New South Wales and Queensland, several similar species, belonging to Cycas as well as Macrotamia, cause poison troubles, similar to muscular paralysis.

The Tree Nettle is hardly classed as an internal poison plant, but stock suffer greatly when they come in contact with the tree in Northern New South Wales and Queensland, for its sting is very virulent and injurious. The leaves are large and poplar-like, and these, as well as the whole tree, are covered with very shining and well-marked stinging hairs. There are other nettle trees similar to this, but with fewer hairs.

This tall parsnip-like plant, growing in sandy soils along coasts as well as inland, has a tall stem up to five feet, with spreading umbels of small white flowers. The leaves are large, somewhat loose, and flabby, deeply incised or lobed, with rough parsnip-like seeds. Little is known of its poisonous properties. The foliage is reputed to be very poisonous, while the roots are not so suspected.

THE EFFECTS OF CLIMATE ON PLANT POISONS :

Frequently, deaths amongst stock prove, on investigation, to be due to poisoning by some particular plant. It is known that plants are capable of being poisonous at one period and non-poisonous at another period of their growth. In addition to this, some plants, while normally innoxious, are poisonous after heavy rain or after a hard frost. Others, again, are only poisonous when in flower or in seed, thus in tracing or attributing a death to a plant, extreme difficulty may be met with, and it is always advisable to consult the plant pathologist of the State and carry on any investigation under his specific direction.

Another curious aspect of the toxic effect of plants is the fact that the plant which is poisonous when grown in one district or area, may show no sign of any toxic effect when grown in a different area, and, on the other hand, plants which are well known in Europe as affording good pasture have been known to develop toxic properties when grown in this country. In certain areas a high percentage of losses have been observed amongst travelling stock, and in most cases these have been proved to be caused by poisonous plants. The above information is inserted so that it may give the stock owner some clue to the causes of stock losses which hitherto have seemed more or less inexplicable. In Western Australia particularly there are numerous indigenous poison plants which are well known, but in other States individual plants of these species are liable to cause trouble before they are recognised.

FLAME CULTIVATION

The destruction of weeds by flame burning is not a new method in their control, but with improved mechanical appliances and scientific research into the significance of fire in agriculture, this method is now receiving considerable attention. Until recently fire had no place in farming, being regarded purely as a destructive force with no practical application. The modern use of flame makes possible the prospect of better farming through improved land preparation, crop planting and maintenance, together with new opportunities for harvesting some crops. The method is called Flame Cultivation, because it uses flame to destroy weeds hitherto undisturbed by mechanical cultivation implements.

The basic purpose of this method is to destroy those weeds actually growing in the crop row. At present their destruction entails manual labour by hoeing, thus imposing on the crop concerned extra labour cost which the crop could not afford to carry.

THE PRINCIPLE OF FLAME CULTIVATION :

Flaming attacks and destroys weeds because the applied heat reduces the plant’s moisture content below its “wilting point.” Within this limit the effects are proportional to the intensity of the heat and the duration of application. Resistance varies with plant varieties in relation to their respective wilting points, whilst throughout the plant frame the effect is greater upon the more succulent portions, such as leaves and shoots than it is upon the more fibrous growth; also of course resistance is equal to plant size. These are the limits within which control is secured to effect selective burning of weeds and NOT crop plant. By proper control of the heat applied and only using it against cultivated plants either sufficiently developed and/or with characteristic hard stem to resist the amount of heat applied it is possible to effect the destruction of young weeds by wilting them off. It is important to remember that the weeds should not be permitted to develop so that their resistance is equal to or greater than that of the cultivated plant.

The Flame Cultivator is simply a framework mounted on to the rear of a tractor incorporating a fuel tank, pumps and

reticulation systems to supply the burners. The burners are mounted on trailing skids which follow the contour of the ground. The trailing arms are hinged to a main beam and are raised, either hydraulically or manually for turning and transit.

FLAME BURNER EQUIPMENT:

In America the use of liquefied petroleum gases and kerosine has enabled the development of a simple design suitable for burning these fuels. A burner which uses kerosine but is still in the developmental stage is at present undergoing tests in Australia, and there does not appear to be any major difficulty to retard its development in this country.

FLAME CULTIVATOR OPERATION :

To successfully destroy weeds it is necessary to drench the crop rows with flame at a level slightly higher than the ground surface. Flame does not flow over the ground and around obstructions, but instead it bounces and is deflected. Thus the more smooth the surface, the better the flame can be applied from both sides of the plant which necessarily shields young weeds growing on the distant side from the burner nozzle.

Trailing burners are adjusted so that two flame jets, one from either side of the crop row, are directed across the undisturbed strip (Fig. 28). The axis of the flame is set at as close an angle to the ground surface as possible, the lower edge of the burner being about 2J inches above the ground surface. This is sufficient to raise it clear of cultivated soil so that loose earth is not piled by the burner’s body, thus FIG. 28. Good temperature causing interference with the flame Inversion. Head deflected _Tl • _n ,

downwards by warm air ^lhe P^{alr ot} owners are staggered so higher up. that the two streams do not collide.

This would cause the flame to be deflected upwards to the more tender portions of the crop plant.

CONTROL OPERATION :

The adjustment of the flame temperature and the regulating of the time of exposure are obtained by varying the ground speed of the tractor. Although the results from the use of flame cultivation are not yet available under Australian field conditions, the following is an indication of the degree of control necessary as determined from tests in the United States of America. The following is extracted from the U.S.A. Journal of Agricultural Engineering.

“If the machine is used solely for the control of weeds and grasses in the crop row, care must be exercised as to what site the plant should be to withstand the intense heat. For crops such as corn, cotton, soybeans, sorghum, etc., plants should be large enough to permit the flame to scorch the ground along with young weeds and grasses, but not strike the buds or tender parts of the crop. Lower leaves and limbs will be burned at this time, though no material damage will occur. SUMMARY :

Although field results alone can determine the suitability and effectiveness of the Flame Cultivator in Australia, it should be obvious that numerous benefits are possible through its use. It has a great potential as a weeder, over the usual straight mechanical type, providing the crop seed or root is sufficiently covered by soil to prevent scorching.

FROST

THE FORMATION OF FROSTS:

On a clear day, heat is radiated from the sun to the earth. This heat passes straight through the air and has little effect upon it. The ground or any exposed surface receives the heat and in due course the air at ground level is heated by contact with the hot ground. Being heated, it tends to rise and even in the absence of any wind there is a tendency to form circulating currents of air, and the warm air is carried up to a considerable height.

On a clear night the direct opposite occurs. The surface of the ground radiates heat away into the cold outer space and the ground surface cools accordingly. The air at ground level is then cooled in turn by contact with the cold ground, and its tendency is to fall, just as hot air tends to rise. Since it is already at ground level and cannot fall any further, it simply lies there and grows more cold. Provided there is no wind, there is nothing to cause a circulation of air, so that while a thin layer of air at ground level continues to cool, the air above will be almost unaffected and will remain fairly warm throughout the night.

This difference between the temperature of air at ground level and the warmer air higher up is known as temperature inversion, differences as high as 11°F. having been recorded between air one foot from the ground and air 25 feet from the ground. The amount of inversion is an important factor in frost prevention, and will vary widely according to weather and locality.

If, during the night, the ground temperature falls to 32°F. or lower, a frost occurs. It is evident that this ground temperature is governed, firstly, by the day temperature and secondly by the amount of surface cooling which takes place at night. Thus one can be prepared for a frost during cool, clear, calm nights, for under these conditions radiation of heat from the ground becomes excessive.

FACTORS AFFECTING DEGREE OF FROST:

Even when the ground surface is frozen, the soil a few inches below the surface is not, while the earth a few feet down is quite warm. Heat flows upwards towards the surface, thus helping to warm it and the air at surface level. Water has a high capacity for storing heat, and moreover wet soil is a good conductor of heat, so that newly-irrigated land will be less susceptible to frost than dry ground, probably to the extent of 2 or 3 degrees. Newly-ploughed soil loosely packed is a poor heat conductor, as are also grass and weeds, and these factors will increase the frost.

During a frost, the coldest air (at ground level) will drift downhill, settling in hollows, thus low situations should be avoided for plantings. The presence of a large body of water tends to lessen the degree of frost, thus sloping land facing a river is less subject to frost damage because there is some outlet for cold air. Timber belts, windbreaks and similar obstructions across the line of air flow do exert a certain retarding effect on the flow of cold air. On a hillside a change in slope to a flat stretch of land can have the same effect.

METHODS OF PREVENTING FROSTS:

Irrigating the land and keeping it clear of grass and weeds will give some benefit, but only against mild frosts. The use of screens made from hessian, twigs or other suitable material will afford some protection, but this method is not usually economical because of the high cost of covering. Various types of wind machines have been tried for frost prevention, but this method is still in the developmental stage. The running costs are moderate, but the capital cost is very high and is therefore unsuited to Australian conditions where severe frosts are infrequent.

Oil burners have proved satisfactory for fighting frosts in most ordinary cases. Of the fuels available for use in these burners, diesel fuel is undoubtedly the best. It has the highest calorific value of all common fuels, and that means that weight for weight it gives out more heat. In a properly-constructed container it is easily lighted, as easily extinguished when necessary, and whilst it is burning it requires no attention.

THERMOMETERS :

These must be accurate and so located that they give a true indication of the temperature of the crop which is being protected. For deciduous fruits which, during the danger period, have virtually no foliage, and are therefore fully exposed to the sky, the thermometers should be equally exposed. In the case of citrus, which are protected by heavy foliage, the thermometers should be equally screened. In all cases thermometers should indicate the earliest onset of frost, and this usually occurs at the lowest level.

There are several types of thermometers available, and advice regarding the most suitable type for any particular purpose can be obtained from the Commonwealth Meteorological Bureau in Melbourne. Whatever thermometers are used, and however they are placed, it is essential that they be mounted uniformly. Also, it is advisable that the thermometers should be checked during an actual frost, so as to learn what temperatures are indicated when the frost first begins to form. This is necessary, as even accurate thermometers show unreliable readings when they are not placed correctly.

ALARM THERMOMETERS:

A simple type of alarm thermometer is shown in Fig. 30. When the temperature falls the alcohol in the left-hand bulb contracts and the mercury moves up the left-hand side of the tube. At 34°F., the mercury touches the upper platinum wire, thus making electrical contact between the two terminals.

The thermometer is connected to a bell, battery and switch, and at the above temperature the bell rings, sounding a frost alarm. The bell is then silenced by means of a switch.

The position of the thermometer is most important, and it should be mounted at the coldest point, or lowest ground level. If a 34 degree alarm thermometer is fully screened from the sky, it may not ring until the temperature by ordinary exposed thermometers is 30 or 31 degrees F., or, in extreme cases, even less. If, on the other hand, it is exposed on its back so that it gets the greatest effect of radiation, it will ring when less exposed instruments are recording about 38 degrees. The grower should bear these points in mind when placing this type of thermometer and he should test it out by noting at what temperature the alarm sounds. The margin between the alarm temperature of 34° and the actual danger point provides a time interval in which the orchardist can get on to the job, and, if the temperature continues to fall, can light the necessary number of burners.

CRITICAL TEMPERATURES

Since the whole object of heating or other protection is to keep the temperature of the crop above danger point, it is essential to know where that lies, and to measure the temperature accurately.

The following table shows the degree of cold which will probably be endured by different crops up to thirty minutes without damage :

THE SHEEP BLOWFLY

Serious losses are yearly inflicted upon the sheep and wool industry by the blowfly pest. So great is the damage that sheep owners should endeavour to combat the menace which retards the industry, and the owners’ and the nation’s income. The blowflies common with strike in sheep are classed under two main headings — Primary flies and Secondary flies. Primary Flies, which actually start the strike, are again divided into two classes.

The Primary Green Blowfly, which causes about 80 per cent, of strikes in this country, is a slender egg-laying fly, coppery to yellow green in colour, and it is rarely found in the house. Most active at temperatures between 70° and 80° F., this fly comes in two main waves each year — Spring and Autumn. The Lesser Brown Blowfly often causes strike in tailing wounds, and it is smaller and more of a house pest than the large brown blowfly. This variety has a blue band down the body and lays living maggots.

Once a strike has started, Secondary flies attack in large numbers; although there are four classes of this type, it is sufficient here to detail only the characteristics of the Secondary Green Blowfly. This fly is much squatter than its Primary counterpart, bluish-green in colour, with transverse lines running across its body and thorax. It is seldom found in the house, and it breeds in decomposing meat in direct contrast to the Primary Fly, which prefers fresh meat. The eggs of the Secondary Green Blowfly develop into hairy maggots.

Although all blowflies go through the same stages during their life cycle, the time varies according to the particular species, and is governed to a large extent by seasonal conditions. Depending on the species, the eggs or maggots laid are hatched quite early in the female’s life. The maggot is active at birth, and moves about freely to feed. It feeds for a period of two to four days, and when fully fed it burrows usually into the surface layers of the soil, where the pupal stage lasts about eight days, before the developed fly appears to complete the cycle.

Each female fly is capable of laying eggs at three days, and lives for about one month, during which time it is possible to lay up to 3,000 eggs.

HOW THE STRIKE STARTS:

It is important to remember that Primary Flies breed mainly on the living sheep. They do not breed in carcasses, although a fresh carcass will attract them for the first day or so. The Primary Fly is attracted to the sheep by the presence of moist, inflamed or injured tissue on the skin, and in the field most of this moisture is due to scalding. This state occurs in the crutch region of the ewes, and is due to the wetting of the wool with urine. If drying out does not occur rapidly the fly is attracted to the moist area and lays its eggs.

EFFECTS OF STRIKE :

After hatching, the maggots work their way through the wool to the skin, where they set up intense irritation, and cause the sheep to bite at the affected part. This action in itself will attract attention to the sheep, as will continued stamping or other signs of discomfort by the animal. As the maggots continue to grow they attack the surrounding tissues, and the infestation spreads rapidly, the wool comes away, exposing a raw surface; the sheep loses condition, gangrene sets in, and may be followed by death.

CONTROL OF THE BLOWFLY ON SHEEP:

The blowfly to some extent can be controlled by trapping or by using poisoned carcasses as bait. It is doubtful whether any of these methods are particularly effective, since it is often difficult to achieve cooperation on the part of one’s neighbour, and neglected areas will produce sufficient flies to nullify almost completely another’s efforts.

Sheep may be treated to reduce t;heir attractiveness to the fly by any of the following methods:—

(a) By maintaining them in healthy condition by methods such as supplying licks, control of liver fluke, and stomach worms.

(b) By leaving sheep with longer tails, approximately 4 inches, and by carrying out the Mules operation to remove surplus breech wrinkles.

(d) By jetting (i.e., spraying the breech area) periodically with arsenical or a similar preparation.

(e) By treating all wounds with Shell Defiance Blowfly Oil so that they will heal rapidly and be protected against fly attack as they heal.

In addition to the above, the normal dipping of sheep has appreciable value in blowfly control, as the arsenical preparation left on the wool will poison the fly larvae. However, the dip loses its effectiveness after a period and complete control of the fly by this means could not be expected.

Shell Defiance Blowfly Oil is based on water insoluble petroleum products of soothing, softening and healing properties. With this base there are blended powerful insecticides which ensure that the wound will be kept clean and healthy. While designed primarily to combat the blowfly, the soothing and healing properties of Shell Defiance Blowfly Oil are such that it can be used for wounds and surgical cuts on all types of stock.

Method of Applying

SHELL DEFIANCE BLOWFLY OIL :

The correct procedure in dressing the sheep prior to the application of Shell Defiance Blowfly Oil is very important since failure to carry out certain precautions will result in incomplete control so that both time and materials are wasted.

(1) Remove all wool from the struck area and, in addition, remove a border of approximately 2 inches of clean wool all round. The wool surrounding the clipped area should be bevelled to prevent the staples falling over the clipped area and becoming soiled.

(2) Examine closely all surrounding wool for “hair tracks” to make sure that there are no adjoining pockets of maggots. A “hair track” appears as a dark line leading from the struck area to an adjoining strike. This is very often found when the strike is well established, and migration of primary maggots is in progress. Such pockets are not always obvious, but if left unattended soon become major strikes. These are sometimes regarded as restrikes, which obviously is not the case. Early detection and treatment as individual strikes are essential.

(3) Shell Defiance Blowfly Oil should be applied with a brush. A suitable type is a stencil brush about lj inches in diameter with bristles about 1^ inches long. The dressing is first of all applied to the clean wool surrounding the strike. This point is most important as treatment of the clean area prevents migration of maggots. Following this the struck area is liberally treated with Shell Defiance Blowfly Oil.

(4) Head Strike. The same procedure is adopted as for a body strike. Examine the horns closely for cracks. Any cracks should be opened and dressed with oil to remove any maggots concealed therein. With a strike following lamb marking, all scabs should be removed and wool clipped from the adjoining area. The wound is then treated as for an ordinary strike. It is well to remember that a flock of sheep containing struck animals should not be packed tightly in yards or trucks, since infection can spread rapidly by contact.

SPRAYING EQUIPMENT

Whilst the choice of the correct spray material and its proper application at the right time are the basic principles underlying efficient pest control, nevertheless a most important part is played by the spray equipment itself. Factors such as the capacity of the plant, the pressure at which it operates during prolonged spraying periods, its mobility and reliability can make or mar the efficiency of any spraying programme, and we therefore propose dealing in some detail with the more important points.

STATIONARY OR MOBILE SYSTEMS

Many growers are giving serious thought to the installation of stationary equipment, because under their conditions this type appears to offer greater efficiency with lower operating costs. The advantages of stationary equipment are briefly as follows:—

Speedier spray application. With mobile equipment a considerable amount of “non-spraying” time occurs, because of time lost travelling to and from the water supply (probably 25% to 30%), and because under excessively wet conditions the equipment cannot travel in the orchard. More time is also spent on adjustments and repairs to mobile equipment, since it is exposed to weather, spray, drift and jolting.

Timeliness of sprays. The whole success of a season’s pest control programme may be endangered by the inability to move a mobile outfit in the orchard at some critical stage.

Reduced running and labour costs. Stationary systems eliminate “non-spraying” time, while fuel costs are less than those required for a mobile plant when the latter is tractor-drawn. In one case well known to us, running costs were reduced from 3/4 per 1,000 gallons to 1/1J per 1,000 gallons. The saving of labour by a stationary system is furthermore important at a time when labour is difficult to obtain.

Ease of application. Slopes and hillsides present little difficulty to stationary system, and there is no damage to cover crops as is the case with a mobile unit. Depreciation and repairs. These are materially less when the pump and engine are housed under permanent cover. However, stationary equipment has disadvantages. These are:— Higher initial outlay. This may be an insuperable barrier in some cases, but particularly with apples and pears where a large number of sprays is applied, the annual saving would soon offset the higher initial outlay. Perhaps with citrus and stone fruit where relatively few sprays are applied each year the cost may not be fully justified. In these cases, however, the economical factors associated with pest control in each individual orchard would need to be given careful consideration.

Time wastage. Despite what has been written under advantages, exceptional circumstances can occur under which time is actually lost using a stationary system Such may be the case when different varieties of trees requiring different treatment are scattered throughout the orchard.

Loss of spray material. Some loss in the pipelines cannot be avoided, but the extent of this loss can be minimised by skilful management in the pumphouse.

The next question to be decided is the capacity required. For proper pest control it is absolutely essential that each variety of tree be covered as quickly as possible. The equipment, therefore, must be capable of handling the required sprays within a week at the outside, otherwise the pests at the bottom of the orchard will be having a grand time before you get around to them.

To arrive at the required capacity one must allow, firstly, for “non-spraying time” (which is in the region of 25-30% for mobile equipment), the likelihood of temporary delays such as adverse weather conditions, and the fact that most equipment manufacturers rate their capacity at maximum operating speed, whereas it is more economical from the viewpoint of fuel and maintenance costs to run the equipment at half speed or even less. All these factors must be carefully considered.

As a general rule, however, it can safely be said that for each acre which must be sprayed at a given time (this applying particularly to apples and pears), the equipment should have a capacity of about 8/20ths of a gallon per minute when operating at the economical half speed. This would mean

that for a 20-acre orchard of apples and pears sufficient plant would be needed to apply 8 gallons per minute at half speed or 16 gallons per minute at full speed, if this is the basis of capacity rating used by the manufacturers.

In America equipment capable of giving an average of 600 lbs. sq. in. at the nozzle appears to be regarded as standard. In Australia there is a need for such high pressure for citrus spraying, to carry the spray through and over the foliage, but experience suggests, however, that a nozzle pressure of 400 lbs. sq. in. is all that is needed to give thorough coverage of deciduous trees.

The pressure at the nozxle should be identical when using mobile or stationary equipment, but stationary plant has the additional job of pumping the spray throughout the orchard. A pressure drop due to frictional losses in the pipelines occurs, and, in addition, where spray has to be pumped uphill there is a further loss due to gravitational effects. Provided the layout is properly planned, however, the pressure lost due to these causes should not exceed 150 lbs. sq. in., but provision for this amount should be made; hence the stationary spray pump must be capable of producing a pressure for deciduous fruits of at least 550 lbs. sq. in., and for citrus of perhaps 650-700 lbs. sq. in.

All equipment should be fitted with a proper pressure regulator, so that when the rod or gun is shut off the surplus spray can return to the vat with the engine running at idling speed rather than under full load. One must ensure that the power unit is adequate, so that it does not have to be run at maximum speed to maintain the pressure and throughput needed.

As a guide the required horsepower has been calculated to be approximately 1 b.h.p. for each 10 gallons pump capacity at 100 lbs. sq. in. Thus, if you require 20 gallons per minute capacity at 500 lbs. sq. in. pressure, you will require a power

From time to time claims are made that rakes will simplify spraying operations and will give better pest control. Experience suggests, however, that when rakes are used one sweep covers such an area that the spray operator may be mistaken as to the thoroughness with which the spray has been applied. In this way the success of the whole season’s pest control may easily be jeopardised.

Rods and guns are both very efficient, but each has its place. In the case of calyx sprays on apples and pears it is important to fill the calyx cup and a spray rod, preferably with “Y” nozzles, should, in the interests of efficient pest control, be used for these sprays. Only by the use of a rod can you spray into those calyx cups which are pointing upwards. At a later stage when the fruit is tending to hang downwards and the thickening foliage might prevent the use of a spray rod inside the tree, a spray gun is quite effective. For big trees it should be remembered that somewhat higher pressure is needed with a spray gun so as to cover the entire tree.

Some spray materials form undesirable and dangerous combinations with others; consequently, every care must be taken to clean out the plant after each spray operation. This applies with equal or greater force to stationary equipment, in which partial or total blockage of piping may follow sedimentation or corrosion by spray materials left in the pipeline. The entire outfit should, therefore, be flushed out after each day’s spraying, and if the spray residues cannot be removed in this way more drastic cleaning methods, such as an alkaline cleaning agent for the spray vat, or dilute hydrochloric acid for the pipelines of stationary equipment should periodically be used.

SOIL FUMIGATION

Nematodes are microscopic worms often known to the farmer as “eel-worms.” This minute animal life attacks a wide range of plants and animals, causing severe economic loss throughout the world. At least 1,800 plant species are known to be subject to attack.

Certain forms, like the Root-knot Nematodes and some species of Meadow Nematodes, have a world-wide distribution, and attack a great range of plants; others are restricted to certain regions and attack only a few hosts — e.g., sugar beet. The Root-knot Nematode is one of the worst and most widely distributed agricultural pests, occurring over a wide range of soil and climatic conditions, and is also a common pest in glass houses and home gardens.

The action of the Root-knot Nematode is to burrow into the feeder roots of trees, vegetables and flowers, causing a gall-like swelling that strangles the life out of both roots and plants. This distorted swelling gives rise to the name “Root-knot.” Since the symptoms are underground, the appearance above ground is often mistaken for lack of water or fertiliser.

Some forms of Nematode are particularly difficult to control because they form cysts or resting stages which are resistant to droughts and difficult to destroy. These cysts can lie dormant in the soil from 10 to 15 years without dying, and may hatch out immediately if a susceptible crop is planted. As a means to combating this expensive pest, the use of Shell D.D. Soil Fumigant provides some extraordinary and satisfying results.

Shell D.D. Soil Fumigant was used in Hawaii, where the pineapple industry was seriously threatened by Nematode infestation, and excellent results were obtained. In California, yields of carrots increased following the use of Shell D.D. Soil Fumigant from 40% to 125%. Lettuce yields increased from 58 crates per acre to 408 crates per acre. In Nevada, yields of first grade potatoes increased from 1,444 lbs. to 25,507 lbs. per acre and in the State of Utah sugar-beet doubled from 11 to 23 tons per acre. Other crops elsewhere in the United States to show increased yields were tobacco, cotton and garden vegetable crops. When used as a preplanting treatment, Shell D.D. Soil Fumigant has given stimulated growth to young citrus and deciduous fruit trees.

Similar results on the productivity of agricultural crops in Australia are possible. Under glass-house conditions, the mean yield of cucumbers per plot was increased from 325 to 664. Furthermore, the fruits in the treated plots were larger with more uniformity of site when Shell D.D. Soil Fumigant was employed as a pre-planting measure.

Shell D.D. Soil Fumigant is a dark coloured liquid mixture with a characteristic odour. Chemically, it is composed of Dichloropropylene and Dichloropropane. When applied, D.D. vapourises through the soil as a gas which is lethal to Nematodes, Wireworms, Moles, Crickets, Ants and other soil inhabiting pests.

METHODS OF APPLICATION :

The Shell Company has developed both small and large equipment for making commercial applications of Shell D.D. Soil Fumigant to broad acres. Some units are designed to treat only a few acres, while others can treat up to 30 acres per day. Although not yet in Australia, the latter equipment (Fig. 32) will prove of inestimable value to the farmer when it becomes available. For hand application of Shell D.D. Soil Fumigant on a commercial scale, an accurate spot injection tool can be used The Shell D.D. Soil Injector consists of a reservoir for the Shell D.D. Soil Fumigant which is delivered down a barrel into a spike fitted with a non-return valve and radial outlets. The spike has an adjustable foot plate which can be set to provide the required injection depth. A plunger can be set to give the correct dosage of Shell D.D. Soil Fumigant. In practice, the injector is thrust into the

ground to the level of the foot plate, and the plunger handle is forced down to the level of the calibrating collar which has been previously set to give the correct dosage.

For more detailed information on the use of Shell D.D. Soil Fumigant, write to the nearest branch of the Shell Company or make enquiries from the Shell representative calling on you.

The transmission of power by belt drive is probably one of the most convenient, as it allows any engine to drive any machine without the careful and complicated work required for direct coupling. In addition to the care and precautions necessary when using belts, the following points are well worth considering:

In the first place, both the engine and the machine driven must be either sufficiently heavy to prevent their moving, or must be fastened down. Belts should be used with the grain side to the pulley, and should run with the load or tight side underneath, as the sag in the upper side helps to grip the pulley and prevent belt slip, because a greater arc of the pulley is actually in contact with the belt.

Belts on pulleys of less than 8-inch diameter should be less than 3/16th inch thick. A vertical belt drive transmits about 10 per cent, less power than a horizontal belt drive. Belt pulleys should be at least 1 inch wider than the belt, and should be convex, in order to keep the belt central on the pulley.

There should never be a greater difference than 6 to 1 in the size of the diameters of the two pulleys used on the belt unless the length of belt is great.

To find the length of belt required, not crossed, add the diameter of the two pulleys together and divide by two and multiply by 3J, and add to this twice the distance between the centres of the shafts.

JOINTING BELTS :

For belts 3 inches wide and over, the holes should be made 1 inch apart and | inch from the joint.

The joint must be cut squarely in order to ensure that when running the belt will run truly and will not wobble.

The following table shows the horse-power which can be transmitted by leather belts:—

BELT TRANSMISSION DATA:

To convert pulley speeds in r.p.m. to belt speeds in feet per minute. Diameter of pulley in feet x r.p.m. x 3.14 = belt speed in feet per minute.

RULES FOR CALCULATING DIAMETERS AND SPEED OF PULLEYS:

Speed of driven pulley in compound drive — Divide product of diameters of driving pulleys by product of diameters of driven pulleys, and multiply the quotient by speed of first driving pulley.

RIGHT ANGLE DRIVE:

If two shafts are running, or required to run at right angles, it is possible to connect these together by means of belting as shown in Fig. 34.

The water supply requirements of a farm are governed by the class of farming practised and by the size and carrying capacity of the property.

For example, a dairy farm requires far more water than any other type, and the average daily supply requirements of a farm may be assessed from the following table:—

The use of impure water is far more harmful to humans than animals. In the past epidemics of dysentery, cholera, and typhoid have been traced to impure or contaminated water supplies. Nevertheless, the spread of diseases, such as contagious abortion of cattle, tuberculosis and influenza of horses can quite easily be the result of impure water.

Water suitable for human consumption and general farming purposes should approximate the qualities listed in the following table:—

Water which contains iron in any great quantity can result in blocked pipes and fittings with a subsequent reduction in the capacity of the pipe. Water which contains iron is not suitable for domestic use. However, for working and general use iron-bearing waters can usually be improved by aeration, followed by a period of settling. With running water aeration is possible by allowing the water to flow over weirs and the like. The addition of lime or aluminium sulphate to the water will counteract the iron, but it is necessary to arrange a sand filter through which the treated water passes on its way to the storage tanks.

Hard waters, that is water that does not readily form a lather with soap, has been blamed for certain digestive troubles and malnutrition in animals; hard water is not suitable for use in mixing dips, and usually it will cause deposits in boilers and other containers in which the water is boiled. Hardness can be overcome by adding washing soda. Mild and temporary hardness can be removed by the addition of slaked lime. This practice also helps to remove organic matter and purify as well as soften the water. In each case the quantity of lime or soda required depends upon the degree of hardness and this can only be determined by having the water analysed.

Where rain water is stored in tanks, it is not wise to leave them uncovered. Pollution is liable to occur, and for that reason strainers should be provided at the inlets, spoutings kept clean, and the tanks regularly cleaned out whenever possible. During heavy rain it is a good practice to turn on the outlet tap so that stale water will escape, thus allowing the tank to gain as much fresh water as possible.

Where green slime appears on the surface of tank water purification can result from the use of copper sulphate. This should be added in the proportion of 1 ounce of crystals to 10,000 gallons of water. The crystals should be dissolved in water and added to the tank by spraying over the surface. In this proportion the copper sulphate is not harmful to humans or to stock. Similar results are possible with the addition of potassium permanganate (condy’s crystals) until a very faint tinge of pink is noticed in a cup of water.

It is advisable to fence off dams to prevent pollution by stock and to plant trees around them so that the water will be kept cool. Otherwise infection to stock by internal parasites may occur. For the same reason supplies of underground water should be protected at the well or bore head lest impure water seeps back into the source of supply.

IRRIGATION AND DRAINAGE

Many farmers have had the unpleasant experience of getting a good crop in a good season, only to find the market glutted and subsequent low prices. Obviously the best time for a good crop is when there is a shortage due to a bad season, and the only way to be sure of this is by means of irrigation. The requirements for successful irrigation are:—

5. Intelligent management, including the selection and use of the correct equipment.

Practically any soil that will permit the root development of the crops grown is suitable, as, for example, lucerne requires for its best growth a deep free soil, whilst pastures will do well on shallow soils. Dried vine and citrus fruits require a deep full soil.

Many streams are of a perennial nature; that is, flowing all the year round, but a great number cease to flow during the summer months, and in consequence storage would be required to enable irrigation to be carried out during this period.

Water is delivered to the distribution point on the land either by gravitation or where the source of supply is a river or creek, by pumping, and where the contour of the land is sufficiently flat it is distributed through a series of head ditches and laterals, either to bays in the case of pastures or lucerne, or furrows for fruit, vegetables and other like crops For the best results the land should be properly laid out after a contour survey has been made, the head ditches and laterals correctly located and permanent structures installed in the

ditches and laterals to control the flow of water. In light soils, it is considered essential to line the ditches with concrete. For lucerne and pastures, the land should be graded and check banked, and the length of the runs dependent on the slope of the ground and its soil texture. For example, light soils with comparatively steep grades require short lengths of from 3 to 5 chains.

In furrow irrigation, the furrows should be laid out on as flat a grade as possible so that a large head of water can be used without the possibility of scour, and without over saturating the head of the furrow. Provided furrows do not exceed 3 chains in length in light soils, no harm should result.

Where the ground is irregular, and does not lend itself to grading or layout for a furrow system, and where the value of the crop intended to be grown warrants it, a spray system would be justified. Spray irrigation consists of the delivery of the water through a system of pipes and sprinklers, and the pipes may be either portable or fixed. With portable systems, the initial cost is considerably lower than that of the fixed systems, but a great deal of labour is involved in moving the pipes during irrigation.

More power is required to deliver water through a spray system than where the water is distributed by gravity, as there needs to be a residual pressure of at least 15 lb. to the square inch at the sprinkler involving the lifting of the water a further 35 feet; thus the engine should be large enough to cope with this demand.

The area which may be irrigated is limited by the supply of water available per hour; but the greatly increased coverage and the fact that water forced through sprinklers is aerated by being broken into particles by impact with the air renders this form of irrigation very much akin to natural rainfall. A spray system has other advantages, such as the complete absence of ditches, with its attendant loss of land and their maintenance, no grading or layout required, and some saving of water in certain circumstances. On the other hand high initial and operating costs would preclude its use except for high value crops.

DRAINAGE :

Effective drainage is essential for the success of any irrigation project. Irrigation without drainage results in soils with excess water, and the accumulation in the soil of harmful concentrations of salts. This salt accumulation results from evaporation on the soil surface, which subsequently draws salt-tainted water upwards, which in turn again evaporates leaving a salt crust on the surface. The chief danger from excess salt is the accumulation of the material in the soil which acts as a plant poison, thus killing the root of the plant, and, although there are methods by which the salt content can be gauged, it is advisable to have the water analysed before any time or money is spent on irrigation. The correction of salt concentration may he effected by the application of substances which neutralise the accumulation in the soil and expert advice in this respect is available from the Department of Agriculture in your respective State.

Surface drainage, which has for its object the removal of storm and excess irrigation water, is necessary in all cases. A surface drainage system should be so laid out that it will deliver the drainage water to a suitable outfall, usually situated at the lowest point on the property. If the fall of the land is such that no suitable outfall exists, it would be necessary to resort to pumping to remove excess water. The lack of surface drainage will cause plant life to die, with the possibility of a water table being built up in the soil which would result in wet feet and salt troubles. A surface drainage system should be of a capacity capable of removing all surplus surface water within two days.

In free subsoils where there is a tendency for a water table to be built up, and where the root of the plant penetrates some distance from the surface, a sub-surface drainage system should be installed. Sub-soil drains consist of short lengths of porous earthenware pipes laid in a trench on a pre-determined grade and the trench refilled. The depth of the trench and the distance between the drainage lines will depend on the class of soil and the position of the clay in the soil. Pipes should not be laid in the impervious clay sub-soil, as penetration of the ground water to the pipes would not be possible.

In this chapter only an outline of the principles governing irrigation and drainage has been given, and it is well to remember that, no matter how efficient the irrigation system may be, its full benefit cannot be experienced unless careful planning is given to the subject of drainage. Unless the land is well suited to natural drainage and the type of soil sufficiently absorptive, a combination which is seldom found together, excess water will ultimately result in waterlogged soil, and under these conditions the growth of crop roots is suspended and helpful soil bacteria are unable to survive. In all cases where irrigation is proposed, expert advice should be obtained. This is available for the preliminary stages, without charge, from the Farm Water Supplies Branches of the Water Supply Commissioners of Victoria and New South Wales. In other States advice is available from the respective

Agricultural Departments, particularly with regard to crop requirements and growth.

THE ENGINE:

There are numerous makes of petrol, kerosine and diesel engines available from which the farmer can make an excellent choice. There are so many factors to be considered in the correct application of engine power to pumping capacities, that the advice of a qualified expert should be sought before installing any plant, the cost and size of which may over-capitalise the irrigation system.

PUMPS

RECIPROCATING PUMPS:

These, again, may be divided into two types, the horizontal force pump and the vertical well pump. In the force pump, the backward movement of the piston sucks water into the cylinder through the non-return suction valve and the forward movement of the piston forces the water through the nonreturn delivery valve. It is essential in this type of pump that the delivery valve should always be open when the pump is running, otherwise there is grave risk of a burst cylinder or pipe. The engine should be shut off before closing the delivery valve. The back pressure of the water may be held by a non-return valve in the delivery line. The lubrication of this type of pump is very simple, consisting usually of glands packed with graphite or tallow impregnated hemp. The driving pulleys and big end may either be lubricated by grease or by means of oil cups or ring oil bearings. The vertical well pump, or windmill pump, consists essentially of a casing forced into the earth down to the level where the water supply is. The windmill or driving agent causes the piston rod to rise and fall. The illustration (Fig. 37) shows the bottom or water end of the casing, A being the casing itself. The water is sucked through the casing A and through the non-return valve D, which allows water or air only to pass in an upward direction into the chamber E. As the piston C rises, it tends to create a vacuum in the chamber E, since it makes an air-tight joint by means of leather or other packing F. As the piston falls, the water is forced through the non-return valve G, which also only allows water to pass in an upward direction, thus the reciprocating motion of the piston continually lifts water upwards. It is advisable to fit

a strainer of some description at the bottom of the casing if possible. Few pumps of this type work satisfactorily where the piston chamber is more than 12 feet above water level. The following table gives the approximate capacity of cylinders in gallons per stroke. The quantity delivered per minute can be calculated, depending upon the number of strokes per minute which are made:—

CENTRIFUGAL PUMPS:

The simple centrifugal pump (Fig. 38) has two main parts, the body, or casing, and the impeller. The water is sucked into the casing through the suction pipe A into the “eye” of the impeller B. The impeller is keyed to the shaft and rotates with it at the same speed. The vanes C throw the ■ water outwards into the volute

shape of the pump casing D, where it flows under pressure into the delivery pipe E. The shaft passes through the casing usually at two points, F and G, which are kept water-tight by means of glands with graphite or tallow and hemp packing. In some types of small pump, the shaft does not extend beyond the eye of the impeller, in which case the bearing H is larger. The bearing is usually Centrifugal pump. ring oiled and lined with white

metal or brorue bushes. A foot valve, or non-return valve, should be placed at the bottom of the suction pipe so that the pump may always remain primed or full of water. A wire strainer should be fitted below the nonreturn valve to prevent rubbish of various kinds from being sucked into the pump itself. The pump should, where possible, not be placed at more than 12 feet above the lowest level of the water.

To stop pumping, close the valve on the delivery side and then stop the pump. After starting up, make certain that the pump is primed, or full of water. The cock K is placed on the highest point of the pump casing for this purpose (Fig. 39). Should a smaller quantity of water be required than is the full pumping capacity of the plant, this may be pumped to a greater height by closing the valve on the delivery side slightly. Increasing the speed of the pump will increase both the quantity and the head to which it may be delivered. Always make certain that the gland G is in good condition, otherwise water will leak into the bearing H, and the lubrication will be ruined.

Lift required = vertical lift -f- equivalent lift of 90 yards of piping -f- equivalent lift of three pipe bends.

The figures used in the foregoing calculation are obtained from the following table, which may be of use:—

N.B.—Right angle elbows and sharp bends must be considered as equal to 3 yards of piping under column 4.

WE RECOMMEND :

ELECTRIC GENERATOR & MOTOR

In construction, the direct current (D.C.) generator and motor are identical, the only difference being in the method in which the wires are connected up. The real difference between the two is that a generator produces electricity by being driven, while a motor uses electricity in driving something else.

The only parts of a generator or motor which need attention are the bearings, the commutator and the brushes. The remainder of the machine requires little attention beyond keeping it fairly clear of dust and oil, and preventing it from becoming excessively damp. These three conditions must be watched, as each tends to produce short circuits and burned-out coils.

The bearings are usually either of the roller or ball type, or ring-oiled sleeve bearings. Roller bearings and ball-bearings should be kept clean and supplied with lubricant where necessary. Ring-oiled sleeve bearings should be watched in order to make certain that the level of the oil in the sump does not fall below the bottom of the oiling ring, since, should this be the case, the oil cannot be carried on to the bearing. Both the grease and the oil in these types of bearings should be completely removed once or twice a year, giving the bearings a thorough cleaning and a fresh supply of grease or oil.

The commutator, after running for some considerable time, will become darkened in colour, and may possibly in time be worn slightly into grooves through the constant friction between it and the brushes. Should this occur, the best method of overcoming it will be to obtain a strip of very fine (No. 00) emery cloth, and, placing it round the commutator, revolve it in such a way that all the high spots of the metal are cleared away. After this operation, it will be necessary to inspect the commutator closely, and make certain that the mica slabs between the commutator bars are not protruding above the copper, and also that no copper dust is filling the gap between the commutator bars.

After prolonged running, it may be found that the brushes are not making contact as they should. The springs keeping the brushes in position should be examined and brought to a light tension. The bearing surface of the brushes may be made to bed more efficiently by placing a strip of fine emery cloth, rough side outwards, on the commutator, pressing the brush on to the cloth and commutator, and slowly pulling the cloth backwards and forwards following the curve of the commutator. Again, care should be taken to see that no dust remains on the commutator. Care should also be taken to see that the leads from the brushes are secure, as these tend to work loose.

In every case, make certain that good contact is made at all connections, and that the connections themselves are tight. Never interfere with connections when the current is switched on, and always guard against possible shocks. Safety lies in the cleanliness of the machine.

A 3 h.p. engine will drive a dynamo (1-J kilowatt) capable of supplying 60 x 20 watt lamps, and requires about 1| pints of petrol or kerosine per 1,000 watt-hours.

THE BATTERY

The purpose of a battery is to store up electrical energy for use when the generator is not running, and also to supply a reservoir of sufficient capacity to ensure that a steady supply is available.

A house lighted from an insufficiently large battery suffers from light flickers, which is both trying and damaging to the eyes.

A battery is merely a collection of storage cells linked up one with another, the number depending upon the voltage and the current required. The storage cell consists essentially of a glass or other non-conducting box in which is contained a series of positive and negative plates. One set of bars connect the positive plates, each set finishing in a marked terminal. Wood or fibre is used to keep the positive and negative plates apart. The cell is filled with an electrolyte or conducting solution, usually sulphuric acid.

The battery, to work at its highest efficiency, must be kept clean, and its terminals should periodically be cleaned, kept bright, and coated with a cover of Shell petroleum jelly to prevent corrosion. The battery should be kept filled up to the point about £ inch above the level of the plates, or up to the level specified by the makers. Distilled water should always be used for filling purposes, since this gives the best and cleanest service. The battery can be tested by means of an hydrometer to ascertain how fully it is charged. If the battery shows an hydrometer reading below standard, it is not fully charged. In some types of batteries, one cell has a permanent hydrometer from which the state of the battery can be read at all times. Care should be taken not to allow the battery to become overcharged or seriously undercharged, as both these states tend to cause considerable damage.

Briefly, the following are the main points to be remembered in the care of a storage battery:—

(2) Give ordinary charges as frequently as the service demands and extended charges periodically.

(8) Avoid over-rapid charging or discharging rates, which cause rapid deterioration of the battery plates by buckling, as well as causing rupture of the separator plates.

Modern milking machines when operated according to the maker’s instructions will give excellent service. Without due regard given to cleaning, however, these machines can quickly become a menace in the production of milk and cream.

The effective sterilisation of equipment is of paramount importance throughout the dairying industry, and the complete removal of milk and milk residues from all equipment is necessary before any sterilisation can be effectively carried out. The general routine of cleaning dairy equipment of all kinds is performed in a number of stages, the effectiveness of each influencing the others, and thus the cost of the whole operation. It is not proposed to describe in detail each of the stages listed here; briefly, however, they are:—

The operator must at all times pay considerable attention to his personal cleanliness. The handling of a dirty leg rope or similar article can undo all the good achieved by prior hand washing. The operator should be observant throughout milking in case a teat cup falls off. Should this occur, the suction should be stopped immediately and the cups washed in clean warm water and dipped in sodium hypochlorite solution before they are returned to the udder. Without these precautions the whole milking can be contaminated from floor dirt from the dropped cup.

The milking shed floor must be kept perfectly clean and manure should never be left, even temporarily, on a floor where machines are operating, for this forms one of the commonest and most dangerous sources of contamination.

Irrespective of whether milking machines are used or not, all dairy farms should have some efficient appliance for heating water. The best form of appliance is a steam boiler from which steam can be obtained under pressure. Other equipment consists of a good supply of some approved trade detergent, brushes and a double trough, one section to contain warm water and the detergent agent for the washing, and the other to contain the very hot water necessary for scalding.

TEEPOL:

All milking utensils which are contacted by milk or cream become greasy, but with the use of a detergent and boiling water, the fat is completely and easily removed. At this stage in the cleansing process the use of TeepoI is strongly recommended.

Teepol, simply described, is a synthetic wetting agent and detergent possessing all the advantages of a soap solution without any of its disadvantages. It is most essential that dairies, food processing plants, milk distributing centres, and the like use the most eificient cleaning agents, for cleanliness assists effective sterilisation, making low bacterial counts possible. Generally, cleaners are composed of blends of various alkalis such as Sodium Carbonate, Sodium Silicates, Sodium Phosphates, and, in some cases, Caustic Soda. Quite often some cleaners used are too alkaline or caustic, causing deterioration in aluminium equipment, and considerable discomfort to handlers. With Teepol these ill-effects are avoided and by virtue of its increased wetting powers less alkaline cleaning solutions can do their work much more effectively. Teepol normally does not replace alkaline cleaners — it aids them.

The reason for the formation of water droplets on a greasy surface is because the water cannot fully wet it, but with Teepol added to the water it spreads into a surface covering film which emulsifies the grease and leaves the surface clean. Teepol is a light amber-coloured liquid, easy to handle and measure. Being neither acid, alkaline nor abrasive, it is harmless to the skin, to clothes, aluminium, tinned and stainless steel equipment, and concrete floors! Teepol is a most

efficient detergent in hard or soft, hot or cold waters, and it has high grease-cutting properties. It is completely soluble in water at any concentration, either acid or alkaline. Unlike the scum that forms when soap is used in hard water, Teepol is non scum forming and will disperse it, if already formed on the water. Teepol has these three properties without which complete cleaning and sterilisation are impossible in the dairying industry.

Teepol penetrates, which means that acid, alkaline, sterilising and rinsing solutions enter every single crack or crevice.

Teepol wets, enabling cleaning solutions to remove thoroughly the most stubborn grease or milkstone deposits.

Every week all rubber portions, including inflations, stoppers and releaser rubbers should be taken off the machine and boiled in a detergent solution. The rubbers should be placed in a suitable bag or perforated container, and boiled for at least ten minutes. They should then be transferred to pure boiling water to remove all traces of the cleaning solution. The result of this treatment is that the inner surfaces of the rubber are completely cleansed of milk fat leaving a smooth finish. As mentioned earlier, the addition of Teepol aids this cleansing process to a large degree, and with Teepol in the water, it is impossible for scum to form which would leave some degree of greasiness on the parts being washed.

Fat of any type is harmful to rubber, and if the rubbers are not given this special and exacting treatment each week they will soon become spongy and germ infested. The rubber tubing and teat inflations should be periodically and carefully examined for cracks and crevices which may have developed, thus forming possible sources of infection.

The use of any abrasives, scrapers or hard brushes can only result in the scoring of the inner surface of the rubber, which will make them harder to keep clean. The rubbers, after cleaning, should be placed in a clean, well ventilated position away from strong direct light.

The same boiling treatment is necessary for the washer ring of the separator bowl for, without regular treatment in a hot caustic soda solution, the rubber ring will become a source of contamination to the cream.

The equipment should be sterilised and dried immediately before milking operations commence, draw sodium hypochlorite solution at the concentration of one teaspoonful to one gallon of water, through the machines. The object of this is to sterilise the equipment, and to wet all milk pipes, rubbers, etc. Milk residue will not so readily adhere to a wet surface.

Before applying the cups, the teats and udder must be manipulated by hand in order to induce the cow to “let down” her milk. A good supply of 0.5% Teepol solution is necessary for washing the udders and the hands of the operator, and it is a good practice to immerse each cup in a bucket of hypochlorite solution before the machine is placed on the cow.

MILKING MACHINE LUBRICATION :

The only part of milking machines usually requiring lubrication is the vacuum pump, but on the efficient working of this unit depends the successful operation of the entire milking machine. The vacuum pump in most cases consists of a slow-running double-acting pump, and, quite apart from the general lubrication of bearings, etc., to prevent wear, it is essential that the oil supplied for piston lubrication seals the piston against the escapement of air past the piston rings. This would impair the efficiency of the pump, thus reducing the vacuum and unduly prolonging the time for milking.

For the correct lubrication of vacuum pump pistons, use Carnea Oil 41. This grade will provide efficient piston seal and insurance against undue wear. It has no tendency to form gummy substances, which would clog the piston rings and interfere with action of the valves. Carnea Oil 41 is also suited for piston rod, bearing and pulsator lubrication. In cases where grease lubricators are provided for bearings and piston rod guides, use Unedo Grease 3.

CREAM SEPARATOR HINTS

It is highly necessary that the manipulation of the cream separator be thoroughly understood, otherwise a correct skimming is not obtained and the machine soon gets out of order. This can be obviated to a great extent if one observes a few rules, which are simple and easily carried out. In working the machine it is important that the handle should be turned at the correct speed, to ensure perfect separation of the butter fat from the skim milk. The number of revolutions to the minute is invariably stamped upon the separator in order to guide the manipulator. When worked at the proper speed — indicated by the maker of the separator — the cream is correctly separated from the milk serum by centrifugal force in the bowl. Perfect separation should only leave a residue of not more than 0.1 per cent, of butter fat in the skim milk.

The machine must be placed on a solid foundation and set perfectly true and level. This is of the utmost importance, otherwise the working parts soon get thrown out of balance as the separator revolves during the skimming process. By means of a spirit level the bowl may occasionally be tested and set true when the necessity for doing so occurs. The stand, or foundation, should also be frequently tested with the level, as it is owing to the working parts being thrown out of balance that bad skimmings occur, with consequent money loss to the vendor and damage to the machine. When the separator vibrates the cause should at once be discovered. This is generally due to a nut or bolt having worked loose. Before, commencing the skimming, all parts should be thoroughly examined and well lubricated. As the bowl revolves at a great speed, it is obvious that there will be much friction, which would soon cause the bearings to wear out in the absence of sufficient lubrication. The machine should at first be started slowly, the speed being worked up gradually until the bowl is running at full and correct speed. The milk may then be poured into the bowl and the separator run at a uniform speed continuously during the separation process. The milk should not be below a temperature of 85 deg. F. to obtain a satisfactory separation. It is, therefore, the better plan to separate as soon as the milk is obtained from the cows. If the milk is too cold it would require to be heated to 110 deg. F. just before being put through the separator.

After the milk has been skimmed the machine should be dismantled at once and all the parts washed in warm water and Teepol, then placed in scalding water. If this work is neglected, the slime in the bowl becomes hardened and consequently becomes much more difficult to remove. The quantity of slime remaining in the bowl is a good indication whether the cows have been milked in a cleanly manner or otherwise. This slime consists chiefly of dirt extracted by centrifugal force from the milk, which is the very best method of cleaning this product. Power separators are easily regulated to the correct working speed, and are generally run in conjunction with the milk heater on the larger and older established dairy farms.

Experience has proved that cotton cloth is the best strainer and much preferable to the wire strainers one frequently observes about the milking sheds. The latter, on an average, leave about four times as much sediment as the cotton cloth. Cheese cloth is sometimes found to be satisfactory, if doubled over to ensure sufficient thicknesses. No strainer will remove bacteria from milk, and it therefore behoves all dairymen to endeavour to prevent dirt from getting into the fluid from the time it leaves the cow until it is put through the separator, and this involves thorough cleansing, followed by sterilisation. SEPARATOR PRECAUTIONS IN BRIEF:

(1) Set dead level on a firm foundation, taking care to have a little play between machine and foundation.

(6) Do not run at too slow a speed; centrifugal force is decreased at low speeds and results in bad skimming.

(7) Irregular turning of the handle results in variation of the butter-fat percentage.

bearings and flywheel periodically. A machine will not do good work if the spur and flywheels are running in a thick, treacle-like mess.

(13) Correct adjustment of the cream screw. The best percentages are as follows:—

Summer time — Long distance transit, 48 per cent.; short distance transit, 40 to 42 per cent.

SEPARATOR LUBRICATION :

Nothing is of more importance in securing ease of operation and freedom from wear than the perfect lubrication of cream separators, and this can only be obtained by the use of the highest quality lubricating oil of correct consistency. Any undue wear on bowl spindles, which revolve at from 5,000 to 10,000 revolutions per minute, according to size, will seriously affect the balance and smooth running of the machine. Oils that are heavy will create drag on the gears and bowl spindles, which not only induces greater effort to operate, but does not allow of sufficient splash to thoroughly lubricate the more inaccessible bearings. Oils that are too light in body will not provide a sufficiently durable oil film in the bearings to prevent wear. Carefully follow out the maker’s instructions relative to the rate of oil feed and, in particular, clean out oil reservoirs and bearings with kerosine or benzine at regular periods. Manufacturers of cream separators have successfully evolved simple methods of lubrication requiring a minimum amount of attention, but their instructions are of much importance, and if carefully followed out will considerably lengthen the life of your cream separator.

SHELL CARNEA OIL (For Hand Separators) :

This is a high quality pale-coloured pure mineral oil, having the correct consistency for the perfect lubrication of hand separators. It will allow the greatest ease of operation and, due to its exceptional purity, will not create sludge deposits in oil reservoirs or gumminess in bearings.

SHELL CARNEA OIL 31 :

This is a heavier grade especially recommended for Power-Driven Separators. It is of the same high quality as Shell Carnea Oil 21, but has additional body and durability necessary for belt-driven machines which are operated under more continuous conditions.

SHELL PRODUCTS

ON THE FARM AND IN THE HOME.

CROSS POWER KEROSINE:

Cross Kerosine has been specially developed to meet the requirements of all makes of tractor and other engines designed to bum power kerosine. The universal popularity of Cross is based entirely on the practical successes which it has achieved as an efficient and economical fuel.

The correct volatility of Cross Kerosine makes certain the complete vapourisation of the fuel under all types of operating conditions. This ensures that the warm-up period on petrol is short and makes the changeover a smooth and speedy operation. It also ensures that crankcase oil dilution is reduced to a minimum.

Cross Kerosine is the most powerful and most economical tractor fuel available. This is because Cross Kerosine possesses three essential characteristics. Firstly, it has a high energy content; secondly, it has the correct volatility to ensure that every drop is in a form in which it will burn completely; and thirdly, it has a high anti-knock value which ensures freedom from “knock” and therefore conversion of the maximum amount of fuel energy into useful work.

PENNANT HOUSEHOLD KEROSINE :

Manufacturers are now providing modern kerosine appliances which are the last word in convenience and comfort for the farmer. These appliances are attractive in appearance, safe and efficient. The range available is now a vast one, and includes refrigerators, hot water storage systems, instantaneous bath heaters, cooking stoves, room heaters, wash coppers, brooders, incubators, blow lamps, brazing lamps, etc.

These modem appliances require a modern fuel — a fuel which is safe in operation and burns cleanly without causing smoke, smell or excessive wick char.

Shell Research has made Pennant Kerosine the finest of all kerosines. It has a high flash point which ensures adequate safety; it burns cleanly without smoke or smell; wicks last longer and need less attention. These characteristics have been built into Pennant Kerosine by the use of the most up-to-date refining equipment and processes.

Manufacturers of all types of modern kerosine appliances recognise Pennant Kerosine as the quality product and recommend it for best results.

SHELL OIL FUELS:

Shell Diesoline — which is a pure distillate fuel with an approximate boiling range of 200°C.-350°C. It is straw coloured and being a distillate is perfectly clean. Its main application is as a fuel for high-speed diesel engines, where a very pure and carefully-refined fuel is necessary.

Shell Diesel Fuel — is a light, full flowing fuel. It is used in medium and low-speed diesel engines (i.ebelow 800 r.p.m., approximately), and it is the recommended fuel for practically all oil burners used under boilers or in furnaces. Although Shell Diesel Fuel is not a completely distilled fuel, it has all the properties necessary to ensure complete combustion in low and medium-speed diesel engines.

SHELL HOUSEHOLD INSECTICIDES

The disappointing results often experienced by householders in their efforts to banish flies and insect pests are sometimes due to a lack of knowledge concerning insecticidal sprays.

Sprays containing D.D.T. only are designed to leave a film where insects crawl. Such a film is slow-acting, and even if sprayed directly at insects, its slow rate of kill is both disappointing and exasperating to those who desire speedy freedom from unhealthy pests.

Shelltox. A scientifically prepared insecticide containing the two main killing agents for all insects and domestic pests. Shelltox contains the maximum useful quantity of Pyrethrum to knock-down and kill insects quickly. The other main killing agent D.D.T. is in sufficient strength to ensure death to insects which escape a killing dose of Pyrethrum. Shelltox is sprayed directly at insects, and therefore does not need as much D.D.T. content as a spray intended to leave a D.D.T. film on surfaces. Shelltox is for the householder who wants to spray directly at insects without leaving a lasting deathdealing coat on surfaces, and since Shelltox contains less D.D.T. than Super Shelltox, it sells at a lower cost.

Super Shelltox. This super spray contains the highest quantity of D.D.T. necessary to give a long-lasting death-dealing coat to all surfaces. Super Shelltox also contains the maximum useful quantity of Pyrethrum for quick-action and instant killing. Super Shelltox is a double purpose spray which can be used for either direct spraying and/or for spraying surfaces for lasting effective pest control.

SHELL LIGHTER & CLEANING FLUID:

A dual-purpose product possessing several outstanding qualities which make it a very useful addition to the family of Shell products for the home. When used in lighters it lights readily and burns with a steady, smokeless flame, and it does not clog the lighter wicks As a Cleaning Fluid it is particularly useful for “spotting” purposes, and it is an excellent solvent for fats, oils, waxes and greases.

Shell Household Oil is available for use in two handy sizes in tins of 4 oz. and 8 oz. capacity, ready for use as oil cans. Shell Household Oil can be used both as a lubricant and a preserver. As a preservative Shell Household Oil gives protection to brightly-plated metal parts inside the home and on the family car. A few drops of Shell Household Oil applied to a rag and rubbed briskly on to wood to be polished, results in a hard dry sheen which will not pick up dust.

Shell Preservax was developed to meet demands for a product which would prevent the splitting at the ends of freshly-felled timber. Sawn or milled timber has a tendency to split at the ends due to the relatively rapid loss of moisture immediately after a new surface is exposed to the weather. The function of Preservax is to slow down the rate of evaporation so that seasoning is more even, thus minimising the tendency of the ends to split.

SHELL HORTICULTURAL PRODUCTS

Many years of highly scientific study and research both in the laboratory and in the field, have gone into the perfecting of Shell Spraying Oils and Grafting Mastics, which to-day are recognised all over Australia as the standard of quality, each for its particular job.

Shell Whitespray. A foliage or summer pre-emulsified spraying oil containing a highly refined oil for the control of red and other scale pests of Citrus; Codling Moth and Light Brown Apple Moth (in combination with lead arsenate), Red Spider. Mites, etc., on Apples and Pears.

Shell Redspray. A miscible or soluble spray for use in the dormant season on deciduous trees for the control of Red Mite, San Jose Scale, Woolly Aphid, etc., etc.

Shellestone. This is a plant hormone spray for the control of pre-harvest drop of Apples and Pears. Whilst preventing the premature drop of fruit, Shellestone will not delay maturity.

Shell Palespray. This is a pre-emulsified spraying oil and is used for the same purpose as Redspray, but has additional advantages over the conventional type red spraying oils in that Palespray can be used in combination with bordeaux and lime sulphur and mixes readily in hard water.

Shell Palespray is the ideal dormant spray, and gives higher oil deposits on the tree, thus obtaining more efficient control of Red Mite, San Jose Scale, Woolly Aphid, etc., etc. Shellicide “D.” A semi-dormant pre-emulsified spraying oil containing a more highly refined oil than even pale or red spray, and can be used in combination with bordeaux or lime sulphur up to the pink stage of Apples.

Shellicide “D” acts both as a spreader and more particularly as a sticker, leading to more uniform and more permanent cover of the fungicide. Shellicide “D” is the ideal “inbetween seasons spray” and mixes readily in hard water. Shell Aphis Spray. A recently-introduced but highly successful spray. Shell Aphis Spray is a product combining the insecticidal effects of D.D.T. and petroleum oil emulsions. It is specifically designed for use on Peaches, Cherries and Nectarines in the late dormant period to control both Green and Black Peach Aphid and Black Cherry Aphid. It is a pre-emulsified concentrate and is miscible in hard water.

Shell Universal D.N.C. Winterspray. A dormant spraying oil which contains a potent organic insecticide — dinitrocresol — and is primarily designed for control of the tough overwintering eggs of the Green Peach Aphid and Black Cherry Aphid, and also provides simultaneous control of San Jose Scale and Red Mite on Peaches and Cherries. This spray mixes readily in hard water, and does not burn the hands or face.

Shell D.D.T. Emulsion (25%). To effectively combat all orchard, vegetable and agricultural pests known to be controlled by D.D.T., the Shell Company has introduced Shell D.D.T. Emulsion (25%) —a D.D.T. concentrate in the form of an emulsion, containing a high percentage of the active form of D.D.T. This extremely efficient, economical spray can safely be applied to foliage at any time of the year, and mixes readily in hard or soft water. An information leaflet, including mixture tables, is available from your local Shell Depot or Agent.

Additionally — Shell D.D.T. Emulsion (25%)—will give excellent results around farm buildings, etc., for control of flies, mosquitoes, and other insect pests.

SHELL GRAFTING MASTICS

Grafting Mastic “H” is a wax base grafting preparation — ideal for sealing grafts and for healing large tree wounds, etc.; preferably should be melted before applying. Suitable for root grafts.

Grafting Mastic “L.” Somewhat similar to Mastic “H,” but more plastic, readily moulded without heating. Suitable for refurnishing and stump grafting provided that cuts are not large, in which case either Mastic “H” or Colgraft is preferably used.

Colgraft. A bituminous preparation giving a strong impervious seal. Particularly useful for large wounds, stump grafts, etc., but not suitable for root grafts, being too durable. Can be thinned out with water to desired consistency.

KEROSINE OPERATED APPLIANCES

With the production and development of modern kerosine-operated domestic appliances, country families now have the opportunity of enjoying the comforts and conveniences so commonplace with city dwellers. It does not require much imagination to realise what domestic kerosine appliances such as the refrigerator, room heater, hot water storage service, bath heater and wash copper can mean to people to whom normal gas and electricity supplies are unavailable.

Nowadays, efficient refrigeration, easy cooking, room warmth and a plentiful supply of steaming hot water are considered necessities for the healthy comfort of the family and the personal convenience of the housewife.

Although space does not permit a complete description of the many kerosine-operated appliances now available, it is of interest to note that Shell Research has played a large part in their development. The Shell Kerosine Laboratories at Fulham, England, have for many years concentrated on the development of kerosine burners and their useful application. In doing this work it has been Shell’s object to encourage manufacturers to make appliances which are safe and depend' able as well as efficient, economical and attractive in appear' ance. It is due to the splendid co'operation between manufacturers and Shell laboratories that many of the kerosine appliances now available are not only modern, but at least the equal of other types from the point of view of reliability, safety and cost of operation.

KEROSINE REFRIGERATORS

ine kerosine refrigerator is technically referred to as an absorption or non-mechanical type to distinguish it from the mechanical electric motor driven variety. The refrigerator unit itself is filled with a mixture of fluids, and it is the small kerosine flame that sets these fluids in a cycle of movement that results in complete and continuous refrigeration. There are no moving and mechanical parts — therefore nothing to wear out and the complete functioning is entirely noiseless.

Throughout the continent from the tropics of Northern Queensland to the cool coastal districts of Southern Australia, kerosine refrigerators have gained a reputation for reliability. A large number of units installed many years ago are still operating satisfactorily, and this has proved that they are built to last. Provided the kerosine refrigerator is cared for as specified by the manufacturer, it will give many years of efficient and trouble-free service. The burner is the nerve centre of the refrigerator, and successful operation demands that the burner be cleaned and cared for in such a way that it always gives a clean, smokeless flame. The makers’ books explain exactly what is necessary to keep the burner in first-class condition — how it should be removed and cleaned, how the wick should be trimmed, and why the fuel level of the tank should not be allowed to drop too low.

Despite the fact that makers in their instruction books warn against the use of dirty kerosine, many operators still fail to heed the warning. The presence of water, dirt or oil in the kerosine, due to careless handling on the part of the operator — is the most common cause of poor burning, and consequent poor refrigeration. A wick which contains any of these contaminants cannot function properly. In addition to its function as a capillary feed to regulate the amount of kerosine available for burning, the wick material also functions as a filter to remove any solid matter in suspension and also water. Water or dust trapped in the wick fibres obstructs the flow of kerosine, and reduces flame height. With some operators, desiring to increase the kerosine flow when using a dirty, damp or oily wick, and to maintain normal heat output, the natural tendency is to turn up the wick. This results in heavy charring because the wick itself burns, and far from being a cure, the initial trouble is intensified.

It is true to say that no other appliance developed in modern times has done more for the comfort and convenience of country people than the kerosine refrigerator. Pennant Kerosine is recognised by reputable manufacturers as the ideal fuel. It is safe in operation and burns cleanly without causing smoke, smell or excessive wick char.

KEROSINE ROOM HEATERS

This domestic appliance has been available for many years but quite a number of them were primitive in design, ugly in appearance, and usually smoky and not very efficient to use. Modem kerosine room heaters are quite different. They are well finished and attractive in appearance; in cost of operation they compare more than favourably with other types of room heaters; and they give a brilliant glow and a comforting heat radiance.

The portable flueless room heater is rapidly gaining popularity mainly because of the variety of attractive types available at very reasonable prices. In the last few years several Australian manufacturers have entered the room heater field, and, in the main, they have concentrated on the development and production of radiant type heaters, either of the pressure or nonpressure blue flame type.

All the non-pressure radiant type heaters on the market embody short drum blue flame burners. The heat from the burner plays directly on to a radiant element fitted to the top of the burner. The glow from the element is thrown forward by a highly-polished metal reflector. The various makes of heater differ from each other in respect of outward appearance, shape of reflector and details of burner design, heating element and fuel consumption, and therefore in degree of heating capacity. The modern kerosine room heater is entirely safe and can be left burning unattended without possible fire risk. The modern heater burns kerosine so completely and cleanly that there is no trace of soot, smoke, smell or harmful fumes. The better makes of radiant type heaters have already found a permanent place in city homes, offices, public halls and schools.

As with any other type of kerosine appliance, success in operation depends on following the maker’s instructions. There are no short cuts and efficiency is guaranteed only by the careful storing and handling of kerosine so that only clean fuel enters the appliance. Pennant Kerosine is exclusively recommended by the more important manufacturers of kerosine room heaters.

KEROSINE HOT WATER STORAGE SYSTEMS

The absence of gas and electricity in certain areas has prevented many people from enjoying the convenience of a constant supply of hot water. Even in some areas where these services are available the high cost of operating gas and electric hot water systems has been beyond the means of many householders.

The kerosine operated hot water system available to-day has been developed to meet the needs of these people who up till now have been denied the convenience of a continuous hot water supply.

Shell for some years has foreseen the possibility of kerosine as a fuel for storage water heating. In an effort to encourage manufacturers to enter this field, the Shell Research Laboratory at Fulham, England, developed and built several water heaters which proved they were a practical proposition. Shell’s first and most important task in this research was to find which type of burner was most suited to Water heating, and this proved to be a special version of the short drum blue flame burner.

Kerosine operated hot water systems are a post-war development in Australia, and although current shortages have hampered production, there are already a large number in operation. Most of these are in the country, but many have been installed in the capital cities, and in both small and large country towns. The storage heaters available and under development fall into two classes:-—

(a) The Circulator Type in which water from a storage cylinder circulates through a small boiler which is heated by a kerosine. burner. The heating unit is usually installed in the laundry, or similar convenient location.

(b) The Direct Heating Type, in which the water storage cylinder is heated directly by the kerosine burner.

Both types possess certain features that will find favour among people who want hot water without worry or extra work. The better makes are safe in operation and have the approval of the fire authorities. They are simple to operate irrespective of whether they are of the manual or thermostatically controlled type, and no structural alterations are required to the house to accommodate a flue since burning is so complete combustion gases are harmless. No maintenance is required beyond the occasional replacement of the kindler wick and cleaning or wick trimming is unnecessary. Compared with other types of water heating appliances, kerosine hot water systems are very economical. The average daily requirement of hot water! (t.e., water at 160°F.) for a family, of four is approximately 35 gallons. Using kerosine, the cost of heating this quantity of water from cold would rarely exceed 7d. or 8d. daily.

KEROSINE COOKING STOVES

The range of kerosine operated cookers nowadays is so extern sive that considerable space would be necessary to describe them in detail. Cookers are available in all sizes and shapes, from the small single burner boiling stove to large ranges complete with ovens. They are attractive in appearance and are built on scientific principles which ensure clean and odourless burning with complete freedom from blackening of cooking utensils. Modern kerosine cookers give a steady flame, high heating efficiency, economy of operation and long periods without attention to the burner. Modern kerosine stoves are fitted with the latest refinements common to gas and electric types, and some incorporate cooking thermometers with transparent panels in oven doors. Of interest to the housewife is the fact that the flame can be controlled in the same way and just as conveniently as a gas flame.

Kerosine stoves have a permanent place, not only in country areas where gas and electricity are unavailable, but also in those areas where the price of gas and electricity is such that the considerable savings effected by using kerosine far outweigh the slightly extra convenience associated with either gas or electricity. Modem kerosine stoves are replacing wood stoves in country areas. With kerosine operated stoves the tedium of collecting wood and its attendant inconveniences are avoided. The kitchen which has a kerosine stove never attains the uncomfortably high temperature associated with wood stoves. This is because the kerosine stove is “on” for the cooking period only, whereas the wood stove is lit well in advance of the required time and continues to burn for a considerable period after cooking is finished.

Blue flame burners of either the pressure or the non-pressure type are invariably employed in cooking stoves. This is because the “blue” flame is very similar to the gas flame, and can impinge on the utensil to be heated without depositing soot.

				TRANS				n
	ENGINE			whereTitt	°d.	FINAL	DRIVE
							Cap.
MAKE AND MODEL	^J,,c" s'ae” ~ '		Cap,	Shell	Cop.	Shell	(c^,s'i	SYSTEM
				Gear			i i„_:n
	32?90°F	90°f	<6	on	<£		<b
Marshall
Models to 1940 Field Marshall	Ro.40	Ro.40		140
Models to 1940 Field Marshall
Mark 1 & II	Ro.30	Ro.30	7	140
M.A.R. (DR3)	Ro.30	Ro.30	m	140	m	140
Massey Harris : Refer Sunshine Massey Harris
Massey Harris : Refer Sunshine Massey Harris
M.M. (Minneapolis -Moline : Refer Twin
City								Gr. Fittings
Morrison Cultivator	50	50						Retinax CD
Munktell McCormick Deering : Refer International McCormick Deering	Ro.30	Ro.30
McDonald Imperial	Ro.40	Ro.40	<t>	140	6
Newman (Diesel)	Ro.20	Ro.30	6	90	6i
(Petrol)	40	50		90	6*
Normag	Ro.30.	Ro.30	12	140EP.	11
Nuffield Universal Oliver Cletrac	40	40	13	140	101
Oliver Wheel
(Kerosine) 60 Senes	30	30	7	140	5
70 Series	30	30	8	140	5i
80 Series	30	30	13	140	10
88 Series	30	30	10	140	3 'A
90.99 Series	30	30	20	140	10
77 (Petrol)	20	30	10	140	41
(Diesel)	Ro.20	Ro.30
Cletrac Crawlers— (Kerosine) C, K, W	40	50		>70°F.				>70 F.
(Prior 1937)			(6	■ or 70				60 or 70
				< 70°F.				< 70 F.
				50				50
AG, AGH	: 30	40	8		61
BG,BGH	30	40	10		^mn
CG	30	40	13		12	Refer Trnni
EG,EN	30	40	8		5	Refer Trnni	.31
Shell	_nil	n ™ an	or 50			Ra. 2C	etc.
Shell	Talpa Oil 20	30, 40 or	50			To. 20, 20, etc
4> Lubricato	r Copacity	= 6 pts		R,c.				.950

ERRATA: Delete all reference to (Prior 1937) Cletrac Crawlers on Page 148

147

GENERAL FARM MACHINERY

Hand pieces Down Shafts Overhead Shafting Down Shafting Gears . . . Blowfly Oil Sheep Branding Oil

Hand Oiling—Shell Limea Oil 68. Hand Greasing—Shell Dark Axle Grease or Shell Unedo Grease 3. All Grease Nipples—Shell Retinax C.

FARM ENGINES

DIESEL OR HEAVY OIL ENGINES

BRITISH WEIGHTS AND MEASURES

f In the North of England half a pint is called a gill, and a true gill a “Noggin.”

The Imperial bushel, introduced in 1826, has a capacity of 2,218.192 cubic inches, and contains 8 gallons or 4 pecks. Previous to this the Winchester bushel had been the standard measure. Its capacity was 2,150.42 cubic inches.

One Imperial bushel contains (1.284 (approx.) cubic feet), or, alter' natively, 1 cubic foot is equal to .779 bushels. ,

To find the capacity of a bin, crib, or waggon, multiply the cubic feet by .779. If .8 be taken, reasonable accuracy will be obtained by deducting 2 bushels for every 100 cubic feet.

To find the cubic feet, multiply the length, width and depth together. Find the capacity of a bin 4 feet wide, 5 feet deep, and 15 feet long.

If the weight per bushel of the grain be known, the total weight of the contents may be obtained by multiplying the number of bushels by the bushel weight, and then dividing by 112 and 20 to convert into cwts. and tons respectively.

TABLE OF EQUIVALENT WEIGHTS

Multiply the rate of application per acre by the average length of the drills (in yards), and divide by the number of yards of drill per acre. This will give the rate per drill. Multiply by the number of drills to be manured. It is most convenient to consider the rate of application in lbs. with artificials, and in cwts. with farmyard manure.

FENCING WIRE AND GALVANISED IRON TABLES

Barbed wire is put up in 1 cwt. coils—20 to the ton. It can be put up in 10 cwt. coils if wanted.

Quantity required per mile of fencing.

Gauge	Length per Cwt.			Weight	Required	per Mile
Gauge	Length per Cwt.	1 Wire		2 Wires	3 Wires	4 Wires	5 Wires
	Yds.	c	q. 1.	c. q. 1.	c. q. 1.	c. q. 1.	c. q. 1.
4	269	6	2 4	13 0 8	19 2 12	26 0 16	32 2 20
5	322	5	1 24	10 3 20	16 116	21 3 12	27 1 12
6	393	4	1 26	8 3 24	13 1 22	17 3 20	22 2 0
7	467	3	3 2	7 2 4	111 6	15 0 8	18 3 10
8	566	3	0 12	6 0 24	9 1 8	12 1 20	15 2 4
9	700	2	2 2	5 0 4	7 2 6	10 0 8	12 2 10
10	882	1	3 27	3 3 26	5 3 25	7 3 24	9 3 23
1 1	1077	1	2 15	3 1 2	4 3 17	6 2 4	8 0 19
12	1333	1	1 8	2 2 i6	3 3 24	5 1 4	6 2 12

Iron wire is 2 per cent less than steel.

The following table shows sizes and approximate weights per mile in "A" and "B" grades.

Estimated weight, 24 inches wide. (Other widths may be estimated pro rata.) The following is merely an approximate guide :—

The answer gives the weight of the four quarters in terms of stones of 14 lbs. Very fat cattle weigh about one-twentieth more, and lean cattle about one-twentieth less than the result obtained by the above method. The relationship between live and dead weight is shown below.

Sixty-four lbs. of carcase and 48 lbs. of offal per 1 cwt. is the usual estimate in the case of both fat cattle and fat sheep. The butcher’s stone is therefore reckoned at 8 lbs., and the price of 8 lbs. dead weight is equivalent to the stone of 14 lbs. live weight. The figures given in the following table are for animals slaughtered after a fast of at least 12 hours.

To ascertain the number of cubic feet contained in each stack, multiply the length, breadth and height f; or, if the stack is round, multiply half circumference, half diameter, and height together, which will give the desired result. Having ascertained the number of cubic feet, it remains to find their equivalent in tons, which is done by dividing the number of cubic feet by the number of cubic feet in a ton, according to the following table:—

It will be borne in mind that the longer hay is stacked the more compact it becomes; hence more feet to the ton are allowed to a new stack than to one three months old, and so on.

(3) Cubic measurement is obtained by multiplying all dimensions (in feet) together.

In case of a circular log, the cubical contents may be ascertained as follows:—

is known by multiplying the length in feet by the breadth in feet by the thickness in inches. If the board be tapering, add the breadth of two ends together, and take half their sum for the mean breadth and multiply the length by this mean breadth.

MEASURE THE CAPACITY OF DIPPING BATH It is absolutely essential that the correct quantity of clean water in the bath be known, to ensure successful dipping. The following simple rule will enable anyone to ascertain the exact quantity of wash his dipping bath contains, i.e.:

Take the measurement at the water-line and the measurement at the bottom in inches, add together and divide by two; this will give the average length of the dip in lineal inches. Take the breadth at the water-line and at the bottom in inches, add together and divide the result by two, and this will give' the average width of the bath. Multiply the average length in inches, by the average width in inches, and multiply the result by the depth in inches, from the water-line to the bottom. This gives the cubic contents in inches. Divide by 277 and the result will be the contents of your bath in imperial gallons.

Length at water line 720 inches, at bottom 540 inches = 720 + 540 -T- 2 = 630 inches average length.

Width at water-line 22 inches, at bottom 10 inches = 22+ 10h-2 = 16 inches average width.

Reckon the tons as pounds; cwts. as shillings; each qr. 3d., and for every 9 lbs., Id., equals—

Multiply the sum named by double the rate per cent., and point off the product one from the right.

Square or Rectangular — Multiply the length by the breadth and the product by the depth; the result, multiplied by 6^ (6.2321) will give the base and contents in gallons.

Circular — Rule A: Multiply the circumference by itself and the product by half the height.

Rule B: Multiply the diameter by itself and the product by five times the height.

CAPACITIES OF TANKS :

Depth in Feet

Size in	Feet	3 feet	4 feet	5 feet
6 by	3........	.. .. 336	448	560
6 „	4........	.... 447	596	745
6 „	5........	.... 558	744	930
6 „	6........	.... 672	896	1,120
7 „	4........	.... 522	696	870
7 „	5........	.... 658	872	1,090
7 „	6........	.... 754	1,132	1,290
7 „	7........	.... 903	1,200	1,505
B „	4........	.... 597	796	995
8 „	5........	.... 744	992	1,240
8 „	6........	.... 894	1,192	1,490
8 „	7........	. . . . 1,044	1,392	1,740
8 „	8........	.. .. 1,194	1,592	1,990
9 „	5........	.... 840	1,120	1,400
9 „	6........	. . . . 1,008	1,444	1,680
9 „	7........	.. .. 1,176	1,568	1,960
9 „	8........	.. .. 1,341	1,792	2,240
9 „	9........	.. .. 1,512	2,016	2,520
10 „	6........	.. .. 1,116	1,488	1,860
10 „	7........	. . . . 1,305	1,740	2,175
10 „	8........	. . . . 1,491	1,918	2,485
10 „	9........	. . . . 1,677	2,236	2,795
10 „	10........	. . . . 1,860	2,480	3,105
11 „	6........	.. .. 1,233	1,644	2,058
11 „	7........	. . . . 1,437	1,916	2,390
11 „	8........	. . . . 1,644	2,192	2,740
11 „	9........	. . . . 1,848	2,464	3,080
11 »	10........	. . . . 2,055	2,740	3,425
11 „	11........	. . . . 2,259	3,012	3,765
12 „	6........	. . . . 1,344	1,792	2,240
12 „	7........	. . . . 1,548	2,064	2,580
12 „	8........	.. .. 1,788	2,384	2,910
12 „	9........	.. .. 2,016	2,688	3,360
12 „	10........	. . . . 2,232	2,976	3,720
12 „	11........	. . . . 2,466	3,288	4,110
12 „	12........	. . . . 2,688	3,584	4,480

TANKS :

WATER :

Area half way, 3,186 ft. x 4 = 12,744, 4 times area half way. 12,744 x 7,296 sum of top and bottom areas = 20,040 ft. 20,040 x 6 depth -5- 6 ft. 9 in. 22,545 cubic feet.

SHELL QUALITY PRODUCTS

• • •

AeroShell Engine Oils, Fluids, Greases and Compounds. Automotive and Tractor Oils and Greases.