Man Labour.

The labour of one man is just equivalent

to of 1 effective horse-power. The labour of 12 men is just equivalent to 1 effective horse-power.

The number of men required to lift water to any height, may be found thus,

Gallons X 10 X height in feet

2,750

+ 11% = {

( number of men

necessary.

The 11 per cent. is added to the result of the calculation to cover friction in the pumps and the pipes.

A very good water lifter for human power is the "Noria," which consists of an endless chain provided with buckets. This is turned round by gearing, the buckets as they arrive at surface automatically emptying themselves as they turn over towards their descent.

With these machines men may raise :

One man-1,000 imperial gallons per hour 15 feet high. Cost of machine being 13-$65.

750 imperial gallons per hour 30 feet high. Cost of machine being £18-$90.

Two men-1,500 imperial gallons per hour 30 feet high. Cost of machine being £24-$120.

Useful Data in this Connection.—

I imperial gallon of water = 0.16 of a cubic foot;

For further figures and calculations with reference to water-quantities, see Section III.

Hand-power Gear.-Where human power is exerted to turn machinery, such as circular or band saws, butter machinery, pumps, and lathes, a good heavy fly-wheel should

be provided, which equalizes the irregularities of the movement.

A good size is 5 feet diameter with a weight of about 400 lbs.

Where two cranks are employed, they are best set at right angles to one another.

Human Endurance.—

"The limits of human endurance are practically summed up in the action of the heart, which normally, in the healthy, will beat 106,000 times in the 24 hours, and its work is computed to be equivalent to the raising of 122 tons I foot high.

"Under severe stress of labour, such as straining at a crank, working a cycle, or rowing, this heart action is considerably increased, and such labour continuously prosecuted probably puts double the above duty on the heart-action."—Lancet.

From these facts will be gathered the limits of the practical application of human power.

Economy. The economy of employing the same labour in directing the operations of a machine, rather than in actually operating it, may be considered thus:

It is a question of the value of the efforts of the man and machine combined compared with the unaided efforts of the man.

The machine will have to accomplish in his hands more than the bare work he did unaided, otherwise there would be no economy in its employment.

If higher wages have to be paid for the service of directing the machine, the earnings of man and machine combined must be to that extent in excess of a man's labour.

Similarly, if the machine consumes materials in the course of its action, its earnings will have to be to that extent greater.

It is, however, manifest that man-labour must be inferior to machinery directed by man to such a degree as to make the latter more economical wherever there is sufficient work to keep machines regularly and fully employed.

A good horse working 8 hrs. per day = 21,000

In cases where there is not sufficient work to keep a larger motor employed regularly, or where the output of the machinery to be operated is limited, and where animals are available, their power may be very advantageously employed in a number of small operations.

Towing or Hauling. The speed of a strong draught horse may be taken at 3 miles per hour.

Oxen do not walk more than 11⁄2 miles per hour.

The following table will show animal work done at various speeds of movement.

MAXIMUM POWER OF A HORSE IN TOWING ALONG A CANAL.

Animal Gears.-The most usual method of applying animal power to the driving of machinery is by means of an apparatus known in the trade as a "horse-gear." This consists of a framing to be placed on the ground, containing a vertical shaft or spindle, on which is mounted a large bevel cog-wheel. The pole to which the animals are to be attached is secured to this spindle, and as it is turned by the animals' rotary walk the bevel-wheel turns, at a correspondingly higher speed, a horizontal pinion, which operates a shaft. This shaft has a flexible joint connected to it, and may be made of any suitable length. As the motion of animals is so slow, it is necessary to have extra multiplying gear added, which increase the speed of the shaft to a proportionate extent. This multiplying gear is usually carried in a separate frame, but new designs are now arranged to carry the whole in the one framing.

Care should be exercised when purchasing animal-gears to see that an arrangement is provided whereby, when the animals stop, the pole stops also. The impetus of the machine will otherwise carry the pole against them and cause an accident by the sudden stoppage of the machinery, or by frightening the animals.

The pulley upon the driven shaft will be proportioned to the speed required by the machine to be driven by it.

Uses of Horse-gears. By means of these horse-gears a number of machines may be operated by relays of horses or oxen, and they may also be obtained complete with sets of well-pumps.

Small sugar-cane crushing mills, as well as corn or meal mills, can be economically operated. A horse applied to one of these latter will crush upwards of 24 bushels per hour of maize, beans, barley, etc., as used for feeding animals.

Ginger crushers for mineral water manufacturers afford another instance of similar nature. Small grinding mills may be operated by a horse, grinding fine meal from maize, oats, beans, barley, peas, etc., from 4 to 24 bushels per hour, according to the degree of fineness reached.

Cotton-gins and condensers should be provided with one horse for every 20 saws. The output varies from 2 to 4 lbs. per hour for each saw, except in Sarat or small-seed cottons, where 3 lbs. per saw per hour would be a maximum.

A brick machine, consisting of a pug-mill and outlet and a cutting table will produce with one horse about 5,000 bricks per day—or with 2 horses say 8,000 per day.

Small oil-mills are very suitably driven by animal power. With 2 pair of oxen about 16 cwt. to 20 cwt. of seeds may be crushed in 10 hours, allowing 5 hours' continuous work to each pair of animals.

Pumping by Animals. For water lifting by animal power, the Noria or bucket pump is widely used abroad. For the watering of vineyards and gardens, irrigating fields, and all purposes where the water is only required to be raised a short distance above the ground level, this apparatus is very suitable. The gears are made suitable for from I to 8 animals, which may be yoked in pairs, and quite a large quantity of water may be by this means raised to a moderate height.

The following table is arranged to show the animal power required for this purpose.