Methods of Economizing Lahour. 
117 
where they are commonly used to cut up the wood for fuel. 
They are of various sizes adapted for one or fur two horses, or 
for a sheep, a dog;, or a calf, any of which, when put in, have no 
option but to do their work, for it is a species of treadmill ; and 
although at first sight it appears a case of cruelt}', I do not believe 
it to be at all more so than any otiier kind of compulsory labour. 
It is not found to distress or injure the animal, and it is un- 
doubtedly the most effectual method of applying a limited amount 
of animal power to such purposes as threshing, winnowing, 
grinding, churning, sawing wood, and all others which require 
rotatory motion, because, in the first place, the speed of the 
animal is directly imparted without the intervention of gearing 
to the axle of tiie driving-wheel ; so if we suppose this to be 
three inches in diameter, and the circumference three feet in 
diameter, and that tlie horse walks at the rate of three miles an 
hour, the velocity at once given to the band on the driving-wheel 
is 36 miles an hour, and tlie force is directly proportioned to tlie 
weight of the animal, undiminished by the friction of cog-wheels. 
Fig. 1. 
Railway Hoi'se-power. » 
The accompanying drav/Ing (Fig. 1) will sufficiently explain the 
nature of the machine, which consists simply of a pen with a floor 
of stout slats resting on an endless web, wliich runs on rollers and 
communicates the motion given to it to the axle of the driving- 
wheel ; the forward end of this pen is raised on a block to give it 
a slight inclination, and, as soon as the wheel is set at liberty, the 
weight of the animal moves the floor backwards with a constantly 
accelerating motion, which is checked onl y by the resistance of the 
work to be done, or by the application of a drag.* 
• In an appendix to this paper is given a detailed calculation by Tilr. Amos, 
