Popular Scientific Recreations, Profusely Illustrated has this to say on the subject of animal motors:
SEWING MACHINE WORKED BY A DOG.
Animals have been employed for all time to draw carriages and the plough etc. But these animal "motors" are usually employed under defective conditions, and therefore without full profit. The inert mass of the animals remains quite unutilized, his force only is employed, and there are many objections on the score of humanity, as well as from a mechanical standpoint, and great muscular tension with suffering may be inflicted upon an animal which is continually mounting a wheel or such contrivance for raising water. There was in the Paris Exhibition a threshing machine put in motion by a horse walking upon a pair of rollers which constituted an "endless" way, and we will now briefly describe a machine which utilizes animal force and weight. It is the invention of M. Richard of Paris, who has made many mechanical apparatus for industrial purposes.
The principle of the invention (fig. 886) consists in the animal utilizing all the force resulting from his dead-weight. A small box contains the dog very easily. In the illustration we see the dog at rest, and in that case he maintains his centre of gravity and exercises no force upon the wheel. But when the box is inclined, the mere weight of the animal is sufficient merely to turn the wheel in the direction of the arrows. The dog, finding himself sliding away, naturally endeavours to move forward, and the rotation of the wheel is continued; the best results are obtained when the body is placed entirely upon the descending line, and this result is owing only to the weight of the animal.
There is a resting-place, just above and outside the "endless" way traversed by the dog. A basin with water is also provided for the animal.
M. Robert was let to this discovery in the following way:— He employs a large number of sewing-machine hands, and finding that the working of the machines had an injurious effect upon the health of the workers, he determined to substitute, in part, other labour for that of female hands. He then thought out his "quadrupedal motors" which are worked by intelligent dogs. There is very little trouble or expense connected with the working, so a great saving is effected, as the dogs cost little, and are cheaply fed. The result is that M. Robert has four heavy machines occasionally at work, which are kept in motion by dogs at a very small expense.
Try as I might, I have not been able to locate the arrows in the diagram referred to in the text, but the description of this marvellous contraption is very clear.
It is good to see that M. Richard (no relation) took full account of the animals' welfare needs by equipping them with a drinking bowl. Those French were very ahead of their time.