The harness used is something like that seen on our pug dogs, crossing the front of the chest and going round the body behind the fore legs; a strap is from this attached to the upright in which the spindle works, and another to a hook outside the wheel, so that the dog is kept in position. Soft, well-kneaded clay, kept well moistened, is sometimes used instead of tan for the bed on which the dog has to work.

The Exerciser itself is a round platform of wood, about 6ft. in. diameter, moving on an axle or pivot. In the diagram given, A is the floor, firmly fastened to which is a circular block of hard wood (B), 18in. in diameter, and 4in. thick, with a smooth upper surface. Through the centre runs the axle or pivot (C), which is a bar of iron 4ft. long and an inch and a half in diameter, with a flange perforated with four holes, and countersunk to secure it finally to the floor with screws. D is a second piece of hard wood, 15in. in diameter, and 4in. in thickness, securely fastened to the underside of the platform (E), the surface of which next to B is also to be made very smooth. The platform should be made of lin. deal, with a hole in the centre to admit the pivot, and have a rim of wood (F) round, about 3in., to keep the spent tan-bark from flying off as the wheel revolves, that being the best material to make the roadway of, damping it occasionally to keep it from getting dry and dusty. It is well to have an inner rim of wood (G) round the axle, to keep the pieces of tan from getting between the pivot and centre hole of the platform.

The dog is fastened by the strap from his harness to the top of the pivot (C); and as he attempts to get away, the platform moves round, and the dog has all the exercise of covering a great distance. Of course, the surface between the pivot (C) and platform (E), and between B and D, should be kept well lubricated with axle-grease or tallow and blacklead. The platform can at times be taken off to clean the friction surfaces, or to set it aside when not required to be used. Care should be taken that it works easily.