The exerciser consists of a disk, 5 ft. in diameter, pivoted in the ground near the kennel. The disk revolves on a 5/8-in. pin set in a post made of a 4 by 4-in. piece of timber. The disk is made of common lumber fastened together with battens on the under side. Our dog seems to enjoy this kind of exercise.—Contributed by Hazel Duncan, Denver, Colo.

Illustration from The Boy Mechanic, Book 2: 1000 Things for Boys to Do

Revolving Disk Exerciser

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