The Repertory of Arts, Manufactures, and Agriculture; Consisting of Original Communications, Specifications of Patent Inventions, Practical and Interesting Papers, Selected from the Philosophical Transactions and Scientific Volume 46 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1824 edition. Excerpt: ... velocity, that the strength of 100 men could not put an immediate stop to its motion. A small lever is to be attached to the stub-box s, made to act upon either the stubs of the wheel ab or cd, or upon neither of them. (This lever is not introduced into the sketch, but it is shewn in the model lodged with the Society.) ciety.) There are to be three notches so placed to receive the end of this lever, that if its end is put into the first notch, the wheel ab will move along with the axis tnn; if put into the third notch, the wheel cd will move along with the axis, but in a contrary direction to that of a b; and if.the end of this lever be put into the second or middle notch, the wheels will then both revolve independent of the axis m n. The handles h h are to be placed at a convenient height for the man to lay hold of, who is to work the treadles with his feet, which will add considerably to his power; the cranks being also kneed in opposite directions gives an advantage to his feet that is not to be gained by a single-winch machine wrought by hand. Now, suppose a waggon upon a platform-carriage such as we have described, ready to ascend the inclined plane, and the end of the stub-box lever in the middle notch, let the man give the fly an accumulated velocity, by working the treadles with his feet, increasing his power by the strength of his arms. When an active boy, properly trained, shifts the end of the stub-lever from the middle notch to the first, then the platform-carriage with its waggon will gradually ascend, the man all the while continuing his exertions on the treadles; the boy watching when the carriage is at its proper height, throws the end of the stub-lever again into the middle notch, and the fly being still kept in motion, ..