# Mechanics or the Doctrine of Motion

• Paperback
By (author)

List price: US\$14.13

Currently unavailable

AbeBooks may have this title (opens in new window).

## Description

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1769 edition. Excerpt: ...P. Then the weight and power will be in equilibrio. The endless or perpetual screw is one that turns perpetually round the axis AB; and whose teeth fit exactly into the teeth of the wheel CD, which are cut obliquely to answer them. So that as AB turns round, its teeth take hold of the teeth of the wheel CD, and turns it about the axis I, and raises the weight W. For by one revolution of the power at P, the wheel will be drawn forward one tooth; and the weight W will be raised the same distance. Therefore the velocity of the power, will be to that of the weight; as that circumference, to one tooth:: that is (by supposition) as the weight W, to the power P. Therefore the power P X velocity of P = WX velocity of W; therefore their motions being equal, they will be in equilibrio.. Cor. If a weight N be suspended at E on the axle EF; then if the power P, is to the weight N:: as the breadth of a tooth X EF, to the circumference described by P X CD. They will be in equilibrio. Or if the power P; is to the weight N:: as radius of the axle Ef, to the radius of the handle FP X by the number of teeth in CD; they will be in equilibrio. For Fig. For power P: weight W:: i tooth: circumference. 46. and weight W: weight N:: EF: CD. therefore P: N:: 1 toothXEF: CD X circumference. Or thus, whilst EF turns round once, P turns round as oft as CD has teeth; whence El: BP X number of teeth:: velocity of N: velocity of P:: P: N. Scholium. 47-As the teeth of the wheel CD, must be cut obliquely to answer the teeth or screw on AB; supposing AB to lie in the plane of the wheel CD; and therefore the wheel will be acted on obliquely by the screw AB. To remedy that, the screw AB may be placed oblique to the wheel, in such a position, that when the teeth of the wheel a