Tracts: Containing: I. Mechanics, Or the Doctrine of Motion: II. |
Common terms and phrases
againſt alfo alſo angle arch axis axle bafe beam becauſe body revolves center of gravity centrifugal force centripetal force circle cofine confequently curve defcend defcribed denfity diameter direction diſtance draw ecliptic ellipfis equal equilibrio falling fcale fecond femi-tangent feveral fide fimilar fince firſt fluid fmall fome force acting fpace fpecific gravity fphere fquare roots friction ftrefs ftrength fuch fufpended fuftain fuppofe fupport furface given Hence horizon hyperbola inclined plane increaſed interfection leffer length lever likewife line of meaſures motion move muſt oppofite orbit paffing parabola parallel pendulum perp perpendicular plane of projection pofition pole of projection preffure primitive Prob projecting point Prop pulley quantity of matter radii radius raiſe reciprocally refiftance reft reprefent right line rope SCHOLIUM ſmall ſpace tangent thefe theſe triangles uſe velocity vibration weight wheel whence whofe
Popular passages
Page 75 - As the distance between the body to be raised, or balanced, and the fulcrum, or prop, is to the distance between the prop and the point where the power is applied, so is the power to the weight...
Page 75 - It is a principle in mechanics, that the power is to the weight as the velocity of the weight is to the velocity of the power.
Page xx - In the early part of his life he attempted to teach a few scholars ; but whether from his concise method, for he was not happy in explaining his ideas, or the warmth of his natural temper, he made no...
Page 96 - In thofe of the third kind, at the power, and dirninifh proportionally from that point. The axles of wheels and pullies, the teeth of wheels, which bear greater weights, or act with greater force, muft be made ftronger. And thofe lighter, that have light work to do. Ropes muft be fo much ftronger or weaker, as they have more or lefs tenfion. And in general, all the parts of a machine muft have fuch a degree of fircngth as to be able to perform its office, and no more.
Page ix - One of these hats of immense superficies, had, by length of time, lost its elasticity, and its brim began to droop in such a manner as to prevent his being able to view the objects before him in a direct line. This was not to be endured by an optician ; he therefore took a pair of...
Page 134 - MISCELLANEOUS PROBLEMS. To find the specific gravity of a body heavier than water. RULE. — Weigh the body in water and out of water, and divide the weight out of water by the difference of the two weights. EXAMPLE. — A piece of metal weighs 10 Ibs. in atmosphere, and but 8i in water ; required its specific gravity.
Page 124 - For the preffure is as the weight, and the weight is as the height of a column of the fluid. PROP. PROP. LXV. Flg...
Page 76 - C (fig. 555.) of the pulley we draw the horizontal diameter AB; then will AB represent a lever of the first kind, its prop being the fixed centre C, from which the points A and B, where the power and weight act, being equally distant, the power P is consequently equal to the weight W. 1317. Hence, if the pulley be put in motion, the power P will descend as fast as the weight W ascends : so that the power is not increased by the use of the fixed pulley, even though the rope go over several of them....
Page 83 - ... so that it may revolve freely, carrying round with it the attached wheel. On the axis is coiled a rope which sustains the weight ; and round the periphery of the wheel is coiled another rope, in a contrary direction, to which is suspended the power. Then supposing the machine to be put in motion, the velocity of the power will be to that of the weight, as the circumference of the wheel to that of the axle ; for it will be perceived that the power must sink through a space equal to the circumference...
Page 203 - C, to D and F, for. the circle DF ; and from A, the projecting point, draw AF/, and AD^, then df will be the tranfverfe axis of the ellipfis. But if D fall beyond the line RE, as. at G,. then: draw. a fine from G backward thro' A to D, and then df is the tranfverfe of an hyperbola.