A System of Natural Philosophy

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Pratt, Woodford and Company, 1847 - Physics - 360 pages

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Page 209 - The circumference of every circle is supposed to be divided into 360 equal parts called degrees, and each degree into 60 equal parts called minutes, and each minute into 60 equal parts called seconds, and these into thirds, fourths, &c.
Page 162 - Lens is a transparent body, generally made of glass, and so shaped that the rays of light in passing through it are either collected together or dispersed. Lens is a Latin word, which comes from lentile, a small flat bean. It has already been shown, that when the rays of light pass from a rarer to a denser medium, they are refracted, or bent out of their former course, except when they happen to fall perpendicularly on the surface of the medium.
Page 218 - The planes of the orbits of all the planets pass through the centre of the sun. The plane of an orbit is an imaginary surface, passing from one extremity, or side, of the orbit to the other. If the rim of a drum-head be considered the orbit, its plane would be the parchment extended across it, on which the drum is beaten.
Page 53 - If the energy of the power be such as to raise the weight at the rate of one foot per minute, the weight may be moved in each minute through that length of the road which corresponds to a rise of one foot. Thus, if two roads rise one at the rate of a foot in fifteen feet, and the other at the rate of one foot in twenty feet, the same expenditure of power will move the weight through fifteen feet of the one, and twenty feet of the other at the same rate. From ' such considerations as these, it will...
Page 273 - The friction of the rubber against the glass plate (or cylinder) produces a transfer of the electric fluid from the rubber to the plate ; that is, the cushion becomes negatively and the glass positively electrified. The fluid which thus adheres to the glass, is carried round by the revolution of the cylinder ; and its escape being prevented by the silk...
Page 103 - ... completed, when a more awful hurricane burst upon them than the most experienced had ever braved. Nothing could withstand it; the sails already furled and closely bound to the yards, were riven away in tatters; even the bare yards and masts were in great part disabled; and at one time the whole rigging had nearly fallen by the board.
Page 209 - Twins, the Crab, the Lion, the Virgin, the Scales, the Scorpion, the Archer, the Goat, the Waterer, and the Fishes. Fig. 183. The 12 signs of the zodiac, together with the sun, and the earth revolving around him, are represented at fig.
Page 142 - The transparent body through which the light passes is called the medium, and it is found in all cases, " that where a ray of light passes obliquely from one medium into another of a different density, it is refracted, or turned out of its former course.
Page 12 - ... and these, in their turn, form the nutriment of animals. Thus is there a perpetual change from death to life, and from life to death, and as constant a succession in the forms and places which the particles of matter assume. Nothing is lost; and not a particle of matter is struck out of existence. The same matter of which every living animal and every vegetable was formed in the earliest ages, is still in existence. As nothing...
Page 160 - If he hold out his hand towards the mirror, the hand of the image will come out towards his hand, and coincide with it, of an equal bulk when his hand is in the centre of concavity; and he will imagine he may shake hands with his image.

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