A System of Natural Philosophy: In which the Principles of Mechanics, Hydrostatics, Hydraulics, Pneumatics, Acoustics, Optics, Astronomy, Electricity and Magnetism, are Familiarly Explained, and Illustrated by More Than Two Hundred Engravings : to which are Added, Questions for the Examination of the Pupils, Designed for the Use of Schools and Academies |
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air pump angle appear atmosphere attraction axis axle ball barometer barrel boat bulk called centre of gravity centrifugal force circle clock colors concave concave mirror consequence convergent convex lens convex mirror degrees diameter direction distance earth eclipse elastic electric equal equator exactly Explain fig falling body feet fluid fulcrum glass heat hence hydrometer illustrated inches inclined plane increased instrument kind of lever length lens less machine magnetic mercury metals miles moon motion move object obliquely orbit orifice parallel particles pass pendulum perpendicular pipe piston plane mirror poles pounds pressure principle proportion pulley quantity of matter raised rays of light reflecting telescope refracted respect retina revolution revolve rise rope round screw seen side space specific gravity stars substances sun's Suppose surface suspended thrown tion tube turned upwards valve velocity vessel vibrations visual angle weight wheel
Popular passages
Page iv - In conformity to the act of Congress of the United States, entitled, " An act for the encouragement of learning, by securing the copies of maps, charts and books, to the authors and proprietors of such copies, during the times therein mentioned ;
Page iv - BBOWN, of the said district, hath deposited in this office the title of a book, the right whereof he claims as author, in the words following, to wit : " Sertorius : or, the Roman Patriot.
Page 128 - ... proceeding, when the captain's order came to prepare with all haste for a storm. The barometer had begun to fall with appalling rapidity. As yet, the oldest sailors had not perceived even a threatening in the sky, and were surprised at the extent and hurry of the preparations: but the required measures were not completed, when a more awful hurricane burst upon them than the most experienced had ever braved.
Page 234 - ... by which it is illustrated, that the sun constantly shines on a portion of the earth equal to 90 degrees north, and 90 degrees south from his place in the heavens, and consequently, that he always enlightens 180 degrees, or one half of the earth. If, therefore, the axis of the earth were perpendicular to the plane of its orbit, the days and nights would...
Page 230 - It has already been explained, that the ecliptic is the plane of the earth's orbit, and is supposed to be placed on a level with the earth's horizon, and hence, that this plane is considered the standard, by which...
Page 128 - ... 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 18 - The intensity of light is found to increase and diminish in the same proportion. '^Thus, if a board a foot square, be placed at the distance of one foot from a candle, it will be found to hide the light from another board of two feet square, at the distance of two feet from the candle.
Page 288 - By connecting together a sufficient number of these jars, any quantity of the electric fluid may be accumulated. For this purpose all the interior coatings of the jars are made to communicate with each other, by metallic rods passing between them, and finally terminating in a single rod. A similar union is also established, by connecting the external coats with each other. When thus arranged, the whole series may be charged, as if they formed but one jar, and the whole series may be discharged at...
Page 213 - Different opinions have been entertained by astronomers respecting the cause of these belts and spots. By some they have been regarded as clouds, or as openings in the atmosphere of the planet, while...
Page 283 - 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...