A System of Natural Philosophy: In which the Principles of Mechanics, Hydrostatics, Hydraulics, Pneumatics, Acoustics, Optics, Astronomy, Electricity and Magnetism, are Familiarly Explained ...Robinson, Pratt, & Company, 1830 - 295 páginas |
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appear atmosphere attraction axle ball barrel called centre of gravity centrifugal force circle colors concave lens concave mirror conductor consequently convex lens convex mirror degrees diameter direction distance diverging earth earth's orbit eclipse elastic electric fluid equal equator equinox Explain fig falling body feet fixed stars focus fulcrum glass heat hence illustrated inches inclined plane increased instrument length lenses less lever longitude machine magnetic mercury meridian metals millions of miles moon motion move object obliquely obvious particles pass pendulum perpendicular piston plane mirror planets poles pounds pressure principle proportion pulley pump quantity of matter raised rays of light reflected reflecting telescope refracted respect retina revolution revolve rope screw seen side solar space specific gravity substances sun and clock sun's Suppose surface telescope thrown tion tube turned velocity vessel visual angle weight wheel
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Página ii - 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." And also to the Act, entitled, " An Act supplementary to an Act, 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,' and extending the benefits thereof...
Página ii - 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.
Página 108 - The people in the neighbourhood, as usual, ascribed its actions to some sort of witchery, and advised the doctor, in case it did* not ebb and flow readily, when he and his friend were both present, that one of them should retire, and see what the spring would do, when only the other was present. HYDRAULICS.
Página 238 - It will be observed by a careful perusal of the above explanation of the seasons, and a close inspection of the figure 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...
Página 208 - The names of the 12 signs of the zodiac are, Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, and Pisces. The...
Página 217 - Different opinions have been advanced by astronomers respecting the cause of these appearances. By some they have been regarded as clouds, or as openings in the atmosphere of the planet, while others imagine that they are the marks of great natural changes, or revolutions, which are perpetually agitating the surface of that planet. It is, however, most probable, that these appearances are produced by the agency of some cause, of which we, on this little earth, must always be entirely ignorant.
Página 130 - ... 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. Nothing could withstand it; the sails already furled and closely bound to the yards, were riven away in tatters; even the bare...
Página 282 - ... the excited substance, and therefore must be transferred from the hand, or silk, to the electric. In the same manner, when the cylinder is made to revolve, the electric matter, in consequence of the friction, leaves the cushion, and is accumulated on the glass cylinder; that is, the cushion becomes negatively, and the glass positively electrified. The fluid, being thus excited, is prevented from escaping by the silk flap, until it comes to the vicinity of the metallic points, by which it is conveyed...
Página 266 - The cause of the tides is the attraction of the sun and moon, but chiefly of the moon on the waters of the ocean. In virtue of the universal principle of gravitation...
Página 197 - From this it is evident that, if the eye of the spectator is moved to another position, he will not see the red ray coming from the same drop of rain, but only the blue, and if to another position, the green, and so of all the others. But in a shower of rain, there are drops at all heights and distances, and though they perpetually change their places, in respect to the sun and the eye, as they fall, still there will be many which will be in such a position as to reflect the red rays to the. eye,...