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 |
Contents
| 9 | |
| 18 | |
| 33 | |
| 40 | |
| 46 | |
| 53 | |
| 59 | |
| 92 | |
| 160 | |
| 161 | |
| 167 | |
| 191 | |
| 199 | |
| 228 | |
| 239 | |
| 245 | |
| 108 | |
| 122 | |
| 128 | |
| 143 | |
| 144 | |
| 150 | |
| 255 | |
| 261 | |
| 271 | |
| 277 | |
| 291 | |
Common terms and phrases
appear atmosphere attraction ball barrel called centre of gravity centrifugal force circle colors concave mirror conductor consequence converging rays convex lens convex mirror degrees diameter direction distance diverging earth earth's orbit eclipse elastic electric fluid equal equator equinoxes Explain fig 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 Natural Philosophy object obliquely orbit parallel rays particles pass pendulum perpendicular piston plane mirror planets poles position pounds pressure principle proportion pulley pump quantity raised rays of light reflected rays 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 whole
Popular passages
Page 207 - 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 234 - 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 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...
Page 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.
Page 79 - There being, then, always a proportion, between the velocity with which the moving force descends, and that with which the weight ascends, whatever this proportion may be, it is necessary that the power should have to the resistance the same ratio that the velocity of the resistance has to the velocity of the power. In other words, "{The power multiplied by the space through which it moves, ma vertical direction, must be equal to the weight multiplied by the space through which it moves in a vertical...
Page 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...
Page ii - Wilson, of the said district, hath deposited in this office the title of a book, the right whereof he claims as author and proprietor, in the words following...
Page 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...
Page 262 - ... moon, or at the time of every new moon. But at these conjunctions, the moon does not come exactly between the earth and sun, because the orbit of the moon is inclined to the ecliptic at an angle of 54 degrees.
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...