A System of Natural Philosophy: In which the Principles of Mechanics, Hydrostatics, Hydraulics, Pneumatics, Acoustics, Optics, Astronomy, Electricity, Magnetism, Steam Engine, and Electro-magnetism, are Familiarly Explained, and Illustrated by More Than Two Hundred Engravings : to which are Added Questions for the Examination of Pupils : Designed for the Use of Schools and Academies |
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angle appear atmosphere attraction axis ball barrel called centre of gravity centrifugal force circle colours concave mirror condenser consequence convergent convex lens convex mirror cylinder degrees diameter direction distance earth earth's orbit eclipse electric fluid engine equal equator equinox Explain fig falling body feet fixed stars focus force fulcrum galvanic glass heat inches inclined plane instrument length lever machine magnet mercury meridian metals miles moon motion move needle north pole object oblique orifice parallel particles pass pendulum perpendicular piece pipe piston planets poles position pounds pressure principle proportion pulley pump rays of light reflected reflecting telescope refracted represented by fig respect retina revolution revolve rope round screw seen side solar space specific gravity steam substances sun's Suppose surface telescope thrown tion tube turned upper vacuum valve velocity vessel vibrations visual angle weight wheel wire
Popular passages
Page 113 - It has been stated, (398,) that Hydrostatics is that branch of Natural Philosophy, which treats of the weight, pressure, and equilibrium of fluids, and that Hydraulics has for its object the investigation of the laws which regulate fluids in motion. If the pupil has learned the principles on which the pressure and equilibrium of fluids depend, as explained under the former article, he will now be prepared to understand the laws which govern fluids when in motion.
Page 243 - Diiferent 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 313 - 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 176 - The ray a, c, is called the incident ray, and the ray c, d, the reflected ray ; and it is found, in all cases, that whatever angle the ray of incidence makes with the reflecting...
Page 149 - ... so as to balance the pressure on the upper side. When this is effected, the piston is immediately drawn again to the top of the cylinder by the weight of the pump rod, and thus the several parts of the engine become in the precise position that they were when our description began ; and in order again to depress the piston, a vacuum must once more be produced by the admission of cold water on the cylinder, and so on continually. The power of these engines, although operating by the pressure of...
Page 173 - 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 139 - ... 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...
Page 81 - Again, suppose the lever, fig. 62, to be thirty inches long from the fulcrum to the point where the power p is suspended, and that the weight w is two inches from the fulcrum.
Page 260 - 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...