A Manual of Natural Philosophy ... |
Other editions - View all
Common terms and phrases
air-pump angle aperture apparent magnitude appear atmosphere attraction axis ball becomes bottom called centre of gravity centrifugal force colors concave concave lens convex convex lens cord course crystalline lens cylinder diameter direction discharge distance earth effect elasticity electricity electrified equal excited body experiment eye-glass fall feet figure fluid force friction glass tube inches inclined plane inductive instrument insulated inverted kind length Let A B lever Leyden jar liquid machine magnet manner means mercury metallic mirror motion move needle north pole object observed particles pass perpendicular piston pith-ball plane plate polarized portion position pounds pressure prime conductor prism produced pulley QUESTION ray of light reflected refracted repelled retina rise screw sealing-wax seen side solid sound south pole spark specific gravity sphere substance supposed surface suspended telescope tion tricity usually valve velocity vessel vibrations weight wheel wire
Popular passages
Page 31 - I shall just offer a few illustrations of the CENTRE OF GRAVITY. The centre of gravity of a body is that point about which all its parts...
Page 100 - With a given base and height, therefore, the pressure is the same whether the vessel is larger or smaller above, whether its figure is regular or irregular, whether it rises to the given height in a broad open funnel, or is carried up in a slender tube. Hence, any quantity of water, however small, may be made to balance any quantity, however great. This is called the hydrostatic paradox.
Page 102 - It seems to me that law cannot be the cause of phenomena, but is an effect produced in our minds by their succession and resemblance. To put a God back of the universe, compels us to admit that there was a time when nothing existed except this God ; that this God had lived from eternity in an...
Page 65 - Mechanical Powers, are certain simple instruments, commonly employed for raising greater weights, or overcoming greater resistances, than could be effected by the natural strength without them. These are usually accounted six in number, viz. the Lever, the Wheel and Axle, the Pulley, the Inclined Plane, the Wedge, and the Screw.
Page 74 - ... very long force arm, great power can be secured from it. The great length of the force arm explains how, by the use of the capstan, a single horse can draw a house along the street — the horse travels many feet at the end of his long lever while the house may be moved only a few inches. The pulley. There are two kinds of pulleys, the fixed and the movable. The fixed pulley gives us no advantage in power or in speed ; it only changes the direction in which the force is applied (Fig. 225). This...
Page 142 - From this voyage we learn also that the pressure of the atmosphere at the level of the sea is not the same in every part of the globe. Barometrical observations show that this pressure increases gradually from the equator to about the 30th parallel, from which it as gradually sinks up to the pole, and falls below the mean of the equator : generally stated, we may say that, south of Cape...
Page 201 - The space between two notes is called an interval ; that from any note to the next, as from the first to the second, or from the second to the...
Page 228 - When a ray of light passes obliquely from one medium to another of different density, it is refracted or bent out of its course.
Page 69 - The most striking example of levers of the third kind is found in the animal economy. The limbs of animals are generally levers of this description. The socket of the bone is the fulcrum ; a strong muscle attached to the bone near the socket is the power; and the weight of the limb, together with whatever resistance is opposed to its motion, is the weight.
Page 334 - Singer, is made by melting together one ounce of tin and two ounces of zinc, which are to be mixed, while fluid, with six ounces of mercury, and agitated in an iron, or thick wooden box, until cold.