A Fourteen Weeks' Course in Natural PhilosophyA.S.Barnes & Company, 1871 |
Términos y frases comunes
acid angle apparatus atom attraction ball battery becomes body chemical chemical affinity clouds coil cold color condensed conductor convex convex lens cool copper cord cubic cylinder Define distance drop earth elastic elec electro-magnet ether waves experiment fall feet filled friction frictional electricity galvanic gases glass tube heat hence hydrogen illustrated inches insulated iron latent heat lens lever Leyden jar liquid Magdeburg Hemispheres magnet mercury metal miles mirror molecules motion needle negative pole nitric acid number of vibrations object oxygen particles passes pendulum piston plate platinum polarized positive pole pressure prime conductor principle produced radiation rays of light reflected refracted rise sensible heat shown in Fig solid sound sound-wave south pole spark specific gravity steam strike substance surface temperature tion tricity vacuum vapor velocity vessel visual angle voltaic waves weight wheel wire zinc
Pasajes populares
Página 197 - We have already seen that when a ray of light passes from one medium to another of different density...
Página 48 - LAW OF GRAVITATION.* — Every particle of matter in the universe attracts every other particle of matter with a force directly proportional to its mass, and decreasing as the square of the distance Fig.
Página 97 - Fig. 7, there can be no gain of power or speed, as the force P must pull down as much as the weight W, and both move with the same velocity. It is simply a lever of the first class with equal arms, and is used to change the direction of the force.
Página 115 - Fig. 79. levelling. It consists of a slightly curved glass tube so nearly full of alcohol that it holds only a bubble of air. When the level is horizontal, the bubble remains at the centre of the tube. SPECIFIC GRAVITY is the weight of a substance compared with the weight of the same bulk of another substance. It is really a method of finding the density of a body. Water is taken as the standard* * A cubic inch of distilled water at a temperature of 62° F., with the barometer at 30 inches.
Página 160 - In one of the cathedrals in Sicily, the confessional was so placed that the whispers of the penitents were reflected by the curved roof, and brought to a focus at a distant part of the edifice. The focus was discovered by accident, and for some time the person who discovered it took pleasure in hearing, and in bringing his friends to hear, utterances intended for the priest alone.
Página 184 - The tick of a watch may be heard from one end of the Church of St. Albans to the other.— At Carisbrook Castle, Isle of Wight, is a well 210 feet deep and 12 feet wide, lined with smooth masonry. When a pin is dropped into the well it is distinctly heard to strike the water.— In certain parts of the Colosseum at London the tearing of paper sounds like the patter of hail, while a single exclamation comes back a peal of laughter.— The Dome of the Baptistry of the Cathedral at Pisa (See Frontispiece)...
Página 61 - It has been discovered that the point of suspension and the centre of oscillation are interchangeable. If, therefore, a pendulum be inverted, and a point found at which it will vibrate in the same time as before, this is known to be the centre of oscillation ; while the old point of suspension becomes the new centre of oscillation. The Pendulum as a Time-keeper.
Página 98 - Since, then, the power is only one-half the weight, it must move through twice the space ; in other words, by taking twice the time, we can lift twice as much. Here power is gained and time lost.
Página 49 - II. The weight of a body above the surface of the earth decreases as the square of the distance from the centre of the earth increases.