Sound, light and heat1881 |
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Common terms and phrases
absorbed amplitude angle of incidence appears aqueous vapour beam body boiling point bulb called carbon carbonic acid causes centre cold colours condensed converted convex convex lens cooling degrees density distance elasticity equal ether expansion Explain feet per second freezing point fundamental note gives glass greater Gridiron Pendulum HALF RATE heat rays Hence hydrogen image is formed increased instrument intensity inversely iron JOHN HEYWOOD latent heat Learn paragraphs lens lenses liquid luminous point medium mercury metal motion musical sounds nodes number of vibrations object parallel rays particles pass pipe pitch placed pressure principal focus prism produced propagated proportion radiation ray of light Réau reflected rays refracted retina rock salt screen shadow solid sound wave specific heat spectrum steam string substance surface takes temperature tension thermometer tube units of heat velocity of sound vibrations per second virtual warm white light
Popular passages
Page 162 - ... destroy every plant capable of being destroyed by a freezing temperature. The warmth of our fields and gardens would pour itself unrequited into space, and the sun would rise upon an island held fast in the iron grip of frost. The aqueous vapour constitutes a local dam, by which the temperature at the earth's surface is deepened : the dam, however, finally overflows, and we give to space all that we receive from the sun.
Page 77 - It may also be defined as the sine of the angle of incidence divided by the sine of the angle of refraction, as light passes from air into the substance.
Page 152 - This spectrum is to the eye what the gamut is to the ear; its different colours represent notes of different pitch. The vibrations which produce the impression of red are slower, and the ethereal waves which they generate are longer, than those which produce the impression of violet, while the other colours are excited by waves of some intermediate length.
Page 12 - The waves at length touch, and then cross each other, carving the surface into little eminences and depressions. Where ridge coincides with ridge, we have the water raised to a double height; where furrow coincides with furrow, we have it depressed to a double depth. Where ridge coincides with furrow, we have the water reduced to its average level.
Page 30 - ... proportion, and act oppositely, the velocity of sound is not affected by a change of density, if unaccompanied by a change of temperature. There is no mistake more common than to suppose the velocity of sound to be augmented by density. The mistake has arisen from a misconception of the fact, that in solids and liquids the velocity is greater than in gases. But it is the high elasticity of those bodies, in relation to their density, that causes sound to pass rapidly through them. Other things...
Page 63 - The incident and the reflected ray are both in the same plane, which is perpendicular to the reflecting surface.
Page 157 - ... portion of the spectrum visible to our eyes. Besides thickness and colour, the polish of a substance influences the transmission. Glass plates of the same size and thickness transmit more heat as their surface is more polished. Bodies which transmit heat ot any kind very readily are not heated.
Page 118 - The two fixed points that are ordinarily chosen for a thermometer are the melting point of ice and the boiling point of water. The...
Page 134 - The tension, and, consequently, the quantity of vapour which saturates a given space, are the same for the same temperature, whether this space contains a gas or is a vacuum.
Page 88 - Since rays that emanate from a point nearer the lens than the principal focus diverge after egress, it is evident that their focus must be virtual and on the same side of the lens as the object. Hence, the image of an object placed nearer the lens than the principal focus is virtual, magnified, and erect, as shown in Fig.