A Cyclopędia of the Physical Sciences: Comprising Acoustics, Astronomy, Dynamics, Electricity, Heat, Hydrodynamics, Magnetism, Philosophy of Mathematics, Meteorology, Optics, Pneumatics, Statics, &c. &cCharles Griffin, 1860 - 903 pągines |
Altres edicions - Mostra-ho tot
A Cyclopędia of the Physical Sciences: Comprising Acoustics, Astronomy ... John Pringle Nichol Visualització completa - 1857 |
A Cyclopędia of the Physical Sciences: Comprising Acoustics, Astronomy ... John Pringle Nichol Visualització completa - 1868 |
A Cyclopaedia of the Physical Sciences: Comprising Acoustics, Astronomy ... John Pringle Nichol Previsualització no disponible - 2015 |
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action angle appear Asteroids atmosphere axis ball battery body carbonic acid centre centre of gravity charge circle coloured conductor connected curve cylinder David Brewster degree density diamagnetic diameter direction distance earth eclipse effect elastic electric currents electricity electrometer electroscope engine equal equation experiments fact fluid force galvanometer gases give given glass gravity heat Heliometer Hence inches instrument iron Joule latent heat length light liquid magnetic mass means measure ment metal method moon motion move observed obtained parallel passing perpendicular phenomena plane plate polarized pole position pressure principle produced proportion quantity rays refraction refractive index retina right ascension roots rotation solar solid space specific heat star substance suppose surface telescope temperature term theorem theory Thermo-dynamic tion tricity tube vapour velocity vertical vessel vibrations weight whole wire zinc
Passatges populars
Pągina 352 - It is hardly necessary to add that anything which any insulated body, or system of bodies, can continue to furnish without limitation, cannot possibly be a material substance; and it appears to me to be extremely difficult, if not quite impossible, to form any distinct idea of anything capable of being excited and communicated in the manner the Heat was excited and communicated in these experiments, except it be MOTION.
Pągina 352 - Heat is a very brisk agitation of the insensible parts of the object, which produces in us that sensation from whence we denominate the object hot ; so what in our sensation is heat, in the object is nothing but motion.
Pągina 375 - The differently coloured shells of which a flame thus consists, may be easily parted out from one another, and demonstrated by a prism. Their cause is the slower rate at which combustion occurs at points more and more towards the interior. On the outside, which we may say is in contact with the air, the combustion is most vigorous and complete, and hence the light there emitted is violet ; but in the most interior portion of the shining shell, resting upon the dark combustible matter, the atmospheric...
Pągina 375 - An envelope consisting of the products of combustion, exterior to the true flame, shining simply as an incandescent body, and its light for the most part overpowered by the brighter portion within. By the aid of the facts thus presented, we can easily explain the nature of the other regional divisions distinguishable in such a flame. There must be a blue portion below; blue, because it consists of the most refrangible rays, which issue forth in abundance, for there the exterior air is most copiously...
Pągina 415 - OAS is a substance in such a condition that the total pressure exerted by any number of portions of it, at a given temperature, against the sides of a vessel in which they are enclosed, is the sum of the pressures which each portion would exert if enclosed in the vessel separately at the same temperature.
Pągina 376 - ... a flame will have when we vary the circumstances of its burning. Tallow or wax, at temperatures greatly beneath their usually understood point of combustion, oxidize with a pale violet phosphorescent light, quite perceptible, nevertheless, in a dark room; and here the light is violet, for the supply of combustible matter is small, and that of the air abundant. The oxidation is therefore thorough and prompt. For a like reason, sulphur, as we commonly see, burns blue; but if a piece...
Pągina 376 - ... to be the seat of a fierce combustion. Of such hypotheses we have given reason for declining the first. Prismatic analysis, which demonstrates no resemblance between the light of the sun and that of any form of electric discharges with which we are familiar, enables us in like manner to reject the second; and upon the whole, facts seem most strongly to prepossess us in favour of the third, in artificial combustions similar fixed lines being observed.
Pągina 376 - When the peach-colored nucleus of the cyanogen flame is properly examined, it yields a series of dark lines and spaces exceeding in number and strength those of the sunlight itself. These fixed lines are the representatives of dark shells, superposed among the shining ones with definite periodicity. In such a cyanogen flame they bear no relation to the burning of the carbon, but must be attributed to the disengagement of the nitrogen.
Pągina 399 - That the planets revolve round the sun in ellipses, having the sun for a common focus : 2. That every planet moves in such a way that the line drawn from it to the sun sweeps over equal areas in equal times : 3.
Pągina 274 - Now it is obvious, from the results which have been quoted, that the supposed "velocity" of transmission of electric signals is not a definite constant like the velocity of light, even when one definite substance, copper, is the transmitting medium, but is largely influenced by the circumstances in which the conductor is placed, being, for instance, much greater when the wire is...