Mathematical and Physical PapersAt the University Press, 1884 |
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amount applied augmentation of difference battery brass cells Cent centims connexion copper slip copper wire critical value current entering curves deflection diagram dimensions diminished diminution direction distance earth electric conductivity electric currents electro-magnetic electrodes entering by end equal equation experiments galvanometer circuit gutta-percha half heat inches indicated induction insulated iron conductor iron wire Joule junctions length longitudinal magnetization magnetizing coil magnetizing current magnetizing force magnetometer mass mechanical value metals meteors miles minute of current motion nearly needle neutral point nickel observed periods permanent piece position potential energy produced residual magnetism resistance reverse round Royal Society scale sensible side siphon recorder slips soft iron solar soldered specimens steel stress Sun's surface telegraph temperature testing conductor theory thermal thermo thermo-electric effect thermo-electric quality thermometers tion transverse tube velocity vertical weight zero zinc zodiacal light
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Page 136 - Col. 1 Col. 2 Col. 3 Col. 4 Col. 5 Col. 6 Col. 7 Col. 8 Col. 9 Col. 10 Col.
Page 95 - Helmholtz's galvanometer, with or without modification. The time of vibration of the suspended magnet, and the efficiency of the copper damper, will be so arranged, that during the electric pulse the suspended magnet will turn from its position of equilibrium into a position of maximum deflection, and will fall back to rest in its position of equilibrium. The possibility of fulfilling these conditions is obvious from the form of the curve I have found to represent the electric pulse. The observer...
Page 30 - What is the absolute density of the luminiferous ether in any part of space ? I am not aware of any attempt having hitherto been made to answer this question, and the present state of science does not in fact afford sufficient data. It has, however, occurred to me that we may assign an inferior limit to the density of the luminiferous medium in interplanetary space by considering the mechanical value of sunlight as deduced in preceding communications to the Royal Society [Trans, RSE ; Mechanical...
Page 34 - It is quite impossible to fix a definite limit to the ratio which v may bear to V; but it appears improbable that it could be more, for instance, than -^, for any kind of light following the observed laws. We may conclude that probably a cubic foot of the luminiferous medium in the space traversed by the earth contains not less than...
Page 104 - What is the cause of these differences in electrical quality is a question not only of much practical importance, but of high scientific interest. If chemical composition is to be looked to for the explanation, very slight deviations from perfect purity must be sufficient to produce great effects on the electric conductivity of copper ; the following being the results of an assay by Messrs.
Page 176 - ... all known vegetables get the greater part of their substance — certainly all their combustible matter — from the decomposition of carbonic acid and water absorbed by them from the air and soil. The separation of carbon and of hydrogen from oxygen in...
Page 78 - Balaklava wire are only such as to be not inconvenient, it would be necessary to have a wire of six times the diameter ; or better, thirty-six wires of the same dimensions ; or a larger number of still smaller wires twisted together, under a gutta-percha covering, to give tolerably convenient action by a submarine cable of six times the length.
Page 151 - The separate wires were each 22 gauge ; the stand complete was No. 14 gauge. Circumference of Finished Cable, 2 inches. Weight in Air, 20 cwt. per nautical mile. Weight in Water, 13'4 cwt. per nautical mile. Breaking Strain, 3 tons 5 cwt., or equal to 4'85 times the cable's weight in water per mile. Hence the cable would bear its own weight in nearly five miles depth of water, or 2'05 times the — Deepest Water to be encountered, 2400 fathoms, being less than -.} nautical miles.
Page 33 - ... and potential energy, of the disturbance in a certain space traversed by it ; and from all we know of the mechanical theory of undulations, it seems certain that this velocity must be a very small fraction of the velocity of propagation in the most intense light or radiant heat which is propagated according to known laws. Denoting this velocity for the case of sunlight at the earth's distance from the sun by v, and calling W the mass in grammes of any volume of the luminiferous ether, we have...
Page 36 - ... among different pieces of matter, in virtue of their relative positions, is called potential energy. To show the use of these terms, and explain the ideas of a store of energy, and of conversions and transformations of energy, various illustrations were adduced. A stone at a height, or an elevated reservoir of water, has potential energy. If the stone be let fall, its potential energy is converted into actual energy during its descent, exists entirely as the actual energy of its own motion at...