Philosophical Magazine

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Taylor & Francis., 1894 - Physics


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Page 175 - ... instances differ, is the effect, or the cause, or a necessary part of the cause of the phenomenon
Page 428 - In the case of any bird soaring, its motion must be sufficiently rapid, so that the action of the inclined surface of its body on the atmosphere may counterbalance its gravity. The force to keep up the momentum of a body moving in a horizontal plane in the air (in which there is so little friction) cannot be great, and this force is all that is wanted.
Page 195 - the change of polarization with time," I would refer especially to the investigation of Dr. E. Root upon this subject, discussed by Professor von Helmholtz, Wisch. Abh., Vol.1., page 835. These experiments by Dr. Root seem to prove clearly that the liberated ions penetrate deeply into the electrode, even when liberated upon but one side of it, as in this case. I take great pleasure in expressing here my thanks and deep obligation to Professor A. Kundt and Dr. L. Arons for their kind sympathy and...
Page 407 - It consists of serpentinized olivine, augite, mica, iron oxide, and a little plagioclase-felspar, with a variable amount of interstitial matter. In many respects it comes very near to the picrite of Inchcolm, which island is 4| miles north of Barnton cutting. It differs from the picrite of Bathgate, and the probability is that the Barnton rock is an offshoot from the same magma as that which supplied the Inchcolm rock.
Page 167 - ... power is in proportion to the chemical affinities producing it; that when it is deficient in force it may be helped by calling in chemical aid, the want in the former being made up by an equivalent of the latter; that, in other words, the forces termed chemical affinity and electricity are one and the same.
Page 428 - ... blended together ; but they were seen distinct against the blue sky. The head and neck were moved frequently, and apparently with force ; and the extended wings seemed to form the fulcrum on which the movements of the neck, body, and tail acted.
Page 428 - ... the fulcrum on which the movements of the neck, body, and tail acted. If the bird wished to descend, the wings...
Page 8 - ... be analogous to that determined experimentally by Brown in the case of two liquids : namely, " the proportion of the three substances in the vapour forming the instantaneous distillate is the same as that of the weights of the three substances in the residue in the still, each weight being multiplied by a suitable constant which is roughly proportional to the vapourpressure of the corresponding liquid.
Page 427 - Demon," to pick out from the internal motions those whose direction is opposed to the main current, and to omit those which are not so, and thus, without the expenditure of energy, to construct a force which will act against the main current itself. But we may go materially further, and not only admit that it is not necessary to invoke here, as Maxwell has done in the case of thermodynamics, a being having...
Page 428 - Except when rising from the ground, I do not recollect ever having seen one of these birds flap its wings. Near Lima, I watched several for nearly half an hour, without once s Loudon's Magazine of Nat. Hist., vol. vii. taking off my eyes: they moved in large curves, sweeping in circles, descending and ascending without giving a single flap.

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