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according acid action amount angle appears ball battery becomes calculated carbon cause chemical Communicated compounds conductivity conductor consequently considerable constant containing copper crystals curve deflection deposits described determined direction distance drop edge-angle effect electric electrodes elements employed equal equation experiments expression fact fluid force further give given glass greater heat hydrogen increased iron junctions known length less light lines liquid magnet mass matter means measured mercury metal method millims molecules motion move nature nearly observed obtained particles pass plane plate platinum portion position possible potential present pressure probably produced proved quantity remarkable removed represented resistance respect rock selenium shown side similar solid body solution substance supposed surface Table temperature tension theory thickness tion tube unit vibrations weight wire
الصفحة 55 - In this instrument the usual action of light is reversed, rotation taking place, the bright convex side being repelled, and the black concave attracted. When the light shines only on the bright convex side, no movement is produced, but when it shines on the black concave side, this is attracted, producing rotation. 15. Radiometer. — A cup-shaped radiometer similar to the above, but having the convex surfaces black and the concave bright. Light shining on this instrument causes it to rotate rapidly,...
الصفحة 53 - ... the latter, causing continuous rotation at the rate of one revolution in 7'5 seconds. When the convex side is screened off, so as to let the light shine only on the concave...
الصفحة 3 - ... between the pressure of a fluid, and the thermal capacities and mechanical energy of a given mass of it, all considered as functions of the temperature and volume ; and Carnot's function of the temperature ; are brought forward for the purpose of pointing out the importance of making the mechanical energy of a fluid in different states an object of research, along with the other elements which have hitherto been considered, and partially investigated in some cases. 84. If we consider the circumstances...
الصفحة 17 - If a wire already twisted be suddenly twisted further, always, however, within its limits of elasticity, cold will be produced ; and if it be allowed suddenly to untwist, heat will be evolved from itself (besides heat generated externally by any work allowed to be wasted, which it does in untwisting). It is assumed that the torsional rigidity of the wire is diminished by an elevation of temperature, as the writer of this article had found it to be for copper, iron, platinum, and other metals (compare...
الصفحة 212 - Prize to be adjudged in 1877 : The Criterion of Dynamical Stability. To illustrate the meaning of the question imagine a particle to slide down inside a smooth inclined cylinder along the lowest generating line, or to slide down outside along the highest generating line. In the former case a slight derangement of the motion would merely cause the particle to oscillate about the generating line, while in the latter case the particle would depart from the generating line altogether. The motion in the...
الصفحة 17 - From thermodynamic theory* it is concluded that cold is produced whenever a solid is strained by opposing, and heat when it is strained by yielding to, any elastic force of its own, the strength of which would diminish if the temperature were raised ; but that, on the contrary, heat is produced when a solid is strained against, and cold when it is strained by yielding to, any elastic force of its own, the strength of which would increase if the temperature were raised.
الصفحة 51 - ... the force impinging on it. By having the driving surface of large size, and making it of a good conductor of heat, such as silver, gold, or copper, a very faint amount of incident radiation suffices to produce motion. The black surface acts as if a molecular* wind were blowing from it, principally in a direction normal to the surface. This wind blows away whatever easily movable body happens to be in front of it, irrespective of colour, shape, or material ; and in its capability of deflection...
الصفحة 320 - The experiments were made upon wires of iron, steel, and copper, the copper wire employed having been obtained from Messrs. Johnson, Matthey & Co. as chemically pure. Two tin cans were obtained open at the top, and pierced at the bottom by necks into which india-rubber corks were inserted ; and through slits in these the wires were passed. The wire was fastened by a clamp in the lower can, and was grasped in the upper one by a pair of wire-drawing dogs attached to the shorter arm of a lever, to the...