A History of the Theory of Elasticity and of the Strength of Materials: pts. 1-2. Saint-Venant to Lord Kelvin

Cover
University Press, 1893
 

Ausgewählte Seiten

Andere Ausgaben - Alle anzeigen

Häufige Begriffe und Wortgruppen

Beliebte Passagen

Seite 454 - In the first place we must not listen to any suggestion that we must look upon the luminiferous ether as an ideal way of putting the thing. A real matter between us and the remotest stars I believe there is, and that light consists of real motions of that matter, motions just such as are described by Fresnel and Young, motions in the way of transverse vibrations.
Seite 430 - On the whole we may fairly conclude that, whilst there is some evidence of a tidal yielding of the earth's mass, that yielding is certainly small, and that the effective rigidity is at least as great as that of steel.
Seite 439 - But now must be invoked minutely accurate experimental measurement to find how nearly the law of simple proportionality holds through finite ranges of contraction and elongation. The answer happily for mathematicians and engineers is that Hooke's law is fulfilled, as accurately as any experiments hitherto made can tell, for all -metals and hard solids each through the whole range within its limits of elasticity...
Seite 368 - 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.
Seite 454 - If I knew what the electro-magnetic theory of light is, I might be able to think of it in relation to the fundamental principles of the wave theory of light. But it seems to me that it is rather a backward step from an absolutely definite mechanical notion that is put before us by Fresnel and his followers to take up the so-called Electro-magnetic theory of light in the way it has been taken up by several writers of late.
Seite 422 - Vol. I, part II, §832, Lord Kelvin and Professor Tait remark that " The precise circumstances under which elastic bodies break have not hitherto been adequately investigated by experiment. It seems certain that rupture cannot take place without difference of stress in different directions. One essential element therefore is the difference between the greatest and least of the three principal stresses. How much the tendency to break is influenced by the amount of the intermediate principal stress...
Seite 461 - The want of indication of any such actions is sufficient to prove that if there are any in nature, they must be exceedingly .small. But that there are such waves, I believe, and I believe that the velocity of propagation of electro-static force is the unknown condensational velocity that we are shaking of. " I say ' believe 'here in a somewhat modified manner.
Seite 478 - ... are not balanced ; we can learn something towards an understanding of the real molecular structure of matter, and of some of its thermodynamic properties, by consideration of the static and kinetic problems which it suggests. Hooke's exhibition of the forms of crystals by piles of globes, Navier's and Poisson's theory of the elasticity of solids, Maxwell's and Clausius' work in the kinetic theory of gases, and Tait's more recent work on the same subject — all developments of Boscovich's theory...
Seite 478 - A body is called homogeneous when any two equal, similar parts of it, with corresponding lines parallel and turned towards the same parts, are undistinguishable from one another by any difference in quality.
Seite 387 - If, when the matter occupying any space is strained in any way, all pairs of points of its substance which are initially at equal distances from one another in parallel lines remain equidistant, it may be at an altered distance ; and in parallel lines, altered, it may be, from their initial direction ; the strain is said to be homogeneous.

Bibliografische Informationen