I. Remarks on the interior melting of ice. By Professor William Thomson, F. R. S. In a letter to Professor Stokes, Sec. R. S

Abstract

In the Number of the ‘Proceedings’ just published, which I received yesterday, I see some very interesting experiments described in a communication by Dr. Tyndall, “On some Physical Properties of Ice.” I write to you to point out that they afford direct ocular evidence of my brother’s theory of the plasticity of ice, published in the 'Proceedings’ of the 7th of May last; and to add, on my own part, a physical explanation of the blue veins in glaciers, and of the lamellar structure which Dr. Tyndall has shown to be induced in ice by pressure, as described in the sixth section of his paper. Thus, my brother, in his paper of last May, says, “If we commence with the consideration of a mass of ice perfectly free from porosity, and free from liquid particles diffused through its substance, and if we suppose it to be kept in an atmosphere at or above 0° Cent., then, as soon as pressure is applied to it, pores occupied by liquid water must instantly be formed in the compressed parts, in accordance with the fundamental principle of the explanation I have propounded—the lowering, namely, of the freezing-point or melting-point, by pressure, and the fact that ice cannot exist at 0° Cent, under a pressure exceeding that of the atmosphere.” Dr. Tyndall finds that when a cylinder of ice is placed between two slabs of box-wood, and subjected to gradually increasing pressure, a dim cloudy appearance is observed, which he finds is due to the melting of small portions of the ice in the interior of the mass. The permeation into portions of the ice for a time clear by the water squeezed against it from such parts as may be directly subjected to the pressure,” theoretically demonstrated by my brother, is beautifully illustrated by Dr. Tyndall’s statement, that “the hazy surfaces produced by the compression of the mass were observed to be in a state of intense commotion, which followed closely upon the edge of the surface as it advanced through the solid. It is finally shown that these surfaces are due to the liquefaction of the ice in planes perpendicular to the pressure."