XIV RECENT PROGRESS OF THE GLACIER THEORY. 



out showing any trace of flaws ; this he attributed to the 

 " regelation " of the water in the crevices. Mr. James Thom- 

 son and his brother, Professor William Thomson of Glasgow,* 

 however, ascribed this consolidation to the effect of intense 

 pressure, causing simultaneous liquefaction, which commences at 

 every point of the interior of the ice to which the pressure ex- 

 tends (according to a previous discovery made by them to that 

 effect), and to its subsequent solidification when the pressure is 

 removed. 



Dr. Tyndall soon applied his experiments on the consolida- 

 tion or moulding of ice, and his adaptation to them of Mr. 

 Faraday's fact of " regelation," to the explanation of the veined 

 structure and movement of glaciers, which certain previous 

 speculations of Mr. Sorby and himself about " planes of cleav- 

 age " had brought under his notice. 



Thus it will be seen how the theory of glaciers became 

 anew, in 1857, a matter of attention to men of science ; and, 

 considering the activity and ingenuity of those engaged in its 

 study, the received doctrines were not likely to be adopted 

 without being first thoroughly canvassed. My theory, among 

 others, was discussed, and I congratulated myself upon the 

 examination which it was likely to receive upon its intrinsic 

 merits. The fact that ice can be moulded under pressure, even 

 in hand specimens, so as completely to recover its continuity 

 under a changed form, was an argument in favour of my inter- 

 pretation of the similar fact occurring in glaciers on a great 

 scale, which appeared to me likely to remove some natural pre- 

 possessions, as well as to throw light on the precise relations of 

 water and ice near the freezing-point of the former or thawing- 

 point of the latter, to which in my writings I had repeatedly 



* Proceedings of the Royal Society of London, 7th May 1857, 23d February 

 and 22d April 1858. 



