224 Royal Society : — 



Englishman aimed, above all things, at the firm establishment of 

 facts. And he did establish them. The future historian of 

 science will not, I think, place these men in antagonism. To 

 each belongs a reputation which will not quickly fade, for the 

 share he has had, not only in establishing the dynamical theory 

 of heat, but also in leading the way towards a right appreciation 

 of the areneral energies of the universe." 



If this recognition of Mr. Joule will not satisfy my critics, 1 

 cannot help it. It is simply a difference of estimate between 

 them and me — a difference which may exist without the least 

 infraction of good faith on either side. There is nothing here 

 to "startle" brave men, or to give the slightest colouring of 

 truth to insinuations regarding u depreciation " and " suppres- 

 sion." However " the walls wherein Davy propounded his trans- 

 cendent discoveries n may feel the want of his great presence, I 

 trust they still contain men not less anxious than he was to act 

 honourably by their fellows, and who would consider the highest 

 rewards of science too dear if purchased by any deviation from 

 this course of action. 



Royal Institution, 

 Feb. 24, 1863. 



XXXII. Proceedings of Learned Societies. 



ROYAL SOCIETY. 



[Continued from p. 154.] 

 May 22, 1862. — Major-General Sabine, President, in the Chair. 



npHE following communications were read : — 

 ■*- "On the Theory of the Motion of Glaciers." By William 

 Hopkins, Esq., F.R.S. 



Almost all the numerous discussions which have taken place during 

 the last twenty years respecting our theories of glacial motion have 

 had for their object the assertion of some particular view, rather 

 than the establishment of a complete and sufficient theory founded 

 on well-defined hypotheses and unequivocal definitions, together 

 with a careful comparison of the results of accurate theoretical in- 

 vestigation with those of direct observation. Each of these views 

 has been regarded, improperly, in the author's opinion, as a Theory of 

 Glacial Motion. The Expansion Theory ignored the Sliding Theory, 

 though they were capable of being combined ; the latter theory was 

 equally ignored by the Viscous Theory, in which, moreover, instead 

 of the definitions of terms being clear and determinate, no definition 

 of viscosity was ever given, though that term designated the funda- 

 mental property on which the views advocated by this theory de- 

 pended. Again, the Regelation Theory is not properly a theory of 

 the motion of glaciers, but a beautiful demonstration of a property 



