Section III , 190Ô. [ 3 ] Trans. R. I^. C. 



PEESIDENTIAL ADDRESS Ï0 SECTION III. 



I. — ÇTlie Physical Constants of Ice. 



By Howard T. Barnes, D.Sc, Macdonald Professor of Physics, McGill 



University. 



INDEX. 



Page. 



Density 4 



Heat of fusion 6 



Heat of sublimation 7 



Spécifie lieat 8 



Thermal conductivity 10 



Coefficient of expansion 11 



Plasticity 13 



Elasticity 14 



Viscosity 15 



Eegelation 18 



Tensile strength 19 



Compressibility 19 



Refractive index and colour 19 



Electrical properties 20 



Crystalline structure 20 



Bibliogi-aphy 25 



The important influence of ice in the operations of Nature has 

 made a study of its physical properties one of great interest. In Canada 

 the development of our water powers has made a knowledge of the phy- 

 sical laws governing the formation of ice one of economic value as well, 



and in this we find the same interest manifested in all northern countries, 



« 



My object in choosing this subject for my presidential address before 

 Section III of the Royal Society of Canada, has been to bring together 

 the more important work that has been done during the past and to 

 make as complete a summary as possible up to date of the literature, in 

 order to supplement the previous work which I have had the honour to 

 present from time to time. 



No attempt will be made to dwell on the industrial side of the ice 

 problem. Great advances have been made in this direction, not only in 

 Canada but in Norway and Russia, as frequent publications received 



