Experiment in Friction of Ice upon Ice. 



441 



found in all glaciers, arising from the friction of the ice in the glacier itself; 

 and that the act of regelation or freezing, accompanies exosmosis from the water 

 into the cells of the ice, the evaporation of part of the water abstracts heat and 

 causes the rest of the water to freeze. 



(6) I do not understand why this action has not been previously suggested, for 

 by pressing four pounds of ice against, or by revolving two blocks of ice such as 

 these, 8 inches in diameter, for an hour, l\ pounds of water can be produced, 

 at a temperature, much above freezing (Fig. 3). The ice was revolved in a 

 metallic chamber, commencing at 32 Fahr., but the temperature soon arrived 

 at 40 , on account of the heat transmitted from the ice to the air touching warm 

 air entering the case, 'and from the water being warmed by friction between 

 the two surfaces it lubricates. I found the friction of ice upon ice to be near 

 that of oak upon oak, well lubricated. This experiment does not appear to 

 have been previously tried, and should be repeated under varying conditions 

 to arrive at the actual co-efficient of friction, and should be tried in the 

 manner adopted by General Morin and others, and in a cold climate. Velocity 

 of movement does not increase friction. Friction is dependent upon mass, dis- 

 tance moved, and nature of surface. The co-efficient of ice is between O'l and CT2. 



The source of water at the bottom of a glacier is, I think, due to the heat 

 generated by friction of ice upon ice, by the movement of the glacier to a great 

 extent. The source of the subsequent congelation, I thiuk, is the evaporation 

 of this water, and its reception by frozen ice. Hitherto the accepted source of 

 the glacial water is only supposed to be that which may be obtained from the 

 snow or ice on the surface of the glacier, melted by the sun's rays, and falling 

 through fissures to the bottom. Ice will evaporate at any temperature, forming 

 vapour, which would pass into the fissures or fractures made by the ice breaking- 

 contact. 



I can only conveniently show that ice rubbed against ice rapidly, produces 

 water freely, in such a case as my experiment. This experiment is somewhat 

 different from the actual case of a glacier. Then regelation only occurs at 32° 

 to the water adherent by molecular attraction to the surfaces of the ice. When 

 a lump of ice is surrounded by a mass of water at 32^, it thaws. It must, 

 however, be remembered that, there is a certain amount of elasticity in ice 

 when a great many yards of ice are set in motion by varying pressures of ice 

 in the rear, and by gravity, when the tension or torsion arrives at a certain 

 limit, fracture ensues ; the divided surfaces rub with great force against each 

 other, and the motion of disruption, although not instantaneous, may be 

 excessively rapid. 



Heat is produced by the friction of any solid against any other solid, and ice 

 is no exception. This heat converts ice into water. No doubt part is imme- 



