8 Canon Moseley on the Mechanical Properties of Ice. 



Experiments on the Shearing of Ice, August 24, 1869. Ther- 

 mometer 70-75°. Diameter of cylinder sheared \\ inch. 



Shearing 

 weight, 

 in lbs. 



Distance 

 sheared*. 



Time 



during 



which the 



shearing 



was 

 allowed to 

 go on, in 

 minutes. 



Unit of 

 shear, in 

 lbs. per 

 square 

 inch. 





180 

 173 

 180 



inch. 

 J 1 ? 



1* 



32 

 36 

 30 



101-86 



97-898 

 101-86 



f The apparatus was hot from previous 

 J handling in these experiments ; the 

 \ ice sheared therefore more easily 

 [ than afterwards. 



202 

 202 

 196 

 196 



5 

 8 

 5 

 8 



* 



30 

 29 



30A 

 30 



114-31 

 114-31 

 110-91 

 110-91 





202 

 202 



180 

 196 



3 

 13 



Tg" 



1 



5 



8 



18 

 20 

 20 

 21 



114-31 

 114-31 



101-86 

 110-91 



1 In these experiments the cylinder of 

 L ice was not turned out of the solid, 

 but formed by regelation. 



210 

 210 





3 

 2 



118-84 



118-84 



J The load was in these experiments 

 \ sufficient to shear the ice rapidly. 



The passage of Radiant Heat through Ice. 

 That ice is diathermanous has been shown by others. I have 

 verified it by the following experiment. Finding that ice could 

 easily be turned in the lathe, I had an ice lens constructed by 

 means of an iron templet whose edge was a circle 12 inches in 

 radius. I thus obtained a lens whose two faces were surfaces 

 of spheres of that radius, and whose focal distance was 19 inches. 

 When the sun's rays were received on this lens, the light streamed 

 through it in abundance, and it was not possible to hold the 

 hand in its focus by reason of the heat. A lucifer-match placed 

 there was instantly lighted. The experiment was repeated three 

 times. Ice lenses would be so easily made and renewed that it 

 would not perhaps be impossible to use them for astronomical 

 purposes in countries the temperature of which is below that of 

 freezing for two or three months of the year. They might be 

 constructed of any size; and ice is to be found of different den- 

 sities, and therefore probably of different refracting-indices. 



* This distance is that shown in fig. 10 by A a or b B. 



