Canon Moseley on the Mechanical Properties of Ice. 5 



in each successive five minutes equalled the mean difference 

 (t — /) between the temperature of the air and that of the ice 

 multiplied by *056, or 



(t-0'056-A/ = 0. 



The Tenacity of Ice. 



I caused a rod of ice to be cut out of a solid block and turned 

 in a lathe (see fig. 4). It was 12 inches in length and had 

 conical ends, from which its diameter tapered to 1^ inch in the 

 middle of its length. To clasp the two ends of the rod so as to 

 apply the strain required to tear the rod asunder, two pieces of 

 wood hinged together (fig. 5) had a cavity cut in each, so that 

 when they were shut and screwed together they enclosed one of 

 the conical ends of the ice. Two such clasps were constructed ; 

 and each had an iron loop fixed to it, by which one end of the 

 ice-cylinder could be hooked up and the other have weights sus- 

 pended to it (fig. 6) . The first set of experiments was made on 

 the 26th of August, 1869 — one of the hottest days of that year. 

 The thermometer ranged in the room from 70° to 75°, and the 

 ice was almost in a deliquescent state. The second set of expe- 

 riments was made on the 27th of October, 1869. There are 

 well known to be great differences in the hardness of different 

 specimens of ice at the same temperature, and yet greater at dif- 

 ferent temperatures. To these correspond different tenacities. 



Experiments on the Tenacity of Ice. 





Diameter at 









Number 

 of expe- 



the point 

 where the 



Strain which tore 

 the ice asunder, 



Tenacity in 

 lbs. per 





riment. 



separation 

 took place, 

 in inches. 



in lbs. 



square inch. 





h 



ft 



120 



73-94 



C Experiments made 



2. 



U- 



104 



70039 



on the 26th of Au- 



3. 



■ k 



102 



92097 



gust, 1869. Iber- 



4. 



if 

 f 



151 



206 



99 42 

 1 



ia mometer 70-75°. 



5. 



4 { 



It bore this load 

 10', and then broke. 



I 116-57 





6. 



* { 



193 



Broke in 14'. 



Bore 122 for 30'; 



\ 10922 



) 



Experiments made 

 } on the 27th of Oc- 



7. 



4 { 

 * I 



then 84 were added, 



and it broke in 5'. 



Bore 150 for 20'; 



1,116-57 

 1 



tober, 1869. 



8- 



then 56 were added, 



I 116-57 









and it broke in 6'. 



J 



; 



