456 0. D. von Engeln — Studies on Ice Structure. 



sure was applied to the top of this composite filling by means 

 of a solid iron plunger turned to a diameter that would just per- 

 mit its easy insertion into the open end of the copper cylinder. 

 This insured all the load being borne by the ice itself. (See 

 fig. 5.) Pressures varying from 500 to 900 lbs. per square inch 

 were applied, over a period of five days. The cylinder bulged 

 after the first few hours. As no notable change in the ice was 

 apparent on removal from the cylinder after this treatment 



Fig. 



Plunger 



Broken Ice 



Pond Ice with principal 

 axis of crystal bundles 

 parallel to direction 

 of pressure. 



Glacier Ice, granules 

 variously oriented 



Pond Ice with principal 

 axis of crystal bundles 

 normal to direction of 

 pressure. 



Fig. 5. Diagram illustrating contents of annealed copper cylinder, using 

 fitted iron plunger. 



except the absence of fracturing and apparent flow indicated 

 by the transparency and coherence of the mass, the same ice 

 core was utilized again. This time an unannealed harder cylin- 

 der was probably used (our notes fail to state) and a solid ice mass 

 assured by filling with water and freezing. Again using the 

 iron plunger, pressures up to 1000 lbs. per square inch were 

 applied and allowed to remain on over night. Next day the 

 load had fallen off to 800 lbs. per square inch and the cylinder 

 was very slightly deformed. The air temperatures during the 

 time of the experiment ranged from 16° to 19° F. 



On removing the ice from this second cylinder it was found 

 to be completely recrystallized. Ends of individual crystals 

 had diameters 1/8 to 3/8 inches, some were smaller. The 



