0. I). von Engeln — Studies on Ice Structure. 459 



was filled with ice fragments and a pressure of approximately 

 3400 lbs. per square inch applied by 5 P. M. of that day. 

 During the night the air temperature decreased to 4°F. Before 

 10:30 A. M. of the next day, when the air temperature was 

 14°F. 3 inches in length of solid ice core had been forced out 

 of the lateral orifice at the base, and the pressure had fallen off 

 to 3000 lbs. per square inch. (See fig. 7.) The projecting 



Fig. ?. 



Fig. 7. Flow of ice under compression. Photographed at 12.15 P. m. 

 on March 6, 1912. Air temperatures ranged between 22°F. when pressure 

 first applied, to 4°F. during night and 14°F. in morning when 3 inches of ice 

 had been protruded. In this figure approximately 4 inches of the " squeezed 

 out " ice rod are shown. Streaks are due to iron substance from orifice and 

 indicate the movement outward. Note downward bend of rod. Parallel 

 rings near end are original, their cause not understood. 



ice rod curved downwards, its end being one-half inch below 

 the level of the orifice. By 2:30 P. M. 4 1/2 inches were pro- 

 jected. By 4:30 P. M. another inch had been squeezed out, 

 the pressure had fallen off slightly and the air temperature 

 had risen to 29°F., at approximately which point it stayed until 

 10 A. M. next morning when 14 inches of ice rod had been 



