Fig. 17. 



Fig. 17. Jan. 1917. Experimental work on E. rampart of lava lake in Halemaumaupit 



(a) Jan. 4, 1917. Looking northwestward across fresh overflows in foreground at ram- 

 part. Part of crag-mass and N.W. outer wall in background. Dipping up liquid lava 

 from lake; 20-foot (t3 m.) pipe with iron pot attached. Fountain splashing over ramparton 

 the right. Note thickness of broken crusts in foreground; these are like the crusts which 

 cover lake. Lake depression 101 ft. (31 m.). Photo Stotts. 



(h) Jan. 11, 1917. First measurement of temperature with Seger cones. Shows bend m 

 pipe where heated most at lake surface ; straight below and above. Cylinder with cones 

 on end of pipe. Lake depression 87 ft. (2(5 m.). Photo Jaggar. 



(c) Jan. 16, 1917. Third test with Seger cones. Pipe immersed m lava on left, anchored 

 with rope right. Lake depression 78 ft. (24 m.). Photo Jaggar. 



