174 Jaggar — Yolcanologic Investigations at Kilaiiea. 



Fig. 4. 



Fig. 4. 1916-17. Stages in development of great crag mass. Photos 

 Jaggar. 



(a) North margin lava lake, June 24, 1916. First stage bench terraced by 

 ui)lift. Talus slopes from collapse of June 5 emerging through bench magma 

 at borders. ])epression 592 ft. (181 m.). 



{h) Same scene on Aug. 16, 1916, terraced bench raised and fissured. Islets 

 in foreground from raised shoals beginning of crag-mass. Depression 390 ft. 

 (119 m.). 



