'< 



■ y -'* 



< ^:0::'' / '' ' : f .,. 



Si|| y 



Photograph by J. W. Shipley 



INSPECTING THE CAVERNOUS MAW OF A GAS-EMITTING VENT 



The gases from these openings are transparent until they begin to condense in the at- 

 mosphere. Therefore it is frequently possible to look into the depths of the earth for many 

 feet. 



*33 



