no THE HAUNTS OF LIFE 



It has happened repeatedly that a closed 

 glass thermometer sent down inside a metal 

 tube has been brought up again powdered to a 

 fine dust. In one experiment made on board 

 the Challenger, a thick glass tube full of air 

 was sealed at both ends, wrapped in flannel, 

 and put inside a copper tube with holes at each 

 end. This was lowered to a depth of 2000 

 fathoms, and was then drawn up again. Not 

 only was the glass tube powdered, but the side 

 of the copper case was crushed inwards by the 

 pressure. Before the empty space caused by 

 the shivering of the glass tube could be filled 

 with water, the side of the copper case was 

 stove in an "implosion," as one of the ex- 

 plorers said, had occurred. 



Because of the pressure, deep-sea animals 

 are "liable to an accident to which no other 

 animal in the world is liable that of tum- 

 bling up." Most fishes have a silvery swim- 

 bladder or air-bladder, which contains gas 

 and enables the fish to accommodate itself 

 to different depths. But this accommodation 

 must take place very gradually, and if a 

 deep-sea fish, in chasing its prey, rises too 

 high or too suddenly, its swim-bladder expands 

 so much that it cannot be controlled by the 



