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Popular Science Mo/if///// 



Detail of impact 

 Contacbor 



"Aluminum top 



Contact 



Flexible 

 diaphraqm 



\ 



Carbide 



contactor 



/ 



Battery 

 Detonatori-I 



Wirej-Jeadinq 

 to cable 



-Explosive 



Hallock parachute depth-bomb. Flexible diaphragm, upon striking water, 

 closes a pair of contacts. Circuit through the electric cable leading to bomb is 

 thus closed; bomb explodes. Length of cable determines depth of explosion. 

 If the diaphragm contactor fails to work, carbide contactors set off the bomb 



violent compressive wave to go out, 

 caving in the side of a submarine in the 

 vicinity as if it were an eggshell. 



According to Edward F. Chandler, a 

 New York expert on underwater develop- 

 ments, one type of effective depth-boml) 

 depends solely on water pressure for 

 explosion. The illustration on the right 

 shows details. 



The bomb may be of any convenient 

 exterior shape, and is customarily 

 ecjuipped with two eyes for the attach- 

 ment of supporting chains at the stern of a 

 destroyer, or other convenient point. The 

 uivderwater jiressure acts simply. Push- 



ing in on the diaphragm shown, it causes 

 a detonator to be fired and the explosive 

 set oflf. The particular depth at which 

 detonation occurs may previously be fixed 

 by adjusting the bolt which projects 

 through the diaphragm and outer shell of 

 the bomb. A graduated scale reading 

 in feet makes this easy. The bolt tightens 

 up or slackens the coil-spring pushing 

 on the underside of the diaphragm, 

 thereby making a correspondingly greater 

 or lesser water pressure necessary to com- 

 press it and produce an explosion. 



Evidently the type described by Mr. 

 Chandler is the result of evolution, and it 



