UNDER SEA WITH HELMET AND CAMERA 



sumed, when reaction is swift. The air bubbles then reach the heart, the 

 brain, the nervous centers, and death results almost immediately from 

 air embolism." 



In one of the earlier chapters in this book, the discomfort experienced 

 by Richard du Pont after ascending from thirty feet without his helmet 

 is mentioned. Discomfort! I should say so! In view of the above quota- 

 tion he can be thankful that he is alive and well today. 



When amateurs begin diving, they are Hkely to become very en- 

 thusiastic and to try out venturesome ideas. One direction for such ex- 

 pansion is to get two divers on the bottom at the same time. If this is 

 done there are special precautions to take because the risk of diving is 

 doubled. No doubling of responsibility should be assumed. Two men 

 must be stationed at two separate pumps, there must be two hose tenders, 

 and it is most desirable to have a fifth person in command of all. The 

 smallest group, including divers, that should attempt this operation is 

 seven. The pump and hose-tender groups should be as far as possible 

 from one another to prevent entanglements. Divers should understand 

 that they must not cross one another's path either in front or rear. This 

 is to avoid tangles of hoses or life lines. Double diving is not recom- 

 mended until those attempting it have learned much more than is given 

 in this short discussion. 



There are certain pathological considerations which should be studied. 

 The effect of air pressure on the ears has been mentioned. This effect 

 is more marked as pressure increases. Some people find it difficult to clear 

 the passages by yawning. Anyone who starts a dive and cannot clear 

 the passages by the time he has descended three or four feet, should 

 ascend until he feels no discomfort, then try again. If he cannot reheve 

 this pressure he had better not dive, for he will have intense pain which 



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