UNDER SEA WITH HELMET AND CAMERA 



side. It escapes from the bottom, where the helmet rests upon the shoul- 

 ders. 



Many times the question has been asked why water does not rise in 

 the helmet, since the bottom is not tightly closed. This is demonstrable 

 by inverting a tumbler and sinking it in a bucket of water. The water 

 rises slightly in the tumbler by compressing the air in it. But since there 

 is no exit for the air the tumbler remains practically free from water. 



The visibility from the helmet here described is somewhat restricted 

 because the diver cannot look on either side of him except by turning 

 his body. Other designs of helmet are made, but this one has been found 

 entirely suitable for the purposes under consideration. One faulty type 

 should be mentioned. Instead of having two flat windows, it is fitted with 

 a single pane of curved glass. The effect of the curved surface when 

 under water is to distort objects viewed to an extent which renders the 

 helmet useless. 



The Hose 



The hose used with the helmet can be the ordinary garden variety, 

 although one of smaller diameter can be used if provided with proper 

 fittings. The smaller hose is easier to handle. Fifty feet will give the 

 diver sufficient radius of activity and the beginner should not use more 

 until he has gained by experience a full realization of the new conditions 

 under which he "lives, moves, and has his being." 



The Pump 



This is purchased with the helmet and is a two cylinder design op- 

 erated by a hand lever. It is screwed securely to a board, and lugs or 

 cleats should be attached to that part of the boat where the pump is to 

 be mounted so that it will be held firmly in position. This is an important 



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