Submarine Appliances And Their Uses
Deep Sea Diving, &c., &c.

which there is no means of trying previously. Experience goes to show that even plain drop safety weights fail at the critical moment ; in fact there are a great many loop holes for the unexpected in air-locks or life-boats carried in the hull, apart from the con- stant encumbrance to the submarine. Another great drawback to the Air-lock or detachable life-saving chamber is, that the air in it is liable to become foul as the crew are getting into it, owing to the for- mation of chlorine gas. Copyright. Photo No. 36. MAN, EQUIPPED WITH THE APPARATUS, FLOATING. It will be noticed that the window of the helmet is wide open. A life-saving device to be efficient must be able to fulfil promptly the three condi- tions previously referred to, and in order to meet them a special form of diving hel- met, which is quite self-contained, and not dependent on any feature which is liable to get out of order, has been designed and patented. This apparatus, of which photo- graphs are reproduced on page 82, has, after exhaustive trials, been adopted by the British Admiralty. 84