ARTIFICIAL ATMOSPHERE

Auckland Star, Volume LXIII, Issue 137, 11 June 1932, Page 3 (Supplement)

ARTIFICIAL ATMOSPHERE

It was Augustus Siebe who invented the first diver's uniform, and his factory by the Thames in London has since supplied thousands of divers with breathing appliances. All kinds of devices which enable fire-fighters and others to breathe comfortably amid flames and poisonous fumes and gases have ueen made, so that with a portable apparatus that can be strapped to the body a man can not only manufacture his air, but can get rid of tll2 poisonous products of respiration.

In the ordinary way the diver has his atmosphere supplied to his helmet through pipes which lead to a pump working on the ship or landing stage from which he ojwrates. He himself has to regulate the pressure and the rate" of supply to .suit his nee<Je. Sometimes a supply of air from above is not possible, and the diver must rely on a portable source. At other times a helmet is used in cases of fire-fighting, which must, of course, be kept supplied iii a simiittr way.

The outfit carried on the body will in such cases supply air for a couple of hours. Part of its oxygen is consumed in breathing, and is converted into poisonous carbon dioxide. This poison is absorbed and destroyed as fast as it is forined by chemical means, and fresh

HAND SHADOWS cause funTry and make this one.

supplies'of oxygen are liberated to take its place. The whole equipment is so compact that a man carrying it call crawl through a hole 15in square.

Another striking achievement is the supply of the necessary conditions for an oxy-acetylene flame to burn under water. The diver, with his own safe supply of air to breathe, can go deep down into the sea with a complete outfit for cutting through the steel plntes of a sunken ship with his blade of fire.

Cylinders of oxygen and of dissolved acetylene are taken to the sea bottom, with a special blowpipe that gives a flame of such terrific intensity that, far from being quenched by the water around it, cuts readily through the plates or bars of the sunken ship. At greater depths than 50ft hydrogen is used. Not only can cutting and boring be carried out mider water, but broken parts can be actually welded.

As far as the diver himself is concerned part of the atmosphere he takes with hirn and maintains under water in his helmet and diving dress becomes absorbed into hia blood.

The diver has been likened to a soda ■water bottle, his blood to the soda water. As he descends, air under pressure is forced into contact with his blood, and the blood takes up hydrogen from the air. When he rises, this excess of nitrogen begins to bubble off, and if he has been down 30 fathoms or so for any length of time and comes up to the surface quickly alarming symptoms vill urise through bubbles of nitrogen forming in the blood and tissues, or even in the spinal cord, causing the paralysis of the legs, known as. diver's palsy. When coming up to the surface a diver must stop at intervals, and by doing gymnastic exercises under the water increase his circulation so that the excess of nitrogen is removed from his system.