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

the pump should be got ready. The pump should always be worked in its chest. The iron caps protecting the crank ends should be removed, the nuts securing them being re- placed. The fly-wheels should then be fitted on the crank shaft, the winch handles shipped, and the nuts on the end of the shaft well screwed up with a spanner. The hinged flaps covering the pressure gauges and the flap at the back of the pump case should be opened, the screw cap on the overflow nozzle of the cistern removed, and the cistern filled with water; the caps of the air delivery connections should be re- moved ; the necessary length of air pipe should be put together carefully with leather washers in place, the union nuts being tightly screwed up by means of spanners. The air pipe should be tested till the pressure shown on the pressure gauge is considerably above that corresponding to the depth to which the diver will have to descend. If a two-cylinder double-acting pump be employed, each cylinder should be tested. If only one diver is going down, his pipe must be joined up to the left-hand delivery nozzle on the pump. Testing Inlet Valve on Helmet.—Before screwing the air pipe to the inlet valve connection of the helmet, a finger should be inserted into the valve in order to see that it is free on its seating and that the spring is working properly. Joining up Air Pipe and Signal Line.—The air pipe and breast-rope (signal line) are now joined up to the helmet. Care must be taken that the plugs of the telephone cable are entered in the proper holes before screwing up the nut on the breast-rope, that the inlet valve on the helmet is correct, and that the leather washers of air pipe coup- ling's are in place before the pipe is screwed up. Two spanners are always to be used in joining up lengths of pipe and in connecting the pipe to the helmet. 'fhe breast-rope should now be joined up to the battery box, and the telephone tested. Air pipe and breast-rope are to be coiled down in large flakes out of the way, so that they may run out easily. Dressing the Diver.—The diver puts on the woollen guernsey, drawers, and long stockings supplied. In cold weather he should put on two or more suits of flan- nels. If the red woollen cap is worn, it must be pulled close down over the head, care being taken to leave no loose end which might possibly obstruct the air outlet. The shoulder pad (if one be worn) is put on and tied under the diver’s arms. He then gets into the diving dress, which in cold weather should be slightly warmed, an assistant lifting it well up to allow him to get his shoulders in easily ; he next puts his arms into the sleeves, the assistant opening the cuffs by inserting the first and second fingers of both hands, taking care to keep his fingers straight. The diver, by pushing, 37