W. A. Cornish

“ Too little air at a great depth would prove doubly dangerous as the diver would be liable to be crushed to death by the waters pressing in upon him without sufficient air pressure to combat them. Air is pumped to the diver through a durable black rubber hose of the ordinary garden variety.
Pure air is employed for all diving purposes. An air reserve is also carried aboard submarines for use in case of emergency. I mention this because I have found that many persons suppose that oxygen is used. Raw oxygen would choke a man—literally burn him to death. ”

“ While we started, his body twitched convulsively—he gasped audibly.
Pungent rum was forced down his throat as he sputtered violently, coughed, and finally breathed regularly. He stared wildly about and raised one arm in the air. It held suspended there for a moment, his face working horribly. He seemed trying to strike out but his arm was held by some invisible force. At last it suddenly was released—flung forward in a frenzied blow and crashed cruelly on the deck.
His lips moved tremulously:
“There are people down there . . . alive!" He choked. “—alive! . . . thousands of them! . . .” ”

“ After a final rehearsal of the pre-arranged call signals Slim dropped beneath the surface.
Deep sea diving is an art—of a sort. A highly intricate, dangerous sort. The air pump, equipped with a high-pressure gauge, is manned by two men. A third operative manipulates a measuring line. Two others attend to the lowering rope. The whole operation is in charge of a supervisor, usually the Senior Officer, who, with a constant eye on his watch, coordinates the depth as indicated by the measuring tape with the air pressure registered by the dial gauge. ”

“ A slip on the part of any one of these workers might prove extremely dangerous to the man below.
The air pressure is increased as the diver is lowered, to counteract the greater volume of water at the lower levels. An over-supply of air near the surface would inflate the suit and neutralize the weight of the diver, reinforced as he is by 334-inch leaden soles, so that he could neither go down nor up. The diver may, however, guard against any such excess of air by manipulating a valve in the side of his helmet. ”

“ The Black Sea derives its name from its murky color, and its color from the dreary reflection of dull, overcast skies. While the Mediterranean is always blue because of the deep sapphire of the sky, the Black Sea is a dark mirror reflecting leaden skies. There are no coloring pigments in the water. ”

“ The apparatus, consisting of an air pump, depth lines, two regulation diving suits with harness equipment, which had been previously rigged on the shore side, was carefully inspected.
Slim was our lead-off man. He was assisted into his suit, and slowly descended the ladder over the side. He paused on a bottom rung, the lower half of his body in the water, while I clamped the heavy glass visor into place. Holding to the ladder with one bare hand, he thrust the other into the sea. ”