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.
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.
The depth line played out slowly. At the end of 11 minutes it showed a depth of 80 feet, then 85, then 90. The signals had come intermittently, but without cessation. When the tape measured 90 feet at the water line it suddenly stopped. It twitched spasmodically for a few seconds and then was still. Only the loose coil floated lazily on the water.
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'“Fright! A fear of something—I don't know what—caused this man’s death."
The man at the line started. The two at the pump turned the handles mechanically, forcing air ninety feet down to their comrade. Two others on the powering rope—as is always the case in an emergency—began to hoist. Not too rapidly for there was no answering signal. The air was being decreased at the same relative rate that it had been applied—minute for minute.
After what seemed an eternity—it was exactly eleven minutes—the inert, rubber-swathed Slim was hauled over the side. The moment that we let go our hold, the suit, crumpling like an empty grain sack, sloughed to the deck in a heap.
The visor was hurriedly unclamped. A pallid face, drained of blood and with wide-open staring eyes, lay beneath. The eyes seemed all white; the pupils had shrunk to mere pin pricks of jet. An expression of rigid terror was frozen on the man’s countenance.
There was no need for a pulmotor. Death—ghastly, stark, horrible—leered from beneath the copper helmet.
Lieutenant Blake, after a hurried examination, stated that death had come from heart failure.
“Fright! A fear of something—I don’t know what—caused this man’s death,” he explained. There were no evidences of the dread “caisson disease,” the scourge of veteran divers. Its symptoms are too easily discerned to mistake.
Fear gripped us—fear of the unknown . . . of the eerie, alien “lost world” beneath unnaturally darkened waters. And then by degrees the initial consternation wore away. It was supplanted by a certain grim seriousness. For it was the summer after the war and men were not unaccustomed to the dead being hoisted over the sides of ships, or to gleaming white canvas bags slipping overboard into the sea while the crew stood by with bared heads.
Slim was loosed from his diving paraphernalia and carried below.
I turned to the second diver who had been preparing to relieve Slim. He was stretching a wide rubber wrist-band and letting it snap back against the palm of, his hand. Perspiration was coursing down his face. It ran in tiny streams to his neck where it was absorbed in a ragged fringe of blue jersey.
A dry laugh caused me to wheel (Continued on page 90)
