As the bell descends below the surface, the pressure of the air becomes very great, being equal to the pressure of the water. A dense atmosphere of this sort has many peculiarities. It is easy enough to breathe, but the pressure on the drum of the ear is frequently inconvenient. An ordinary whisper will sound as loud as the customary tones of the voice, and if there are two persons in the bell, and one of them speaks as he would naturally speak in the open air, he will seem to the other to be shouting with the full power of his lungs. A slight blow upon any metallic substance within the bell will sound like a very heavy one, and any noise that would cause no inconvenience in the open air may become absolutely painful in the dense atmosphere in the inside of a diving-bell.
A diving-bell must be made very heavy to carry it downward, and large weights are generally placed around its mouth. A shelf inside serves as a seat for the occupant, and when it is lowered to the bottom, the ground can be leisurely surveyed or examined for whatever object the diver has in view. Sometimes, when two persons descend in a bell, one of them may leave the bell by diving into the water, and then returning, but he cannot go very far. Submarine armor, however, enables him to go quite a distance away from the bell, and return at his leisure. Submarine armor possesses many advantages over the ordinary diving-bell. A man encased in a submarine suit can remain under water for a long time, and move about pretty much as he likes.
SUBMARINE ARMOR.
Submarine armor consists of a water-proof suit, completely encasing the body of the wearer. It is put on in two sections; the trousers have shoes attached to them, with heavy leaden soles, and at the waist they are firmly fastened to a metallic ring. The upper part of the suit covers the arms, the head, and the chest, and the lower part of it is fastened to a ring which exactly meets the other. The upper part of the suit is put on, and after it the second, or lower part. The two rings are then fastened together by means of screws, and a thin band of rubber upon them excludes both air and water. The head of the diver is enclosed in a helmet made of brass or other metal, and having a thick plate of glass in front. Air is conveyed inside this helmet by means of a rubber tube, and an air pump must be kept in constant operation, to supply the man in armor with the necessary amount of air. The foul air escapes through a valve in the top, just as it escapes from the top of the diving-bell. A suit of clothing of this sort does not add to the beauty of its wearer; it is very cumbersome, and I greatly doubt if it ever becomes fashionable for an afternoon promenade on Broadway. The helmet might answer very well as a disguise, for the reason that the face of the wearer is almost, and generally quite, invisible.
When a diver is properly encased in his armor, he is swung off from the side of the boat or ship, and sinks into the water. The leaden soles upon his shoes carry him straight down, and serve to keep his feet in the proper place and position. The tube supplies him with air, and he can walk about and use his hands freely. He can handle the pick and shovel, and can enter the cabin of a sunken ship; in fact, he can go in any place where the flexible tube can be made to follow; but all the time he is below, the pump must maintain a steady motion, and the valve in the top of his helmet must work freely. A slight accident may cause his death: should any of the machinery of the pump give way, or some careless person on the ship step upon the tube as it lies along the deck, the diver might lose his life. It sometimes happens that on being drawn to the surface the diver is found dead. Some slight accident has cut off his supply of air, and cutting off the air has deprived him of life.
Sunken ships have been explored by means of this diving armor, and sometimes large amounts of treasure are recovered through its use. In some cases miners have prosecuted their operations under water by means of this apparatus. A few years since an expedition was fitted out to examine a wreck of a ship which was sunk more than half a century ago on the coast of South America. She was known to have a great deal of treasure on board. Operations had been undertaken frequently by means of common divers and diving-bells to recover this treasure, but none of the enterprises had been rewarded with success. With their submarine armor to aid them, the new explorers were successful, and were handsomely rewarded for their efforts.
Thrilling stories are told by men who have thus gone below the surface of the water. Some time ago a diver was sent down to examine a steamer that had been sunk in about sixty feet of water, and had carried down many of its passengers. The man went down, and made two or three efforts without success to enter the cabin of the vessel. On the fourth visit he accomplished his object, and reached the cabin. Soon he made a signal to be drawn up. When he was on the deck of the ship, and the armor was removed, he fainted. When he recovered, he was asked the cause of his faintness, and replied,—
A HORRIBLE SIGHT.
“It’s enough to make any man faint to see what I have seen. I went into the cabin of that ship; it was full of water, of course; but that wasn’t all. It was full of the bodies of those passengers that went down when the ship was lost. There was a slight motion of the water, caused by the ground swell; and, as I entered the cabin, the water slowly swayed backward and forward, and swung these bodies with it. At the very door one of them brushed against me, or rather rolled against me, and its dead, glassy eyes stared directly in the face of my helmet, not six inches away. I knew it was dead, but there seemed to be a life-like expression in that cold and stony face. I passed by it, and had gone but a few feet before I encountered another body; and as I looked along the cabin, the vessel, being slightly careened, received a dim light through its windows. Those bodies swinging with the motion of the water seemed more like living than like dead forms. There was a combination of life and death in their paleness which was absolutely horrible; and not for all the treasure this ship contains will I go down again.”
The diver positively refused to repeat his descent, at least in that part of the ship; but others, less sensitive than himself, were found to go down and complete the exploration. None of them, however, appeared anxious to continue on that sort of work, and all were heartily glad when the exploration in the cabin was completed.