In 1783, Mr. Spalding, of Edinburgh, who had made some improvements upon the mechanical arrangements of Halley’s bell, but had retained the barrel air service, engaged to recover some of the cargo of an East-Indiaman which had been sunk on the Kish Bank, Ireland. He and his assistant went down, and after the first supply of air was exhausted the barrels were sent down as usual. No signal having been given for some time, the bell was drawn up, and Mr. Spalding and his assistant were found to be dead. It is supposed that by some means they failed to discharge the air from the barrels into the bell, and were consequently suffocated. The barrel service was always more or less dangerous, from its liability to get out of gear, and if Spalding had adopted the invention of Smeaton, he would not have lost his life in the manner he did.
The improved diving-bell was soon generally adopted by engineers, and played an important part in the works which have so altered the port of Ramsgate. The great engineer Rennie made constant use of the diving-bell in fixing the foundations of the eastern jetty, and in protecting it in parts against the attacks of the sea by a shield of solid masonry. It was extensively used in the construction of the Plymouth Breakwater. M. Esquiros, who visited the divers during the progress of that great work, gave an interesting account of their modus operandi:—
“But we now,” says he, “approached the breakwater—that causeway of giants—by the side of which we soon discovered an old dismasted ship. This vessel is rough in appearance, and covered over with a kind of pent-house roof. In it live, as in a floating house, the operatives who are still working at the breakwater. They pass, alternately, one month on board ship and one month on shore. One of their little sources of profit consists [pg 82]in the sale of small fancy articles, which they say that they cut out with the blades of their pocket-knives from the rocks which they bring up from the bottom of the sea. Very soon I heard the loud throbbing of machinery, snorting and puffing like so many marine monsters; it was the wheezy noise of the air-pumps which supply the bells when buried under water....
“I then noticed a small boat managed by a sailor rowing it, which glided under the mouth of the bell, and from this hollow I saw emerge a pair of large loose boots, reaching above the knees, which, being followed by another pair of large boots, convinced me that two men were jumping down into the skiff. The boat itself, in fact, at once got clear of the dome, under which it had been half hidden, and I saw it come back to the vessel with two workmen on board, wet up to the waist and covered with mud. They had just finished making their half-day under the water, and appeared to be fatigued. Their swarthy complexions were tinged on the cheeks and forehead with a bright sanguine hue. The position of the bell was not at all altered; it was as if they wished to give it an opportunity to dry itself and breathe a little fresh air. It was then dinner hour for the men employed at the works. I had just been a spectator of the process of raising the bell to the surface; I now had to see it let down again to the bottom of the sea.
“The same little boat which brought the two workmen to the great floating house took them back again, after an hour’s rest, to the vicinity of the diving-bell, which, hung just over the water, looked very much like an immense iron box open at the bottom. The procedure in making ready for the descent has really something rather imposing about it, and to an excited imagination might very well suggest the preparations for the execution of a sentence of death. Nothing is wanting for the purpose; the scaffold, the secret cell, and the gulf of the menacing waves are all there. The divers, thank goodness! do not in the least anticipate such a fate, but, on the contrary, seem proud to walk safely over the bottom of the sea, where so many others have found their grave. Be this as it may, the boat soon places itself underneath the bell, raised as it is three or four feet above the surface. The two workmen climb one after the other up into the inside, helped by an iron ring hung to the arched roof, which can easily be laid hold of by the hands. They take their places on two wooden benches fixed at a certain height in the hollow of the bell. Sometimes four, or even six, workmen have to find seats in this curious vehicle. When all this is done the boat goes away, and in another moment the voice of the foreman gives the order, ‘Lower away.’...
“In places where the water is troubled by sand, the diver often passes through a kind of twilight or submarine fog, which compels him to light his lamp. More often, on the contrary, the light is sufficiently strong to enable him to read a newspaper in small type. A story is told even of a lady who wrote a letter in the diving-bell, and dated it thus: ‘16th June, 18—, at the bottom of the sea.’ Her courage obtained for her among the divers the sobriquet of the Diving Belle.
“I also wished to make my mind easy as to the lot of the poor workmen whom I had seen descending in the bell. The foreman assured me that they enjoyed every comfort in it. Have they not seats to rest themselves on, a wooden ledge on which to place their feet, an assortment of tools and necessary utensils suspended on a cord [pg 83]or hooked on to the walls of their hut, which is nearly as well furnished as that of Robinson Crusoe’s? From all this explanation I was bound to conclude, unless the foreman was mixing up a little irony in what he told me, that the divers were quite ‘at home’ in the bell. The fact is, that really they pass in it a great part of their existence. Almost all of them suffer a great deal at first from a violent pain, which they themselves define as ‘a toothache gone into the ears,’ and they have a humming in the head, ‘as if some one had let fly a swarm of bees there;’ but these troublesome symptoms disappear after the second or third descent. Their confidence in this dry chamber, almost isolated in the midst of the turmoil of the ocean, approaches sometimes to temerity. In 1820, Dr. Collodon, of Geneva, who had gone down in a diving-bell on the coast of Ireland, bethought himself that at the depth at which he then was, a stone, or any other trifling cause obstructing the action of the air-valve, would be sufficient to enable the water to invade the bell. He confided this not very reassuring reflection to one of the divers who was with him. The latter, smiling, answered him by merely pointing out with his finger one of the glazed loopholes which were over their heads. The doctor examined it attentively, and ascertained, in fact, that the glass was cracked sufficiently to allow bubbles of air to escape pretty freely. This was a very different and more serious cause of uneasiness than the rather improbable contingency of an obstruction of the air-valve. The diver was well aware of the cracked glass, and cared nothing about it.”
Some time since, when the present writer descended in the diving-bell exhibited in London, a seal which then disported in the tank would rub its nose outside against the little glass windows, and look in, as though wondering what on earth a visitor was doing there in his element! The same poor animal afterwards came to grief in a very sad way. When the water was drained off out of the tank the seal got into the pipes below, and thence to the sewers. It was found, still alive, some time after, in the sewers of the Euston Road, a considerable distance away, but succumbed later to the mephitic influences of the filthy stream.
M. Esquiros continues:—“ ‘They are just beginning to work’ was soon remarked to me by the superintendent, who followed, even under the waves, every movement of his labourers. The nature of their operations varies, of course, very much according to the undertaking in which they are engaged. The two divers who had just gone down had for their task to clear away round the adjacent portion of the foundation of the breakwater. As soon as they reach the bottom they jump off their seat, and, armed with a pickaxe, begin to dig into the moist sand in order to get out the stones. It often happens that the movement of the tide or some other cause disturbs the water round the rocky base of the breakwater. The workmen have then much trouble in seeing clearly, and complain that ‘the water is muddy.’ Generally, however, the water is so transparent, that even a cloud passing across the sky is visible at the bottom of the sea. The workmen also can labour with nearly as much ease and quite as much energy as if they were on land. The movements they themselves make in conjunction with the circumstances which surround them occasionally cause something like a thick mist to rise before their eyes, hiding from them the nearest objects; they get quit of it by [pg 84]calling for an ‘air bath.’ The air-pump redoubles its pace in working, and sends down to them through the pump an extra current of air, which soon blows away the mist.
“I was very soon enabled to judge for myself as to their industry; sacks which they had filled with muddy sand, and buckets laden with stones, came up to the surface every moment, drawn by cords. One might have fancied it to be the mouth of a mine, to which invisible arms were constantly sending up fragments of rock; but here the mine was the sea. The nature of their digging did not allow them to work very long together in the same place. The divers had already requested by signal to have their position shifted on the bed of the sound. How would they manage to comply with their wish? As regards air and locomotion, the men shut up in the bell depend entirely on the apparatus working on the surface. The chief organ of movement is a sort of traveller on four wheels, running over two tramways, allowing it to come and go in every direction. Immediately on the signal being given from below, the bell was raised from the bottom of the sea, like a heavy balloon. This operation was, of course, carried out by means of chains, and the diving-bell remained for a minute or two motionless in mid-water, like the pendulum of a stopped clock. But the traveller begins to move, and as it also acts as a crane, the pulley on the surface and the bell under water shift their position at the same time. The divers call this ‘travelling.’ They can thus move from north to south, from east to west, backwards and forwards. As they are in motion, if they come upon a piece of rock which encumbers the bed of the sound, they give the signal to stop, and the bell becomes stationary, and then descends again slowly towards the block of stones. If [pg 85]they have been carried on a little too far, and want to retrace their steps, they communicate afresh with the men working on the surface, and the obliging machinery soon brings them to the exact point desired.”