Chief Engineer Murphy now took command. Before letting down the buoys, the first thing evidently to be done was to find out, if possible, the precise point where the Projectile lay. For this purpose, the Nautilus was clearly the only part of the machinery that could be employed with advantage. Its chambers were accordingly soon filled with water, its air reservoirs were also soon completely charged, and the Nautilus itself, suspended by chains from the end of a yard, lay quietly on the ocean surface, its manhole on the top remaining open for the reception of those who were willing to encounter the dangers that awaited it in the fearful depths of the Pacific. Every one looking on was well aware that, after a few hundred feet below the surface, the pressure would grow more and more enormous, until at last it became quite doubtful if any line could bear the tremendous strain. It was even possible that at a certain depth the walls of the Nautilus might be crushed in like an eggshell, and the whole machine made as flat as two leaves of paper pasted together.
Perfectly conscious of the nature of the tremendous risk they were about to run, Marston, Morgan, and Murphy quietly bade their friends a short farewell and were lowered into the manhole. The Nautilus having room enough for four, Belfast had been expected to be of the party but, feeling a little sea sick, the Professor backed out at the last moment, to the great joy of Mr. Watkins, the famous reporter of the N.Y. Herald, who was immediately allowed to take his place.
Every provision against immediate danger had been made. By means of preconcerted signals, the inmates could have themselves drawn up, let down, or carried laterally in whatever direction they pleased. By barometers and other instruments they could readily ascertain the pressure of the air and water, also how far they had descended and at what rate they were moving. The Captain, from his bridge, carefully superintended every detail of the operation. All signals he insisted on attending to himself personally, transmitting them instantly by his bell to the engineer below. The whole power of the steam engine had been brought to bear on the windlass; the chains could withstand an enormous strain. The wheels had been carefully oiled and tested beforehand; the signalling apparatus had been subjected to the rigidest examination; and every portion of the machinery had been proved to be in admirable working order.
The chances of immediate and unforeseen danger, it is true, had been somewhat diminished by all these precautions. The risk, nevertheless, was fearful. The slightest accident or even carelessness might easily lead to the most disastrous consequence.
Five minutes after two o'clock, the manhole being closed, the lamps lit, and everything pronounced all right, the signal for the descent was given, and the Nautilus immediately disappeared beneath the waters. A double anxiety now possessed all on board the Susquehanna: the prisoners in the Nautilus were in danger as well as the prisoners in the Projectile. Marston and his friends, however, were anything but disquieted on their own account, and, pencil in hand and noses flattened on the glass plates, they examined carefully everything they could see in the liquid masses through which they were descending.
For the first five hundred feet, the descent was accomplished with little trouble. The Nautilus sank rather slowly, at a uniform rate of a foot to the second. It had not been two minutes under water when the light of day completely disappeared. But for this the occupants were fully prepared, having provided themselves with powerful lamps, whose brilliant light, radiating from polished reflectors, gave them an opportunity of seeing clearly around it for a distance of eight or ten feet in all directions. Owing to the superlatively excellent construction of the Nautilus, also on account of the scaphanders, or suits of diving armor, with which Marston and his friends had clothed themselves, the disagreeable sensations to which divers are ordinarily exposed, were hardly felt at all in the beginning of the descent.
Marston was about to congratulate his companions on the favorable auspices inaugurating their trip, when Murphy, consulting the instrument, discovered to his great surprise that the Nautilus was not making its time. In reply to their signal "faster!" the downward movement increased a little, but it soon relaxed again. Instead of less than two minutes, as at the beginning, it now took twelve minutes to make a hundred feet. They had gone only seven hundred feet in thirty-seven minutes. In spite of repeated signalling, their progress during the next hour was even still more alarming, one hundred feet taking exactly 59 minutes. To shorten detail, it required two hours more to make another hundred feet; and then the Nautilus, after taking ten minutes to crawl an inch further, came to a perfect stand still. The pressure of the water had evidently now become too enormous to allow further descent.
The Clubmen's distress was very great; Marston's, in particular, was indescribable. In vain, catching at straws, he signalled "eastwards!" "westwards!" "northwards!" or "southwards!" the Nautilus moved readily every way but downwards.
"Oh! what shall we do?" he cried in despair; "Barbican, must we really give you up though separated from us by the short distance of only a few miles?"
At last, nothing better being to be done, the unwilling signal "heave upwards!" was given, and the hauling up commenced. It was done very slowly, and with the greatest care. A sudden jerk might snap the chains; an incautious twist might put a kink on the air tube; besides, it was well known that the sudden removal of heavy pressure resulting from rapid ascent, is attended by very disagreeable sensations, which have sometimes even proved fatal.