When we had all entered, the door was closed upon us. We looked at each other, wondering what would be done next, and we soon found out. Our conductor, previous to starting the lock, gave us what he termed a few useful hints, so that we might be able to make the trip as agreeable as possible under all the circumstances.
“Now, gentlemen,” said he, “in descending, you will find a disagreeable sensation, particularly about your ears. You will find great ease by closing the nostrils every few seconds,—as the pressure of the air will act upon the tympanum of the ear,—and also by inflating your cheeks to their full extent.”
These instructions were given that we might cause an artificial pressure upon the inside of the ear, and thus prevent its rupture.
Our conductor then proceeded to turn a cock, to admit the air forced from above. In a moment it rushed in with a tremendous force, making a noise similar to that of a locomotive blowing off steam. The effect of this was anything but pleasant. A sudden deafness seemed to overtake us, as if a cannon had been fired under our noses; our voices were also changed, and appeared cracked, and we almost wished our curiosity had not led us so far.
A HEAVY PRESSURE OF AIR.
This feeling was caused by the air rushing too fast into the orifice of the ear. There was just sufficient light inside the lock to discern our faces, and that was all. It took five or six minutes to get the necessary amount of pressure into the lock, and then the air was turned off.
We seemed suddenly to lose our footing, and then to regain it; and no sooner had we righted ourselves than we had another sudden shoot, and this continued until we reached the bottom. The actual descent was made in about a minute and a half, or perhaps two minutes; but owing to the pain we suffered, it appeared to be three times as long.
The sensation we experienced was certainly very disagreeable and painful, and for a pleasure trip I certainly would not recommend any one to undertake the journey. Should a lady go down, however strong-minded she might be, I would not answer for the consequences. One of the party was so much affected by the pressure of the air that our conductor had to turn off the cock frequently. The stranger’s ears pained him greatly, and blood began to spurt from them.
Having reached the bottom of the caisson, where the workmen were digging out the earth and blasting rock, we were detained in the lock some minutes, to allow the admission of air of the same density as that below. This being done, I descended a short iron ladder leading into the bottom of the caisson, and speedily found myself standing on the bed of the river, seventy-eight feet below water-mark.
There were several men working in their shirt sleeves, with big drops of perspiration rolling off their cheeks. The subterranean vault was very well lighted with gas forced down the pipes in the same manner as the air; and it is a curious fact, that in the compressed air a foot burner gives as much light as a four foot one would in the ordinary atmosphere. The caisson seemed to be full of steam, as if a hundred washerwomen were plying their avocation at the tub. The bottom of the caisson is divided into several chambers by means of iron and wood partitions, with entrances leading into each other. The air does not seem impure nor unpleasant. According to an examination made a few days before my visit, it was then found to contain a small percentage of carbonic acid, but not enough to do any harm.