"Accordingly Richards, the engineer, and myself entered the boat and closed the hatch. This shut us off from the air, and our breathing now depended entirely on the compressed-air reserve. After waiting a few moments and finding no ill effects from the compressed air, I decided to submerge. I drew back the little iron levers on either side of my head (these operated the Kingston valves in the bottom, through which water was admitted to the ballast tanks). Almost immediately the boat began to settle, giving us the suggestion of slowly descending in an elevator. I now looked through the ports in the superstructure and observed that the bow had entirely disappeared and the water was within a few inches of the glass. A second or two later everything grew dark and we were entirely submerged, and nothing could be seen through the ports excepting a dark-green blur. "Our next suggestion was a slight jar when the vessel struck the bottom. It might also be mentioned here that we had no light except the glow that came through the conning tower. This just about sufficed to read the gauges, but was too poor to be of much interest to the engineer. The engine was not needed at that time, however, but we decided to carry a small lantern, to be used when any adjustment was necessary, but not otherwise, as it consumed too much of our precious oxygen. "Richards having made an examination and found everything tight, I decided to blow out the ballast and come up. Accordingly I opened the valve admitting air to the ballast tank, and at once heard a hiss that told me that the air was driving out the water. The green blur on the ports in the conning tower grew lighter as I gazed through them until suddenly the light of full day burst through, almost dazzling me. After blinking my eyes a few times I looked out again and saw the familiar surroundings of the 'Gap.' I now opened the hatch and stood on the seat, thus causing my head and shoulders to protrude from the tower. As soon as I was observed doing this a cheer burst from the crowd of observers on the dock, among whom opinion was equally divided as to whether we would ever emerge alive from our dive or not. We had now demonstrated the fact that our boat was tight, that our air was sufficient for breathing, and that our ballasting system was perfect.