On the engine-room telegraph of the submarine is a word that does not figure on the apparatus of other types of warships: it is "Dive." The commander told me that we were going down very soon. I observed that the destroyer had turned around and was heading out to sea. We were almost at a stop, when our skipper told me to get into the conning-tower well and to be down far enough to give him room. It must be realised that immediately after the order to submerge has been rung in the engine-room the conning-tower hatch is closed. Hence the commander and his helmsman have no time to lose when the submarine is going under, as it takes forty-five seconds to submerge an under-sea craft, and at times, if pressed, it can be accomplished in thirty seconds. Up to that time I had not devoted much attention to the inside of the conning-tower hatch, beyond glancing at the brass ladder. Soon I discovered that there were two ladders, and that the distance to the inside deck of the boat was about twice as great as I had imagined. After I had taken my foot off the last rung of the ladder and stepped on the chilled, wet canvas-covered iron deck, my head was in a whirl at the sight of the bowels of brass and steel. The skipper had set the arrow at "Dive," and we were going down and down--a motion which is hardly perceptible to the layman. The activity below and the intricate mechanism of the craft caused me to think more of what the men were doing than of my own sensations. I wondered how one man could learn it all, for the skipper must have an intimate knowledge of all the complicated machinery of his vessel. There were engines everywhere and little standing room--at least, that is how it appeared on the first glance, and even afterwards it was clear that no adipose person could hope to survive aboard a submarine. No sooner had the engine-room received the order to submerge than the captain followed his helmsman down the conning-tower hatch, and he lost not a second in getting to the periscope--the eye of his vessel. Soon my attention was arrested by the sight of two men sitting side by side turning two large wheels. One kept his eye on a bubble and turned his wheel to control the hydroplanes to keep the craft level, and the other man's eyes also watched a bubble in a level. His share of the work was to keep the vessel at the depth ordered by the commander.