On another trip we had a college professor on board who could not understand exactly how our men could get out of the boat. I told him to come into the diver’s compartment and I would explain it to him. Accordingly he reluctantly, as I thought, entered the compartment, which in the _Argonaut_ is a little room only four feet long and a little wider. After closing the door I noticed that the colour was leaving his face and a few beads of perspiration were standing out upon his forehead, and had he been any one else than a professor or, possibly, a newspaper man, I would not have gone any further with the experiment. The door, however, was closed and securely fastened. I then opened the valve a full turn, and the air began to rush in with a great noise. He grabbed hold of one of the frames and glanced with longing eyes at the door we had just entered. I then turned off the air and said, “By the way, Professor, are you troubled with heart disease?” He said, placing his hand over his heart, “Why, yes, my heart is a little affected.” Remarking, “Oh, well, this little depth will not hurt you,” I turned on the air again after saying to him, “If you feel any pain in your ears swallow as if you were drinking water.” He immediately commenced swallowing, and during that half-minute or so we were getting the pressure on I believe he swallowed enough to have drunk a bucketful of water. After getting the desired pressure I stooped down and commenced to unscrew the bolts, holding the door which leads out into the water. Our professor said, “What are you doing now?” I answered, “I am going to open this door so that you can see the bottom.” Throwing out his hands he said, “No, no. Don’t do that. I would not put you to that trouble for the world.” However, about that time the door dropped down, and as he saw the water did not come in the colour returned to his face, and he exclaimed, “Well, if I had not seen it I would never have believed it!” Mr. Lake declares that as a submarine torpedo-boat his vessel will be practically invincible. She could, he claims, approach a stationary enemy on the bottom and rise up under the water and secure a time-fuse torpedo to her bottom, and she could be fitted with tubes to fire automobile torpedoes. She could also find cables to repair or cut them, and could be used for countermining purposes. The _Argonaut_ is, however, intended not so much for warfare as for recovering treasures from the deep, and for the coral, sponge, pearl, and similar industries. It has been calculated that of the cargoes, treasures and vessels lost in the merchant service the aggregate amounts to over one hundred millions of dollars per year, and the loss has, of course, been going on for many years.