The supply-ship was quite a little institution herself. Approaching her from shore the night before, her lights beneath the dull moon and thin, drifting clouds had loomed up like a dancing-hall across the lonesome harbor waters. When we got aboard, we found her the relic of what had once been a fine block of a three-masted coaster; but moored forward and aft she was now, as if for all time, and no longer showing stout spars and weather-beaten canvas--nothing but two floors of white-painted boarding above her old bulwarks. She was a boarding-place, a sort of club, for the crew and attendants, as well as a supply station for the submarines which in these New England waters were being tried out for one of the warring Powers. Voices and cigar-smoke as we stepped aboard, and more or less quiet breathing, with partly closed and open living and sleeping rooms, denoted that men were discussing, arguing, sleeping, and otherwise passing a normal evening. Looking farther, we saw that down in the insides of her--where formerly she stowed noble freights of coal or lumber or, sometimes, hay and ice--were now a boiler and engine room, and a good, big repair-shop. This night, while the gale came howling and the sea rolling and the solid rain sweeping against the sober old sides of our supply-ship--on this night, the finest kind to be sitting in a warm cabin, we sat and, while the smoke rolled high, aired our views of the real things in the world; and the most real thing in the world just then being a submarine, we got this: "Danger? Of course, there's some danger. So is there danger in bank-fishing, in log-jamming down in Maine, in mining deep down, and in aeroplaning. "You want to get a sub right. A sub is a ship modelled different from most ships, of course, and built stronger to stand pressure, but only a ship, after all, with special tanks in her. She's on top of the water and wants to go down. Good. She fills her tanks and down she goes. She's down and wants to come up. All right. She empties her tanks and up she comes. She's got to. She couldn't stay down with her tanks empty if she wanted to--not unless she blew a hole in her side, or left her hatches open. "Of course if her tanks don't work right! But we showed you three different ways to-day how she can beat that game. And anyway, no matter what happens, unless you're cruising deep, it's only a few feet to the top. Not like a crazy aeroplane a thousand feet up in the air! Something happens in an aeroplane, and where are you? With a busted stay or bamboo strut and you a mile in the air, where are you? Volplane? Maybe. But if you didn't--down you'd come atumbling like a hoop out of the clouds. That's 90 per cent--yes, maybe 99 per cent--of the submarine game: See that everything is right mechanically with your sub, then get a competent crew and--well, you're ready."