The screws, like those of most quite modern ships, were driven by the simple contrivance of a constant stream of liquid air, contained in very powerful tanks, exploding through capillary tubes into non-expansion slide-valve chests, much as in the ordinary way with steam: a motor which gave her, in spite of her bluff hulk, a speed of sixteen knots. It is, therefore, the simplest thing for one man to take these ships round the world, since their movement, or stopping, depend upon nothing but the depressing or raising of a steel handle, provided that one does not get blown to the sky meantime, as liquid air, in spite of its thousand advantages, occasionally blows people. At any rate, I had tanks of air sufficient to last me through twelve years' voyaging; and there was the ordinary machine on board for making it, with forty tons of coal, in case of need, in the bunkers, and two excellent Belleville boilers: so I was well supplied with motors at least. The ice here was quite slack, and I do not think I ever saw Arctic weather so bright and gay, the temperature at 41°. I found that I was midway between Franz Josef and Spitzbergen, in latitude 79° 23' N. and longitude 39° E.; my way was perfectly clear; and something almost like a mournful hopefulness was in me as the engines slid into their clanking turmoil, and those long-silent screws began to churn the Arctic sea. I ran up with alacrity and took my stand at the wheel; and the bows of my eventful Argo turned southward and westward. * * * * * When I needed food or sleep, the ship slept, too: when I awoke, she continued her way. Sixteen hours a day sometimes I stood sentinel at that wheel, overlooking the varied monotony of the ice-sea, till my knees would give, and I wondered why a wheel at which one might sit was not contrived, rather delicate steering being often required among the floes and bergs. By now, however, I was less weighted with my ball of Polar clothes, and stood almost slim in a Lap great-coat, a round Siberian fur cap on my head. At midnight when I threw myself into my old berth, it was just as though the engines, subsided now into silence, were a dead thing, and had a ghost which haunted me; for I heard them still, and yet not them, but the silence of their ghost.