An unusually severe pitch, for the sea was rising, had lifted the big throbbing screw nearly to the surface, and it was spinning round in a kind of soda-water - half sea and half air - going much faster than was proper, because there was no deep water for it to work in. As it sank again, the engines - and they were triple expansion, three cylinders in a row - snorted through all their three pistons. "Was that a joke, you fellow outside?It's an uncommonly poor one. How are we to do our work if you fly off the handle that way?" "I didn't fly off the handle," said the screw, twirling huskily at the end of the screw-shaft. "If I had, you'd have been scrap-iron by this time. The sea dropped away from under me, and I had nothing to catch on to. That's all." That's all, d'you call it?" said the thrust-block, whose business it is to take the push of the screw; for if a screw had nothing to hold it back it would crawl right into the engine-room. (It is the holding back of the screwing action that gives the drive to a ship.) "I know I do my work deep down and out of sight, but I warn you I expect justice. All I ask for is bare justice. Why can't you push steadily and evenly, instead of whizzing like a whirligig, and making me hot under all my collars?" The thrust-block had six collars, each faced with brass, and he did not wish to get them heated. All the bearings that supported the fifty feet of screw-shaft as it ran to the stern whispered: "Justice - give us justice." "I can only give you what I can get," the screw answered. "Look out! It's coming again!" He rose with a roar as the Dimbula plunged, and "whack - flack - whack - whack" went the engines, furiously, for they had little to check them. "I'm the noblest outcome of human ingenuity - Mr. Buchanan says so," squealed the high-pressure cylinder. "This is simply ridiculous!" The piston went up savagely, and choked, for half the steam behind it was mixed with dirty water. "Help! Oiler! Fitter! Stoker! Help I'm choking," it gasped."Never in the history of maritime invention has such a calamity over-taken one so young and strong. And if I go, who's to drive the ship?" "Hush! oh, hush!" whispered the Steam, who, of course, had been to sea many times before. He used to spend his leisure ashore in a cloud, or a gutter, or a flower-pot, or a thunder-storm, or anywhere else where water was needed. "That's only a little priming, a little carrying-over, as they call it. It'll happen all night, on and off. I don't say it's nice, but it's the best we can do under the circumstances." "What difference can circumstances make ~. I'm here to do my work - on clean, dry steam. Blow circumstances!" the cylinder roared. "The circumstances will attend to the blowing. I've worked on the North Atlantic run a good many times - it's going to be rough before morning."