[Illustration:  “AN UNUSUALLY SEVERE PITCH ...  HAD LIFTED THE BIG THROBBING SCREW NEARLY TO THE SURFACE.”]

Then two converging seas hit the bows, one on each side, and fell away in torrents of streaming thunder.

“Ease off!” shouted the forward collision bulkhead.  “I want to crumple up, but I’m stiffened in every direction.  Ease off, you dirty little forge filings.  Let me breathe!”

All the hundreds of plates that are riveted on to the frames, and make the outside skin of every steamer, echoed the call, for each plate wanted to shift and creep a little, and each plate, according to its position, complained against the rivets.

“We can’t help it! We can’t help it!” they murmured.  “We’re put here to hold you, and we’re going to do it.  You never pull us twice in the same direction.  If you’d say what you were going to do next, we’d try to meet your views.”

“As far as I could feel,” said the upper-deck planking, and that was four inches thick, “every single iron near me was pushing or pulling in opposite directions.  Now, what’s the sense of that?  My friends, let us all pull together.”

“Pull any way you please.” roared the funnel, “so long as you don’t try your experiments on me.  I need fourteen wire ropes, all pulling in opposite directions, to hold me steady.  Isn’t that so?”

“We believe you, my boy!” whistled the funnel stays through their clenched teeth, as they twanged in the wind from the top of the funnel to the deck.

“Nonsense!  We must all pull together,” the decks repeated.  “Pull lengthways.”

“Very good,” said the stringers; “then stop pushing sideways when you get wet.  Be content to run gracefully fore and aft, and curve in at the ends as we do.”

“No, no curves at the end.  A very slight workmanlike curve from side to side, with a good grip at each knee, and little pieces welded on,” said the deck beams.

“Fiddle!” said the iron pillars of the deep, dark hold.  “Who ever heard of curves?  Stand up straight; be a perfectly round column, and carry tons of good solid weight.  Like that!  There!” A big sea smashed on to the deck above, and the pillars stiffened themselves to the load.

“Straight up and down is not bad,” said the frames who run that way in the sides of the ship, “but you must also expand yourself sideways.  Expansion is the law of life, children.  Open out!  Open out!”

“Come back!” said the deck beam, savagely, as the upward heave of the sea made the frames try to open.  “Come back to your bearings, you slack-jawed irons!”

“Rigidity!  Rigidity!  Rigidity!” thumped the engines.  “Absolute, unvarying rigidity—­rigidity!”

“You see!” whined the rivets in chorus.  “No two of you will ever pull alike, and—­and you blame it all on us.  We only know how to go through a plate and bite down on both sides so that it can’t and mustn’t and sha’n’t move.”