terminals Fleury's Ray will wink and disappear and must be laboriously built up again. This means half a day's work for all hands and an expense of one hundred and seventy-odd pounds to the G. P. O. for radium-salts and such trifles.

"Now look at our thrust-collars. You won't find much German compo there. Full-jewelled, you see," says Captain Hodgson as the engineer shunts open the top of a cap. Our shaft-bearings are C. M. C. (Commercial Minerals Company) stones, ground with as much care as the lens of a telescope. They cost £37 apiece. So far we have not arrived at their term of life. These bearings came from "No. 97," which took them over from the old "Dominion of Light," which had them out of the wreck of the "Perseus" aëroplane in the years when men still flew linen kites over thorium engines!

They are a shining reproof to all low-grade German "ruby" enamels, so-called "boort" facings, and the dangerous and unsatisfactory alumina compounds which please dividend-hunting owners and turn skippers crazy.

The rudder-gear and the gas lift-shunt, seated side by side under the engine-room dials, are the only machines in visible motion. The former sighs from time to time as the oil plunger rises and falls half an inch. The latter, cased and guarded like the U-tube aft, exhibits another Fleury Ray, but inverted and more green than violet. Its function is to shunt the lift out of the gas, and this it will do without watching. That is all! A tiny pump-rod wheezing and whining to itself beside a sputtering green lamp. A hundred and fifty feet aft down the flat-topped tunnel of the tanks a violet light, restless and irresolute. Between the two, three white-painted turbine-trunks, like eel-baskets laid on their side, accentuate the empty perspectives. You can hear the trickle of the liquefied gas flowing from the vacuum into the bilge-tanks and the soft gluck-glock of gas-locks closing as Captain Purnall brings "162" down by the head. The hum of the turbines and the boom of the air on our skin is no more than a cotton-wool wrapping to the universal stillness. And we are running an eighteen-second mile.

I peer from the fore end of the engine-room over the hatch-coamings into the coach. The mail-clerks are sorting the Winnipeg, Calgary, and Medicine Hat bags: but there is a pack of cards ready on the table.

Suddenly a bell thrills; the engineers run to the turbine-valves and stand by; but the spectacled slave of the Ray in the U-tube never lifts his head. He must watch where he is. We are hard-braked and going astern; there is language from the control-platform.

"Tim's sparking badly about something," says the unruffled Captain Hodgson. "Let's look."

Captain Purnall is not the suave man we left half an hour since, but the embodied authority of the G. P. O. Ahead of us floats an ancient, aluminum-patched, twin-screw tramp of the dingiest, with no more right to the 5,000 foot lane than has a horse-cart to a modern town. She carries an obsolete "barbette" conning-tower—a six-foot affair with railed platform forward—and our warning beam plays on the top of it as a policeman's lantern flashes on the area sneak. Like a sneak-thief, too, emerges a shock-headed navigator in his shirt-sleeves. Captain Purnall wrenches open the colloid to talk with him man to man. There are times when Science does not satisfy.

"What under the stars are you doing here, you sky-scraping chimney-sweep?" he shouts as we two drift side by side. "Do you know this is a Mail-lane? You call yourself a sailor, sir? You ain't fit to peddle toy balloons to an Esquimaux. Your name and number! Report and get down, and be——!"

"I've been blown up once," the shock-headed man cries, hoarsely, as a dog barking. "I don't care two flips of a contact for anything you can do, Postey."

"Don't you, sir? But I'll make you care. I'll have you towed stern first to Disko and broke up. You can't recover insurance if you're broke for obstruction. Do you understand that?"

Then the stranger bellows: "Look at my propellers! There's been a wulli-wa down under that has knocked us into umbrella-frames! We've been blown up about forty thousand feet! We're all one conjuror's watch inside! My mate's arm's broke; my engineer's head's cut open; my Ray went out when the engines smashed; and ... and ... for pity's sake give me my height, Captain! We doubt we're dropping."

"Six thousand eight hundred. Can you hold it?" Captain Purnall overlooks all insults, and leans half out of the colloid, staring and snuffing. The stranger leaks pungently.

"We ought to blow into St. John's with luck. We're trying to plug the fore-tank now, but she's simply whistling it away," her captain wails.

"She's sinking like a log," says Captain Purnall in an undertone. "Call up the Banks Mark Boat, George." Our dip-dial shows that we, keeping abreast the tramp, have dropped five hundred feet the last few minutes.

Captain Purnall presses a switch and our signal beam begins to swing through the night, twizzling spokes of light across infinity.

"That'll fetch something," he says, while Captain Hodgson watches the General Communicator. He has called up the North Banks Mark Boat, a few hundred miles west, and is reporting the case.

"I'll stand by you," Captain Purnall roars to the lone figure on the conning-tower.

"Is it as bad as that?" comes the answer. "She isn't insured, she's mine."

"Might have guessed as much," mutters Hodgson. "Owner's risk is the worst risk of all!"

"Can't I fetch St. John's—not even with this breeze?" the voice quavers.

"Stand by to abandon ship. Haven't you any lift in you, fore or aft?"

"Nothing but the midship tanks and they're none too tight. You see, my Ray gave out and—" he coughs in the reek of the escaping gas.

"You poor devil!" This does not reach our friend. "What does the Mark Boat say, George?"

"Wants to know if there's any danger to traffic. Says she's in a bit of weather herself and can't quit station. I've turned in a General Call, so even if they don't see our beam some one's bound to help—or else we must. Shall I clear our slings. Hold on! Here we are! A Planet liner, too! She'll be up in a tick!"

"Tell her to have her slings ready," cries his brother captain. "There won't be much time to spare.... Tie up your mate," he roars to the tramp.

"My mate's all right. It's my engineer. He's gone crazy."

"Shunt the lift out of him with a spanner. Hurry!"

"But I can make St. John's if you'll stand by."

"You'll make the deep, wet Atlantic in twenty minutes. You're less than fifty-eight hundred now. Get your papers."

A Planet liner, east bound, heaves up in a superb spiral and takes the air of us humming. Her underbody colloid is open and her transporter-slings hang down like tentacles. We shut off our beam as she adjusts herself—steering to a hair—over the tramp's conning-tower. The mate comes up, his arm strapped to his side, and stumbles into the cradle. A man with a ghastly scarlet head follows, shouting that he must go back and build up his Ray. The mate assures him that he will find a nice new Ray all ready in the liner's engine-room. The bandaged head goes up wagging excitedly. A youth and a woman follow. The liner cheers hollowly above us, and we see the