Fuller leant over the side. It was too dark to discern anything.

Prudence forbade him to flash the torch upon the invisible support--a support so light and frail that the wonder of it all was that it hadn't given way under the force of the impact with the waves.

The crippled seaplane was tossing and rolling under the combined action of the short crested waves and the stiff breeze. It wanted about two hours to daylight. Meanwhile every minute saw the amphibious craft drifting further and further from sh.o.r.e.

There were no signs of the "Hippodrome." Possibly the seaplane carrier had resumed her voyage, in the supposition that the missing hornet had made one of the fishing harbours on the Yorkshire coast.

The absence of any wireless call rather knocked that theory on the head. On the other hand the "Hippodrome" could not, without great risk of being submarined, since she was unaccompanied by destroyers or patrol-boats, steam seaward on an apparent wild-goose chase for her errant child.

"She's holding, I fancy," said Fuller referring to the suspected float. "Anyhow we've kept afloat so far and there's no reason why we shouldn't do so until I tackle this most refractory motor."

Making cautious use of the flash lamp the pilot minutely examined the complicated mechanism. It was not long before the mischief was discovered. Not only was the petrol-tank completely perforated by three shrapnel bullets, but the pipe leading from it to the carburetter had been cut clean through. That accounted for the engine running for some seconds before coming to a stop. Until the last of the petrol in the carburetter had been drawn into the cylinders firing was still taking place.

Further examination revealed the fact that, the motor was otherwise undamaged, although, judging by the holes in the fuselage and through the planes, it seemed wonderful that pilot and observer had escaped being hit.

"Can I bear a hand?" enquired Kirkwood.

"No, thanks," was the reply. "Close enough quarters as it is. We should only be tumbling over one another."

By the aid of a piece of flexible tubing lined with indiarubber the broken portions of the petrol pipe were temporarily reunited. The next step was to plug the holes in the tank. This task was performed by means of a metal instrument consisting of a metal rod of about a third of an inch in diameter and four inches in length. Two thirds of the length was threaded and fitted with a "b.u.t.terfly" nut in front of which was a cylindrical plug of guttapercha faced with indiarubber. At the other extremity was a swivelled cross-bar of about an inch in length and so arranged that it could lie in a straight line with the rod.

This end Fuller inserted in one of the perforations in the side of the tank. Then, giving the rod half a turn, he allowed the swivel bar to fall into a position at right angles to the rod. It was then impossible to withdraw the latter owing to the cross-piece engaging on the inner side of the tank.

The flight-lieutenant's next move was to screw the pliable plug hard against the perforated metal by means of the "b.u.t.terfly" nut, and by so doing hole No.1 was repaired--the first of six. While Fuller was engaged upon the work of making good defects Kirkwood, his mind still uneasy on the subject of the float, lowered himself over the side.

Gaining the upper side of the float he felt along it with his hand.

As he did so a wave swept the frail buoyant structure.

"By Jove!" he exclaimed. "This is a treat. The water is quite warm."

Compared with the intense coldness of the upper air the sea, at this time of the year, was indeed tepid. The contrasted temperature acted like balm to his numbed hands. He revelled in the comfort.

While thus engaged the A.P. discerned a large object looming through the darkness--a cylinder nearly a yard in diameter. It was floating with very little of its bulk showing above the surface, and, owing to the comparatively rapid drift of the seaplane, it appeared to be moving steadily through the water and bearing straight down upon the float.

For a brief instant Kirkwood remained stock still in his rec.u.mbent position, unable to raise a finger or utter a cry. The object was a floating mine.

He could discern the horns with remarkable clearness, for the thing seemed surrounded by an aura of phosph.o.r.escent light. One blow from the underside of the float upon those delicately adjusted projections with which the mine simply bristled would result in utter annihilation.

Kirkwood's mind was steeled to the dangers of a ten or fifteen thousand feet fall through s.p.a.ce; but this, to him, unusual danger literally took the wind out of his sails.

Then, like a flash, the reaction set in. The will to cope with sudden perils a.s.serted itself. A plan, unpretentious in all its details, formulated in his active brain.

Throwing himself flat upon the float and grasping one of the supports with his left hand, the A.P. hung as far in front as he possibly could without losing his balance. His outstretched hand came in deliberate contact with the drifting horror. The smooth, slimy surface--for the mine had evidently been in the water for some time--offered no resistance, and he thrust until his fingers "brought up" against one of the horns.

How far short of the minimum pressure required to snap the brittle projection and allow the chemicals contained therein to ignite Kirkwood was never to know. He was just aware that either the seaplane or the mine was swinging clear--perhaps it was a mutual "get out of my way" affair.

Sc.r.a.ping the for'ard outer corner of the float by a bare six inches the infernal contrivance, fended off by the A.P.'s outstretched hand, glided past, until with a sigh of relief the observer watched it disappear in the darkness.

For quite a minute he hung on, his heart beating like a piston, his eyes peering through the blackness ahead. Floating mines, he knew, were generally in considerable numbers. The fact that one peril had been averted was no guarantee that all danger from these jettisoned cylinders of potential death was over.

"Where the Christopher Columbus are you, old bird?" exclaimed Fuller, who, pausing in his work, had missed the rest of the "crew."

"What, down on that float? What's wrong now?"

"We nearly b.u.mped into a mine," reported the A.P. "The beastly thing was within six inches of my nose."

"A miss is as good as a mile," remarked the pilot nonchalantly. "If the thing had gone up six inches or six feet wouldn't have made any difference. They wouldn't have found either of us, and there wouldn't be enough of the pair of us to make a satisfying meal for a solitary North Sea herring. Look here. Up with you and give me a hand at filling the tank. I want to test my handiwork."

By the time the repairs were completed to the satisfaction of all hands, grey dawn was breaking over the wild North Sea. As far as the eye could penetrate the haze that hung about in detached patches the expanse of water was unbroken. Not a sail of any description was in sight and the beetling cliffs of the Yorkshire coast had long since dipped beneath the horizon.

"Fill her right up now," continued the pilot, indicating the repaired tank. "It's lucky we had so many spare tins of stuff on board. We'll mop up most of the petrol during the plug home against the wind, I reckon."

Fuller, deep in final adjustments, and Kirkwood hard at work emptying the contents of the petrol-cans into the tank, were unaware of the new menace that threatened them, until a huge grey shape loomed up within fifty yards to windward of the seaplane.

The shape was a German submarine mine-layer, She was running awash, while on the short, narrow platform in the wake of her conning-tower stood a couple of officers and a half a dozen seamen.

"You vos surrender make!" shouted one of the Germans.

"I'll see you to blazes first!" retorted Fuller as he frantically manipulated the starting mechanism.

For once the accurately-timed engine failed to respond to the master-hand. A mutinous back-fire was the only result. Fuller tried again but ineffectually.

The Hun submarine then thought it time to b.u.t.t in. This she did most neatly but none the less completely by running her nose into the resistless structure of the jibbing seaplane. Her rate of speed was but three or four knots, but that was enough. Amidst the rending of struts, the crashing of the shattered floats and the harp-like tw.a.n.g of severed tension-wires the luckless 445B turned absolutely over and disappeared beneath the waves, leaving pilot and observer struggling in the water.

"Dash it all!" soliloquised Fuller as he struck out for the submarine. "This is the second time the Huns have nabbed me. I'll bet there'll be a third. Just my rotten luck. Come on, old bird, half a dozen more strokes. They are going to heave us out of the ditch."

CHAPTER XIV

b.u.t.tERFLY

"I SAY, pater."

"Eh?" e.j.a.c.u.l.a.t.ed Peter Barcroft without looking up from his work, which happened to be revising a proof.

"I saw Betty Deringhame last night. I forgot to tell you," began Billy as a "preliminary canter" to the recital of his raid-night adventure.

"More fool you," grumbled his parent.

"I beg your pardon----" began the flight-sub, rather taken aback not by his sire's brusqueness, for Barcroft Senior when engaged in the non-creative work of proof-reading was like a bear with a sore head, but by the off-hand manner in which he had received the announcement of the girl's name.

"Look here!" exclaimed Peter, throwing down his pen and incidentally bespattering with ink the long, narrow sheet of printed matter. "Why on earth you want me to preach you a homily on the evils of betting----"

"Betting?" interrupted Billy. "I said nothing about betting. What I said was: 'I--saw--Betty--Deringhame--last--night.'"

Peter swung round in his revolving chair, and raised his eyebrows in mild surprise.

"Did you?" he asked. "My mistake, but why did you murmur that most interesting news into my deaf ear? What's she doing in this part?"