CHAPTER XII
Investigations
On the following night, as soon as the bugles sounded "Lights out", Hamerton returned to his labours. Barricading the door and wrenching up the loosened slabs of stone, he descended beneath the floor, wriggled through the hole in the parting wall with comparative ease, and with renewed energy began to prise away at the stubborn cement. At about every quarter of an hour he would seize the projecting stone and shake it violently. Perhaps he had become hardened to the work, for he imagined that the cement was not so hard or tenacious as it had been when he began operations. "The cement is cracking," signalled Detroit, who for the last two hours had been lying at full length on the floor feeling for the first decisive tremor of the paving stone.
Then Hamerton had an inspiration. He knew that the stone was wedge-shaped; perhaps by pressing upwards against it he might force it out of position.
Crouching immediately under the projecting piece of masonry, he applied his shoulder to the base of the wedge and exerted all his strength.
For a few seconds there appeared to be no result, then, almost without warning, the stone gave quite a couple of inches, till it was flush with the adjoining slabs.
Detroit felt it rise. Desperately he wrenched at it with his bare hands. Hamerton, rolling over on his back, pushed as hard as he could with his foot. The next instant he felt the American's sinewy fingers grasping him by his toes.
"Chuck it, old man!" whispered the Sub. "That's my toes you've got hold of."
"Guess I don't care, so long as I've got hold of some part of you," was the glad response. "Let's have your hand, then."
It did not take very long for the hole to be enlarged sufficiently to allow Hamerton to enter the American's cell. By a sheer piece of luck the aperture bore the same relative position to the floor as did the one in the adjoining room. It was almost in the corner, where, in the daytime, by contrast with the light filtering through the window, it was almost dark.
For some considerable time the reunited comrades whispered in tense, excited tones, their conversation being the outcome of joy rather than the discussion of a definite plan of action. But by degrees they grew calmer, and Detroit asked what the next move was to be.
"Get out of this show as soon as possible," announced Hamerton with determination.
"And then? We are not paladins; we cannot hope to overpower the whole garrison. There are sentries at every few yards; every boat is guarded. We will have to remain hidden on this little rock till hunger compels us to give ourselves up."
"We'll risk that. In almost every enterprise there is an element of chance that oft leads to success. Once we break out of this place we'll have a good look round. They've condemned me as a spy, and, by Jove, I'll do a little espionage!"
"And I'll have a shot at it," added Detroit. "Who knows but that some day the United States Navy may be glad of certain information concerning this island."
"'Of course we may stumble upon a boat," continued Hamerton. "In that case we'll appropriate her without the slightest compunction, get under way, and trust to luck to be picked up by a passing steamer. A few miles either to the north or south, and we'll be right in the regular steamer tracks across the North Sea."
"But the searchlights?" objected Detroit. He was game enough for any enterprise, but with natural caution he preferred to weigh up the risks.
"If we start just before dawn we need not worry about searchlights. I noticed they ceased operations at 4 a.m. the other day. We ought to be able to put five miles between us and the rock before it is light enough for them to spot us."
"All right, then!" assented the American. "But we're not out of the wood yet. What's the next performance?"
"I'm off back to my cell. Take care to replace the stone carefully and fill up the joints with dust. I'll leave you this little tool—I can't let you have the handle, for, as you see, it's the leg of a stool. If you feel particularly energetic, old man, you might start at the sockets of the window bars. You'll have to be very cautious. Do they march you out for exercise?"
"Every day. Why?"
"I have an hour of it also. Thus I was able to take stock of the building. Your window is directly above a flight of steps; mine is some distance clear of it. Consequently your window is the more convenient one for us to tackle."
"I'll have a slog at it."
"Good! Well, I'm off. Au revoir till to-morrow night!"
The next day passed in a most tedious fashion. Hamerton was on thorns more than once, for in his heated imagination he fancied that his jailers purposely prolonged their visits to his cell.
"To-morrow," announced Hans, "you will roll up your blankets. Clean ones will be served out. You will also have to scrub your floor, because the governor of the prison and the medical officers are going to make an inspection."
This was disconcerting news. It was a case of to-night or not at all, for it was quite evident that should the two comrades not succeed in making their escape before the morrow, the visiting authorities would be almost certain to discover the displaced stones in the floor.
Accordingly the Sub continued his preparations. In spite of his hearty appetite he set aside one-half of his day's rations, since it was doubtful whether he would be able to obtain food outside.
Evening came with a furious easterly gale. The wind howled, heavy drops of rain fell in torrents and beat in at the open window, for during the summer months the glass was regularly removed from all the prison cells.
Hamerton welcomed the storm. It was an asset in their favour, although for the time being it was useless to expect to be able to get away from the island in a boat.
"How are you getting on?" he asked, as he crawled into Detroit's cell.
"Guess I've just about shifted those bars," was the American's reply. "The cement was rotten."
"It's too early to make the attempt yet," said the Sub.
"Rather," agreed Detroit; "besides, we haven't made the ropes yet. Bear a hand with this blanket; we'll soon manage that, I think."
"Pretty tough stuff," commented Hamerton, as the property of the German Government was remorselessly torn into strips. "All the same I'd rather have a good piece of manila or three-strand hawserlaid tarred rope. Even a sheet would make a better rope."
In spite of his objections Hamerton tackled the task with energy, and as a result of their joint labours the comrades had the satisfaction of being in possession of thirty feet of apparently serviceable rope.
"Time!" whispered the Sub laconically.
Five minutes sufficed to complete the removal of the bars. Hamerton, having made one end of the rope fast to the bed frame, clambered up the ledge, and listened intently. Not a sound was audible above the howling of the wind and the hissing of the rain. The Heligoland searchlights were not running, but from Sandinsel four powerful beams were swaying across the cloudy sky like gigantic inverted pendulums.
"All clear!" he whispered.
Detroit handed up the coiled rope. The Sub was about to drop it into the black vault beneath him, when he saw the glimmer of a lantern on the rainswept pavement below. Crouching on his narrow perch the Sub waited. The rays of the lantern reflected in the puddles of the courtyard; it glinted upon naked steel and upon the brass helmets of a file of soldiers.
"What's up?" whispered Detroit, unaware of the reason of the delay.
"Hist!" exclaimed Hamerton, not trusting himself to say more.
Straight towards the staircase came the men. The Sub felt his head throbbing violently. They were more than likely sent to escort the alleged spies to another place of detention.
With a dull crash the butts of a dozen rifles struck the stone pavement as the men halted and grounded arms. With bent shoulders, in a vain attempt to shelter themselves from the rain, the soldiers waited while the sergeant, lantern in hand, ascended the steps, followed by an enormous bloodhound.
Hamerton durst not crane his neck to see what went on almost underneath the window. He could distinguish Hans's voice replying to the sergeant's questions, but the din of the storm prevented the listener from understanding the nature of the conversation.
Then, after what seemed to be an age of terrible suspense, the Sub saw the sergeant return to his men. The soldiers recovered their arms, faced about, and marched towards the outer gateway. The light vanished, and the tramp of their feet was soon lost in the moaning of the wind.
Hamerton waited no longer; at any moment the jailers might intrude. Noiselessly he allowed the coil of blanket-rope to drop into space, then, grasping one of the bars which still remained, he assisted Detroit to clamber up beside him.
"You go first," he whispered. "You're lighter than I am. If the rope should break when I descend, don't wait, but clear out."
"I won't," replied Detroit. "We'll stand by each other at all costs. Well, here goes!"
The next moment he was lost to sight. Hamerton could feel the rope stretching and jerking under the strain of the descending man's weight. Presently the tension ceased. The American had reached the steps beneath the window.
Without hesitation Hamerton followed. He realized that should the soft fabric give way a fall of about ten feet, followed by a headlong tumble down the stone steps, would be the inevitable result, and to a man weighing close on fifteen stone that was far from pleasant to contemplate.
But the rope stood the strain, and with a muffled exclamation of thankfulness Hamerton felt his feet touched one of the stone steps.
"Heave away!" he whispered, placing the rope in Detroit's hands. Both men pulled their hardest. The blanket rope parted, leaving about ten feet of it in their possession. Then the American saw his companion do a strange act. Hamerton drew a packet from his pocket, and, holding his nose tightly with his left hand, scattered something on the ground. It was as much as Detroit could do to restrain his curiosity.
The outer wall with its array of spikes presented little difficulty. Detroit clambered on to Hamerton's shoulder, grasped one of the revolving rods, and passed the bight of the rope around it. By this means he was able to draw himself up and crouch astride of the obstacle until Hamerton swarmed up beside him. The drop on the other side was a more nerve-racking ordeal, for neither of the fugitives knew what was beneath them. Fortunately it was a vegetable garden belonging to one of the jailers, and the soft earth effectually neutralized the otherwise nasty jar of a twelve-foot drop.
Once again Hamerton stopped to scatter something from the packet. Detroit recognized it now. It was pepper. It nearly made him sneeze. Then he realized what his companion was about. Hamerton meant to baffle the bloodhounds that were kept on the island for the purpose of assisting the sentries in arresting all suspicious characters and maintaining the jealously guarded secrets of the island fortress.
"Now, which way?" whispered Detroit. "To the Unterland?"
"Rather not," replied the Sub. "It's too well guarded. We'll strike inland and make good use of our liberty until the alarm is raised."
Guided by the chain of searchlights, which were now in full swing, Hamerton and his companion set off in a north-westerly direction. Once clear of the buildings they felt the force of the wind, which had now backed to the north-west. It was a struggle for them to keep their feet. Every now and again a vicious blast would bring them up "all standing", as Hamerton would have described it in naval parlance. As for the rain, it was too torrential to aid their flight, for at any moment they might blunder upon the sentries, since they could see barely twenty yards ahead, and that only very indistinctly.
Away on the right a wind motor, perched on a cast-iron tower, added to the din. It was one of several used for generating electric current for the searchlights, and could, if necessary, be lowered into a concrete-lined pit, so as to be out of reach of a hostile fire.
Hamerton pushed forward, counting the number of the steps he took. At the sixty-first he stopped abruptly and threw himself flat upon the grass, an example that Detroit promptly imitated.
Just in front of them was a high barbed-wire fence. On the furthermost side a sentry was standing, his hands resting on the muzzle of his rifle and his head bowed till the brim of his flat-topped cap touched his fixed bayonet.
For nearly five minutes the man remained in this position, though fortunately his face was turned slightly away from the two recumbent figures on the ground. Then, sloping his rifle, the sentry faced about and stolidly marched away, following the direction of the fence.
"There must be some object in posting a sentry so far from the road and away from the cliff," thought Hamerton. "I'll investigate."
With that he rose to his feet, grasped the lowermost of the barbed wires, and held it up as high as the tension would allow. The quick-witted American understood, and, throwing himself flat on the ground, crawled under the formidable fence. In turn he performed a like service for the Sub, and the two adventurers found themselves within an entanglement out of which they could not easily escape should their presence be detected by any of the sentries.
While negotiating the fence Hamerton noticed one remarkable thing: the standards supporting the spiked wires were set in hinged sockets. Also, about five feet from the fence lay several half-rounded pieces of metal, each about ten feet in length.
"They are in the habit of lowering the fence for something," said the Sub to himself. "These sections are to place over the wire when it is lying on the ground. Seems as if they take rather fragile objects into the enclosure; which, I wonder?"
"Steady on!" cautioned Detroit. "Here's something."
The something proved to be the stone facing of a steep incline cut into the earth. The investigators had the choice of two routes, either to bear away to the left and follow the natural terrain, or take the right-hand direction and descend the incline. They chose the latter.
The shelving ground was slippery with rain. Close to the concrete wall was a small channel through which the surface water poured in a miniature torrent. Extreme caution was necessary, since at any moment the two comrades might find themselves precipitated over the edge of a pitfall.
"Come this way," said Hamerton in a low voice. "I want to find out the width of this incline." And setting off at right angles to his previous direction he began to measure the distance. At the eightieth pace—equal to one hundred and twenty feet—the adventurers found themselves confronted by a wall similar to the one on the other side of the incline. They had stumbled upon a broad way, leading they knew not whither or for what purpose.
"Keep to this side," continued Hamerton. "It's more sheltered."
"Better not," objected Detroit. "If there are any people about they will naturally choose the lee side of this wall. We can't get much wetter, and we stand a better chance over there."
"Right!" assented the Sub. He was not above paying good heed to the American's sagacity.
Accordingly they retraced their steps to the left wall of the incline and then resumed the downward direction. Higher and higher grew the wall, till it was lost to sight in the darkness. It seemed as if they were descending into the bowels of the earth. Presently both men involuntarily paused. Through the rain-laden atmosphere came a red glare. It only lasted a few seconds and then disappeared.
"A furnace," whispered Hamerton. "Luckily it was not on our side. Ha! what's that?" His feet came into contact with the metal rail of a narrow-gauge tram line, emerging from a cave-like chamber in the wall and running athwart the incline. Further investigations revealed the presence of a siding on which were several trucks laden with coal. The trucks had been filled by means of a number of shoots. Close by, under a lean-to shed, were nearly a hundred barrels, some empty and lying in disorder, and others filled and stacked in tiers.
Even as Hamerton and his companion were making this discovery an arc lamp above their heads was switched on, flooding the ground with its powerful light. Simultaneously the door of the subterranean store was thrown open and a row of trollies, propelled by an electric motor, emerged from a tunnel that had hitherto escaped their notice.
To stay where they were meant detection. Flight was equally dangerous, since they would have to cross the brilliantly lighted ground. By a common impulse the Sub and his comrade vaulted into two upturned barrels.
They were just in time. The trucks came to a standstill almost opposite their place of concealment, and a squad of men, dressed in engineers' uniform, began to fill the tilt-wagons. This they did by the aid of small electric cranes. Rapidly the heads of the requisite number of barrels were stove in, and the casks, raised by means of cliphooks attached to the wire ropes of the cranes, were emptied into the waiting trucks.
Hamerton could overhear the sergeant in charge of the party grumbling about the weather.
"Be careful, men," he cautioned; "if the moisture gets to the alum there will be a row. Now, sharp with the trucks, or Herr Captain will be in a rage. 'Z 21' must be filled before daylight. Hurry up, I say."
Away rumbled the trucks, the men either clambering upon them or returning to the subterranean room from which they had emerged. The arc lamp was switched off and all was dark once more.
Then the blaze of red light reappeared. Hamerton understood. This was the hydrogen factory where the gas for filling the Zeppelins was manufactured. He remembered that woollen or linen fabrics saturated in a solution of alum become practically non-inflammable. There were the men shovelling lumps of alum into one of the retorts.
"I have it," he muttered triumphantly. "They have discovered a process of making hydrogen practically non-explosive. By Jove! I wish I could wrench the secret from them. However, it's a step in the right direction."
Noiselessly the pair emerged from their place of concealment. Detroit was curious to know the nature of the conversation, but for the present it was extremely hazardous to speak. He had, however, made the discovery of the former contents of the barrel in which he was hidden, for happening to put his finger to his lips the unpleasant taste of alum asserted itself.
Stepping cautiously over the tram lines, since one of them might be a "live rail", Hamerton and Detroit resumed their down-grade journey till they had traversed nearly a quarter of a mile of the incline.
"I believe we've tumbled upon the approach to a submarine tunnel to Sandinsel," whispered Detroit.
"Much too wide for that," replied the Sub, "unless, of course, there is a subsidiary tunnel. But, look, we are getting to the end. There's rock ahead of us."
The incline terminated in a large circular basin roughly two hundred yards in diameter. Opening out of it were three lofty artificial caves, hewn out of the sandstone. This much Hamerton was able to observe in a momentary burst of starlight through a rift in the swiftly-moving clouds.
"Come on," he said. "We're in luck's way. There's no one about. Follow the cliff; I'm curious to see what is in these caves."
The first cavern was apparently empty. The floor was paved with slabs of cement, the walls were of glared brick. Close to the mouth was a little hut, the door of which was locked; but judging by the number of insulated wires running from it the Sub concluded it was the operating station for lighting the vast recess.
The second cave, its entrance being almost at an angle of ninety degrees with the first, was tenanted. Both men recognized in the snub-nosed object projecting far above their heads the bow of a military Zeppelin.
Hamerton could have danced with sheer delight. He had discovered what was supposed to be the shell-proof lair of three powerful airships. Deep in the bowels of the earth they were immune from hostile shell. A high-angled fire might result in a projectile dropping into the vast circular pit, but the possibility of the aircraft being damaged by fragments of shells was guarded against by the provision of massive steel doors sliding on rollers.
Evidently the Zeppelins were being made ready for a flight, for the doors were wide open. In the third cavern lights burned at the farthermost end, and a party of officers and men were busily engaged in overhauling the after-car.
"Seen enough?" asked Detroit. "Let's quit."
"Suppose we must," replied Hamerton reluctantly. "It must be close on dawn, and we'll have to find a place to stow ourselves away."
"I say," began the American.
"Well?"
"That airship facing the incline can come out of its dogbox all right, but I don't see how the others can be turned. There can't be more than a few feet between their extremities and the cliff when they are hauled out."
"They can be guided round by ropes."
"Hardly. The faintest bump would do no end of damage."
"I wish the whole crowd of them would meet with no end of damage," said the Sub vengefully. "But come on, we mustn't hang about here till morning. I heard those fellows say that one of the airships was to be made ready by daybreak."
"One minute; I guess I'd like to look around over there," said Detroit, pointing to the centre of the circular bed of the pit. So saying, he made his way cautiously from the shelter of the cliff, and Hamerton, guessing that his comrade was on the verge of a new discovery, followed.
For the first ten yards the floor was literally covered with a network of tram lines. There were treble parallel tracks, points, and sidings galore. It reminded the Sub of a miniature Clapham junction.
Presently Detroit stopped abruptly.
"I thought so," he announced. "We've hit the edge of a gigantic turntable. This is how they slew round their blessed Zeppelins."
The floor of the turntable was almost as smooth and level as a billiard table. There was not a single projection that would form the slightest hindrance to its intended burden. Almost in the centre were a couple of flat trapdoors for the purpose of gaining access to the machinery underneath, but the actual moving of the turntable was controlled by means of electric switches from a cabin close to the wall of the basin.
"Say, why not hide down there?" suggested Detroit, pointing to one of the trapdoors.
"Good idea!" assented Hamerton. "I don't suppose anyone goes down except to oil the machinery. The place looks large enough to hide a dozen people quite comfortably. Besides, we might be able to see something by daylight. Give me a hand with this lid."
Luckily the traphatch was not locked. The authorities regarded themselves as being immune from the inquisitiveness of intruders and the mischievousness of small boys.
Detroit descended first by means of a vertical iron ladder. Hamerton followed, and was in the act of reclosing the lid of the aperture when the whole of the Zeppelin sheds and approaches were illuminated by arc lamps fixed from brackets to the side of the cliff.
And right in the centre of that blaze of light, his head and shoulders showing conspicuously above the level of the turntable, Hamerton remained as if rooted to the spot. The sudden glare temporarily blinded him. He felt incapable of moving hand or foot.