CHAPTER XVIII
THE DERELICT OBSERVATION BALLOON
"WELL done, old man!" exclaimed Tressidar as he climbed back into thebasket car. "That was a brilliant idea of yours. Look here, you knowsomething of aeronautical work; I don't, so you had better pilot thiscontraption."
Fuller shook his head.
"This isn't a clinking little biplane," he said, "It is completely atthe mercy of the wind. But we mustn't grumble; we're leaving Sylt along way beneath us."
Looking over the edge of the car, Tressidar could discern practicallythe whole of the long, narrow island, which is twenty miles in lengthand averaging two miles in breadth. Owing to the fact that it wasdead low water the island appeared to be a vast peninsula, joined tothe Schleswig shore by a broad belt of sand. North and south of theisland and running respectively south-east and north-east were twoextensive estuaries that almost met at the causeway connecting Syltwith the mainland.
"Which way are we drifting?" asked Tressidar anxiously.
"Hanged if I can make out," replied Fuller. "We've apparently strucka calm patch. The wind was certainly sou'sou'west when we kicked off.See--the smoke from those buildings: it had a decided drift towardsthe Danish frontier."
"A good easterly gale would be more my mark," said Tressidar. "Wewould then stand a chance of getting picked up by our patrol craft."
"Unless they started to shell us with the most amiable intention ofsending a couple of supposed Huns to blazes," added the flight sub."So, in the circumstances, Denmark is good enough for me, even if weare lucky enough to fetch it."
For some moments there was silence, broken only by the barking of adog some thousands of feet below Then Fuller, who had been leaningover the side, shrugged his shoulders.
"We're dropping, I'm afraid," he announced. "It's close on sunset,and with the fall of temperature the buoyancy of the gas-bag suffers.See what you can chuck overboard."
The balloon, being hitherto used as a captive observation machine,was unprovided with an aneroid, or indeed any instrument formeasuring the altitude. During the last ten minutes it had driftedsteadily in a north-easterly direction, so that, unless the windchanged, the aeronauts were faced with the possibility of "landing"somewhere in the North Sea instead of the shores of Jutland.
Overboard went the rifle, two hundred rounds of ammunition, thetelephone, and other miscellaneous articles, all of which stood agood chance of doing a certain amount of damage to the Germantorpedo-boats at the mouth of Lister Deep. A revolver and fifty smallcartridges Tressidar retained, arguing with himself that they mightbe useful.
"There's a fog coming up," he said, after studying the panoramic viewthrough a pair of binoculars. "A night mist, I suppose. It will makethings jolly awkward when we do land."
"It will be a jolly good thing for us very soon," corrected Fuller."Look, what do you make of that?" And he pointed in the direction ofthe now distant fortress of Sylt.
"Taubes," exclaimed Tressidar laconically.
"Or Fokkers," added the flight-sub. "Two of the brutes; they'll behard after us in a brace of shakes. In fact I think they are headingin our direction already."
"Thank heaven it's getting dark," said the sub. fervently, foralready the land was shrouded in the gloom of twilight. "And it'sgetting fairly thick up here. I can hardly discern the aeroplanes."
"They have a bigger object to look for than we have," said Fuller."We'll have to do one thing or the other--go up or down. Going downmeans irreparable loss of hydrogen."
"There's nothing left in the way of ballast to sling overboard."
"Yes, in due course," remarked the flight sub. "I see a couple ofstraps round the basket. We'll have to strap ourselves to the nettingand cut the car adrift. It's our only chance."
Tressidar realised the gravity of the situation. The balloon, by nomeans fully inflated when they boarded her, was appreciably losinglifting power both by the minute yet none the less certain porosityof the envelope and by the fall of temperature. He shuddered,strong-minded though he was, at the idea of having to literally hangin the air with the prospect of a terrific drop to earth should thethin cordage of the netting give way.
Presumably the German airmen were reluctant to plunge into the mist,that was now spreading far and wide and increasing in height. Theywere still climbing spirally, evidently with the idea of gaining animmense altitude before swooping down upon the derelict balloon.
And every moment's delay meant that their chances decreased and thatthe odds against the fugitives diminished.
The balloon, still falling, was now swallowed up in the fog. Todescend prematurely meant either falling upon the German island ofRom, or else into the German territorial waters. In either caserecapture was a foregone conclusion.
The low drone of an air propeller announced the disconcerting factthat one of the Fokkers was approaching. Quickly the noise increased,but in which direction--whether above or below--neither of theBritish officers could determine.
Then, with a rush of displaced air that caused the balloon to swayviolently, the aeroplane swept beneath it at the rate of an expresstrain. Too late had the Huns spotted their quarry. To attempt to risewould result in collision with disastrous results to friend and foe.All the Huns could do was to depress the horizontal steering-ruddersand dip sharply underneath the balloon before describing a curve andapproaching it at an altitude that would enable them to use theirweapons of offence. In this case the Germans hoped to recapture thetwo officers alive, and with that object in view they wereendeavouring to perforate the envelope of the balloon sufficiently tosend it with comparative slowness to the ground.
"Now!" exclaimed Fuller.
Both men hacked desperately with their knives they had found in thecar. The basket dropped and was lost to sight in the darkness.Tressidar and his companion, clinging to the network, were almostunaware of any change of altitude, although there was a slightdowndraught of air, until the balloon emerged from the bank of mistinto the gathering darkness.
Tressidar gave a sigh of relief. There were no signs of the secondGerman aeroplane. Evidently it was engaged, as was its consort, inhunting for the balloon in the fog, which was very much like lookingfor the proverbial needle in a bottle of hay--with the grave risk ofan aerial collision thrown in.
By degrees the drone of the propellers died away and complete silencereigned. It was becoming bitterly cold. The two men, ill-clad for anight in the clouds, shivered violently. Their hands lost all senseof touch. Had it not been for the leather straps that encircled theirbodies they would have been compelled to drop--to be dashed intounrecognisability upon the ground six thousand feet below.
Half an hour passed. Overhead the stars were shining brightly.Obliquely beneath them a dull blurr of light was visible. It was thesearchlights of Sylt. Further away, and in the opposite direction,lights of varying intensity glimmered through the now dispersing fog.
"Hurrah!" exclaimed the flight sub. "The coastwise lights of Denmark.They can't be German, for the bounders are as cautious about showingas much as a candle-light as we are. That patch of luminosity must bethe town of Esbjerg."
"We're getting nearer," declared Tressidar after another interval,during which the balloon had revolved half a dozen times on its ownaxis, for in the absence of the cable connecting it with the earththe supplementary gas-bag failed to serve its purpose of keeping theballoon steady.
"And falling," added Fuller. "We'll have to stand by for a jolly goodold bump, I fancy."
They had now good reasons for supposing that they were over Danishterritory, for beneath them numerous lights were twinkling. It was asyet only nine o'clock, and the villagers had not yet retired to rest.To the southward--for the aeronauts were now able to determine thecardinal points of the compass by means of the Pole Star--the lightsended abruptly, indicating the frontier line between a nation atpeace and a nation at war.
"Rub your hands well," cautioned Fuller. "You'll have to be slippygetting that buckle unfastened. Directly we touch w
e must cast offsimultaneously, or one of us will have another voyage through theair. We are now less than a thousand feet up, I think."
The balloon was again falling, although its descent was by no meansrapid. The chums could now hear sounds coming from the countrybeneath them; even a horse trotting and a man whistling. Yet, withthe exception of the lights, nothing was visible. Even the nature ofthe country, whether flat or hilly, open or wooded, was veiled by thedarkness.
"What's that?" asked Tressidar, as a number of dark conicalprojections seemed to flit past only a few feet beneath them.
"Tree tops," replied Fuller. "We've just missed being left on the topbranches of some pines. By Jove, there's quite a steady breeze. If wecrash into anything there'll be trouble."
Almost as he spoke Tressidar's feet came in contact with the ground.Then like an indiarubber ball the balloon shot ten feet in the airand again dropped, until the sub. found his boots trailing over afield of grass.
"Stand by!" shouted Fuller warningly. "Mind you don't get entangledin the netting."
Both men unbuckled their straps. They were now clinging with bothhands to the network. The bumps became more and more violent, as theballoon lost buoyancy, but at the same time their rate of progressover the ground was too quick to enable them to find a footing.
Suddenly their boots caught in the top rail of a fence.
"Let go!" shouted Fuller.
Tressidar obeyed promptly, to find himself sprawling head downwardsin a ditch. Regaining his feet, he found his chum kneeling a few feetfrom him. There was no sign of the balloon. Relieved of thetwenty-four stone weight of the two passengers, it had soared upwardsonce more and had vanished from their sight.