"Hanged if I can make out," replied Fuller. "We've apparently struck a calm patch. The wind was certainly sou'sou'west when we kicked off. See—the smoke from those buildings: it had a decided drift towards the Danish frontier."

"A good easterly gale would be more my mark," said Tressidar. "We would then stand a chance of getting picked up by our patrol craft."

"Unless they started to shell us with the most amiable intention of sending a couple of supposed Huns to blazes," added the flight sub. "So, in the circumstances, Denmark is good enough for me, even if we are lucky enough to fetch it."

For some moments there was silence, broken only by the barking of a dog some thousands of feet below Then Fuller, who had been leaning over 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 for measuring the altitude. During the last ten minutes it had drifted steadily in a north-easterly direction, so that, unless the wind changed, 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, the telephone, and other miscellaneous articles, all of which stood a good chance of doing a certain amount of damage to the German torpedo-boats at the mouth of Lister Deep. A revolver and fifty small cartridges Tressidar retained, arguing with himself that they might be useful.

"There's a fog coming up," he said, after studying the panoramic view through a pair of binoculars. "A night mist, I suppose. It will make things 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 of the now distant fortress of Sylt.

"Taubes," exclaimed Tressidar laconically.