"Yes, firing a one-pound shell, almost the identical weapon we mount on our seaplanes. Every blessed experiment these Germans make seems directed solely against the recognized means of offence adopted by the British Government."
"Shrapnel's the thing."
"Aye, coarse-charged with irregular pieces of metal in the place of the bullets used in shells when directed against troops. These Zeppelins, with their non-explosive hydrogen and their fireproof, shot-closing envelopes will be a tough nut to crack in the next war, I fancy. Look here, Detroit, old man, this stuff's worth keeping. We'll divide it into four parts, and wear it in our shoes like cork socks; then, if we are collared, we may stand a chance of keeping it in our possession."
While the two friends were thus engaged the dull boom of a gun fired thrice in quick succession struck their ears. This was followed by a bugle-call that Hamerton recognized as the "Assembly" of the German Army. This was taken up in other parts of the island till the whole garrison was aroused.
Hamerton glanced at his watch. It was just after seven o'clock, at which hour their jailers were wont to bring in the prisoners' breakfasts.
"They've discovered we've broken ship," he said. "Hans and company have found that our cells are empty. Now comes the fun."
It seemed as if the caves in the sandstone cliffs surrounding the Zeppelin station disgorged human beings, for within a few seconds of the alarm being given two hundred men were drawn up in divisions, while their officers were discussing amongst themselves the probable reason for the unexpected summons.
Up ran a portly sergeant-major. He was almost out of breath, yet he spoke in such a loud voice that the Sub was able to interpret every word.
"A message has just come through on the telephone, Herr Major," he announced; "those rascally English spies have escaped. The general orders are that all commanding officers shall post double sentries over all confidential posts; the rest of the men are to be employed in the search. No leave is to be granted until the spies are recaptured."
The major shrugged his shoulders. He was not at all pleased with the telephone message, since he had arranged to spend the following Sunday at Flensburg.