Bubbling with latent insubordination, Furst and Krauss at their posts at the auxiliary ballast-tank valves obeyed promptly. In spite of all their revolutionary tendencies and expressions of general "fed-uppedness," they realised that their lives depended upon the prompt execution of their hated superior's orders. Knowing nothing of what was going on without, they submitted to discipline as the only remedy for their present predicament. After a period of ten minutes' total submergence the periscope shoved its squat snout above the surface—like a reluctant puppy about to receive a hiding. When a periscope is in danger of getting a blinding blow in the shape of a six-pounder shell, or the hull to which it belongs is liable to be pulverised by a trio of torpedoes, the need for extreme caution becomes apparent.
"They have not observed us," muttered von Preugfeld with fervent gratitude to the providence that looks after Hun submarines. "There's 'X 5' painted on her bows. Know what that means, Eitel?"
Von Loringhoven confessed that he did not. In spite of a careful perusal of all works dealing with numbers and nomenclature of British shipping—and Berlin was kept fairly up-to-date in such matters—the mystic symbol "X 5" was to him an unknown quantity. Incidentally it recalled days when he was studying mathematics at the Kiel Naval College.
The ober-leutnant steadied the periscope and touched a switch. Immediately, by the introduction of a special lens, the "field" covered by the eye-piece of the periscope was reduced, but the object actually seen was considerably magnified. It was like looking through a telescope.
"They are men of the English Air Force," he observed. "I believe—here, Eitel, look—the man walking for'ard. What do you make of him?"
"Donnerwetter!" ejaculated von Loringhoven. "Surely it is our friend von Preussen?"
"Yes," replied the ober-leutnant. "Von Preussen playing the part of a Jonah to an English whale. I wonder what he does there?"
"It would be well to clear out and leave him alone, Herr Kapitan," suggested von Loringhoven. "It could only be that von Preussen is engaged in highly important confidential work that brings him afloat again. Himmel! He is a clever fellow."
The ober-leutnant tugged at his moustache thoughtfully. Eager to have a finger in any pie without the risk of burning himself, he was loth to take his subordinate's advice. Here, apparently, was an unarmed craft, crewless, with the exception of a few officers. To him it suggested that highly confidential experiments were being carried on—so important that no one beneath the rank of officer was permitted to be present. Perhaps they were staff officers of high rank?
Eagerly von Preugfeld kept each man under observation. The trench-coats gave no indication of their wearers' rank, but —disappointing fact—none of the officers wore gilt leaves round the peaks of their caps. The sailing-boat alongside was also a puzzle. Why should the experimenters make use of an insignificant sailing-boat when there were steam pinnaces and motor launches available?