"Wonder what damage that's done?" remarked Captain M'Bride.
"I'll see, sir, if you wish," said the Lieutenant.
"Do, by all means, Mr. Osborne," was the rejoinder. "I'll make my way to the centre and await you there."
Before Osborne returned, two more shells had been fired by the submarine. Whatever damage they might have caused, they also did good, for the bursting projectiles had the effect of cooling the ardour of the approaching Arabs. Absolutely fearless as far as bullets are concerned, they have a wholesome respect for high-explosive shells which would, in their opinion, render a True Believer a sorry spectacle when he came to present himself at the gates of the Mohammedan paradise.
"No casualties, sir," reported Osborne. "The first shell fell short; the others pitched thirty yards over. One has blown a big gap in our zariba, unfortunately."
"Strafe her!" exclaimed Captain M'Bride. "She'll be improving on that before long, I'm afraid."
Even as he spoke there came a loud rumble from seawards—a long drawn-out report, totally unlike the crisp bark of the German submarine's quick-firers. Where the modern pirate had been was merely a dense cloud of greyish smoke.
"She's properly strafed, sir," declared the Lieutenant delightedly, grasping what he absent-mindedly took to be his uniform cap, with the result that on removing his calico headgear he brought a handful of his own hair with it.
"Internal explosion," suggested the skipper. "Well, we've something to be thankful for. Half our difficulties wiped out in one fell swoop."
Slowly the smoke dispersed, for there was now practically no wind. The sea, momentarily agitated by the explosion, had resumed its oil-like aspect. Not a vestige of wreckage was visible to mark the grave of yet another of the inglorious pirates. It was indeed a just retribution. The U-boat, in common with other German war-ships, had been in the habit of discharging her torpedoes without previously setting the sinking mechanism according to the recognized rules of war. Therefore, in the event of a torpedo missing its mark, it would, at the end of its run, float, and thus become a sort of derelict mine, instead of sinking to the bottom as these weapons are supposed to do.