"Say ten and you'll be nearer the mark," declared Denbigh. "She's trapped, and we have to thank Mr. Armstrong for doing the trick."
"Good man!" exclaimed the young skipper of the Crustacean, bringing his hand down upon the shoulder of the bashful mate of the Myra, after Denbigh had related the circumstances in which the Pelikan was prevented from ascending farther up the river. "I'll have to inform Holloway, our senior officer. He's under the same impression that I was. But what did you say about those torpedo-tubes?"
Concisely Denbigh explained the position and nature of the German shore defences.
"It strikes me pretty forcibly that you'll come in most handy," said Stirling. "It's not the Pelikan that is now our principal objective. She, apparently, is done for, unless the river forms a fresh bed round the hull of the sunken tramp. The batteries are our pigeon."
"You were saying that the Crustacean is practically torpedo-proof," Denbigh reminded him. "In what way?"
"She's of very shallow draught. Unless a torpedo were set to travel only a few feet beneath the surface—in which case much of the bursting power of the war-head would be wasted—the 'tin-fish' would pass harmlessly under her bottom. If, however, a torpedo did explode, there's a cellular space of more than twenty feet between the outer and inner hulls. These compartments are stuffed with something. I can't tell you because I don't know myself what the stuff is. All I know is that it's fireproof and its specific gravity is approximately the same as sea-water. Hence, in the event of a hole being blown in the shell of the outer hull our stability will hardly be affected."
At that moment a signalman approached and saluted.
"Senior officer reports approach of sea-plane parent ship Simplicita, sir."
"Very good," replied Stirling, then addressing his companions he added, "That's excellent. We are having a couple of sea-planes to spot for us. The Simplicita, an old light cruiser, has been fitted out as a floating base for aerial work. With luck they've managed to stow a couple of 'planes on her."
Before the Simplicita joined the flotilla the senior ship hoisted another signal. It ran: