Opening the door, Fordyce entered the sound-proof cabinet.
"What's wrong now, Chalmers?" he asked.
"Something fishy, sir," replied the man, stepping aside. "Will you stand here a minute, sir?"
The Sub took up a position between the two concave disks. He could distinctly hear the bass hum of the Zeppelin's aerial propellers, while faintly through the right-hand disk came the thud of a marine "screw".
That meant that on the starboard hand, abeam if anything, a vessel was under way.
"Very good; carry on, Chalmers," said the Sub as he relinquished the apparatus to the man's charge. "I'll report to the Captain."
"What's that?" enquired the Hon. Derek, without turning his face from the vision of his expected victim. "Vessel to starboard? Nothing in sight up-topsides, by Jove. All right, carry on. We'll tackle our Zeppelin friend first of all, and then see what it is that's worrying you."
Fordyce could not but admire his skipper's coolness. Somewhere within audible distance of R19 was another under-water craft, hostile, no doubt, and intent upon the British submarine's destruction, unless—jealous thought!—it were another of the E Class stalking the crippled airship. Whichever it might be, the Hon. Derek was resolved to leave her severely alone, risking a torpedo or being rammed until he had had a smack at the huge gas-bag.
"Up with her!" ordered the Lieutenant-Commander.
There was no necessity to blow the ballast-tanks. R19 had been kept to 19 feet solely by the action of the deflected horizontal diving rudders. Like an ungainly porpoise the submarine "broke surface", and the guns' crews raced up the ladders and through the now open hatchways.