"Hurry up there!" sang out the Lieutenant-Commander impatiently, for he could see Crosthwaite's form silhouetted against the blaze of electric light.

There was no time to be lost. Patrol-boats were already hastening to the scene. Judging his distance Dick leapt, falling into the sea between the submarine and the hulk, and fortunately missing any of the struts that supported the horizontal girders. As he rose to the surface the two seamen who had remained on deck to cast off the hawser grabbed him by the shoulders and hauled him into safety.

"THE TWO SEAMEN HAULED HIM INTO SAFETY"

Just then a furious burst of quick-firing guns shook the air. With complete indifference to the fact that half a dozen of their own patrol-boats were hastening towards the hulk, the nearest batteries had opened fire.

Fortunately the patrol-boats flung about and steamed off from the danger-zone as hard as their engines could go.

"What are those fools firing at?" asked Huxtable, making way for the dripping form of the Sub as he descended the conning-tower hatchway. The Lieutenant-Commander knew that the batteries were not firing at the British craft, for she was quite invisible to the gunners. The shells were churning the water all around a dark object drifting with the current.

It was the drum which Dick had thrown overboard. Picked up by the united glare of a dozen search-lights, ineffectually shelled by twenty or thirty quick-firers, the drum floated serenely towards the Bosphorus.

Huxtable saw his chance and took it. So intent were the Turkish gun-layers upon blowing to pieces what they imagined to be the conning-tower of the hostile submarine, that neither they nor the men working the search-lights thought of anything else. Save for the shell-torn water in the immediate vicinity of the drifting drum, the sea was shrouded in intense darkness.