German U-boats are really submersibles. That is to say, the outer shell conforms to the shape of an ordinary ship, with a broad deck, whereas British submarines resemble a fat cigar. Internally they are cylindrical, the space intervening between the compartments and the shell affording accommodation for the ballast tanks. The theory is that vessels built to this design are more seaworthy and easier to handle. U 36, which was building when war broke out, was divided into ten compartments, below which were the steel cylinders containing compressed air for freshening the atmosphere, oil fuel, lubricating oil, and water-ballast tanks, and the accumulators for driving the dynamos when travelling beneath the surface. The officers’ combined ward-room and sleeping quarters were for’ard, immediately behind the bow torpedo compartment. Adjoining were the crew’s quarters, divided by a steel bulkhead from the control chamber, situated below the conning-tower. In the control chamber the steering wheel, periscope, projection table on which a surface view was thrown after the manner of a camera obscura, water-pressure dial, and other delicate and necessary instruments for the safety and navigation of the ship were distributed. Proceeding toward the stern, the petty officers’ quarters, the machine-room with its heavy oil engines for surface work and electric motors for progression when submerged, and the stern torpedo compartment were to be found. U 36 was one of the “new Super-Dreadnought submarines,” to quote an American correspondent who saw them under construction at Kiel. On these, he added, “the Germans appear to be banking.” The autumn of 1915 witnessed the introduction of mine-laying submersibles. The trotyl-filled cylinders were dropped on recognized trade routes without the slightest regard for the rights of neutrals. The mines were kept in a special chamber, ingeniously contrived so that it could be flooded without the water entering elsewhere, and released through a trap-door. Thus another weapon was added to the submarine’s armoury. It answered all too well. “They can follow your mine-sweeper,” said Sir Edward Carson, “and as quickly as you sweep up mines they can lay new ones without your knowing or suspecting.” In 1914 the enemy had only one means of sowing these canisters of death, namely, by surface vessels. It will be recollected that the _Königin Luise_ was sunk in the North Sea on the morning of the 5th August while on this hazardous duty. Germany’s opportunity for hurting us in this manner was of short duration. The British Navy asserted itself, with the result that the enemy was perforce compelled to find a new method. He resorted to the use of specially fitted submarines.