"And good luck!" exclaimed the Lieutenant-Commander. It was the naval way of bidding farewell to a comrade about to undertake a risky enterprise—a pithy expression conveying a wealth of possibilities of thought.
Assisted by willing helpers, the Sub and the two seamen donned their diving-dresses. These were of the "self-contained" type, in which the cumbersome life-line and air-tube are dispensed with. The dresses were of "armoured" rubber and canvas, specially contrived to withstand high pressures. The copper helmet was fitted with three large scuttles, so that the wearer could see what was going on on either side by merely turning his head, and thus doing away with the necessity of having to keep the desired object in view directly in front. At the back of the helmet was a flexible metal tube supplying chemically-treated air from a reservoir to the wearer. The reservoir was strapped to the small of the back, if such an expression can be applied to an inflated diving-dress. Immediately above the breathing-apparatus container was another contrivance of strong elastic material, capable of being expanded to double the size of a football. Normally it lay flat and compact against the diver's shoulders. Strapped across the chest, immediately below the leaden weight attached to the collar of the helmet, was a strong copper receptacle connected with the deflated bag on the diver's back, and fitted with a stopcock and a small but powerful suction-pump. This contrivance took the place of the life-line in the older type of dress; for, should a man wish to rise from the bottom of the sea, all he had to do was to release the compressed air from the copper container into the expanding bag, until the buoyancy of the latter overcame the weight of the diver's equipment.
Each of the three men was equipped with a knife, hack-saw, crowbar, a small slate and pencil for communication purposes, and an electric lamp. Their bare hands were protected from the numbing cold by a thick coating of tallow.
Their helmets having been placed over their heads, and secured by "butterfly nuts" to their rubber-lined metal collars, Fordyce and his assistants entered the diving-chamber, the inner door of which was secured by clamp locks capable of being operated either from within or without.
The Sub's next task, after securing the door, was to flood the diving-chamber. This was done by means of a stopcock communicating with the water outside, while the weight of the inrushing fluid was compensated by expelling a similar quantity from one of the auxiliary ballast-tanks, in order not to disturb the trim of the submarine.
The diving-compartment filled, Fordyce threw open the door in the submarine's side; then, groping until he found the lowermost of a series of rungs, he made his way to the deck, where he awaited his companions.
Thence the three went towards the bows, flashing their lamps in order to discover the nature of the entanglement. Although each light was of 500 candle-power, the rays were effective only for a distance of five or six yards, but they were sufficient to enable Fordyce to see that a huge large-meshed steel net enclosed R19 on both sides, while towards the bows it contracted, thus preventing further progress in that direction.
Cautiously the Sub lowered himself upon the bow diving-rudder on the starboard side. Examination showed that no part of the net was holding it; but the one to port was stubbornly enmeshed.
By dint of careful tackling by means of crowbars, the three men succeeded in freeing the projecting plate from the net. As far as could be seen, there was now nothing for'ard to prevent the submarine gathering sternway. Obviously the principal difficulty lay in the fact that one of the propellers had fouled.
"By Jove, what's that?" mentally enquired the Sub, as the light of his electric lamp fell upon a huge, ill-defined object less than six feet from R19's bows. It was a part of the upper works of a large tramp vessel, lying slightly on one bilge, and almost hidden by a lavish growth of barnacles and seaweed.