Some submarines, besides being equipped with torpedo tubes, carry other tubes for laying mines. In most instances this is only a secondary function of the submarine. There are, however, special mine-laying submarines. Others, especially of the Lake type, have diving compartments which permit the employment of divers for the purpose of planting or taking up mines.

Disappearing anchors, operated by electricity from within the boat, are carried. They are used for steadying the boat if it is desired to keep it for any length of time on the bottom of the sea in a current.

From this necessarily brief description it can be seen readily that the modern submarine boat is a highly developed, but very complicated mechanism. Naturally it requires a highly trained, extremely efficient crew. The commanding officers must be men of strong personality, keen intellect, high mechanical efficiency, and quick judgment. The gradual increase in size has brought a corresponding increase in the number of a submarine's crew. A decade ago from 8 to 10 officers and men were sufficient but to-day we hear of submarine crews that number anywhere from 25 to 40.

In spite of the marvellous advances which have been made in the construction, equipment, and handling of the submarine during the last ten years, perfection in many directions is still a long way off. How soon it will be reached, if ever, and by what means, are, of course, questions which only the future can answer.

CHAPTER XV
ABOARD A SUBMARINE

Submarines have been compared to all kinds of things, from a fish to a cigar. Life on them has been described in terms of the highest elation as well as of the deepest depression. Their operation and navigation, according to some claims, require a veritable combination of mechanical, electrical, and naval genius—not only on the part of the officers, but even on that of the simplest oiler—while others make it appear as if a submarine was at least as simple to handle as a small motor boat. The truth concerning all these matters lies somewhere between these various extremes.

It is quite true that except on the very latest "submerged cruisers" built by the Germans, the space for the men operating a submarine is painfully straitened. They must hold to their positions almost like a row of peas in a pod. From this results the gravest strain upon the nerves so that it has been found in Germany that after a cruise a period of rest of equal duration is needed to restore the men to their normal condition. Before assignment to submarine duty, too, a special course of training is requisite. Submarine crews are not created in a day.

What the interior of the new German submarines with a length of 280 feet, and a beam of 26 feet may be, no man of the Anglo-Saxon race may know or tell. The few who have descended into those mysterious depths will have no chance to tell of them until the war is over. Nor is it possible during wartimes to secure descriptions even of our own underwater boats. But the interior of the typical submarine may be imagined as in size and shape something like an unusually long street car. Along the sides, where seats would normally be, are packed wheels, cylinders, motors, pumps, machinery of all imaginable kinds and some of it utterly unimaginable to the lay observer. The whole interior is painted white and bathed in electric light. The casual visitor from "above seas" is dazed by the array of machinery and shrinks as he walks the narrow aisle lest he become entangled in it.

Running on the surface the submarine chamber is filled with a roar and clatter like a boiler shop in full operation. The Diesel engines are compact and powerful, but the racket they make more nearly corresponds to their power than to their size. On the surface too the boat rolls and pitches and the stranger passenger, unequipped with sea legs grabs for support as the subway rider reaches for a strap on the curves. But let the order come to submerge. The Diesels are stopped. The electric motors take up the task, spinning noiselessly in their jackets. In a moment or two all rolling ceases. One can hardly tell whether the ship is moving at all—it might for all its motion tells be resting quietly on the bottom. If you could disabuse your mind for a moment of the recollection that you were in a great steel cigar heavy laden with explosives, and deep under the surface of the sea you would find the experience no more exciting than a trip through the Pennsylvania tubes. But there is something uncanny about the silence.