this decision it is interesting to follow the various measures of retaliation adopted by both sides and to note the part taken, either directly or indirectly, by the submarine; the creation of danger zones, the indiscriminate use of mines and torpedoes, the lengthened contraband lists-all the various successive moves by which the belligerents, actuated by the policy of military necessity, have trespassed more and more upon the rights of neutrals and noncombatants. But in spite of the scientific triumph of the modern U-boat, and notwithstanding the toll of shipping sacrificed, a careful study of all sides of the question seems to lead to the conclusion that in the end the submarine will not vindicate the expectations of those who hail it as a decisive factor of modern war. The submarine may be able to prevent a close blockade by the enemy; but it does not seem to be able either to break the grip of a distant blockade or to establish an effective submarine blockade as a countermeasure.

The Submarine's Limitations Submarines are of many different types and sizes, which may be divided into two general classes: the smaller coast-defense submarine of moderate cruising capacities, and the larger seagoing submarine with greater fighting and cruising abilities. The first-mentioned class comprises the five-hundredton to eight-hundred-ton submarines, and includes the familiar E, F, G, H, K, and L boats of our navy. Germany uses these types chiefly in the North Sea, Baltic Sea, and other home waters. The other and more modern class includes the larger U-boats operating on the high seas.

The most recent of Germany's large submarines may be described as the fighting consorts of the Deutschland. Although little is known positively about them, the following approximate characteristics may be attributed: tonnage, 2,000; Diesel engines of 6,000 to 8,000 horse power, giving a surface speed of 18 to 20 knots and a submerged speed of 12 to 14 knots; a cruising radius at most economical speed of about 7,000 miles; and an armament of one or two small calibre (three inch or four inch)

guns in addition to about sixteen torpedoes.

These are formidable craft, capable of doing much damage, especially if operating from a secret base supplied and provisioned by ships like the Deutschland. But they have difficulties to overcome. The problems of submarine navigation have not all been satisfactorily solved. When submerged the speed is slow, making it necessary to rise to the surface in order to overtake even moderately fast freighters. It is then that the trader's guns for defense become dangerous.

Moreover, the distance the submarine can go below the surface on a stretch is still comparatively short, probably 150 miles for the newest U-boats is an overestimate. When the limit is reached the submarine either has to remain stopped or come to the surface to recharge her batteries. If the submarine is forced to keep below the surface, besides having a reduced speed, she cannot use her guns and therefore has to draw upon her limited supply of expensive torpedoes. Nor is it an altogether easy matter to manoeuvre a submarine by periscope so as to score a hit on an alert merchant

man.

Advantages of Armed Ships

Suppose a submarine on the edge of the war zone, either stopped or cruising slowly on the surface looking for merchantmen. Smoke is sighted, say, at twenty-five or thirty thousand yards. The submarine would probably manoeuvre to get in the path of the quarry and then submerge at a range of about fifteen to twenty thousand yards before there were likelihood of her being sighted by the supposedly armed trader. If the merchantman should come straight on, to destroy her is comparatively easy; but if, instead of this, a zigzag, irregular course should be steered, the submarine would have to estimate the changes through her periscope and manoeuvre to keep ahead of the merchantman, with consequently more likelihood of being discovered and less likelihood of getting near enough for a sure shot. If the periscope should be seen by the trading vessel, she would probably open fire and turn away. Shots

splashing in front of a submarine's periscope would hamper her manoeuvring abilities and the chances of getting a hit in a stern-on target steering a zigzag course would, unless close aboard, hardly be worth expending a torpedo. To catch the trader, unless a slow one, the submarine would have to come to the surface and risk destruction by gun fire.

All these limitations contribute to make the submarine vulnerable and less effective. Although nets, aircraft, and the lighter submarine chasers will not be as competent against seagoing submarines as against the smaller coast submarines, both because of the greater size of the former and because of the rougher weather and sea conditions to be contended with, still they may do some good while more effectual methods are being developed. Undoubtedly the United States Navy will be of great help in solving this problem-but it would be improper at this time to discuss our navy's share in the game.

Until means of neutralizing the submarines are found they will take great toll from merchantmen. It is folly not to realize that they are destroying many vessels, and not to acknowledge that merchantmen run risks, especially under conditions of poor visibility at night, in fog, and in mist. Early dawn is also a critical time for the trader. But it is probable, as schemes of co-operation are developed between the submarine-hunting navies and the shipping they are trying to safeguard, that these dangers will be lessened.

Future of the Submarine

The question of the future of underwater craft is conjectural, but it is possible to make some tentative deductions from the trend along which development has so far proceeded.

The submarine is always asking for a greater cruising radius, more speed, better habitability, and more power. It is also reported that new designs call for an increased number of torpedoes, together with guns and armor protection for surface fighting. There is perhaps a new type of submarine under construction or possibly already afloat, some idea of

which might be had by conceiving a sort of submersible monitor of about 4,000 to 6,000 tons displacement, carrying a turret mounting two six-inch guns so attached to the hull as to present when firing only armor-protected parts above the water. A division of these submersible monitors, accompanied by a few Deutschlands fitted as troop-carrying and supply ships, might set out from a blockaded coast, steam to distant parts, and there seize, fortify, and hold with considerable tenacity an advance base from which to operate against commerce. Such an expedition might do a lot of damage unless met and defeated by the determined measures of an equally enterprising adversary.

The evolution of the submarine appears to be toward the submersible battleship; but the consensus of naval opinion at present seems to be that a supersubmersible capable of navigating under the water and also strong enough to fight battleships on the surface involves an almost prohibitive cost, which would be out of proportion to the advantages gained. By increasing the tonnage of the submarine its mechanical difficulties are aggravated. On the other hand, the large tonnage of the surface battleship is like a reserve of wealth, which may be expended in any desirable way; if underwater attack is a serious menace to the battleship some of this tonnage can be drawn upon to supply suitable protection, such as a series of outer and inner bottoms so constructed and subdivided as to make the ship practically nonsinkable; or, if attack from the air is dangerous, reserve tonnage may be drawn upon for aero defense-and so on. In estimating the value of the submarine in wars to come it would appear safe, therefore, to assume that in future struggles for control of the seas the rôle of the submarine will always be secondary to that of surface ships.

Summary of Results

In making a brief survey of the naval activities of the war it is seen that the submarine has been of no great value to the superior navies controlling the seas, but has been practically the only effective

naval weapon of the inferior fleets. When used against the enemy battle squadrons it has influenced strategy and tactics and scored a few minor successes in sinking some of the older men-of-war, but generally speaking has produced no very important results. When used against merchant ships the submarine has been unable to attain effectiveness while complying with the rules and usages of international law, but by resorting to unscrupulous methods it has become a dangerous commerce destroyer; and the suppression of this evil must be one of the tasks of the navies at war with Germany.

The war has shown that the chief tactical value of the submarine is for defense, to hold the enemy at a distance. The fleet submarine has also demonstrated an offensive value which may be useful in attaining a tactical advantage. Ir. addition,

it is not to be denied that the submarine has raised havoc with both neutral and belligerent commerce. But the submarine blockade has not proved effective, and the lawless methods of the U-boat have aroused a worldwide condemnation. The reactive effect of Germany's submarine war on commerce may easily prove so damaging as to more than counterbalance any temporary advantage gained.

It may be inferred, therefore, that the United States needs submarines both to help defend her coasts and to operate as a tactical subdivision of the fleet. A lesson also learned is that, although the submarine is not now, and probably never will be, a dominating factor in naval warfare, it should be squarely faced as a serious menace which to combat successfully under certain circumstances might demand our utmost ingenuity and energy.

THE

HE following document, which is believed to be authentic, indicates the method used by the German Government to obtain unanimous press support for the present submarine campaign: General Command, Seventh Army Corps, Dept. 11d., No. 1149.

Münster, February, 1917. No. 545: NOTICE

TO NEWSPAPER AND EDITORIAL OFFICES, &C. CONFIDENTIAL. NOT TO BE COPIED. SECRET

Newspapers are requested to act on the following advice when discussing unlimited "U" boat war:

1. Opinions regarding the usefulness of the measures and of the time chosen, after the decision has been made, would have the effect of weakness and lack of harmony, would encourage the enemy, and perhaps induce wavering neutrals to come in.

4. Toward America it is advisable to use the outward forms of friendliness. Unfriendliness would increase the danger of America coming in-the breaking off of diplomatic relations, even active participation, hangs in the balance. The attitude of the press must not increase this danger.

5. The navy, fully conscious of its power, enters into this new section of the war with firm confidence in the result. It is recommended that the phase be called unlimited, not ruthless, "U" boat war.

6. Material, personnel, and appliances are being increased and approved continually; trained reserves are ready.

7. England's references to the perfection of her means of defense, which are intended to reassure the English people, are refuted by the good results of the last months.

8. Each result is now much more important, because the enemy's Mercantile Marine is already weakened, the material used up. Much colored personnel.

9. The psychological influence should not be underestimated. Fear amongst the enemy and neutrals leads to difficulties with the crews, and may induce neutrals to keep ships in harbor.

10. "U" boat war is now exclusively a part of the combined method of waging war, therefore a purely military matter.

chamber contains the motor which operates the screws and the auxiliary motor that controls the depth rudder. While the other compartments of the torpedo are water tight, the machine chamber is POWDER CHAMBER

TORPEDO

LOADED TORPEDO TUBE

pierced with holes through which it is filled with sea water, thus keeping the motor cool. The rear cone, also called the rear float, contains a considerable quantity of ordinary air. Here is found the gyroscope-whose function is to keep the torpedo going straight in its original direction-with its auxiliary motor, the screw shafts, and a compartment for gearing.

The screws turn in opposite directions, the force being transmitted through two concentric shafts. These shafts are hollow; it is through their tubes that the compressed air escapes on emerging from the motor, producing the bubbles that betray the track of the torpedo on the surface of the water. This track, visible to the naked eye at 800 or 1,000 yards, can scarcely be seen 100 yards away if the sea is rough. The "tail" is formed by a frame, inside of which the screws and rudders

move.

As the torpedo propels itself and guides itself by its own power, the firing of it has no other object than to launch it in the water in the right direction. The process differs according as the torpedo is fired from the surface or under water.. Both methods are used in torpedo

boats and battleships. To fire the torpedo from the surface a cannon tube is used, charged with one-half to two-thirds of a pound of powder. This tube is usually installed on the deck, mounted on a truck that permits it to be aimed like an ordinary gun.

Firing under water is the only method that can be used by submarines. Every navy maintains secrecy regarding its apparatus for this purpose, but the machinery all belongs to one of two types-(1) a shuttle tube manipulated inside the ship, with the muzzle fitted into the hull; (2) a cradle fixed in the water at the side of the ship and containing the torpedo, which goes forth under the propulsion of its own screw after this has been started from the interior of the vessel. The Armstrong tube, which is

T

FIRING THE TORPEDO

represented in the accompanying diagrams, belongs to the former class.

The effects of a charge of 200 pounds of guncotton exploding against the side of a vessel are likely to vary according to the point struck, the depth below the surface, and the strength of the hull. The best torpedoes travel to a distance of six miles, with a speed of about twenty-five knots; by limiting the range to two or three miles a speed of thirty-five knots can be obtained, or about twenty yards a second. Within 500 or 1,000 yards there is a chance of hitting the target; at 2,000 yards the chances are meagre, and beyond 3,000 yards the probable lateral deviation is more than 150 meters.