with the somewhat careless haste of a man who took advantage of disconnected moments of leisure, and these moments were evidently subject to abrupt and prolonged interruptions. Many repetitions and trivial incidents have been omitted in this translation; but, in order to express the personality of the Author, the rendering has been as literal as possible, and it shows the strange mixture of sentimentality and ferocity peculiar to the psychology of the Germans.

Part of the book gives a technical description,—not so much of the construction of a submarine as of the nature of its activities,—which presents us an unusual opportunity to glean a few valuable facts from this personal and intimate account of a German U-boat. We are inclined to a certain grim humor in borrowing the candid information given to us Americans so unconsciously by Freiherrn von Forstner, for he could hardly suppose it would fall into the hands of those who would join the fighting ranks of the hated enemy, as, in his bitter animosity, he invariably calls the English whenever he refers to them.

Several chapters in this book are simple narratives of the commander's own adventures during the present naval warfare waged against commerce. His attempts at a lighter vein often provoke a smile at the quality of his wit, but he is not lacking in fine and manly virtues. He is a loyal comrade; a good officer concerned for the welfare of his crew. He is even kindly to his captives when he finds they are docile victims. He is also willing to credit his adversary with pluck and courage. He is never sparing of his own person, and shows admirable endurance under pressure of intense work and great responsibility. He is full of enthusiastic love for his profession, and in describing a storm at sea his rather monotonous style of writing suddenly rises to eloquence. But in his exalted devotion to the Almighty War Lord, and to the Fatherland, he openly reveals his fanatical joy in the nefarious work he has to perform.

It is difficult to realize that this ardent worship of detail, and this marvelous efficiency in the conservation of every resource, are applied to a weapon of destruction which directs its indiscriminate attacks against women and children, hospital transports, and relief ships. Nothing at the present day has aroused such fear as this invisible enemy, nor has anything outraged the civilized world like the tragedies caused by the German submarines.

This small volume may offer new suggestions to those familiar with the science of submarine construction, and it may also shed a little light, even for lay readers, on a subject which for the last three years has taken a preëminent place in the history of the War.

INTRODUCTIONToC

THE CHALLENGE TO NAVAL SUPREMACY

I

In a letter to William Pitt, of January 6, 1806, relating to his invention of a submersible boat, Robert Fulton wrote prophetically, "Now, in this business, I will not disguise that I have full confidence in the power which I possess, which is no less than to be the means, should I think proper, of giving to the world a system which must of necessity sweep all military marines from the ocean, by giving the weaker maritime powers advantages over the stronger, which the stronger cannot prevent."

It is interesting to note that, about a hundred years later, Vice-Admiral Fournier of the French Navy stated before a Parliamentary committee of investigation that, if France had possessed a sufficient number of submersibles, and had disposed them strategically about her coasts and the coasts of her possessions, these vessels could have controlled the trade routes of the world. He said also that the fighting value of a sufficient number of submersibles would reëstablish the balance of power between England and France.

The history of naval warfare during the last few months has confirmed the opinions of these two authorities, although in a manner which they in no way anticipated.

Direct comparison is the usual method by which the human mind estimates values. We would measure the strength of two men by pitting them against each other in physical encounter; in the same way, we are prone to measure the combative effect of weapons by pitting them in conflict against other weapons. But modern warfare is of so complex a nature that direct comparisons fail, and only a careful analysis of military experience determines the potentiality of a weapon and its influence on warfare. Robert Fulton and Admiral Fournier both indicated that they believed in the submersible's supremacy in actual encounter with capital ships. The war, so far, has shown that, in action between fleets, the submersible has played a negative part. In the Jutland Bank battle, the submersible, handicapped in speed and eyesight, took as active a part, as a Jack Tar humorously put it, "as a turtle might in a cat fight." Not even under the extraordinary conditions of the bombardment in the Dardanelles, when the circumstances were such as lent themselves strikingly to submarine attack, did these vessels score against the fleet in action.[1]

It is easy to understand why the submersible did not take a vital part in any of the major naval actions. In the naval battle of to-day we have a number of very high-speed armored craft fighting against one another over ranges extending up to 17,000 yards. There is a constant evolution in the position of the ships which it is impossible to follow from the low point of vantage of a periscope, for the different formations of ships mean nothing to the submersible commander. He is so placed that his range of vision is extremely limited, and, on account of the low speed of his boat while submerged, he can operate over only a very limited area of water while the other vessels are moving many miles. Then, too, he is extremely vulnerable to the effect of enemy shells and to the ramming of enemy ships. Under these conditions the submersible commander is more or less forced to a policy of lying ambushed to surprise his enemy. It is said that the "Lusitania" was decoyed into a nest of submersibles. There was but little chance of torpedoing her in any other way. There is also the statement that Admiral Beatty passed with his battle-cruisers through a flotilla of enemy submersibles without being touched.

Submersibles cannot attack their target in definite formations as do surface vessels, and therefore they cannot operate in numbers with the same effectiveness as do the latter. They must maneuver more or less singly, and at random. Being limited to the torpedo, which, when they are submerged, is their sole weapon of attack, they have an uncertain means of striking their armed enemy. The eccentricities of the automobile torpedo are well known; but, even eliminating the fact that this missile is unreliable, the important question of accuracy in the estimate of range and speed which the submersible commander has to make before firing the torpedo must be considered. There is usually