waters crowded with shipping about the British Isles. The larger number of their casualties came from Allied craft and mines.

If one seeks to make an impartial estimate of the comparative efficiency of the German under-sea force, one must not fail to consider with their widely advertised successes how enormous was the number of their opportunities as they attacked both their enemy's shipping and that of neutrals—at all times of huge proportions. Again and again they failed, either because of lack of skill or because of cowardice. While our largest submarines were of less than 550 tons, scarcely two thirds the size of most of the enemy boats, and they were surpassed in engines and general equipment, it would be hard indeed to persuade an American officer that our force was not unqualifiedly superior ship for ship.

The contempt which American and English officers alike felt for Germans and their methods of submarine warfare is well expressed in the verse of a British officer:

TO FRITZ *

I wish that I could be a Hun, to dive about the sea,

I wouldn't go for merchantmen, a man-of-war for me;

There are lots of proper targets for attacking, little Fritz,

But you seem to like the merchantmen, and blowing them to bits.

I suppose it must be easy fruit to get an Iron Cross

By strafing sail and cargo ships, but don't you feel the loss

Of the wonderful excitement when you face a man-of-war

And tearing past you overhead the big propellers roar?

When you know that it's a case of "May the fish run good and true," For if they don't, it's ten to one, it's R. I. P. for you?

Although perhaps you can't be blamed-your motives may be pure—
You're rather new to submarines-in fact an amateur;

But we'd like to take your job awhile and show you how it's done,
And leave you on the long patrol to wait your brother Hun.
You wouldn't like the job, my lad-the motors turning slow,
You wouldn't like the winter-time storm and wind and snow,
You'd find it weary waiting, Fritz-unless your faith is strong-
Up and down on the long patrol-How long, O Lord, how long?
We don't patrol for merchant ships, there's none but neutrals there,
Up and down on the old patrol, you can hear the E-boat's prayer:
"Give us a ten-knot breeze, O Lord, with a clear and blazing sky,
And help our eyes at the periscope as the High Sea Fleet goes by."

5

From Songs of the Submarine by Klaxon, London, 1917.

The Future of the American Submarines

At various times during the war the public press proposed that the powers should make impossible a repetition of atrocities on the sea by signing a compact renouncing forever the use of submarines. Reformers were at the same time preaching the doing away with all armies and navies. And yet now, more than a year since peace has nominally come to distressed nations, fighting is still going on through almost the whole stretch of eastern Europe and occasionally on the water. Meanwhile the United States, Great Britain, Japan, and such naval powers as are not too badly crippled in finances as to be unable are going forward with their building programs, including as an important item the construction of larger and more powerful submarines.

In naval circles there seems to be no disposition at the present time to eliminate them. If it be urged that the service on submarines is hazardous, so is that on destroyers and battleships. And in this particular what can be classed with the risks the aero corps are subjected to, both in peace and in war? If it be argued that this weapon was inexpressibly cruel in the war, the answer is the Germans made it so, and they made every weapon cruel, on land as well as sea, and they made cruel their occupation of Belgium, Poland, and Russia. England, though sending her aggressive submarines into the Sea of Marmora and the Baltic, committed no atrocities.

The war demonstrated that the submarine is a hard foe to catch. This the British proved to their enemy's entire satisfaction in the Dardanelles and the Sea of Marmora and in the Baltic. And the Germans persuaded the British and Yanks of the same. Is it not surprising that 33 German submarines (the average number, according to Admiral Sims, that were at sea in the summer of 1918, distributed about the British Isles and France, on the American coast, and in the Mediterranean), this small force with scarcely more men than would be the complement of a single battleship in war, should have kept busy a million British, American, French, and Italian seamen, all on the defensive?

American officers in the Submarine Force, returning from Europe at the end of the war, showed optimism and enthusiasm because they saw the possibilities of the submarine. Whereas it would be childish to belittle Germany's technical achievements, yet an impartial inquiry, we believe, would show that in the

development of the submarine Germany has contributed little. The original idea was English, and American inventive genius made it practical. Even under the great pressure due to war, when the Germans were fully convinced that this craft would bring victory, they developed nothing to compare with the British types. They advertised widely the 2000- and 3000-ton boats they were building, but if there was anything in the type, the war was not long enough to perfect it. They did build submarines of more than ordinary size, with corresponding endurance and cruising radius, but the largest were a disappointment. By their increase in size they had lost in speed and agility. And they were far from being invulnerable.

Much more interesting than the German under-sea dreadnoughts were the British K-boat and the R-boat, both developed during the last of the war. The former is an oil burning ship, with turbine engines, whose propelling force on the surface is steam. She has also a small Diesel engine so as to get quickly under way. She can make 23 knots on the surface, and 8 knots submerged. Just as everything in the K-boat is devoted to speed on the surface, so in the R-boat all is concentrated on speed submerged. This is attained by sacrificing everything to storage batteries. Though compared with her sister ship, she can scarcely more than creep on the surface-7 to 8 knots an hour-when submerged she is capable of 14 knots.

Our submarines demonstrated the progress they themselves had made, when for the first time in the winter following the war certain of their number, the O-boats, joined the Fleet in their practice at Guantanamo. In the Fleet maneuvers they succeeded several times in making successful approaches upon battleships and theoretically torpedoing them.

In any future war with a maritime power, near or far, the officers of the submarine force are fully convinced that their boats will play no insignificant rôle. If the enemy should be remote, the only embarrassment would be the need of a base where fuel, ammunition, and supplies could be renewed and repairs made. Granted this facility, they feel confident of their ability to carry on a protracted war at the enemy's very doors. What greater safeguard could there be for our own coasts?

The future of the American submarine is assured because it is adapted to our national genius. The American youth is full

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of resourcefulness, he has the spirit of initiative, and he enjoys responsibility. For the exercise of these qualities only the hydroplane and the destroyer, of our permanent Navy, offer opportunities to be at all compared with those of the submarine. As one young officer who had been at Bantry Bay remarked, "When a submarine is out for an eight-day patrol, receiving during that time not a single order, it is all up to the commanding officer." Highly technical though the submarine is, reserve officers in considerable numbers served on them during the war, and most of them gave an excellent account of themselves. No officers are likely to remain on a submarine for more than a limited period; but the service, however hard and trying at times it may be, that develops resourcefulness, initiative, and responsibility is preparing them for highest usefulness.

[COPYRIGHTED]

U. S. NAVAL INSTITUTE, ANNAPOLIS, MD.

THE POULSEN ARC

By LIEUTENANT ELLERY W. STONE, U. S. N. R. F.

The widespread adoption of the Poulsen arc for all long distance radio transmission and, in particular, its use aboard many ships of the navy and at all high power naval radio stations ashore should make this comparatively recent system of radio transmission of interest to naval officers. It is hoped, therefore, that a paper on its theory and operation may be found of value to those officers assigned to radio duty afloat or ashore and to others interested in the radio art.

The Poulsen arc is unique in that it was probably the first practical system of continuous or undamped wave transmission. While we have witnessed the adoption of the vacuum tube as a generator of undamped oscillations as well as the increasing advent of the radio frequency generator, the Poulsen arc will undoubtedly remain the pioneer in this field.

The Poulsen arc was named after its inventor, Valdemar Poulsen of Copenhagen, a Danish physicist and engineer, and is used abroad and in this country for practically all high power installations. In the United States, credit is due the Federal Telegraph Company of San Francisco for its development.

In the consideration of this system, it may be advisable to review briefly some elementary features of radiotelegraphy.

It will be remembered that J. C. Maxwell, an English physicist, established the electromagnetic identity of light waves. He demonstrated that they were electric waves traveling at the rate of 300,000,000 meters (186,000 miles) per second on or through a medium which, for want of a better name, is termed the luminiferous ether. Considering their similarity to waves on water, we may measure them by determining the distance between two successive crests of a series of waves. This quantity is called the