Two records Guynemer made which have not yet been surpassed—the first, the one described above of dropping three Fokkers in two minutes and thirty seconds, and rounding off the adventure by himself dropping ten thousand feet. The second was in shooting down four enemy machines in one day. His methods were of the simplest. He was always alone in his machine, which was the lightest available. He would rather carry more gasoline and ammunition than take along a gunner. The machine gun was mounted on the plane above his head, pointing dead ahead, and aimed by aiming the whole airplane. Once started the gun continued firing automatically and Guynemer's task was to follow his enemy pitilessly keeping that lead-spitting muzzle steadily bearing upon him. In September, 1917, he went up to attack five enemy machines—no odds however appalling seemed to terrify him—but was caught in a fleet of nearly forty Boches and fell to earth in the enemy's country.

One of the last of the air duels to be fought under the practices which made early air service so vividly recall the age of chivalry, was that in which Captain Immelman, "The Falcon," of the German army, met Captain Ball of the British Royal Flying Corps. Immelman had a record of fifty-one British airplanes downed. Captain Ball was desirous of wiping out this record and the audacious German at the same time, and so flying over the German lines he dropped this letter:

Presently thereafter this answer was dropped from a German airplane:

The word spread far and wide along the trenches on both sides. Tacitly all firing stopped as though the bugles had sung truce. Men left cover and clambered up on the top to watch the duel. Punctually both flyers rose from their lines and made their way down No Man's Land. Let an eye witness tell the story:

But the Germans, too, had their champion airmen, mighty fliers, skillful at control and with the machine gun, in whose triumphs they took the same pride that our boys in France did in those of Chapman, Rockwell or Thaw, the British in Warneford, or the French in Guynemer. Chief of these was Captain Boelke, who came to his death in the latter part of 1917, after putting to his credit over sixty Allied planes brought down. A German account of one of his duels as watched from the trenches, will be of interest:

Methods of air-fighting were succinctly described in a hearing before the Senate Committee on Military Affairs, in June, 1917. The officers testifying were young Americans of the Lafayette Escadrille of the French army. To the civilian the testimony is interesting for the clear idea it gives of military aviation. The extracts following are from the official record:

The witness then took up the nature and work of some of the heavier machines. He testified:

It would be gratifying to author and to reader alike if it were possible to give some account of the progress in aërial equipment made by the United States, since its declaration of war. But at the present moment (February, 1918), the government is chary of furnishing information concerning the advance made in the creation of an aërial fleet. Perhaps precise information, if available, would be discouraging to the many who believe that the war will be won in the air. For it is known in a broad general way that the activities of the Administration have been centred upon the construction of training camps and aviation stations. Orders for the actual construction of airplanes have been limited, so that a chorus of criticism arose from manufacturers who declared that they might have to close their works for lack of employment. The apparent check was discouraging to American airmen, and to our Allies who had expected marvellous things from the United States in the way of swift and wholesale preparation for winning battles in the air. The response of the government to all criticism was that it was laying broad foundations in order that construction once begun would proceed with unabated activity, and that when aircraft began to be turned out by the thousands a week there would be aviators and trained mechanics a-plenty to handle them. In this situation the advocates of a special cabinet department of aeronautics found new reason to criticize the Administration and Congress for having ignored or antagonized their appeals. For responsibility for the delay and indifference—if indifference there was—rested equally upon the Secretary of the Navy and the Secretary of War. Each had his measure of control over the enormous sum voted in a lump for aviation, each had the further millions especially voted to his department to account for. But no single individual could be officially asked what had been done with the almost one billion dollars voted for aeronautics in 1917.

But if the authorities seemed to lag, the inventors were busy. Mention has already been made of the new "Liberty" motor, which report had it was the fruit of the imprisonment of two mechanical experts in a hotel room with orders that they should not be freed until they had produced a motor which met all criticisms upon those now in use. Their product is said to have met this test, and the happy result caused a general wish that the Secretaries of War and of the Navy might be similarly incarcerated and only liberated upon producing plans for the immediate creation of an aërial fleet suited to the nation's needs. If, however, the Liberty motor shall prove the complete success which at the moment the government believes it to be, it will be such a spur to the development of the airplane in peace and war, as could not otherwise be applied. For the motor is the true life of the airplane—its heart, lungs, and nerve centre. The few people who still doubt the wide adoption of aircraft for peaceful purposes after the war base their skepticism on the treachery of motors still in use. They repudiate all comparisons with automobiles. They say:

It is perfectly true that a man can run his car repeatedly from New York to Boston without motor trouble. But the trouble is inevitable sooner or later. When it comes to an automobile it is trifling. The driver gets out and makes his repairs by the roadside. But if it comes to the aviator it brings the possibility of death with it every time. If his motor stops he must descend. But to alight he must find a long level field, with at least two hundred yards in which to run off his momentum. If, when he discovers the failure of his motor, he is flying at the height of a mile he must find his landing place within a space of eight miles, for in gliding to earth the ratio of forward movement to height is as eight to one. But how often in rugged and densely populated New England, or Pennsylvania is there a vacant level field half a mile in length? The aviator who made a practice of daily flight between New York and Boston would inevitably meet death in the end.

The criticism is a shrewd and searching one. But it is based on the airplane and the motor of to-day without allowance for the development and improvement which are proceeding apace. It contemplates a craft which has but one motor, but the more modern machines have sufficient lifting power to carry two motors, and can be navigated successfully with one of these out of service. Experiments furthermore are being made with a device after the type of the helicopter which with the steady lightening of the aircraft motor, may be installed on airplanes with a special motor for its operation. This device, it is believed, will enable the airplane so equipped to stop dead in its course with both propellers out of action, to hover over a given spot or to rise or to descend gently in a perpendicular line without the necessity of soaring. It is obvious that if this device prove successful the chief force of the objections to aërial navigation outlined above will be nullified.

The menace of infrequent landing places will quickly remedy itself on busy lines of aërial traffic. The average railroad doing business in a densely populated section has stations once every eight or ten miles which with their sidings, buildings, water tanks, etc., cost far more than the field half a mile long with a few hangars that the fliers will need as a place of refuge. Indeed, although for its size and apparent simplicity of construction an airplane is phenomenally costly, in the grand total of cost an aërial line would cost a tithe of the ordinary railway. It has neither right of way, road bed, rails, nor telegraph system to maintain, and if the average flyer seems to cost amazingly it still foots up less than one fifth the cost of a modern locomotive though its period of service is much shorter.

Just at the present time aircraft costs are high, based on artificial conditions in the market. Their construction is a new industry; its processes not yet standardized; its materials still experimental in many ways and not yet systematically produced. A light sporting monoplane which superficially seems to have about $250 worth of materials in it—exclusive of the engine—will cost about $3000. A fighting biplane will touch $10,000. Yet the latter seems to the lay observer to contain no costly materials to justify so great a charge. The wings are a light wooden framework, usually of spruce, across which a fine grade of linen cloth is stretched. The materials are simple enough, but every bit of wood, every screw, every strand of wire is selected with the utmost care, and the workmanship of their assemblage is as painstaking as the setting of the most precious stones.

"REMEMBER THE LEAST NEGLIGENCE MAY COST A LIFE!" is a sign frequently seen hanging over the work benches in an airplane factory.

When stretched over the framework, the cloth of the wings is treated to a dressing down of a preparation of collodion, which in the jargon of the shop is called "dope." This substance has a peculiar effect upon the cloth, causing it to shrink, and thus making it more taut and rigid than it could be by the most careful stretching. Though the layman would not suspect it, this wash alone costs about $150 a machine. The seaplanes too—or hydroaëroplanes as purists call them—present a curious illustration of unexpected and, it would seem, unexplainable expense. Where the flyer over land has two bicycle wheels on which to land, the flyer over the sea has two flat-bottomed boats or pontoons. These cost from $1000 to $1200 and look as though they should cost not over $100. But the necessity of combining maximum strength with minimum weight sends the price soaring as the machine itself soars. Moreover there is not yet the demand for either air-or seaplanes that would result in the division of labour, standardization of parts, and other manufacturing economies which reduce the cost of products.

To the high cost of aircraft their comparative fragility is added as a reason for their unfitness for commercial uses. The engines cost from $2000 to $5000 each, are very delicate and usually must be taken out of the plane and overhauled after about 100 hours of active service. The strain on them is prodigious for it is estimated that the number of revolutions of an airplane's engine during an hour's flight is equal to the number of revolutions of an automobile's wheels during active service of a whole month.

It is believed that the superior lightness and durability of the Liberty motor will obviate some of these objections to the commercial availability of aircraft in times of peace. And it is certain that with the cessation of the war, the retirement of the governments of the world from the purchasing field and the reduction of the demand for aircraft to such as are needed for pleasure and industrial uses the prices which we have cited will be cut in half. In such event what will be the future of aircraft; what their part in the social and industrial organization of the world?

Ten or a dozen years ago Rudyard Kipling entertained the English reading public of the world with a vivacious sketch of aërial navigation in the year 2000 A.D. He used the license of a poet in avoiding too precise descriptions of what is to come—dealing rather with broad and picturesque generalizations. Now the year 2000 is still far enough away for pretty much anything to be invented, and to become commonplace before that era arrives. Airships of the sort Mr. Kipling pictured may by that period have come and gone—have been relegated to the museums along with the stage-coaches of yesterday and the locomotives of to-day. For that matter before that millennial period shall arrive men may have learned to dispense with material transportation altogether, and be able to project their consciousness or even their astral bodies to any desired point on psychic waves. If a poet is going to prophecy he might as well be audacious and even revolutionary in his predictions.

Mr. Kipling tried so hard to be reasonable that he made himself recognizably wrong so far as the present tendency of aircraft development would indicate. With the Night Mail, is the story of a trip by night across the Atlantic from England to America. It is made in a monster dirigible—though the present tendency is to reject the dirigible for the swifter, less costly, and more airworthy (leave "seaworthy" to the plodding ships on old ocean's breast) airplanes. If, however, we condone this glaring improbability we find Mr. Kipling's tale full of action and imaginary incident that give it an air of truth. His ship is not docked on the ground at the tempest's mercy, but is moored high in air to the top of a tall tower up which passengers and freight are conveyed in elevators. His lighthouses send their beams straight up into the sky instead of projecting them horizontally as do those which now guard our coasts. Just why lighthouses are needed, however, he does not explain. There are no reefs on which a packet of the air may run, no lee shores which they must avoid. On overland voyages guiding lights by night may be useful, as great white direction strips laid out on the ground are even now suggested as guides for daylight flying. But the main reliance of the airman must be his compass. Crossing the broad oceans no lighted path is possible, and even in a voyage from New York to Chicago, or from London to Rome good airmanship will dictate flight at a height that will make reliance upon natural objects as a guide perilous. The airman has the advantage over the sailor in that he may lay his course on leaving his port, or flying field, and pursue it straight as an arrow to his destination. No rocks or other obstacles bar his path, no tortuous channels must be navigated. All that can divert him from his chosen course is a steady wind on the beam, and that is instantly detected by his instruments and allowance made for it. On the other hand the sailor has a certain advantage over the airman in that his more leisurely progress allows time for the rectification of errors in course arising from contrary currents or winds. An error of a point, or even two, amounts to but little in a day's steaming of perhaps four hundred miles. It can readily be remedied, unless the ship is too near shore. But when the whole three thousand miles of Atlantic are covered in twenty hours in the air, the course must be right from the start and exactly adhered to, else the passenger for New York may be set down in Florida.

It is not improbable that even before the war is over the crossing of the Atlantic by plane will be accomplished. Certainly it will be one of the first tasks undertaken by airmen on the return of peace. But it is probable that the adaptation of aircraft to commercial uses will be begun with undertakings of smaller proportions. Already the United States maintains an aërial mail route in Alaska, while Italy has military mail routes served by airplanes in the Alps. These have been undertaken because of the physical obstacles to travel on the surface, presented in those rugged neighbourhoods. But in the more densely populated regions of the United States considerations of financial profit will almost certainly result in the early establishment of mail and passenger air service. Air service will cut down the time between any two given points at least one half, and ultimately two thirds. Letters could be sent from New York to Boston, or even to Buffalo, and an answer received the same day. The carrying plane could take on each trip five tons of mail. Philadelphia would be brought within forty-five minutes of New York; Washington within two hours instead of the present five. Is there any doubt of the creation of an aërial passenger service under such conditions? Already a Caproni triplane will carry thirty-five passengers beside guns—say, fifty passengers if all other load be excluded, and has flown with a lighter load from Newport News to New York. It is easily imaginable that by 1920 the airplane capable of carrying eighty persons—or the normal number now accommodated on an inter-urban trolley car—will be an accomplished fact.

The lines that will thus spring up will need no rails, no right of way, no expensive power plant. Their physical property will be confined to the airplanes themselves and to the fields from which the craft rise and on which they alight, with the necessary hangars. These indeed will involve heavy expenditure. For a busy line, with frequent sailings, of high speed machines a field will need to be in the neighbourhood of a mile square. A plane swooping down for its landing is not to be held up at the switch like a train while room is made for it. It is an imperative guest, and cannot be gainsaid. Accordingly the fields must be large enough to accommodate scores of planes at once and give each new arrival a long straight course on which to run off its momentum. It is obvious therefore that the union stations for aircraft routes cannot be in the hearts of our cities as are the railroad stations of to-day, but must be fairly well out in the suburbs.

A form of machine which the professional airmen say has yet to be developed is the small monoplane, carrying two passengers at most, and of low speed—not more than twenty miles an hour at most. In this age of speed mania the idea of deliberately planning a conveyance or vehicle that shall not exceed a low limit seems out of accord with public desire. But the low speed airplane has the advantage of needing no extended field in which to alight. It reaches the ground with but little momentum to be taken up and can be brought up standing on the roof of a house or the deck of a ship. Small machines of this sort are likely to serve as the runabouts of the air, to succeed the trim little automobile roadsters as pleasure craft.

But Kiel, Wilhelmshaven and Zeebrugge are likely to change all this. The constant contemplation of those nests for the sanctuary of pestiferous submarines, effectively guarded against attack by either land or water, has stirred up the determination of the Allies to seek their destruction from above. Heavy bombing planes are being built in all the Allied workshops for this purpose, and furthermore to give effect to the British determination to take vengeance upon Germany, for her raids upon London. It is reported that the United States, by agreement with its Allies, is to specialize in building the light, swift scout planes, but in other shops the heavy triplane, the dreadnought of the air is expected to be the feature of 1918. With it will come an entirely novel strategic use of aircraft in war, and with it too, which is perhaps the more permanently important, will come the development of aircraft of the sort that will be readily adaptable to the purposes of peace when the war shall end.

THE SUBMARINE BOAT

CHAPTER XI
BEGINNINGS OF SUBMARINE INVENTION

In September, 1914 the British Fleet in the North Sea had settled down to the monotonous task of holding the coasts of Germany and the channels leading to them in a state of blockade. The work was dismal enough. The ships tossing from day to day on the always unquiet waters of the North Sea were crowded with Jackies all of whom prayed each day that the German would come from hiding and give battle. Not far from the Hook of Holland engaged in this monotonous work were three cruisers of about 12,000 tons, each carrying 755 men and officers. They were the Cressy, Aboukir, and Hogue—not vessels of the first rank but still important factors in the British blockade. They were well within the torpedo belt and it may be believed that unceasing vigilance was observed on every ship. Nevertheless without warning the other two suddenly saw the Aboukir overwhelmed by a flash of fire, a pillar of smoke and a great geyser of water that rose from the sea and fell heavily upon her deck. Instantly followed a thundering explosion as the magazines of the doomed ship went off. Within a very few minutes, too little time to use their guns against the enemy had they been able to see him, or to lower their boats, the Aboukir sank leaving the crew floundering in the water.

In the distance lay the German submarine U-9—one of the earliest of her class in service. From her conning tower Captain Weddigen had viewed the tragedy. Now seeing the two sister ships speeding to the rescue he quickly submerged. It may be noted that as a result of what followed, orders were given by the British Admiralty that in the event of the destruction of a ship by a submarine others in the same squadron should not come to the rescue of the victim, but scatter as widely as possible to avoid a like fate. In this instance the Hogue and the Cressy hurried to the spot whence the Aboukir had vanished and began lowering their boats. Hardly had they begun the work of mercy when a torpedo from the now unseen foe struck the Hogue and in twenty minutes she too had vanished. While she was sinking the Cressy, with all guns ready for action and her gunners scanning the sea in every direction for this deadly enemy, suddenly felt the shock of a torpedo and, her magazines having been set off, followed her sister ships to the ocean's bed.

In little more than half an hour thirty-six thousand tons of up-to-date British fighting machinery, and more than 1200 gallant blue jackets had been sent to the depths of the North Sea by a little boat of 450 tons carrying a crew of twenty-six men.

The world stood aghast. With the feeling of horror at the swift death of so many caused by so few, there was mingled a feeling of amazement at the scientific perfection of the submarine, its power, and its deadly work. Men said it was the end of dreadnoughts, battleships, and cruisers, but the history of the war has shown singularly few of these destroyed by submarines since the first novelty of the attack wore off. The world at the moment seemed to think that the submarine was an entirely new idea and invention. But like almost everything else it was merely the ultimate reduction to practical use of an idea that had been germinating in the mind of man from the earliest days of history.

We need not trouble ourselves with the speculations of Alexander the Great, Aristotle, and Pliny concerning "underwater" activities. Their active minds gave consideration to the problem, but mainly as to the employment of divers. Not until the first part of the sixteenth century do we find any very specific reference to actual underwater boats. That appears in a book of travels by Olaus Magnus, Archbishop of Upsala in Sweden. Notwithstanding the gentleman's reverend quality, one must question somewhat the veracity of the chapter which he heads:

"Of the Leather Ships Made of Hides Used by the Pyrats of Greenland."

He professed to have seen two of these "ships," more probably boats, hanging in a cathedral church in Greenland. With these singular vessels, according to his veracious reports the people of that country could navigate under water and attack stranger ships from beneath. "For the Inhabitants of that Countrey are wont to get small profits by the spoils of others," he wrote, "by these and the like treacherous Arts, who by their thieving wit, and by boring a hole privately in the sides of the ships beneath (as I said) have let in the water and presently caused them to sink."

Leaving the tale of the Archbishop where we think it must belong in the realm of fiction, we may note that it was not until the beginning of the seventeenth century that the first submarine boat was actually built and navigated. A Hollander, Cornelius Drebel, or Van Drebel, born in 1572, in the town of Alkmaar, had come to London during the reign of James I., who became his patron and friend. Drebel seems to have been a serious student of science and in many ways far ahead of his times. Moreover, he had the talent of getting next to royalty. In 1620 he first conceived the idea of building a submarine. Fairly detailed descriptions of his boats—he built three from 1620-1624—and of their actual use, have been handed down to us by men whose accuracy and truthfulness cannot be doubted. The Honorable Robert Boyle, a scientist of unquestioned seriousness, tells in his New Experiments, Physico-Mechanical touching the Spring of the Air and its Effects about Drebel's work in the quaint language of his time:

But yet on occasion of this opinion of Paracelsus, perhaps it will not be impertinent if, before I proceed, I acquaint your Lordship with a conceit of that deservedly famous mechanician and Chymist, Cornelius Drebel, who, among other strange things that he perform'd, is affirm'd, by more than a few credible persons, to have contrived for the late learned King James, a vessel to go under water; of which, trial was made in the Thames, with admired success, the vessel carrying twelve rowers, besides passengers; one which is yet alive, and related it to an excellent Mathematician that informed me of it. Now that for which I mention this story is, that having had the curiosity and opportunity to make particular inquiries among the relations of Drebel, and especially of an ingenious physician that married his daughter, concerning the grounds upon which he conceived it feasible to make men unaccustomed to continue so long under water without suffocation, or (as the lately mentioned person that went in the vessel affirms) without inconvenience; I was answered, that Drebel conceived, that it is not the whole body of the air, but a certain quintessence (as Chymists speak) or spirituous part of it, that makes it fit for respiration; which being spent, the remaining grosser body, or carcase, if I may so call it, of the air, is unable to cherish the vital flame residing in the heart; so that, for aught I could gather, besides the mechanical contrivances of his vessel, he had a chymical liquor, which he accounted the chief secret of his submarine navigation. For when, from time to time, he conceived that the finer and purer part of the air was consumed, or over-clogged by the respiration and steam of those that went in his ship, he would by unstopping a vessel full of this liquor, speedily restore to the troubled air such a proportion of vital parts, as would make it again, for a good while, fit for respiration whether by dissipating, or precipitating the grosser exhalations, or by some other intelligible way, I must not now stay to examine, contenting myself to add, that having had the opportunity to do some service to those of his relations that were most intimate with him, and having made it my business to learn what this strange liquor might be, they constantly affirmed that Drebel would never disclose the liquor unto any, nor so much as tell the nature whereof he had made it, to above one person, who himself assured me what it was.

This most curious narrative suggests that in some way Drebel, who died in London in 1634, had discovered the art of compressing oxygen and conceived the idea of making it serviceable for freshening the air in a boat, or other place, contaminated by the respiration of a number of men for a long time. Indeed the reference made to the substance by which Drebel purified the atmosphere in his submarine as "a liquor" suggests that he may possibly have hit upon the secret of liquid air which late in the nineteenth century caused such a stir in the United States. Of his possession of some such secret there can be no doubt whatsoever, for Samuel Pepys refers in his famous diary to a lawsuit, brought in the King's Courts by the heirs of Drebel, to secure the secret for their own use. What was the outcome of the suit or the subsequent history of Drebel's invention history does not record.

Throughout the next 150 years a large number of inventors and near-inventors occupied themselves with the problem of the submarine. Some of these men went no further than to draw plans and to write out descriptions of what appeared to them to be feasible submarine boats. Others took one step further, by taking out patents, but only very few of the submarine engineers of this period had either the means or the courage to test their inventions in the only practicable way, by building an experimental boat and using it.

In spite of this apparent lack of faith on the part of the men who worked on the submarine problem, it would not be fair to condemn them as fakirs. Experimental workers, in those times, had to face many difficulties which were removed in later times. The study of science and the examination of the forces of nature were not only not as popular as they became later, but frequently were looked upon as blasphemous, savouring of sorcery, or as a sign of an unbalanced mind.