VI Fighters of the Sky
At about the time that the German War Lord, resplendent in the eagle-crowned helmet and silver cuirass of the Guard Cuirassiers, was haranguing in sonorous phrases the punitive expedition which was about to depart for China, two young mechanics in greasy overalls were at work in an obscure machine-shop in an Ohio city on a strange invention which was destined to prove a far more potent weapon than the Kaiser’s boasted “shining sword.” Now it is certain that at this period the All Highest had never heard of these young mechanics, and though they, of course, had heard of him, I imagine that to the accounts of his spectacular doings which appeared almost daily in the newspapers they paid about as much attention as they did to the gaudy lithographs on the local bill-boards which heralded the annual visit of the circus. Yet, could William of Hohenzollern have looked a dozen years into the future, he would have seen that these two silent, earnest, unassuming brothers from the Middle Western town were destined to have a profounder effect on the future of the great empire which he ruled, and, indeed, on the history of the world, than he and all the princes, soldiers, and statesmen who surrounded him.
Notwithstanding the jibes and forebodings of the professional critics, the ponderous sarcasms of senators and congressmen, and the sensational stories of failure which have appeared in the press, there are few more brilliant chapters in our national history than the story of the airplane. Do you realize, I wonder, that the airplane is the development of barely a decade? Had a life-insurance company, ten years ago, learned that one of its policy-holders was planning to take a ride in a “flying-machine,” it would promptly have cancelled his policy. Yet to-day planes carrying the air-post between the cities of the Eastern seaboard go booming down the air-lanes as regularly as express-trains and without attracting much more attention.
The story of the airplane, so far as its relation to the American Army is concerned, begins on the little flying-field of Fort Myer, on the Virginia side of the Potomac, opposite Washington. In the late winter of 1907 the Signal Corps had issued an advertisement and specifications for a heavier-than-air flying-machine, the chief requirement being that it must remain in the air for an hour without landing. Most of us will remember the world-wide interest which was aroused by this promised realization of the dream of the ages. During the trials the eyes of the world were centred on the parade-ground at Fort Myer. The President and the members of his cabinet were in frequent attendance and even Congress adjourned when it was announced that a flight would take place. The story of how the strange contrivance, looking like a combination of a box-kite, a baby-carriage, and a windmill, which had been brought on from Dayton by the two sober-faced brothers, was trundled out onto the field; how, after skimming along the ground, it rose into the air as gracefully as a swallow, and how, after fulfilling every condition imposed by the War Department, the first machine was purchased by the government, needs no elaboration here. The most amazing feature of the affair, barring only the performance of the airplane itself, was the fact that during the eight years following the demonstration at Fort Myer the entire appropriations by the government for military aeronautics amounted to less than a million dollars. Think of it, my friends! With the secret of aerial navigation in our hands—a secret which had been sought for by scientists all down the ages—Congress devoted less money to its development during the first eight years than it spent on many a post-office or government building. But the astounding apathy which characterized our attitude toward this epoch-making invention did not extend to the great European nations. They, always seeking to obtain military superiority, instantly recognized the significance and the potentialities of those early flights at Fort Myer. France, in particular, during the next few years making marked advances in aircraft design and construction. Thus it came about that when the war-cloud burst over Europe in the summer of 1914 the United States, where the airplane had its birth and where it had first demonstrated its practicability, possessed only a few decrepit and almost obsolete training-machines, while our fliers could almost have been numbered on the fingers of one’s two hands. Whose was the fault for this deplorable and inexcusable condition? A certain amount of blame undeniably attaches to the army, for in those days many of our higher officers were graduates of the old Indian-fighting school, who regarded with doubt and scepticism the claim that these new-fangled flying-machines could have any real military value. I think, however, that the real cause of the neglect in developing the airplane could have been found in the building with the great white dome which stands at the far end of Pennsylvania Avenue.
As a direct consequence of our systematic discouragement of airplane development, when we entered the war there was no such thing as an aviation industry in the United States and the number of aeronautical engineers and designers was so small as to be practically negligible. In this respect the problem of developing an air-fleet was unique. The United States had built ships before, it had manufactured cannon, rifles, ammunition, it had fed and clothed and housed armies, and it had at its command thousands of men qualified to do these things and do them well, but, barring a handful of experts in Dayton and Buffalo, there was no one in this country with experience in the designing or building of either training or fighting planes. In short, the government was faced with the problem not merely of developing a new industry, but of creating it.
In April, 1917, there were being built in the United States only four makes of aircraft engines that were sufficiently developed to be of any military value, and even these were useful only for primary training. We had no engines suited for service on the battle-front, or, indeed, even for the advanced training of pilots. Though the largest engine manufactured in the United States at this time developed about 220 horse-power, it had not measured up to the exacting requirements of combat. The other American-built engines ranged from 90 to 135 horse-power. It being evident, therefore, that the existing American engines could be used only for purposes of preliminary instruction, it was accordingly decided that their further manufacture should be limited to the training requirements. As a result of this decision, by far the greater part of the primary training of pilots has been conducted with the Curtis 90 horse-power engine, a quantity production of which was obtained early in the war, this engine being particularly valuable owing to the very satisfactory training-plane which had been designed around it. Considerable use was also made of the Hall-Scott 100 horse-power engine until the Curtiss motor could be manufactured in sufficient numbers to meet all demands for primary training. Two European engines, the Gnome 100 horse-power and the Hispano-Suiza 150 horse-power, were also being put into production in the United States at this time. These engines represented the highest product of European design and engineering skill, and were in a perfected and standardized state, at least according to European ideas, when their manufacture was undertaken in this country. But the changes involved in adapting them to manufacture by American methods required so much time, and the advances made in aeronautical engineering were so rapid, that before they could be produced in sufficient numbers they were almost obsolete for service on the front. These two engines were, however, of unquestioned value for advanced training purposes, the Hispano-Suiza in particular playing an important part in this work. Later another European engine, the 80 horse-power Rhone, was also put into production.
One of the serious mistakes into which the Allies had fallen at the time the United States entered the war was the development of such a multiplicity of types of engines and planes that it was impossible to have a large number of any one of them. Indeed, by the spring of 1917, there were almost as many types of planes skimming over the Western Front as there were types of motor-cars skimming over American roads. As a direct consequence of this condition, the trained personnel had grown to such proportions that it was estimated that from thirty to fifty men were required on the ground to keep each plane in the air. It was obvious, therefore, that unless this large number of trained attendants could be materially reduced, it would be hopeless to expect to put thousands of fighting planes into the air within a reasonable time, for, on this basis, 1,000 planes would require from 30,000 to 50,000 men to take care of them. It was realized, moreover, that copies of foreign designs could not be made available in time to answer the insistent demand that America should put on the front an air force of overwhelming proportions.
Although, immediately upon the declaration of war, an aircraft commission had been sent to Europe for the purpose of gathering first-hand information, public sentiment would not have permitted the government to sit idly by and wait with folded hands for this commission to make its report. What the country demanded was action with a capital A. Now it is not generally known, perhaps, that, instead of engines being designed for certain types of aircraft, the most successful airplanes are designed around specific engines. And, as the development of the engine requires the greatest expenditure of effort and time, some one suggested that, instead of waiting for the members of the commission to come home and tell about the European engines they had seen, to manufacture which under American conditions might well prove impracticable, an all-American engine, combining the best features of the various European types but particularly adapted for manufacture under domestic conditions, be designed by the best engineering talent in the country and immediately placed in production. At a meeting of representatives of the Signal Corps—which then had charge of military aeronautics—and the Aircraft Production Board it was decided to put this suggestion into immediate execution, at the same time purchasing in Europe whatever equipment might be available in order to tide over the period while the all-American engine was being put into production.
At noon on May 29, Lieutenant-Colonel J. G. Vincent and Lieutenant-Colonel E. J. Hall, two of the most brilliant automotive engineers in America, shut themselves in a room of the New Willard Hotel in Washington. When they left that room again on the afternoon of the 31st, though haggard from lack of sleep, they had in their hands the completed assembly drawings of an entirely new airplane engine. Thus was born the famous Liberty engine, about which hundreds of speeches have been made and thousands of columns have been written in scepticism, in criticism, and in praise. As the result of the enthusiastic co-operation of some ten manufacturers, each of whom produced those parts for which his factory was best fitted, the first Liberty, an 8-cylinder, was built in thirty days. The first 12-cylinder engine completed its official endurance test eighty-two days from the time the order for samples was given, the unqualified success of this test removing the Liberty from the realm of experimentation to that of established reputation. In just one year from the day that Lieutenant-Colonels Hall and Vincent pushed the thumb-tacks into their drawing-boards in the hotel room, 1,100 Liberty “twelves” were produced—a remarkable illustration of the ability and ingenuity of American engineers and the energy and resourcefulness of American manufacturers. Thanks to the energetic co-operation of many manufacturers, more than 14,000 Liberty engines had been completed when the Armistice was signed. There are few finer passages in the history of America’s participation in the war than the story of how our manufacturers put aside their private interests and their commercial rivalries and threw themselves and their organizations, heart and soul, into the work of building an airplane that would make America mistress of the skies.
When the signing of the Armistice brought our efforts to an abrupt conclusion, there had been developed, tested, and adopted by the army four types of airplanes, production of which would have started early in 1919. They were the Lepere, or L. U. S. A. C. II, a two-seated fighting-plane equipped with a Liberty engine; the U. S. De Havilland 9-A, a day-bombing and reconnaissance plane also fitted with the Liberty engine; the huge Martin bomber, with a gross weight of nearly 5 tons, driven by two Liberty engines; and the Loening, a two-seated combat plane fitted with the 300 horse-power Hispano-Suiza engine.
A striking illustration of the new problems and extraordinary ramifications incident to this great new industry which so suddenly came into existence in the United States is the fact that it was found necessary to despatch an agricultural expert post-haste to India to purchase enormous quantities of castor-beans, as it was at first believed that castor-oil was the only satisfactory lubricant for these new types of high-speed, high-power engines. India’s stock of castor-beans being quickly exhausted by the immensity of our demands, more than 100,000 acres of the bean were planted in the United States. Meanwhile, research work with mineral oils was carried on intensively, a lubricant eventually being developed which proved satisfactory in practically every airplane engine except the rotary type, for which castor-oil is still preferred.
But the aircraft problem was by no means solved with the development and production of the Liberty engine. Far from it. To build airplanes requires wood; the best timber in the world is none too good; and of suitable timber there was a comparatively limited supply. The best wood known for airplane construction is the Sitka spruce, which combines the required qualities of strength, resiliency, and lightness. This spruce grows mostly in the Pacific Northwest, along the tide-lands of Washington and Oregon, at a low elevation. But not all the planes were built of spruce, fir, as it grows in the Northwest, being largely used for the heavier wing-beams. Port Orford cedar was eagerly utilized whenever it could be obtained. It is of somewhat smaller growth than spruce or fir, but a straighter-grained wood, harder and more dense than either of the others. Of this splendid wood there is, however, only a comparatively small quantity, 2,000,000,000 feet, perhaps, anywhere in the world, mostly near Coos Bay, on the coast of Oregon. Being less affected by water than any of the other woods, it was reserved for use in seaplanes. The government commandeered the entire supply of Port Orford cedar for aircraft production, but released it upon the signing of the armistice.
There is plenty of suitable airplane timber—spruce, cedar, and fir—in the Far Nor’west—miles and miles and miles of it. The mountain-slopes are as solid a black with the evergreens as though a giant had painted them with soot. “Massed in their black battalions stand the bleak, barbarian pines.” Foolish men have tried to destroy these forests. Twenty years ago a colony of Poles settled amid the virgin forests of the Olympic Peninsula—a portion of the United States which to this day remains virtually unexplored. Timber was not worth a dollar a million feet then. On the chance that the ground might be tilled if the timber could be cleared off, the settlers started a fire that burned over ten square miles and destroyed timber which, at prevailing prices, would be worth close to half a million dollars. The great area of blackened waste which remains is still known as “The Polander Burn.”
Now spruce, curiously enough, had not been considered a valuable wood for the ordinary lumber trade; the lumbermen held it a doubtful asset that was hardly worth the cutting. As a result of this condition, the commercial supply was neither large enough nor well enough selected and prepared to meet our aircraft requirements when the declaration of war suddenly made it one of the most desired and most valuable woods in existence. Thus it came about that, the lumbermen being unable to supply the demand, the army had to go instantly into the business of producing this wood in theretofore undreamed-of quantities. The work of getting out the spruce fell, rather oddly, to the men who had been among the first to volunteer for extrahazardous service in France. Before the war, when airplanes were looked on merely as toys of the rich, the supervision of military aeronautics was assigned to the Signal Corps, on the assumption that if flying had any part in warfare it would probably be that of signalling, for which reason, and the more potent one that no other branch of the service knew what to do with it, it had to be wished on some one. And of all the branches of the army, possibly none save the Flying Section of the Signal Corps—as the Air Service was then known—had a more adventurous and devil-may-care personnel. The Signal Corps made its original appeal to the men who wanted to get out and do things: to be in front, to wave the little red-and-white flags under shell-fire, to sound the long yell, to see the enemy first, to be the eyes and ears and nerves of the whole army. But, as I have already explained, the army had to have the spruce in order to carry out its aviation programme, and aviation was under the Signal Corps, and it was from the Signal Corps, therefore, that the men were drawn to go out to the Northwest and get the spruce. Thus it came about that the boys who enlisted at the very beginning in order that they might have the danger and excitement of laying the field telegraphs and telephones, of dashing madly along shell-swept roads on roaring motorcycles, of wig-wagging and semaphoring word of the enemy’s movements from in front of the armies, were shipped westward instead of eastward, were given axes instead of Enfields and peaveys instead of pistols, and fought their share of the war in the gloomy depths of the primeval forest, or on the logging railroads and in the sawmills which they built in bitter cold and driving rain.
Labor conditions were undeniably bad in the Northwest at the beginning of the war. There is an old proverb that “A farm lease is a conspiracy on the part of the tenant and the absentee landlord to rob the land.” Lumbering was almost as bad. The owners were avaricious and arrogant, the men stubborn and defiant. The owners would not make camp improvements because “the men would not stay on the job,” and the men would not stay because “the owners didn’t make things decent.” And, to make things worse, the paid German propaganda was rampant, unchecked in the woods, for the Wilhelmstrasse fully realized how vital it was to cripple the American air programme. Germany knew better than we did the war possibilities of the Pacific Northwest. She couldn’t buy spruce there for her planes, but she could mobilize her spies and trouble-makers and hinder the production for and the delivery of spruce to the United States and her allies. And she did her worst. Some day there will be told the story, the “inside” story, of the campaign waged in the Great Woods by the secret forces of Germany—a campaign consisting of strikes, I. W. W. demonstrations, forest-fires, railway wrecks, dynamited bridges, damaged machinery, infernal machines, shootings, systematic intimidation, and all the other deviltries of a vicious and unscrupulous enemy. The spies and secret agents which Germany planted in the forests of the Northwest formed a part of the vast army of which the Kaiser boasted to Ambassador Gerard. But the Hun made a miscalculation. There were not enough spies; there were too many Americans.
The War Department has rarely shown greater wisdom than when it gave a colonel’s commission to Brice P. Disque, an ex-captain of Regulars who had left the army to accept the wardenship of the Michigan State Prison, and put him in charge of spruce production. Captain Disque had his blanket-roll packed and aboard ship for service in France when he was called to Washington, just as the transport was setting sail, and ordered to go to the Northwest and investigate lumbering conditions. His report showed that the right man had been found to direct the Titanic job of getting out the spruce; he was commissioned a colonel and later a brigadier-general, and the story of the spruce production tells the rest.
To the tact and vision of General Disque is due the creation of that remarkable organization known as the Loyal Legion of Loggers and Lumbermen, an association conceived to bring capital and labor together in one mighty machine driven solely by patriotism. Under the inspiration thus provided, both sides agreed to submit their differences to the United States Army, as represented in the person of General Disque, as final arbiter. The eight-hour day was agreed to; camp sanitation and better living conditions of every kind were demanded; a uniformly liberal wage-scale for all classes of labor was adopted; a standard mess was arranged to check the inordinate waste of food in the lumber-camps; the owners were given profitable prices for their output under the new conditions, and the small men were assured of receiving a square deal from their powerful corporate rivals. Some of these questions were settled through regular military channels, but most of them through the medium of the L. L. L. L. Once a matter could be shown to be reasonable and fair to every one concerned, it was officially adopted, as by a majority vote, and business as well as patriotic reasons demanded that every one should cheerfully acquiesce in the decision. The Loyal Legion works—for it has been made permanent—through its local assemblies; any local disagreement is taken to the district council—which is formed from local representatives of both employer and employees, there being eight of these district councils in the Coast Division and four in the Inland Empire. Any question which cannot be settled by a district council goes to the Central Council, composed of one employer and one employee from each district; while General Disque, as the head of the Legion, has been the final arbitrator in such questions as the Central Council could not settle. Since this plan was definitely adopted, however, so strong a spirit of patriotic fairness has been developed on both sides that nothing has gone to him for settlement or revision. Nothing could more strongly emphasize the success of the Legion, which now has a membership of nearly 130,000, than the fact that at a mass convention, held shortly after the signing of the Armistice, at which more than 900 local councils were represented, it was voted almost unanimously to perpetuate the organization, to continue the publication of its official bulletin, and to invite General Disque to continue as the Legion’s head. Were the people of the Pacific Northwest to receive no other reward for their sacrifices in the war, they have reason to feel amply repaid by the creation of the Loyal Legion and the resultant ending of the long-standing feud between capital and labor, the expulsion of the I. W. W.’s and similar discordant and dangerous elements, the betterment of working and living conditions for the lumbermen, and the commencement of an era of peace and prosperity in the Great Woods.
Unless you have been in the Northwest during the rainy season you can have no adequate conception of the difficulties under which the spruce squadrons labored. The coastal districts of Oregon and Washington have one of the heaviest rainfalls recorded anywhere on earth. Unkind people have said of the Pacific Northwest that it has but two seasons—the rainy season and August. But that is an exaggeration. The local newspapers alternately boast of and apologize for the reputed 180 inches, or 15 feet, of annual precipitation. With that as a basis for one’s calculations, the old man who sold the town site of Simescarey, the terminus of the spruce road which the government has built into the Olympic Peninsula, has had 450 feet of water descend upon his head—for the inhabitants of that region scorn umbrellas—in the thirty years that he has resided there. After a winter spent in the Northwest—and having passed one there, I know whereof I speak—one might easily believe that the sentry at an Oregon spruce-camp was not joking when he came in to the commanding officer to report the damages done by the rain.
“Sir,” he apologized, “I don’t like to be a pessimist, but things ain’t going right to-day. Most of the fish in the lake are dead since last night’s rain. The lake raised so fast that some of ’em got beyond their depth and was just naturally drowned; the rest couldn’t swim up fast enough, and bein’ surface fish and not used to much depth, their bladders busted and there ain’t a fit fish left in the whole bunch. Every duck but one is dead, too; the rain beat their heads into a mush—all but the one that got caught in a steel trap set for a muskrat and that saved his life—he stayed under water where it was dry. Believe me, sir, that was the wettest rain last night I ever see.”
Because, as I have already explained, the lumbermen did not consider spruce a profitable wood to handle, few of the spruce forests had been penetrated by railroads. So Disque and his Legionaries set out to build railways themselves—13 lines with more than 300 miles of trackage. The forests tapped by these new lines and their branches have, it is estimated, an ultimate production of 33,000,000,000 feet of lumber, a quantity almost beyond the comprehension of the human brain. In order to visualize it, it must be translated into commonplace, every-day terms. Let us assume that it requires 20,000 feet of lumber to build an average 5 or 6 room house. Taking this as a basis, the railways built by Disque and his spruce squadrons have brought within the reach of commerce enough timber to build almost 2,000,000 of these comfortable American homes, with sufficient waste wood to keep them heated for a generation. When the war ended, 174,000,000 feet of aircraft lumber had been cut and shipped—enough to build dwellings for the inhabitants of a good-sized city.
The government planned to have all the airplane stock from the Northwest cut at the one great cut-up plant at Vancouver, near Portland. This huge mill, the largest in the world, was built by the army in forty-five days and has handled more than a million and a half feet of lumber in twenty-four hours. But with the extension of the airplane programme, whereby the Spruce Division was called upon to furnish stock for all the Allies, more capacity was required and three other great plants of almost equal size were planned, one being ready for opening, one almost completed, and one projected when the Armistice was signed. These four huge mills would, it is estimated, have furnished the United States and her allies with close to 100,000,000 feet of airplane lumber a month.
The silent, peaceful forests of the Northwest seemed separated from the war by a million miles, a score of generations. But when the word was flashed from Washington to Disque to “Go ahead,” the primeval silence of the woods was suddenly shattered by a million bellowing echoes of battle. The war had come to America. Almost overnight the battle-front moved 6,000 miles westward—from the forests of the Argonne to the forests of Oregon. The trucks were brought in—endless caravans of grunting, straining monsters; the soldiers came, 30,000 in all; the loggers, graders, hard-rock men, sawyers, surveyors, engineers; the pile-drivers, the donkey-engines, the steam-shovels perched on wheels, the train-loads of food and tools and powder; the patient, sweating horses and the creaking wagons, thousands upon thousands of them. The wood roads were black with traffic; they fairly smoked with the fierce fight for speed. The highways were dust in the early fall, where the 5 or 15 ton loads ground the roads to powder. Then the wet weather came—fogs, mists, drizzles, showers, floods—the rainy season that grows the incomparable forests of the Northwest.
They splashed through it all, soldiers and Legionaries alike; they waded, they swam, they shivered and swore, and beat their hands over the brush fires—but the stream of supplies never stopped nor checked. The railway gangs, following close on the heels of the axemen, laid their twin lines of steel through the dripping forest faster than Kitchener laid down his desert railway to Khartoum, the locomotives crawling one mile, two miles, deeper into the wilderness each night. Night and day the forest trails were busy. Shuttling back and forth, loaded both ways with materials and men, teams and trucks and trains struggled for speed. Headlights, lanterns, shouted warnings, guided the night traffic along the sombre, shut-in ways. Clankings, clatterings, gasoline coughings, the honk of horns and the hoot of locomotives filled the air. The silent forest became a bedlam of sound, of action.
The spruce! The fir! The wings of victory! Berlin heard it, saw it first. The splitting blasts that showered the forest lakes with stones, the shouting, heaving din of the construction-camps, the crash of the trees as they fell before the axe and saw of the woodsmen, the whine of the cables through the sheaves as the huge logs were snaked into position for loading, the rumble and roar of the heavy-laden log-trains, the shriek of the giant saws in the mills—all these sounds fell upon the listening ears at German Great Headquarters with a growing menace, as ominous as the tattoo of the machine-guns, as the thunderous blast of the great Allied cannon, as the victorious cheers of the charging Yanks. They meant that the spruce was coming! The planes were coming! A few months more and the boasted Hindenburg Line would be a joke. The Germans knew that they could not build trenches in the clouds. That was the real reason why they were attacked by yellow fever in the fall of 1918.
The engines and the planes themselves being in production, the next problem to be solved by the War Department was to provide our new aerial navy with armament in the form of machine-guns. Fighting in the air, it should be remembered, is entirely a development of the Great War, the adaptation of machine-guns for airplane use having practically all taken place since 1914. Though the records show that a machine-gun was successfully fired from an airplane in this country in 1912, and though the French had a few heavy planes fitted with mitrailleuses at the outbreak of the war, it was not until 1915 that machine-guns were carried by planes on active service. Prior to that time aviators depended on service and automatic rifles, pistols, shotguns shooting large shot held together by wires—miniature editions of the chain-shot used by early sea-fighters—and also carried darts and grenades to drop on the enemy. As a matter of fact, in one of the first aerial combats of the war, which took place on the Eastern Front between a Russian aviator and an Austrian, weapons were not used at all. The Russian determined to wreck his adversary and, in pursuance of this plan, so manœuvred his plane that the tips of his wings were just beneath the wings of the Austrian. He then suddenly elevated that end of his plane, hoping to upset the Austrian, but the result was that both machines collided and fell to the ground. Major Eric T. Bradley, formerly in the British Army but now an officer of the American Air Service, tells of having flown over the lines in 1915 armed with a twelve-gauge double-barrel shotgun loaded with buckshot tied together with wire, which swished through the air like the lash of a whip and occasionally hit something—usually by chance.
The development of methods for controlling machine-guns so that they can be fired through the area traversed by the propeller has had a vast effect on aerial combat, and an understanding of the problems involved is necessary in order to appreciate the difficulties which had to be overcome. The various devices which have been developed for controlling the fire of a machine-gun so as to cause the bullets to miss the blades of the propeller are commonly known as synchronizing or interrupter gears. These terms are, however, somewhat inaccurate, as it is only occasionally that the speed of the propeller is equal to the rate of fire of the gun, which is the condition of synchronization; moreover, the gun is not interrupted, but is caused to fire at the proper moment so that the bullet will miss the propeller-blade. “Gun control” would be a more descriptive name for the device.
Tractor airplanes—those which have the engine and propeller in front—were early found to be better suited to combat work than planes of the “pusher” type, which have the propeller behind, because they possess greater manœuvring powers and are better able to defend themselves. With these planes was developed the fixed aircraft machine-gun. This gun is fixed rigidly to the plane, pointing straight ahead, parallel to the line of flight. The first fixed guns were mounted on the upper plane so as to shoot over the arc described by the propeller, but these were not satisfactory owing to the difficulty in reloading the gun. To overcome this very obvious disadvantage the gun was lowered, which brought its line of fire inside the arc described by the propeller blades. Thus arose the difficulty caused by shooting into the propeller, to solve which countless experiments were made and numerous expedients tried. At first the blades were armored at the points where the bullets would strike, with steel of a shape calculated to cause the bullets to glance off, but this system was never satisfactory. Then the experiment was tried of wrapping the propeller with linen to keep it from splintering, as it was found that several bullets could be fired through a propeller thus treated without causing it to break. Throughout the summer of 1915 all of the Nieuport fighting-planes used by the French were fitted with fixed guns shooting through the propeller—if a bullet hit the propeller it either went through it or it wrecked it.
There is considerable disagreement as to who invented the device for controlling the fire of a machine-gun so as not to strike the blade of the propeller, but it is admitted that the Germans were the first to make any extensive use of it, introducing it on the Fokker monoplanes, which caused so much damage on the Western Front in 1915. Shortly thereafter the Allies adopted similar devices. When the United States entered the war neither the Ordnance Department nor the Aviation Section of the Signal Corps had had any experience worthy of the name with aircraft guns. And if they were ill-informed on the subject of guns, they were appallingly ignorant on the subject of gun controls. A few months of study and experiments served to materially increase the War Department’s knowledge along these lines, however, and by the time the planes were ready to receive the guns we had adopted a device known as the Constantinisco control. I should explain, perhaps, that there are two distinct types of gun control, both of which were in use when hostilities ceased. One is hydraulic, the other mechanical. The operation of both types is somewhat similar. In each case a cam mounted on the shaft of the engine actuates a plunger which in turn operates the rest of the mechanism. In the mechanical gun control the impulse of the cam is transmitted to the gun through a series of rods, causing the gun to fire at the exact moment when there is no propeller-blade in front of the muzzle. In the hydraulic type the impulse of the cam is transmitted to the gun through a system of copper tubes containing oil under high pressure. The hydraulic control, known as the Constantinisco, was adopted for use on American planes, particularly the De Havilland 4, which carries two fixed Marlins, each firing at the rate of 650 shots a minute. By employing the maximum rate of fire, 1,300 shots could be fired in a minute through the blades of the propeller, which would make 1,600 revolutions in the same space of time—without the blades being struck by a single bullet.
A machine-gun intended for aerial use must be absolutely reliable in operation. If a gun jams on the ground there is usually time to overhaul it or to replace it. Not so in the air. There a jam or a malfunction is almost certain to prove disastrous, if not fatal, to the gunner, who is left completely at the mercy of his adversary. An aircraft gun must also function properly in any position in which it is likely to be placed by the manœuvres of the plane. Likewise, an intensely high rate of fire is essential. For groundwork 500 shots per minute is reckoned as sufficient for the machine-gun, for a higher rate of fire would only result in several bullets hitting the same man. But a considerably higher rate of fire—up to 1,000 shots a minute, in fact—is demanded of aircraft guns, this being necessitated by the great speed at which airplanes move. The gunner, remember, can train on his target for only a few seconds, sometimes for only a fraction of a second, at a time, and it is essential, therefore, that he should have at his command the greatest possible volume of fire. Do you appreciate that, were an airplane flying parallel to, say, a high board fence, at a speed of 100 miles an hour, and shooting at right angles at that fence with a gun firing 880 shots a minute, the bullet-marks on the fence would be ten feet apart?
Single-seater machines carry only fixed guns, which are mounted with the barrel parallel to the axis of the airplane. These guns, which are synchronized so as to shoot through the propeller, are put into action by a trigger on the “joy-stick” of the plane and are aimed by pointing the entire airplane at the enemy. Flexible guns are used only on two-place machines, being operated by the observer or gunner. They are carried on the Universal mount, which permits of the gun being pointed in any direction. All of the flexible aircraft guns used by the Allies were based on the principle of the Lewis gun, the invention of a retired American army officer, Colonel Isaac Lewis. The chief difference between the ground and aircraft models is that in the latter the cooling radiator is eliminated, as aircraft guns are never fired continuously for any length of time.
When the United States entered the war the Vickers was the only type of fixed gun in use on either English or French planes and was used on all the planes which General Pershing bought in France. When the Equipment Division of the Signal Corps faced the machine-gun situation in September, 1917, it was alarmed to find that the entire production of Vickers in the United States had already been contracted for to supply the imperative requirements of the infantry. There was another gun on the market at this time, however—the Marlin—and toward its development for aircraft use the officers of the Signal Corps bent all their energies. Though the Marlin was adopted in the face of violent opposition, it resulted in providing sufficient fixed guns to arm the American planes, the wisdom of the action being proved by the fact that up to the time of the Armistice no other fixed guns were ready for delivery. The Marlin has been adapted to all American-built planes which carry fixed or synchronized guns, over 37,000 having been produced up to December, 1918. This gun shoots.30-calibre ammunition at the rate of 600 to 650 shots a minute and is fed from a belt of the disintegrating metal-link type. In December, 1917, the first order was placed for Lewis aircraft guns, over 39,000 of them being delivered to the American Air Service within the following twelvemonth. A notable improvement in the aircraft model of the Lewis gun was an increase in the depth of the magazine pan, so that each magazine holds 97 cartridges instead of 47 as previously. The Browning aircraft machine-gun was just coming into production when the war ended. This weapon embodies the best features of every known machine-gun and would probably have replaced all other types in use. It is a belt-fed gun of the recoil type—both the Marlin and Lewis are gas-operated—is as near fool-proof as a machine-gun can be made, and has the amazing rate of fire of 950 shots a minute. Of it the inventor is said to have remarked: “If it had four more parts it could play a tune; if it had seven more parts it could talk.”
The ammunition for fixed aircraft guns, such as the Marlin and Browning, is carried in belts containing a maximum of 500 rounds. In the earlier days of the war these belts were of woven web, but it was found that taking care of them, when empty, in the limited space of the fuselage, was always a source of annoyance and not infrequently a source of danger to the aviator. To remedy this a belt was designed and furnished to the American Expeditionary Forces which consisted of small metallic links held together by the cartridges themselves. As the gun fires, the links drop apart, chutes being provided so that they fall clear of the airplane. Another minor though interesting feature of aircraft armament is the small electric heater which is now provided for the purpose of keeping the gun warm and thus preventing the oil from congealing in high altitudes.
Efforts to make the bursts of fire from aircraft guns of maximum effectiveness have led to the development of three distinct types of ammunition—tracer, armor-piercing, and incendiary. The tracer type of ammunition was developed to assist the gunner in correcting his aim, and is equally useful by night or day, as the course of the bullet can be traced by a trail of white smoke in the daytime and by a bright spark at night. Armor-piercing ammunition has a projectile consisting of a hard steel core with a soft nickel casing. The object of this ammunition, as its name implies, is to pierce any of the metallic parts of an enemy plane, particularly the gasoline-tanks or the engine, the soft nickel casing acting as a lubricant and preventing the steel core from glancing off. Incendiary ammunition is loaded with yellow phosphorus. When the cartridge is fired the rifling in the barrel of the machine-gun opens a small hole in the case of the projectile, thus permitting the phosphorus to come in contact with the air, whereupon it immediately ignites and sets fire to any inflammable part of a plane which it may hit. It is customary to load the belts or pans of aircraft machine-guns with these three types of special ammunition in a certain sequence, depending upon the notions of the pilot himself. A sequence commonly used was, first, the tracer cartridge, which assisted the gunner in correcting his aim; next, two or three armor-piercing cartridges, in the hope that they would pierce the enemy’s gasoline-tank or damage his engine; and then one or two incendiary cartridges, which if the gasoline-tank was pierced would ignite the leaking gasoline and set fire to the machine. This sequence was continued throughout the loading of the belt or pan.
Another branch of sky warfare which was being rapidly developed was aerial bombing. Though bombs of a sort were used by Italian aviators against the Arabs during the Libyan campaign, and by American soldiers of fortune serving with the Villista forces in northern Mexico, these attempts were so amateurish and ineffective as to merit no serious consideration. It may be said that the first bombs dropped from an aircraft in the history of warfare were those loosed from the German Zeppelin which raided Antwerp in August, 1914. I speak with a certain personal knowledge of my subject, for the first bomb dropped on the night in question exploded less than a hundred yards from the window in which I was sitting, demolishing a house and killing three persons.
Many people seem to be under the impression that bomb-dropping is about as simple as dropping a brick out of an upper-story window onto the head of a man beneath. This is not so. As a matter of fact, it is extremely difficult to drop a bomb from an airplane so that it will hit a desired target, for, owing to the speed at which the plane travels, the bomb when released does not drop to the ground vertically, but falls in a parabolic curve, something like that described by a man who jumps from a street-car when it is in motion. For this reason the bomb must be released some moments before the airplane is directly over the target, the ability of an aviator to determine the exact moment to pull his release mechanism being acquired only through long experience. Bomb-sights have recently been perfected, however, which have largely eliminated this element of chance. These sights have numerical scales mathematically calculated, so that when adjusted for height, air-speed as shown by the air-speed indicator, and calculated speed of the wind with or against the airplane, two sighting points are moved into such a position that if the bomb is dropped when the desired target comes in line with them, it will reach its objective—provided, of course, the aviator has made his calculations and set his sights correctly. All this sounds rather complicated, I know, and it is complicated, but if the pilot uses the sight correctly his chances of hitting his target are enormously increased. All bombing planes are fitted with quick-release mechanisms, which hold the bombs firmly in a vertical or horizontal position, according to the type and size carried. On the smaller bombing planes, such as the De Havilland 4, the release mechanisms are placed underneath the fuselage or the lower wings, but on the large types, such as the Handley-Page, the bombs are carried inside the fuselage. By a quick jerk of a lever the pilot releases his bomb precisely as a hangman, by jerking a lever, drops the trap on which the condemned man stands. And the consequences are usually much the same in both cases.
There were three distinct types of bombs—demolition, fragmentation, and incendiary—in use by the American Air Service when the war ended. American demolition bombs are made in 50, 100, 250, 500, and 1,000 pound weights, the 100 and 250 pound sizes being used chiefly. These bombs consist of a light steel casing filled with TNT or other high explosive and a detonator separated from the explosive by a safety-pin. When the bomb is released from the airplane the safety-pin is automatically pulled out, permitting the detonator to slide down into such a position that the bomb will explode the instant it strikes the ground. These demolition bombs are primarily designed for use against buildings, fortifications, and other heavy structures where a high-explosive charge is desired. Had the war continued long enough to have permitted of our aviators letting loose a few 1,000-pound bombs on some of the trans-Rhine strongholds, the Germans would have learned what the San Francisco earthquake was like. Fragmentation bombs are considerably smaller, the size most frequently used weighing twenty pounds. They have a thicker case than the demolition bombs and are constructed so as to explode a few inches above the ground. These bombs are for use against troops in trenches or in the open and depend upon the scattering of the fragments for their effect. Incendiary bombs weigh about fifty pounds and contain charges of oil emulsion, thermite, and metallic sodium, which burn for several minutes with the intense heat of a plumber’s blow-lamp. They are used against ammunition-depots, storehouses, and other structures of inflammable construction, the purpose of the metallic sodium being to discourage the efforts of any one who attempts to put out the fire, as it explodes violently when water is poured on it.
Comparatively few persons realize, I suppose, that fireworks almost identical with those we used to set off on the Fourth of July in the good old days before the safe-and-sane laws went into effect are utilized in aerial warfare and form a valuable and often vital asset for the aviator. Most of these aerial pyrotechnics resemble in their effects the colored lights and the Roman candles of our childhood and are used for signalling from the airplane to the ground and vice versa, or from one plane to others in the air at the same time. For this purpose every active service airplane carries one or more signalling pistols, depending upon the number of the crew. These rather formidable-appearing weapons, which look not unlike the big-barrelled affairs the pirates were wont to carry in their scarlet sashes, are similar to the Very pistols used in the trenches; their ammunition consists of cartridges very similar to shotgun shells, but larger, containing stars of various colors, like those in Roman candles, and the necessary powder charge to eject the stars. Three colors, red, green, and white, are furnished, the color of the star being indicated on the base of the cartridge, which is also serrated in such a manner that the aviator can tell the color by touch when flying at night. By different combinations of these colors an almost endless variety of signals can be conveyed. One of the strangest and most fascinating night sights on the Western Front was to see these countless stars, scarlet, yellow, emerald, shot from invisible airplanes, drifting across the purple velvet of the sky. The stars are clearly visible in the daytime and were used for many purposes, such as indicating the position of enemy troops, the presence of hostile aircraft, requests for assistance from other planes, and as a means of transmitting orders from the leader of a squadron to other machines in formation. At night the signalling pistol is of exceptional value in aiding the aviator to effect a safe landing. When approaching his home-field the pilot fires a light of a prearranged color, and if answered by a light of a proper color from the ground, he knows that the field is clear of obstructions and other machines and safe to land on. Pilots have also used their signalling pistols for firing into their gasoline-tanks and thus setting fire to their machines when forced to land in enemy territory. There are also a few cases on record of the pilot being able to hold enemy soldiers at bay with his signalling pistol long enough to prevent them from extinguishing the fire.
Night-flying is one of the most hazardous duties of the aviator, the chief danger being in the difficulty of making a safe landing. Night-landing fields are, as a rule, well illuminated by flood-lights, but near the front this was not always advisable or safe, and, owing to the difficulty of judging the distance of the machine above the ground in the darkness, accidents were by no means uncommon. In order to minimize this danger there was developed the “wing-tip flare,” which consists of a small cylinder of magnesium material in a metallic holder, one of which is fitted under each lower wing of the plane. The flares are ignited by an electric current and are controlled by push-buttons, one for each flare, in the pilot’s cockpit. In making a night-landing, when the pilot judges the plane to be but a few feet above the ground, he presses one of the buttons. The flare instantly ignites and for about fifty seconds burns with a light of approximately 20,000 candle-power, which, reflected on the ground by the under surface of the wing, enables the pilot to judge his distance and effect his landing without trouble.
The requirements of night-bombing have led to the development of a new and very interesting form of pyrotechnic known as the “airplane flare.” This flare, which weighs thirty-five pounds, is contained in a cylindrical case of sheet-iron about four feet long and five inches in diameter. The flare consists of an illuminating charge, capable of giving 32,000 candle-power for approximately ten minutes, which is attached to a silk parachute twenty feet in diameter. The cylinder is attached to the airplane by a light release mechanism similar to those used for holding bombs. On the end of the cylinder is a small pinwheel, which, revolved by the rush of air as the released cylinder hurtles downward, ignites the illuminating charge and at the same time detonates a small black-powder charge sufficient to eject the flare and its tightly rolled parachute from the case. The parachute immediately opens and the burning flare descends very slowly, illuminating a large area of territory underneath almost as brightly as though it were day. These flares were used particularly for night-bombing raids, the pilots thus being enabled to illuminate the objectives so that they could accurately drop their bombs. On several occasions, when raiding airplanes were met by heavy fire from the enemy’s antiaircraft batteries, it was found that the light from these flares was so dazzling as to make it impossible for the gunners to take accurate aim. So wide is the radius illuminated by these flares, and so intense their light, that it has been found possible by their aid to obtain aero photographs of excellent detail even on the darkest nights. I can personally vouch for the amazing brilliancy of these flares, for I saw one dropped by the Germans during one of their air-raids on Paris in the summer of 1918. It apparently landed on the Pont Alexandre III or in the Seine, yet both banks of the river, the façades of the Grand and the Petit Palais, and the Champ Elysées for several blocks in both directions were almost as bright as though illuminated by a midday sun. Standing alone in the Cours de la Reine, I had the feeling that the Kaiser’s eye was on me and that, having discovered me, he intended to drop upon me one of his steel visiting-cards. The brilliancy and unexpectedness of the glare reminded me of boyhood days in the Thousand Islands, when the captain of the Island Wanderer, making his nightly excursions amid the clustered, cottage-dotted isles, took keen delight in suddenly turning the beam of his powerful search-light upon some affectionate pair love-making on the shore.
It has been said that the airplane is the eye of the army, and it is equally true that the camera is the eye of the airplane. Nothing more strikingly emphasizes the enormous importance attached to pictures taken from the air, showing the progress of the operations, than the fact that, during the offensive in the Argonne, the American photographic sections made one hundred thousand aero photographs of the battle-lines in four days.
As aerial photography was an entirely new military subject at the outbreak of the war in 1914, there were no precedents to act as guides, nor was there any special apparatus in existence. Consequently, the entire art of aerial photography was developed and brought to its present state of perfection by the Allies under the incentive of military necessity and after the war had begun. As trench warfare made aerial photography not only important but vital to the success of any proposed operations, the changes and improvements in the apparatus employed came with incredible rapidity, practices employed one week becoming obsolete the next. By April, 1917, the British Air Service alone had issued approximately 280,000 prints, and this number was equalled, if not surpassed, by the French Section Photographique. At the beginning of the war it was possible to fly at low altitudes and secure reasonably satisfactory pictures with such cameras, plates, and lenses as were then available. But as antiaircraft artillery was developed, the planes were forced to climb higher to keep out of their range, and owing to the necessity for longer-focus lenses, special plates, and color filters to overcome the haze existing between the camera and the earth, photography at these high altitudes became increasingly difficult.
When the United States entered the war the British, French, and Italians were using plates exclusively and we followed their lead, it not being until some months later that we turned to films. At this time the British were using 4 × 5 plates, and cameras equipped with lenses of from 8 to 12 inch focus. Instead of making contact prints from these negatives, enlargements 6½ × 8½ were made on glossy paper, it being claimed that this process gave greater control in printing. Whether the British system really had all the advantages claimed for it is open to question, but in any event we adopted it and followed it through the first nine months of the war. The great masters of photography in Rochester were by no means content to let another nation set the pace for the United States, however, and in January, 1918, a concern in that city completed a very remarkable aero camera, radically different from anything which had been seen in Europe up to that time, which was promptly adopted by the War Department. This camera, which took an 18-cm. by 24-cm. picture, had a focal length of 20 inches, held a roll of film on which 100 successive exposures could be made, and weighed only 35 pounds. Its most novel feature was the “vacuum back,” consisting of a perforated sheet which extended across the top of the chamber and over the face of which the film passed. A slight air-suction, produced by a Venturi tube placed where it would catch the rush of air past the plane, served to hold the film absolutely flat—for the slightest curvature of its surface would play havoc with the perspective of a picture taken from a height, say, of 10,000 feet. This ingenious instrument was driven by an electric motor which changed the film and automatically set the shutter, the observer having only to start the machinery going and regulate its speed according to the rate of travel of the airplane in order to obtain a series of pictures forming a continuous photograph of the territory over which the machine was passing.
Another picturesque phase of aerial photography of which the public was permitted to know next to nothing was the so-called “gun camera,” the invention of Thornton Pickard, of Altringham, England. This camera, which was designed for the purpose of training aerial gunners, imitated as closely as possible a Marlin aircraft machine-gun, and in order to make a picture it was necessary for the operator to go through the same movements as in firing a Marlin gun. The picture was made through a circular graticule synchronized with the sight on the fixed machine-gun, so if the film, upon being developed, showed that the gunner had scored a “hit” with the camera, he would have been equally successful with an actual machine-gun. The gun cameras as developed in the United States were of two kinds: one, using a regular Brownie film, took one picture each time the trigger was pulled; the other, which was virtually a motion-picture camera so constructed as to exactly replace the magazine on a Lewis gun, gave a “burst” of exposure with a rapidity equalling that of a machine-gun firing a burst of shots, and was used for training aviators in the handling of their flexibly mounted Lewis guns. The resulting film, or bromide print, consisted of a string of silhouettes of the supposed enemy plane, each with an image of the gun-sights superimposed to show where the gun was held, with reference to the target, at the instant the picture was taken.
The enormous numbers of pictures taken from the skies necessitated a corresponding development and manufacture of travelling dark rooms, seventy-five complete units of these machines being built and shipped overseas. These consisted of mobile photo laboratories, having all the equipment necessary for the rapid production of prints in the field, for when important operations are in progress it is imperative that the aero photographs reach the staff at the earliest possible moment after they are taken. The dark rooms, which were mounted on trucks, were equipped with apparatus for generating the current used in the lamps and enlargers, while trailers were fitted with sinks, tanks, enlarging cameras, and other necessary photographic apparatus. The fact should not be overlooked, moreover, that provision had to be made for training the vast and for the most part inexperienced personnel of the photographic sections in the countless new and peculiar phases of taking pictures from the skies.
In considering the development of military aeronautics it must be borne in mind that the maximum altitudes attained by airplanes increased enormously during the war. In 1914 the record for altitude was 26,246 feet, or slightly less than five miles. By January, 1919, the record had been raised to 30,500 feet, an increase of more than four-fifths of a mile. In 1915 the Western Front pilots worked at 7,000 feet without fear of attack from the ground, and few machines flew at heights of more than 10,000 feet. In fact, the “ceiling” with the early equipment was about 12,000 feet. In the closing months of the war, however, as a result of the development of the antiaircraft artillery, it became necessary for aviators to climb to 15,000 feet over the enemy lines, and tactics of the air made that machine safest which could fly highest.
Now it may not have occurred to you that the higher you ascend the greater becomes the decrease in atmospheric pressure. At 19,000 feet the pressure of the atmosphere is one-half the pressure at sea-level. That means that a given amount of air in the lungs of an aviator flying at that height gives only half the oxygen that it would were he on the ground. It is, then, the lack of oxygen, and not, as many suppose, the low pressure itself, which makes men weak and slow of action at high altitudes. Though these facts have been determined by medical research, it is a curious phase of the flyer’s psychology that most aviators laugh at the idea. Yet any one who has crossed the Rockies or ascended one of the Alpine peaks by funicular has noticed that as the altitude increases the breathing becomes quicker and deeper, the heart beats faster and faster. But though the pilot may, as he asserts, continue to feel perfectly fit and well, he is not as efficient as when near the ground. His reactions become slower, he is less prompt to judge distances, to aim his guns, to fire, to manœuvre his plane—and this despite the fact that he is usually quite unconscious of any impairment of his faculties. He will feel dizzy but perfectly happy—autointoxication, I believe the doctors call it—whereas, as a matter of fact, he has lost his judgment; and if he attempts to stay at these altitudes he will gradually pass into a condition of partial and sometimes total unconsciousness, lose control of his machine, and come crashing to the earth.
The imperative necessity of maintaining flyers at the highest possible efficiency was brought home to the aviation authorities through studying the reports of English air-casualties during the first year of the war. The records divided these as follows: 2 per cent were due to the enemy, 8 per cent were due to the plane, and 90 per cent were due to the men, which clearly indicated that something was radically wrong with the personnel and that prompt action was necessary. A thorough study of the situation disclosed the fact that practically all of the flying personnel was suffering from what is known to scientists as oxygen fatigue, caused by flying for many hours a day at high altitudes where there was not enough oxygen to feed the body. As a result of this discovery, Lieutenant-Colonel Dreyer, of the Royal Army Medical Corps, designed an oxygen apparatus for use by the British air forces, the manufacture of which was immediately begun in Paris. So pressing was the need for these apparatus that an automobile was kept waiting at the plant where they were being manufactured to rush each one to the front as soon as it was finished.
An original model of this apparatus was brought to the United States shortly after we entered the war, but as it was made entirely by hand, it had to be redesigned to meet our manufacturing conditions. The perfected oxygen equipment, as used in the American Air Service, consists of a small tank, or tanks, according to the amount of oxygen carried, a pressure device, a face-mask covering the mouth and nose, and a tube connecting the mask with the oxygen reservoir. The American mask has combined with it the interphone whereby the pilot and observer can converse with each other while in the air and, in certain cases, the receiver of the radio telephone. In May, 1918, six complete apparatus were sent overseas by special messenger to be tried out under battle conditions, and when the war ended 5,000 had been manufactured and accepted. All American military planes flying at an altitude of over 10,000 feet are now fitted for the installation of oxygen equipment. This includes day-bombing, pursuit, and chase planes, and a percentage of night-bombing and observation machines. So much importance was attached by the military authorities to supplying our flying-men with oxygen that a special oxygen division was organized and sent to France for the purpose of installing the apparatus in the planes. Yet, as I have previously remarked, the flyers themselves persist in regarding the apparatus, probably because of the discomfort involved in wearing it, with amused scepticism.
Of all the inventions which have sprung from the war, none is more amazing, to my way of thinking, than the radio telephone. Think of standing on the ground and holding a conversation in a normal tone of voice with an aviator so high in the sky that you cannot see his airplane with the naked eye. Think of it! Before we entered the war, any one save a handful of enthusiastic scientists would have ridiculed such a suggestion, yet to-day, at any one of a score of flying-fields, you can sit at an office desk and converse with aviators in the clouds as easily as though you were sitting opposite them at a dinner-table.
The enormous advantage which such an invention would give to the army possessing it was early recognized by certain electrical engineers and a few scientifically minded officers of the Signal Corps, and, as a result of their enthusiasm, before the first contingent sailed for France work had been begun on the development of a radiotelephone set for airplanes. There is no necessity of recounting the innumerable experiments and heart-breaking failures before the first real successes were obtained. So far as the radio part of the problem was concerned, a solution was had in a comparatively short time. But working this apparatus in a swift-moving and terrifically noisy airplane was quite a different matter, it was quickly discovered, from working it under ordinary conditions on the ground, the roar of the engine and the rushing air making it impossible to hear one’s own voice, much less the weak signals of the receiver. One of the first problems to be solved, therefore, was to design a head-set which would exclude these noises while at the same time permitting the voice of the telephone to be heard. The answer was found in a form of aviator’s helmet fitting the head so closely as to exclude virtually all extraneous sounds save those coming through telephone-receivers inserted in the helmet so as to fit the ears. No sooner was this problem solved, however, than another one demanded solution. A means had been devised for protecting the receivers from outside noises—but how about the transmitter? Every one knows how sensitive the ordinary telephone-transmitter is to extraneous sounds, so it does not require much imagination to picture how impossible it would be for the aviator to make his voice heard in a transmitter alongside a 200 horse-power airplane engine. But a brilliant series of experiments, conducted largely by Mr. J. P. Minton, of the Western Electric Company, resulted in a form of telephone-transmitter or microphone which possessed the remarkable quality of being insensible to engine and wind noises and at the same time highly responsive to the tones of the voice. With these two elements in hand it was thought that the problem was solved, but three more months of unremitting work were required to perfect the apparatus to a state where it was practicable for use by others than experts. At last everything was ready, however, and in December, 1917, the officials of the Aircraft Production Board and the joint Army and Navy Technical Boards announced that they would witness an exhibition of the apparatus at the Moraine Flying-Field at Dayton. Two days before the date set for the demonstration a group of the engineers and mechanics who had been working over the problem almost night and day during the preceding six months descended, with many cases of paraphernalia, on the Ohio town. Only the enthusiasts who for the preceding half-year had spent their days working over the problem and their nights dreaming of it believed that the exhibition would prove successful. Every one else was sceptical. The plan was to have two planes, both carrying radio sets, in the air at the same time, while the visiting officials listened in at a ground-station located on the top of a near-by hill. That night the inventors and their assistants congregated in a room of the hotel where they were staying and worked out a scenario and held a rehearsal of the morrow’s programme. A famous electrical expert represented one plane and a young engineer represented the other, while the inventors, sitting in the middle of the room, gave them their orders and sent them sailing over beds, chairs, and tables as it was hoped their planes would manœuvre in the clouds the next day. No one slept very well that night. The morning was cold and dismal, in keeping with the spirits of all concerned. Upon the arrival of the exalted ones, among whom were several of the foremost scientists and inventors of America, they were shown the apparatus installed in the two planes and were told what it was expected to do. They were then escorted up to the little station on the hill, where a loud-speaking receiver had been connected with the wireless apparatus, so that all could hear without the use of head-sets. The planes left the ground, and after what seemed an interminable length of time, there came from the receiver the first faint sounds which indicated that they were ready to perform. The officials, with their coat-collars about their ears, appeared only mildly interested and several gave unmistakable signs of being bored. Suddenly, without the slightest warning, out of the horn of the loud-speaker came the words: “Hello, ground-station! This is Plane Number One speaking. Do you get me all right?” The bored expressions on the faces of the officials changed to expressions of amazement tinged with awe. Instead of the confusing dash-dot-dash which they associated with wireless, here was a human voice coming out of space clear and distinct—yet the speaker was two miles in the air. Soon the same signal came from the other plane and the exhibition was on. Under command from the ground the planes were manœuvred all over that part of the country. They climbed and volplaned and circled. They were sent on scouting expeditions and reported what they saw as they travelled through the air. Continuous conversation was carried on, even when the planes were out of sight, and finally, upon command, they came tearing down the skies like two huge homing pigeons and landed where directed. From that moment the radio telephone was sold to the government. It was no longer a question as to whether it would work, but how soon and in what quantity its manufacture could be started.
The primary object of the airplane telephone is to make it possible for the commander of an air-squadron to control the movement of his men in the air just as a drill-sergeant directs the evolutions of a platoon on the ground. For this purpose extra-long range is not required or, indeed, desired, the distance over which they can talk being purposely limited to two or three miles, so that the enemy cannot overhear except when actually engaged in combat. Then it does not matter.
Neither my space nor my knowledge of electrical engineering are sufficient to permit of explaining in detail the working of the radio telephone. It is enough to say that a wind-driven generator supplies electric current to a couple of vacuum tubes mounted in a box filled with coils and condensers. These tubes transform the dynamo current into a high-frequency alternating current which is fed out into space through the antenna. This antenna consists of a copper wire about 200 feet long, which with a lead weight on the end trails out behind the airplane when it is in flight. Normally this wire is wound up on a reel, being let out and wound in as occasion demands. With the special form of telephone-transmitter already described, the words of the aviator are impressed on this wire, the electric waves thus set in motion radiating out into space, where they are picked up by similar antennæ either on other planes or on masts on the ground. The receiving process is the exact reverse of that used in sending, other vacuum tubes taking the high-frequency current from the antenna and transforming it so that it can be heard in the form of speech in the telephone fitted in the aviator’s helmet or in the loud-speaking horn on the ground. That is about as near as I can come to explaining the radio telephone without writing a book.
One of boyhood’s most joyous recollections is that of “balloon day” at the county fair, when the great yellow spheroid in the middle of the race-track enclosure slowly filled (oh, so slowly, it seemed!), bulged, tugged at its moorings, and at last rose majestically skyward, the aeronaut, a lithe figure in spangled tights, waving down to the sea of upturned faces as he swung at ease in his cobweb-like trapeze. But, though the recollection of the balloonist’s skill and daring remains sharp and clear in our minds, so much space has been devoted in the war books and the news despatches to the exploits of the aviators that we seem to have completely lost sight of the no less hazardous work of those daring souls who, day after day, in heat and cold, in snow and drenching rain, sat huddled in their frail baskets under the swaying gas-bags, often a mile above the ground, and through their glasses watched what the enemy was doing, heedless of the repeated attempts made by the enemy’s gunners and flyers to bring them down. Though they have received practically no share of the publicity and praise which has been showered upon the flying-men, the officers and men of the Balloon Section of the Air Service deserve from the public its deepest gratitude and appreciation. The perilous nature of their work is shown by the fact that in the last six weeks of the war twenty-one American balloons were lost, six being destroyed by shell-fire and fifteen by enemy planes. Its importance is emphasized by the fact that the Germans gave official credit to their aviators of one and a half planes for every balloon brought down.
At the beginning of the war the artillery-fire of the Allies was directed for the most part by airplanes. Their work, however, left much to be desired. Though the plane observers could locate targets fairly well, they frequently lost touch with their batteries through the difficulty of sending and receiving wireless or visual signals from the swiftly moving craft. Thus there came into use the captive balloon, which by the end of the war had practically replaced the airplane as a director of gun-fire wherever possible, thus making the artillery infinitely more efficient than ever before. Sitting comfortably aloft, the observer in the basket of a kite-balloon had the whole panorama of his particular station spread beneath him like a map in bas-relief, being able to detect, with the aid of powerful glasses, anything transpiring within a radius of ten miles or more. He was constantly in touch with his batteries by telephone and could not only give the gunners, by means of co-ordinated maps, the exact location of their target and the effect of their bursting shells, but could keep the staff informed of enemy troop movements, airplane activities, and preparations for impending attacks. The balloonist became, indeed, a veritable sentinel of the skies, hovering over the battle-lines with the persistency and the keen, long-range vision of a hawk. He played a less spectacular part in the great drama than the airplane scout or fighter in the latter’s free and dazzling flights, but his duties were scarcely less important. Nor did he suffer from ennui during his stays aloft. When a kite-balloon went up along the battle-front it at once became the subject of the keenest attention by the enemy because it was known to be up on business and was certain to be the cause of damage unless it was forced down. Long-range, high-velocity guns were trained on it and, from the upper levels of the air, planes came swooping down upon it in their attempts to dash through the screen of shells from the antiaircraft guns and put an incendiary bullet into the sausage-shaped, elephant-colored gas-bag which so insolently defied them. And a bullet which got home meant the instant ignition of the highly inflammable hydrogen, the quick destruction of the balloon and, perhaps, the occupants of the basket as well, unless they could get away in their parachute. From the moment the gas leaped into flame until the fall of the balloon was rarely over fifteen or twenty seconds, so quick thinking and quick work was called for if the men in the basket were to jump to safety. The pilot of the airplane could dodge and swerve and slip away from the guns by a hundred shrewd devices; not so the pilot of the kite-balloon anchored to its windlass. He had to carry on his abstruse mathematical calculations unconcernedly, his spare moments being enlivened by watching the flash of an enemy gun on a distant hill and then waiting twenty or thirty seconds for the whining messenger of death to reach him, pondering, meanwhile, on the accuracy of that particular gunner. As a matter of fact, few direct shell-hits on a balloon were recorded during the war, most of the balloons which were brought down having been accounted for by incendiary bullets from diving planes. Just as some sportsmen devote their energies to moose and elk and grizzlies while others specialize on smaller game, so some of the airplane pilots made a specialty of hunting “sausages,” and at this thrilling and highly perilous sport became amazingly expert. When the Crown Prince’s assaults on Verdun were at their height, I saw eight French aviators start out to bring down eight German balloons. Within less than thirty minutes seven of the drachen had come down in flames—which shows that a balloonist was not a good life-insurance risk. The average life of an observation balloon on the Western Front was estimated to be about fifteen days. Sometimes it lasted only a few minutes. There is a record of an American balloon passing unscathed through the whole period of American activity on a busy sector, but it was generally considered that a balloon which has seen five or six months of ordinary non-war service has done its duty and is unsafe because of the deterioration of the fabric.
In August, 1914, Germany had perhaps a hundred kite or “sausage” balloons, France and England a very few. The German type was known as the “Drachen,” and consisted of a gas-cylinder of rubberized cloth about sixty-five feet long and twenty-seven feet in diameter, with hemispherical ends. For stability a lobe, about a third of the diameter of the cylinder, was attached to the underbody of the gas-bag and curved up around the end. This lobe, made of a lighter fabric than the bag itself, automatically filled with air as the balloon ascended and acted as a rudder to hold the balloon in line. For further stability three tail-cups, one behind the other, with mouths open to the wind, were attached to the rear of the balloon.
While the Drachen balloon was a rather clumsy affair and proved unstable in high winds, its importance as an adjunct to the artillery was early recognized by the Allies, for the results of its work daily became more apparent. Though the armies of France, England, Italy, and the United States made repeated experiments in an attempt to evolve a type which should possess greater stability and permit of higher altitudes being attained, it remained for Captain Caquot, of the French Army, to produce a balloon which possessed both of these qualities, his name now being used as a designation for the type which he invented and which was in general used by the Allied armies during the last year of the war. The Caquot received its greatest compliment from Germany when her army adopted this type of balloon and discarded the Drachen.
The Caquot is an elongated gas-bag, ninety-three feet long and twenty-eight feet in its widest diameter, made of rubberized cotton cloth and sharply streamlined. Hydrogen gas is the ascensive power used, lifting the cable, two men, basket, and all other equipment to a maximum altitude, in the best weather conditions, of over 5,000 feet. It has a balloonet, or air-chamber, within the main body of the gas-envelope, which as the balloon ascends fills automatically with air through a simple scoop placed under the nose of the balloon. The air and gas chambers are separated by a diaphragm of cloth. When the balloon is fully inflated this diaphragm rests on the underbody of the gas-envelope, there being no air in the balloonet. When the balloon descends, minus the several hundred feet of hydrogen which has escaped into the air, it would lose its shape and grow flabby, a condition of considerable potential danger, were it not for the balloonet, or air-chamber, coming into play. As the air is driven in through the scoop, precisely as an air-scoop fixed in the port-hole of an ocean liner brings air into a cabin, the diaphragm rises and takes up the lost bulk in the gas-envelope above. In other words, the escaping gas is replaced by air by means of what amounts to an elastic air-envelope below the gas-envelope. Is that quite clear? Three lobes of rubberized fabric give stability to the balloon. They are filled automatically by the wind, if it blows, and, expanding to their full capacity, act as rudders to hold the balloon steady. If there is no wind there is, of course, no need for the lobes and they hang loosely, like elephants’ ears, Caquots frequently being called “elephants” because of these drooping lobes.
When the United States entered the war we were practically without this type of aircraft, the only balloon possessed by our military forces on the Mexican border having been the gift of an Akron rubber company to the Ohio National Guard. In April, 1917, the whole production of military balloons in the United States was not over two or three a month, but at the request of the government the various rubber manufacturers went whole-heartedly into the business of production, so that when the war ended we were producing ten balloons a day. Up to November 11 there had been produced for the United States Army alone 1,025 balloons of all types, 642 of these being the final Type R Observation Balloon. Propaganda and target balloons were likewise developed and produced, as were new-type parachutes, canvas balloon hangars, and 1,221,582 feet of steel cable—a sufficient length of single-strand, specially manufactured wire to more than reach around the globe.
One of the chief difficulties which had to be overcome was the question of a sufficient supply of cotton cloth of proper strength and texture, for balloon cloth was practically unknown in this country when we entered the war. In order to keep up with the balloon schedule of the War Department, the manufacturers required millions of yards of a very high-grade cloth with a weave of 140 threads to the inch both ways. At first the wastage due to imperfect balloon cloth was enormous, frequently running as high as 60 per cent, but by care and effort this was reduced to perhaps 10 per cent in total from the loom to the balloon. The wastage was largely caused by “slubs,” knots, and other imperfections of weaving, which prevented an even surface for rubberizing and consequently impaired the strength and gas-holding qualities of the cloth. Hundreds of inspectors, both factory and government employees, were necessary to get an approximately perfect fabric, and all had to be developed for this work. Indeed, the making of balloon cloth in the United States amounted to the development of an entirely new industry, for which thousands of men had to be specially trained for months. It will give you a better conception of the magnitude of this new industry, perhaps, when I tell you that to make ten balloons a day it was necessary for the cotton-mills to weave about 600,000 yards of this special balloon cloth a month, and this required 3,200 looms. It is a tribute to the skill of the American weavers that reports from the front stated that the American fabric burnt very much more slowly than that made in Europe, thus giving the observer more time to get away in his parachute and minimizing the danger of the burning balloon falling on him.
Everything connected with the kite-balloon presented more or less of a problem because it was new. The mobile windlass, for example, by which the balloon was let up and pulled down on its cable, had to be developed from nothing. But the genius of the American manufacturer overcame this difficulty as it did every other in the manufacture of instruments for war. Though steam was the motive power first used for balloon windlasses, before the close of the war American ingenuity had developed both gas and electric windlasses which were thoroughly efficient. The mobile windlass could move on the road under its own power at a speed of twenty miles an hour, and could tow a balloon in the air at the rate of five miles an hour, or even better if necessity demanded. The gasoline windlass has made a record pull-down of 1,600 feet a minute, bringing down its balloon at a speed more than three times that of the fastest passenger-elevator.
A sufficient supply of hydrogen gas was, at the beginning, another of the balloon problems. Hydrogen, before the war, was a by-product in the manufacture of commercial oxygen, and only a small quantity was used in this country. But the sudden demand for millions of cubic feet of this gas was promptly met by the establishment of government plants and the expansion of privately owned ones. Though by far the greater part of the gas used in balloons at home and abroad was made at permanent supply stations and shipped to the points where it was needed, in steel cylinders, an extremely ingenious type of portable generator was developed for the manufacture of hydrogen in the field. When these portable hydrogen generators were unnecessary or unavailable, the gas shipped from long distances was stored in high-pressure cylinders or “nurse balloons,” the latter being simply huge bags of rubberized fabric, each with a capacity of 5,000 cubic feet of hydrogen, which were used in the same way as the ordinary steel gasometers to be seen in any American city.
Hydrogen is itself an inflammable gas, and when mixed with air or oxygen is dangerously explosive. It has, therefore, always been a source of great concern to balloonists, who had long dreamed of a non-inflammable, non-explosive gas, sufficiently light to function as does hydrogen. It was known that helium was such a gas, but it was, until very recently, so scarce and costly that its use in balloons had scarcely been given a serious thought. Not more than 100 cubic feet of helium had ever been produced up to the time we started our balloon programme, and it was valued at $1,700 a cubic foot. Scientific investigators in the employ of the government discovered about this time, however, that certain natural gases in the United States contained limited quantities of helium, and the problem then resolved itself into one of extracting the helium from these gases in sufficient quantities, and at a sufficiently low cost, to make practical its use. Funds were forthcoming and, under the supervision of the Navy Department and the Bureau of Mines, the process of gas liquefaction was put into operation, with the result that on the day of the Armistice there were on the docks, ready for shipment overseas, 147,000 cubic feet of helium with a pre-war value of a quarter of a billion dollars. Plants were under construction which, had the war continued, would have produced 50,000 cubic feet of this gas a day at a cost of approximately ten cents per cubic foot. The importance of this discovery cannot be overestimated, for it marks the opening of a new era in lighter-than-airship navigation. In war it will make the incendiary bullet, which has caused the destruction of countless balloons, a joke. The only way to bring down a balloon filled with helium will be literally to tear it apart by a direct hit with a high-explosive shell. Under peace conditions, it opens up undreamed-of possibilities in the development of new types of dirigible airships, as the danger from lightning, static electricity, and sparks of any kind has been entirely eliminated. To cross the Atlantic in a helium-filled balloon will be safer, so far as danger from fire is concerned, than to cross the continent in a train.
Do you remember that hot September afternoon at the county fair when you sat perched on the white-washed race-track fence, your face turned skyward, and watched with fascinated eyes the tiny yellow globule, high, high in the blue, which you had seen rise from the ground half an hour before as a giant gas-balloon? And do you remember how, as you watched, the band in the grand stand suddenly stopped playing and an awed hush fell upon the crowd, and you saw a tiny something detach itself from the yellow globule and drop into space, at first falling with sickening speed, then slower, still slower, until the object, which you knew was a man in pink tights (though sometimes, in order to heighten the sensation, it was a young and, of course, beautiful woman), landed quite gently in a distant field? In those days we little dreamed that the strange, umbrella-like contrivance which brought the aeronaut safely to earth would ever be used for any other purpose than to thrill the admission-paying multitudes, but the emergencies and necessities provoked by the Great War turned things with which we were all familiar to unfamiliar uses, as, for example, when it converted a farm tractor into a fighting-tank. Thus it was that the observers came to use parachutes to escape from their burning balloons just as the inmates of an office-building dash down the iron fire-escapes when somebody shouts “Fire!”
At first the individual or one-man parachute was used to insure the escape of the observer in the basket from his burning balloon, but though the man escaped, the valuable maps and records were lost. In order to save these records there was invented the basket parachute. This was considerably larger in diameter than the individual parachute, and when cut away brought the basket with all that it contained—men, records, instruments, everything—safely and quickly to the ground. All the observer had to do was to pull a cord and he started downward. It was easier than stepping into an elevator and saying: “Ground floor, please.” Amazingly few fatalities occurred in the hundreds of cases in which the individual and basket parachutes were used in actual war service or in training. I heard of one balloon observer who was forced to make four parachute jumps in a single day, and of another who made three in four hours, two balloons being burned over his head. Thirty parachute jumps were made by American observers during the Argonne offensive alone. Yet the safety of the parachute is demonstrated beyond all question by the fact that during the entire time the American forces were in the field only one death occurred as the direct result of a parachute drop, and in that particular instance the burning balloon fell directly on top of the open parachute, setting it on fire and allowing the observer to fall the rest of the distance to the earth.
It is interesting to note that the use of parachutes is relatively new compared even with ballooning. The man who developed the parachute and who first descended safely to earth by its means—Thomas S. Baldwin—now holds a major’s commission in the American Air Service, and during the war had direct charge of the inspection of all army balloons and parachutes. As the result of a life spent in performing aerial exploits of all kinds, under all conditions and in all parts of the world, Major Baldwin knows what is and what is not safe, so that when a balloon or parachute was sent into action the observer always had the satisfaction of knowing that the world’s most famous balloonist had given it his O. K.
Speaking of parachute jumps reminds me of an incident which actually occurred on one of the American sectors toward the close of the war. Despite the fact that only one American balloonist lost his life in making a parachute jump—and in that case the fatality was caused by the burning balloon falling on and setting fire to the parachute—a very considerable element of risk is involved in the performance. In fact, it became the custom to recommend a man making a parachute jump for the Distinguished Service Cross, or, if he was operating with the French, for the Croix de Guerre.
Just before the opening of the Argonne offensive an observation balloon over the American lines was attacked by a German plane and sent down in flames, the observer escaping by means of his parachute.
“You’ll get the D. S. C. all right,” his friends greeted him, as he disentangled himself from the parachute harness.
“We’re sending up another balloon in a few minutes,” said the commanding officer. “Want to try it again?”
“Surest thing you know, sir,” replied the grinning youngster.
But before the second balloon had been in the air an hour another enemy plane swooped down upon it, like a hawk on a chicken-yard, and it too burst into flame. Again the observer floated to safety beneath his parachute.
“I guess I’ve got that D. S. C. copper-riveted this time,” he remarked; but, when a third balloon ascended, he was in the basket. Once more a German plane came tearing down the skies, a stream of bullets ripped the silken gas-bag, and for the third time that day the observer reached the earth by the parachute route.
“You’ll probably get the Croix de Guerre as well as the D. S. C.,” his friends assured him. “The French are strong for this sort of thing. They may even give you the Legion of Honor.”
Treading on air, the youngster returned to balloon headquarters. Tacked on the bulletin-board in the hallway was a General Order. He paused to glance at it. This is what he read:
“It is hereby directed that the custom of recommending officers making parachute jumps for the Distinguished Service Cross or other decorations be discontinued.”
Though the question of providing proper clothing for our flying-men and balloon observers did not loom large when compared with the vast problems involved in the production of engines, spruce, balloon cloth, bombs, and machine-guns, it was nevertheless an exceedingly important one, for an aviator cannot do his work if he is cold, and it is always bitterly cold in the higher air-lanes. A man flying at 20,000 feet, say, suffers more from the cold than he would on the ice-fields at the North Pole. Aviators are commissioned officers, and when not at work wear the regular uniform, which, as in the case of all officers, is furnished by the officer himself. But the clothing required for work in the air, being of a highly special character and very expensive, is loaned to the flyers by the government. In view of this, it is a source of satisfaction to know that it was frankly admitted on the front that our flyers were by far the best and most efficiently equipped of any nation.
After many tests and much development, the following outfit was devised: On the head was worn, in moderate weather, first a woollen hood, or helmet, so designed as to fit closely over the entire head and shoulders. In extremely cold weather, or for high-flight work, there was worn a silk hood of like design and double thickness, having between its layers an electrically heated unit connected by copper-wire cables extending through the suit proper with the generator on the engine of the plane. Over this silk hood was worn a soft-leather helmet lined with fur, the face was entirely covered with a wool-lined leather mask, and the eyes were protected by goggles. When it was necessary for the aviator to use the radiotelephone, however, the fur-lined helmet was replaced by the radio helmet, a leather affair somewhat similar in design to the other but so fashioned as to contain the receivers of a wireless telephone. For high-flight work, in addition to the above equipment, a rubber oxygen mask, which contained a transmitter permitting the wearer to speak as well as hear by wireless, was also worn. This mask was attached by a flexible tube to a tank of oxygen carried in the plane, being so arranged that it automatically fed the aviator with the amount of oxygen required for the altitude at which he was flying.
Over the body was worn a one-piece flying suit of waterproof, airproof material, reaching from throat to feet, buttoned tightly at wrists and ankles, and lined throughout with fur. Through these suits, between the fur and the outer coverings, were placed wire cables terminating in snap-fasteners at neck, wrists, and ankles, to which could be attached silk-covered wires leading to other electrical heating units in the helmets, gloves, and moccasins, all of which were warmed by a current drawn from the generator on the engine. Hence, though our aviators not infrequently flew in a temperature of thirty degrees below zero, they were as warm and comfortable as though they were sitting before a log fire at home—much more comfortable, in fact, than were their relatives and friends in America on the fireless Sundays which made uncomfortable the first winter of the war. On his hands the aviator wore, in addition to the electrically heated gloves, a pair of muskrat gauntlets extending nearly to the elbow; on his feet, over the electrically heated moccasins, another pair of moccasins, lined with sheepswool, reaching almost to the knees. It is scarcely necessary to add that our air-fighters spent more time in dressing than does a chorus-girl in a comic opera, and that when they were dressed they looked like a cross between an Arctic explorer and a deep-sea diver.
The question of obtaining the fur for lining this clothing presented a perplexing problem, for there were required vast quantities of pelts or skins of extreme warmth and sufficiently strong to withstand rough usage, but not too bulky or heavy. After considerable investigation it was found that these requirements were met by the skin of the Nuchwang dog, which inhabits one of the provinces of north China, though I have no doubt that sable or ermine would have answered the purpose equally well had cost been no consideration. The demands of the American Air Service required practically all of these skins that could be had in China and necessitated the lifting of an embargo to bring them into the United States, which, thanks to the co-operation of the War Trade Board, was obtained. The last purchase before the Armistice was signed called for 500,000 of these dog-skins. A strange thing, was it not, that the lust for power of one William Hohenzollern, late of Berlin and Potsdam, should bring about, among countless other things, the slaughter of half a million dogs in far-off China? Though figures are, as a rule, dry things, the magnitude of the Air Service’s clothing problem can be better appreciated by my giving a few of them. The work in hand for air-clothing when the Armistice was signed involved upward of $5,000,000. Fifty thousand fur-lined flying suits at $36.25; over a 100,000 leather helmets at $4.50; a like number of leather coats at prices ranging from $10 to $30, and 80,000 goggles at $3.50 a pair reflect the major items and explain how the government spent some of the money which you paid for your Liberty Bonds.
Though in this chapter I have attempted to sketch the manifold phases of America’s preparation for obtaining supremacy in the sky, I have purposely left until the last the most important phase of all—the flying-men themselves. The personnel side of the Air Service, including the selection, training, organization, and operation of the flying forces, developed, within the year following America’s declaration of war, into one of the most remarkable educational systems in this or any other country, with a larger student body and a more diverse curriculum than any university in the world. Teaching men to fly, to send messages by wireless, to operate machine-guns in the air, to gauge the effectiveness of artillery-fire by its bursts, to read and make maps, to operate gas-engines, and to travel hundreds of miles by compass; teaching other men to read the enemy’s strategy from aerial photographs, and still others to repair instruments, ignition systems, propellers, airplane wings, and motors, required a vast network of schools and flying-fields, a huge force of instructors, many of whom themselves had to be trained, and an amazing mass of equipment and curricula.
The pilot is the heart and brain of the whole flying apparatus. Parts of the airplane may break without serious result, but when the pilot breaks, even momentarily, nothing is left to direct the flight. The man and the machine come crashing to the ground. The early view that any one who “had the nerve” could fly caused hundreds of unnecessary deaths and an enormous avoidable waste of material. The lesson, for which we paid in bitter and costly experience, was that it is essential to choose flyers who are especially fitted for particular work, and then to keep them in condition to perform their duties at all times by using the same thought and care which is expended in the feeding, exercising, and conditioning of a race-horse. Nature, remember, never intended man to fly in the same sense that she did not intend him for life in a submarine. Conditions are unnatural from the time he leaves the ground until he returns. There are countless obstacles which he must overcome. He flies in an atmosphere deficient in that oxygen which is “the breath of life”; he is subjected in war to the shell-fire of antiaircraft guns and attack by enemy aircraft; he travels through space at a speed far exceeding that of the fastest express-train. In attaining altitudes and breathing rarefied air, the flyer is shaking his fist in the face of nature.
It is imperative, therefore, to classify the flyer for the kind of work he is physically capable of performing. Some men are not able to fly at higher levels than a few thousand feet without suffering deleterious effects, while others may operate at five miles above the surface of the earth without physical harm. It is necessary to know a flyer’s limitations before his training is specialized, for the saving of time and money, and, indeed, the flyer himself. Just as the trainer of a varsity track team classifies his available material into sprinters, distance men, broad jumpers, high jumpers, and weight throwers, so the director of a flying-school must classify his material into men fitted for combat, observation, and bombing. It would be an obvious waste of time and effort to train a man for combat work at high altitudes and then discover that his physical limitations permitted only of his doing bombing work at comparatively low levels. In order to accomplish this work of classification, branch research medical laboratories were established at the various flying-fields, which, by means of certain standardized tests, especially the one on the “rebreather” machine, placed the flyers in their proper categories. The rebreathing tests were conducted in a room so designed, by the gradual expulsion of its oxygen, as to create the exact and various conditions that would exist at any known altitude. Physicians and physiological experts, themselves supplied with oxygen through tubes, remained in the room throughout the tests, closely observing the effect produced on the candidate by the gradual decrease of the oxygen supply. It was soon found that a man’s faculty to respond to sight, sound, and touch becomes more dormant as the air becomes more rarefied, and it was to offset this condition that the oxygen apparatus which I have described in preceding pages was designed. The effect of low oxygen upon the mental process varies greatly, however, according to the individual. He usually becomes mentally inefficient at an altitude at which there is as yet no serious failure of his vital bodily functions. By simple tests of mental alertness during these rebreathing experiments, such as directing the candidate to press designated buttons controlling electric lights of certain colors, controlling a volume of sound by operating a pedal with his feet, and the like, it was easy to determine that one flier would lose his mental alertness at 15,000 feet, while another would retain full control of his faculties at nearly double that height.
In order to accomplish the best results, a comprehensive programme was undertaken, providing for the standardization of both tests and examiners. Sixty-seven military units were established, each examining from ten to sixty applicants a day, there being required, in addition to the complete physical examination embracing all the features ordinarily required of men entering the military service, rigid tests of the special senses of vision, hearing, and motion sensing. Yet, despite the severity of the tests to which the candidates were subjected, the records show that 70.7% of the applicants qualified. But the work of the surgeons did not end when they had passed a man as physically fitted for training as an aviator. On the contrary, it had only begun. The candidate was not only kept under the closest medical observation during his training days, but this observation did not relax even after he had become a fully fledged flyer with the silver wings embroidered on his breast, for the “flight surgeon” who was attached to every squadron was instructed to keep the flyers physically fit and to carefully investigate the causes of all such accidents as might be attributed to the mental or physical failure of the flyers themselves. Keeping the flyer fit was by no means as simple a matter as it sounds, for it included seeing that the men took the necessary amount of physical exercise, the provision of proper recreation, watching the state of fatigue of the individual, making arrangements for leave or furlough, determining the quantity and nature of their food and the questions of alcohol and tobacco, and re-examining them at frequent intervals. Any one who knows how temperamental many flying-men are inclined to be will realize that the flight surgeons held no sinecures.
During the last few months of the war an apparatus was perfected whereby students could acquire flying experience and training without leaving the ground. This machine, known as the “Ruggles Orientator,” is a modification of the universal joint, composed of three concentric rings so pivoted as to permit the fuselage, which is pivoted within the innermost ring, to be put through every possible evolution experienced in actual flying—the candidate being able to experience, while safely on the ground, the sensations of nose-diving, tail-diving, side-slipping, looping the loop, and all the rest—everything, in fact, except forward progression. I feel certain that a man of Mr. Ruggles’s amazing ingenuity could have satisfied both the parent and child of the ancient verse:
“‘Mother, may I go in to swim?’
‘Yes, my darling daughter.
Hang your hose on a hickory limb,
And don’t go near the water.’”