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@@ -0,0 +1,6482 @@ +Project Gutenberg's Aeroplanes and Dirigibles of War, by Frederick A. Talbot + +This eBook is for the use of anyone anywhere at no cost and with +almost no restrictions whatsoever. You may copy it, give it away or +re-use it under the terms of the Project Gutenberg License included +with this eBook or online at www.gutenberg.org + + +Title: Aeroplanes and Dirigibles of War + +Author: Frederick A. Talbot + +Posting Date: July 21, 2008 [EBook #793] +Release Date: January, 1997 + +Language: English + +Character set encoding: ASCII + +*** START OF THIS PROJECT GUTENBERG EBOOK AEROPLANES AND DIRIGIBLES OF WAR *** + + + + + + + + + + +AEROPLANES AND DIRIGIBLES OF WAR + +By Frederick A. Talbot + + + + +PREFACE + +Ever since the earliest days of the great conquest of the air, first by +the dirigible balloon and then by the aeroplane, their use in time of +war has been a fruitful theme for discussion. But their arrival was +of too recent a date, their many utilities too unexplored to provide +anything other than theories, many obviously untenable, others avowedly +problematical. + +Yet the part airships have played in the Greatest War has come as a +surprise even to their most convinced advocates. For every expectation +shattered, they have shown a more than compensating possibility of +usefulness. + +In this volume an endeavour has been made to record their achievements, +under the stern test of trial, as an axiom of war, and to explain, in +untechnical language, the many services to which they have been and may +be applied. + +In the preparation of the work I have received assistance from many +sources--British, French, Russian and German--from official reports and +from men who have played a part in the War in the Air. The information +concerning German military aircraft has been obtained from Government +documents, most of which were placed at my disposal before the outbreak +of war. + +The use of aircraft has changed the whole art and science of warfare. +With its disabilities well in hand, with its strength but half revealed, +the aerial service has revolutionised strategy and shorn the unexpected +attack of half its terrors. The Fourth Arm is now an invaluable part of +the complex military machine. + +F. A. TALBOT. + + + + CONTENTS +CHAPTER + + I. The introduction of aircraft into military operations + II. The military uses of the captive balloon + III. Germany's rise to military airship supremacy + IV. Airships of war + V. Germany's aerial dreadnought fleet + VI. The military value of Germany's aerial fleet + VII. Aeroplanes of war + VIII. Scouting from the skies + IX. The airman and artillery + X. Bomb-throwing from air-craft + XI. Armoured aeroplanes + XII. Battles in the air + XIII. Tricks and ruses to baffle the airman + XIV. Anti-aircraft guns. Mobile weapons + XV. Anti-aircraft guns. Immobile weapons + XVI. Mining the air + XVII. Wireless in aviation + XVIII. Aircraft and naval operations + XIX. The navies of the air + + + + + +CHAPTER I. THE INTRODUCTION OF AIRCRAFT INTO MILITARY OPERATIONS + +It is a curious circumstance that an invention, which is hailed as +being one of the greatest achievements ever recorded in the march of +civilisation, should be devoted essentially to the maiming of humanity +and the destruction of property. In no other trend of human endeavour +is this factor so potently demonstrated as in connection with Man's +Conquest of the Air. + +The dogged struggle against the blind forces of Nature was waged +tenaciously and perseveringly for centuries. But the measure of success +recorded from time to time was so disappointing as to convey the +impression, except in a limited circle, that the problem was impossible +of solution. In the meantime wondrous changes had taken place in the +methods of transportation by land and sea. The steam and electric +railway, steam propulsion of vessels, and mechanical movement along +the highroads had been evolved and advanced to a high standard of +perfection, to the untold advantage of the community. Consequently it +was argued, if only a system of travel along the aerial highways could +be established, then all other methods of mechanical transportation +would be rendered, if not entirely obsolete, at least antiquated. + +At last man triumphed over Nature--at least to such a degree as to +inspire the confidence of the world at large, and to bring aerial travel +and transportation within range of realisation. But what has been the +result? The discovery is not devoted to the interests of peace and +economic development, but to extermination and destruction. + +At the same time this development may be explained. The airship and +aeroplane in the present stage of evolution possess no economic value. +True, cross-country cruises by airship have been inaugurated, and, up to +a point, have proved popularly, if not commercially, successful, +while tentative efforts have been made to utilise the aeroplane as +a mail-carrier. Still, from the view-point of the community at large +aerial travel is as remote as it was centuries ago. + +It is somewhat interesting to observe how history is repeating itself. +When the Montgolfiers succeeded in lifting themselves into the air by +means of a vessel inflated with hot air, the new vehicle was hailed not +so much as one possessed of commercial possibilities, but as an engine +of war! When the indomitable courage and perseverance of Count von +Zeppelin in the face of discouraging disasters and flagrant failures, at +last commanded the attention of the German Emperor, the latter regarded +the Zeppelin craft, not from the interests of peace, but as a military +weapon, and the whole of the subsequent efforts of the Imperial admirer +were devoted to the perfection of the airship in this one direction. + +Other nations, when they embarked on an identical line of development, +considered the airship from a similar point of view. In fact, outside +Germany, there was very little private initiative in this field. +Experiments and developments were undertaken by the military or naval, +and in some instances by both branches, of the respective Powers. +Consequently the aerial craft, whether it be a dirigible airship, or an +aeroplane, can only be regarded from the military point of view. + +Despite the achievements which have been recorded by human endeavour +in the field of aerial travel, the balloon per se has by no means been +superseded. It still remains an invaluable adjunct to the fighting +machine. In Great Britain its value in this direction has never been +ignored: of late, indeed, it has rather been developed. The captive +balloon is regarded as an indispensable unit to both field and sea +operations. This fact was emphasised very strongly in connection with +the British naval attacks upon the German forces in Flanders, and it +contributed to the discomfiture of the German hordes in a very emphatic +manner. + +The captive balloon may be operated from any spot where facilities exist +for anchoring the paying out cable together with winding facilities for +the latter. Consequently, if exigencies demand, it maybe operated from +the deck of a warship so long as the latter is stationary, or even from +an automobile. It is of small cubic capacity, inasmuch as it is only +necessary for the bag to contain sufficient gas to lift one or two men +to a height of about 500 or 600 feet. + +When used in the field the balloon is generally inflated at the base, to +be towed or carried forward by a squad of men while floating in the air, +perhaps at a height of 10 feet. A dozen men will suffice for this duty +as a rule, and in calm weather little difficulty is encountered in +moving from point to point. This method possesses many advantages. +The balloon can be inflated with greater ease at the base, where it is +immune from interference by hostile fire. Moreover, the facilities for +obtaining the requisite inflating agent--hydrogen or coal gas--are more +convenient at such a point. If the base be far removed from the spot at +which it is desired to operate the balloon, the latter is inflated at a +convenient point nearer the requisite position, advantage being taken of +the protective covering offered by a copse or other natural obstacle. + +As is well known, balloons played an important part during the siege +of Paris in 1870-1, not only in connection with daring attempts to +communicate with the outer world, but in reconnoitring the German +positions around the beleaguered city. But this was not the first +military application of the aerial vessel; it was used by the French +against the Austrians in the battle of Fleurus, and also during the +American Civil War. These operations, however, were of a sporadic +character; they were not part and parcel of an organised military +section. + +It is not generally known that the British War office virtually +pioneered the military use of balloons, and subsequently the methods +perfected in Britain became recognised as a kind of "standard" and +were adopted generally by the Powers with such modifications as local +exigencies seemed to demand. + +The British military balloon department was inaugurated at Chatham under +Captain Templer in 1879. It was devoted essentially to the employment +of captive balloons in war, and in 1880 a company of the Royal Engineers +was detailed to the care of this work in the field. Six years previously +the French military department had adopted the captive balloon under +Colonel Laussedat, who was assisted among others by the well-known +Captain Renard. Germany was somewhat later in the field; the military +value of captive balloons was not appreciated and taken into serious +consideration here until 1884. But although British efforts were +preceded by the French the latter did not develop the idea upon accepted +military lines. + +The British authorities were confronted with many searching problems. +One of the earliest and greatest difficulties encountered was in +connection with the gas for inflation. Coal gas was not always readily +available, so that hydrogen had to be depended upon for the most part. +But then another difficulty arose. This was the manufacture of the +requisite gas. Various methods were tested, such as the electrolytic +decomposition of water, the decomposition of sulphuric acid by means of +iron, the reaction between slaked lime and zinc, and so forth. + +But the drawbacks to every process, especially upon the field of battle, +when operations have to be conducted under extreme difficulties and +at high pressure, were speedily recognised. While other +nations concentrated their energies upon the simplification of +hydrogen-manufacturing apparatus for use upon the battle-field, Great +Britain abandoned all such processes in toto. Our military organisation +preferred to carry out the production of the necessary gas at a +convenient manufacturing centre and to transport it, stored in steel +cylinders under pressure, to the actual scene of operations. The method +proved a great success, and in this way it was found possible to inflate +a military balloon in the short space of 20 minutes, whereas, under the +conditions of making gas upon the spot, a period of four hours or more +was necessary, owing to the fact that the manufacturing process is +relatively slow and intricate. The practicability of the British idea +and its perfection served to establish the captive balloon as a military +unit. + +The British military ballooning department has always ranked as the +foremost of its type among the Powers, although its work has been +carried out so unostentatiously that the outside world has gleaned very +little information concerning its operations. Captain Templer was an +indefatigable worker and he brought the ballooning section to a high +degree of efficiency from the military point of view. + +But the British Government was peculiarly favoured, if such a term +may be used. Our little wars in various parts of the world contributed +valuable information and experience which was fully turned to account. +Captive balloons for reconnoitring purposes were used by the British +army for the first time at Suakim in 1885, and the section established +its value very convincingly. The French military balloon department +gained its first experience in this field in the previous year, a +balloon detachment having been dispatched to Tonkin in 1884. In both +the Tonkin and Soudan campaigns, invaluable work was accomplished by the +balloon sections, with the result that this aerial vehicle has come to +be regarded as an indispensable military adjunct. Indeed the activity of +the German military ballooning section was directly attributable to the +Anglo-French achievements therewith. + +In this work, however, the British force speedily displayed its +superiority and initiative. The use of compressed hydrogen was adopted, +and within the course of a few years the other Powers, realising the +advantages which the British department had thus obtained, decided to +follow its example. The gas is stored in cylinders under a pressure +varying from six to ten or more atmospheres; in other words from about +80 to 140 or more pounds per square inch. Special military wagons +have been designed for the transport of these cylinders, and they are +attached to the balloon train. + +The balloon itself is light, and made of such materials as to reduce +the weight thereof to the minimum. The British balloons are probably the +smallest used by any of the Powers, but at the same time they are +the most expensive. They are made of goldbeater's skin, and range in +capacity from 7,000 to 10,000 cubic feet, the majority being of the +former capacity. The French balloon on the other hand has a capacity +exceeding 18,000 cubic feet, although a smaller vessel of 9,000 cubic +feet capacity, known as an auxiliary, and carrying a single observer, is +used. + +The Germans, on the other hand, with their Teutonic love of the immense, +favour far larger vessels. At the same time the military balloon section +of the German Army eclipses that of any other nations is attached to the +Intelligence Department, and is under the direct control of the General +Staff. Balloon stations are dotted all over the country, including +Heligoland and Kiel, while regular sections are attached to the Navy +for operating captive balloons from warships. Although the Zeppelin and +aeroplane forces have come to the front in Germany, and have relegated +the captive balloon somewhat to the limbo of things that were, the +latter section has never been disbanded; in fact, during the present +campaign it has undergone a somewhat spirited revival. + +The South African campaign emphasised the value of the British balloon +section of the Army, and revealed services to which it was specially +adapted, but which had previously more or less been ignored. The +British Army possessed indifferent maps of the Orange Free State and the +Transvaal. This lamentable deficiency was remedied in great measure by +recourse to topographical photographs taken from the captive balloons. +The guides thus obtained were found to be of extreme value. + +During the early stages of the war the hydrogen was shipped in cylinders +from the homeland, but subsequently a manufacturing plant of such +capacity as to meet all requirements was established in South Africa. +The cylinders were charged at this point and dispatched to the scene of +action, so that it became unnecessary to transport the commodity from +Britain. The captive balloon revealed the impregnability of Spion Kop, +enabled Lord Roberts to ascertain the position of the Boer guns at the +Battle of Paardeburg, and proved of invaluable assistance to the forces +of General White during the siege of Ladysmith. + + + +CHAPTER II. THE MILITARY USES of THE CAPTIVE BALLOON + +Although the captive balloon is recognised as indispensable in military +operations, its uses are somewhat limited. It can be employed only in +comparatively still weather. The reason is obvious. It is essential that +the balloon should assume a vertical line in relation to its winding +plant upon the ground beneath, so that it may attain the maximum +elevation possible: in other words, the balloon should be directly +above the station below, so that if 100 yards of cable are paid out the +aerostat may be 100 yards above the ground. If a wind is blowing, the +helpless craft is certain to be caught thereby and driven forwards or +backwards, so that it assumes an angle to its station. If this become +acute the vessel will be tilted, rendering the position of the observers +somewhat precarious, and at the same time observing efficiency will be +impaired. + +This point may be appreciated more easily by reference to the +accompanying diagram. A represents the ground station and B the position +of the captive balloon when sent aloft in calm weather, 300 feet of +cable being paid out. A wind arises and blows the vessel forward to the +position C. At this point the height of the craft in relation to the +ground has been reduced, and the reduction must increase proportionately +as the strength of the wind increases and forces the balloon still more +towards the ground. At the same time, owing to the tilt given to the +car, observation is rendered more difficult and eventually becomes +extremely dangerous. + +A wind, if of appreciable strength, develops another and graver danger. +Greater strain will be imposed upon the cable, while if the wind be +gusty, there is the risk that the vessel will be torn away from +its anchoring rope and possibly lost. Thus it will be seen that the +effective utilisation of a captive balloon is completely governed by +meteorological conditions, and often it is impossible to use it +in weather which exercises but little influence upon dirigibles or +aeroplanes. + +The captive balloon equipment comprises the balloon, together with the +observer's basket, the wire-cable whereby it is anchored and controlled, +and the winding apparatus. Formerly a steam engine was necessary for +the paying in and out of the cable, but nowadays this is accomplished by +means of a petrol-driven motor, an oil-engine, or even by the engine of +an automobile. The length of cable varies according to the capacity of +the balloon and the maximum operating height. + +The average British balloon is able to lift about 290 or 300 pounds, +which may be taken to represent the weight of two observers. On the +other hand, the French and German balloons are able to carry four times +this weight, with the exception of the French auxiliaries, which are +designed to lift one observer only. The balloons of the two latter +Powers have also a greater maximum altitude; it is possible to ascend to +a height of some 2,000 feet in one of these. + +The observing station is connected with the winding crew below either +by a telephone, or some other signalling system, the method practised +varying according to circumstances. In turn the winding station is +connected with the officer in charge of the artillery, the fire of which +the captive balloon is directing. The balloon observer is generally +equipped with various instruments, such as telescope, photographic +cameras, and so forth, so as to be able, if necessary, to prepare a +topographical survey of the country below. By this means the absence +of reliable maps may be remedied, or if not regarded, as sufficiently +correct they may be checked and counter-checked by the data gained +aloft. + +Seeing that the gas has to be transported in cylinders, which are +weighty, it is incumbent that the waste of this commodity should be +reduced to the minimum. The balloon cannot be deflated at night and +re-inflated in the morning--it must be maintained in the inflated +condition the whole time it is required for operation. + +There are various methods of consummating this end. One method is to +haul in the balloon and to peg it down on all sides, completing the +anchorage by the attachment of bags filled with earth to the network. +While this process is satisfactory in calm weather, it is impracticable +in heavy winds, which are likely to spring up suddenly. Consequently +a second method is practised. This is to dig a pit into the ground of +sufficient size to receive the balloon. When the latter is hauled in it +is lowered into this pit and there pegged down and anchored. Thus it +is perfectly safe during the roughest weather, as none of its bulk is +exposed above the ground level. Furthermore it is not a conspicuous +object for the concentration of hostile fire. + +In some instances, and where the military department is possessed of +an elaborate equipment such as characterises the German army, when +reconnaissance is completed and the balloon is to be removed to another +point, the gas is pumped back into the cylinders for further use. Such +an economical proceeding is pretty and well adapted to manoeuvres, but +it is scarcely feasible in actual warfare, for the simple reason that +the pumping takes time. Consequently the general procedure, when the +balloon has completed its work, is to permit the gas to escape into the +air in the usual manner, and to draw a fresh supply of gas from further +cylinders when the occasion arises for re-inflation. + +Although the familiar spherical balloon has proved perfectly adequate +for reconnoitring in the British and French armies, the German +authorities maintained that it was not satisfactory in anything but calm +weather. Accordingly scientific initiative was stimulated with a view to +the evolution of a superior vessel. These endeavours culminated in the +Parseval-Siegsfeld captive balloon, which has a quaint appearance. It +has the form of a bulky cylinder with hemispherical extremities. At one +end of the balloon there is a surrounding outer bag, reminiscent of a +cancerous growth. The lower end of this is open. This attachment serves +the purpose of a ballonet. The wind blowing against the opening, which +faces it, charges the ballonet with air. This action, it is claimed, +serves to steady the main vessel, somewhat in the manner of the tail of +a kite, thereby enabling observations to be made as easily and correctly +in rough as in calm weather. The appearance of the balloon while aloft +is certainly curious. It appears to be rearing up on end, as if the +extremity saddled with the ballonet were weighted. + +British and French captive balloon authorities are disposed to discount +the steadying effect of this attachment, and, indeed, to maintain that +it is a distinct disadvantage. It may hold the vessel steadier for the +purpose of observation, but at the same time it renders the balloon a +steadier target for hostile fire. On the other hand, the swaying of a +spherical balloon with the wind materially contributes to its safety. +A moving object, particularly when its oscillations are irregular +and incalculable, is an extremely difficult object at which to take +effective aim. + +Seeing that even a small captive balloon is of appreciable +dimensions--from 25 to 33 feet or more in diameter--one might consider +it an easy object to hit. But experience has proved otherwise. In the +first place the colour of the balloon is distinctly protective. The +golden or yellowish tinge harmonises well with the daylight, even in +gloomy weather, while at night-time it blends excellently with the +moonlight. For effective observations a high altitude is undesirable. At +a height of 600 feet the horizon is about 28 miles from the observer, +as compared with the 3 miles constituting the range of vision from +the ground over perfectly flat country. Thus it will be seen that the +"spotter" up aloft has the command of a considerable tract. + +Various ways and means of finding the range of a captive balloon have +been prepared, and tables innumerable are available for committal to +memory, while those weapons especially designed for aerial targets are +fitted with excellent range-finders and other instruments. The Germans, +with characteristic thoroughness, have devoted considerable attention +to this subject, but from the results which they have achieved up to +the present this guiding knowledge appears to be more spectacular and +impressive than effective. + +To put a captive balloon out of action one must either riddle the +envelope, causing it to leak like a sieve, blow the vessel to pieces, or +ignite the highly inflammable gas with which it is inflated. Individual +rifle fire will inflict no tangible damage. A bullet, if it finds +its billet, will merely pass through the envelope and leave two small +punctures. True, these vents will allow the gas to escape, but this +action will proceed so slowly as to permit the vessel to remain aloft +long enough to enable the observer to complete his work. A lucky rifle +volley, or the stream of bullets from a machine gun may riddle the +envelope, precipitating a hurried descent, owing to the greater number +of perforations through which the gas is able to escape, but as a rule +the observer will be able to land safely. + +Consequently the general practice is to shatter the aerostat, and to +this end either shrapnel, high explosive, or incendiary shells will be +used. The former must explode quite close to the balloon in order to +achieve the desired end, while the incendiary shell must actually +strike it, so as to fire the gas. The high explosive shell may explode +effectually some feet away from the vessel, inasmuch as in this instance +dependence is placed upon the terrific concussion produced by the +explosion which, acting upon the fragile fabric of the balloon, brings +about a complete collapse of the envelope. If a shrapnel is well placed +and explodes immediately above the balloon, the envelope will be torn to +shreds and a violent explosion of the gas will be precipitated. But as +a matter of fact, it is extremely difficult to place a shrapnel shell so +as to consummate this end. The range is not picked up easily, while +the timing of the fuse to bring about the explosion of the shell at the +critical moment is invariably a complex problem. + +One favourite method of finding the range of a balloon is shown in the +accompanying diagrams. The artillery battery is at B and the captive +balloon, C, is anchored at A. On either side of B and at a specified +distance, observers O1 and O2 respectively are stationed. First a shell +is fired at "long" range, possibly the maximum range of the gun. It +bursts at D. As it has burst immediately in the line of sight of B, but +with the smoke obscured by the figure of the balloon C, it is obvious +to B that the explosion has occurred behind the objective, but at what +distance he cannot tell. To O1 and O2, however, it is seen to have burst +at a considerable distance behind C though to the former it appears to +have burst to the left and to the second observer to the right of the +target. + +Another shell, at "short" range, is now fired, and it bursts at E. The +explosion takes place in the line of sight of B, who knows that he has +fired short of the balloon because the latter is eclipsed by the smoke. +But the two observers see that it is very short, and here again the +explosion appears to O1 to have occurred to the right of the target, +while to O2 it has evidently burst to the left of the aerostat, as +revealed by the relation of the position of the balloon to the bursting +of the shell shown in Fig. 3. + +A third round is fired, and the shell explodes at F. In this instance +the explosion takes place below the balloon. Both the observers and the +artillery man concur in their deductions upon the point at which +the shell burst. But the shell must explode above the balloon, and +accordingly a fourth round is discharged and the shell bursts at G. + +This appears to be above the balloon, inasmuch as the lines of sight +of the two observers and B converge at this point. But whether the +explosion occurs immediately above the vessel as is desired, it is +impossible to say definitely, because it may explode too far behind to +be effective. Consequently, if this shell should prove abortive, the +practice is to decrease the range gradually with each succeeding round +until the explosion occurs at the critical point, when, of course, the +balloon is destroyed. An interesting idea of the difficulty of picking +up the range of a captive balloon may be gathered from the fact that +some ten minutes are required to complete the operation. + +But success is due more to luck than judgment. In the foregoing +explanation it is premised that the aerial vessel remains stationary, +which is an extremely unlikely contingency. While those upon the ground +are striving to pick up the range, the observer is equally active in his +efforts to baffle his opponents. The observer follows each successive, +round with keen interest, and when the shells appear to be bursting at +uncomfortably close quarters naturally he intimates to his colleagues +below that he desires his position to be changed, either by ascending to +a higher point or descending. In fact, he may be content to come to the +ground. Nor must the fact be overlooked that while the enemy is trying +to place the observer hors de combat, he is revealing the position of +his artillery, and the observer is equally industrious in picking up the +range of the hostile guns for the benefit of his friends below. + +When the captive balloon is aloft in a wind the chances of the enemy +picking up the range thereof are extremely slender, as it is continually +swinging to and fro. While there is always the possibility of a shell +bursting at such a lucky moment as to demolish the aerial target, it is +generally conceded to be impossible to induce a shell to burst within +100 yards of a balloon, no matter how skilfully the hostile battery may +be operated. + +The value of the captive balloon has been demonstrated very strikingly +throughout the attack upon the entrenched German positions in Flanders. +Owing to the undulating character of the dunes the "spotters" upon the +British monitors and battle ships are unable to obtain a sweeping view +of the country. Accordingly captive balloons are sent aloft in some +cases from the deck of the monitors, and in others from a suitable point +upon the beach itself. The aerial observer from his point of vantage is +able to pick up the positions of the German forces and artillery with +ease and to communicate the data thus gained to the British vessels, +although subjected to heavy and continuous hostile fire. The difficulty +of hitting a captive balloon has been graphically emphasised, inasmuch +as the German artillerists have failed to bring down a solitary balloon. +On the other hand the observer in the air is able to signal the results +of each salvo fired from the British battleships as they manoeuvre at +full speed up and down the coastline, while he keeps the fire of the +monitors concentrated upon the German positions until the latter have +been rendered untenable or demolished. The accuracy of the British +gun-fire has astonished even the Germans, but it has been directly +attributable to the rangefinder perched in the car of the captive +balloon and his rapid transmission of information to the vessels below. + +The enthusiastic supporters of aerial navigation maintained that +the dirigible and the aeroplane would supersede the captive balloon +completely. But as a matter of fact the present conflict has established +the value of this factor more firmly than ever. There is not the +slightest possibility that the captive balloon sections of the +belligerents will be disbanded, especially those which have the +fruits of experience to guide them. The airship and the aeroplane have +accomplished wonders, but despite their achievements the captive balloon +has fully substantiated its value as a military unit in its particular +field of operations. + + + +CHAPTER III. GERMANY'S RISE TO MILITARY AIRSHIP SUPREMACY + +Two incidents in the history of aviation stand out with exceptional +prominence. The one is the evolution of the Zeppelin airship--a story +teeming with romance and affording striking and illuminating glimpses +of dogged perseverance, grim determination in the face of repeated +disasters, and the blind courageous faith of the inventor in the +creation of his own brain. The second is the remarkable growth of +Germany's military airship organisation, which has been so rapid and +complete as to enable her to assume supremacy in this field, and that +within the short span of a single decade. + +The Zeppelin has always aroused the world's attention, although this +interest has fluctuated. Regarded at first as a wonderful achievement +of genius, afterwards as a freak, then as the ready butt for universal +ridicule, and finally with awe, if not with absolute terror--such in +brief is the history of this craft of the air. + +Count von Zeppelin can scarcely be regarded as an ordinary man. He took +up the subject of flight at an age which the majority of individuals +regard as the opportune moment for retirement from activity, and, +knowing nothing about mechanical engineering, he concentrated his +energies upon the study of this science to enable him to master the +difficulties of a mechanical character incidental to the realisation of +his grand idea. His energy and indomitable perseverance are equalled by +his ardent patriotism, because, although the Fatherland discounted his +idea when other Powers were ready to consider it, and indeed made +him tempting offers for the acquisition of his handiwork, he stoutly +declined all such solicitations, declaring that his invention, if such +it may be termed, was for his own country and none other. + +Count von Zeppelin developed his line of study and thought for one +reason only. As an old campaigner and a student of military affairs +he realised the shortcomings of the existing methods of scouting +and reconnoitring. He appreciated more than any other man of the day +perhaps, that if the commander-in-chief of an army were provided with +facilities for gazing down upon the scene of operations, and were able +to take advantage of all the information accruing to the man above who +sees all, he would hold a superior position, and be able to dispose +his forces and to arrange his plan of campaign to the most decisive +advantage. In other words, Zeppelin conceived and developed his airship +for one field of application and that alone-military operations. +Although it has achieved certain successes in other directions these +have been subsidiary to the primary intention, and have merely served to +emphasise its military value. + +Von Zeppelin was handicapped in his line of thought and investigation +from the very first. He dreamed big things upon a big scale. The +colossal always makes a peculiar and irresistible appeal to the Teutonic +nature. So he contemplated the perfection of a big dirigible, eclipsing +in every respect anything ever attempted or likely to be attempted +by rival countries. Unfortunately, the realisation of the "colossal" +entails an equally colossal financial reserve, and the creator of this +form of airship for years suffered from financial cramp in its worst +manifestation. Probably it was to the benefit of the world at large +that Fortune played him such sorry tricks. It retarded the growth of +German ambitions in one direction very effectively. + +As is well known Zeppelin evolved what may be termed an individual line +of thought in connection with his airship activities. He adopted what is +known as the indeformable airship: that is to say the rigid, as opposed +to the semi-rigid and flexible craft. As a result of patient experiment +and continued researches he came to the conclusion that a huge outer +envelope taking the form of a polygonal cylinder with hemispherical +ends, constructed upon substantial lines with a metallic skeleton +encased within an impermeable skin, and charged with a number of smaller +balloon-shaped vessels containing the lifting agent--hydrogen gas--would +fulfil his requirements to the greatest advantage. Model after model was +built upon these lines. Each was subjected to searching tests with the +invariable result attending such work with models. Some fulfilled the +expectations of the inventor, others resolutely declined to illustrate +his reasonings in any direction. + +The inevitable happened. When a promising model was completed finally +the inventor learned to his sorrow what every inventor realises in time. +His fortune and the resources of others had been poured down the sink +of experiment. To carry the idea from the model to the practical stage +required more money, and it was not forthcoming. The inventor sought +to enlist the practical sympathy of his country, only to learn that in +Germany, as in other lands, the axiom concerning the prophet, honour, +and country prevails. No exuberant inventor received such a cold douche +from a Government as did Count Zeppelin from the Prussian authorities. +For two years further work was brought practically to a standstill: +nothing could be done unless the sinews of war were forthcoming. His +friends, who had assisted him financially with his models, now concluded +that their aid had been misplaced. + +The inventor, though disappointed, was by no means cast down. He clung +tenaciously to his pet scheme and to such effect that in 1896 a German +Engineering Society advanced him some funds to continue his researches. +This support sufficed to keep things going for another two years, +during which time a full-sized vessel was built. The grand idea began +to crystallise rapidly, with the result that when a public company was +formed in 1898, sufficient funds were rendered available to enable the +first craft to be constructed. It aroused considerable attention, as +well it might, seeing that it eclipsed anything which had previously +been attempted in connection with dirigibles. It was no less than 420 +feet in length, by 38 feet in diameter, and was fitted with two cars, +each of which carried a sixteen horse-power motor driving independent +propellers rigidly attached to the body of the vessel. The propellers +were both vertical and horizontal, for the purpose of driving the ship +in the two planes--vertical and horizontal respectively. + +The vessel was of great scientific interest, owing to the ingenuity of +its design and construction. The metallic skeleton was built up from +aluminium and over this was stretched the fabric of the envelope, +care being observed to reduce skin friction, as well as to achieve +impermeability. But it was the internal arrangement of the gas-lifting +balloons which provoked the greatest concern. The hull was divided +into compartments, each complete in itself, and each containing a small +balloon inflated with hydrogen. It was sub-division as practised in +connection with vessels ploughing the water applied to aerial craft, the +purpose being somewhat the same. As a ship of the seas will keep afloat +so long as a certain number of its subdivisions remain watertight, +so would the Zeppelin keep aloft if a certain number of the gas +compartments retained their charges of hydrogen. There were no fewer +than seventeen of these gas-balloons arranged in a single line within +the envelope. Beneath the hull and extending the full length of +the latter was a passage which not only served as a corridor for +communication between the cars, but also to receive a weight attached +to a cable worked by a winch. By the movement of this weight the bow or +stem of the vessel could be tilted to assist ascent and descent. + +The construction of the vessel subsequently proved to be the easiest and +most straightforward part of the whole undertaking. There were other and +more serious problems to be solved. How would such a monster craft come +to earth? How could she be manipulated upon the ground? How could she +be docked? Upon these three points previous experience was silent. One +German inventor who likewise had dreamed big things, and had carried +them into execution, paid for his temerity and ambitions with his life, +while his craft was reduced to a mass of twisted and torn metal. Under +these circumstances Count Zeppelin decided to carry out his flights +over the waters of the Bodensee and to house his craft within a +floating dock. In this manner two uncertain factors might be effectively +subjugated. + +Another problem had been ingeniously overcome. The outer envelope +presented an immense surface to the atmosphere, while temperature was +certain to play an uncertain part in the behaviour of the craft. The +question was to reduce to the minimum the radiation of heat and cold to +the bags containing the gas. This end was achieved by leaving a slight +air space between the inflated gas balloons and the inner surface of the +hull. + +The first ascent was made on July 2nd, 1900, but was disappointing, +several breakdowns of the mechanism occurring while the vessel was in +mid-air, which rendered it unmanageable, although a short flight was +made which sufficed to show that an independent speed of 13 feet per +second could be attained. The vessel descended and was made fast in her +dock, the descent being effected safely, while manoeuvring into dock was +successful. At least three points about which the inventor had been in +doubt appeared to be solved--his airship could be driven through the air +and could be steered; it could be brought to earth safely; and it could +be docked. + +The repairs to the mechanism were carried out and on October 17th and +21st of the same year further flights were made. By this time certain +influential Teuton aeronautical experts who had previously ridiculed +Zeppelin's idea had made a perfect volte-face. They became staunch +admirers of the system, while other meteorological savants participated +in the trials for the express purpose of ascertaining just what the ship +could do. As a result of elaborate trigonometrical calculations it was +ascertained that the airship attained an independent speed of 30 feet +per second, which exceeded anything previously achieved. The craft +proved to be perfectly manageable in the air, and answered her helm, +thus complying with the terms of dirigibility. The creator was flushed +with his triumph, but at the same time was doomed to experience +misfortune. In its descent the airship came to "earth" with such a shock +that it was extensively damaged. The cost of repairing the vessel was +so heavy that the company declined to shoulder the liability, and as the +Count was unable to defray the expense the wreck was abandoned. + +Although a certain meed of success had been achieved the outlook seemed +very black for the inventor. No one had any faith in his idea. He made +imploring appeals for further money, embarked upon lecturing campaigns, +wrote aviation articles for the Press, and canvassed possible supporters +in the effort to raise funds for his next enterprise. Two years passed, +but the fruits of the propaganda were meagre. It was at this juncture, +when everything appeared to be impossible, that Count Zeppelin +discovered his greatest friend. The German Emperor, with an eye ever +fixed upon new developments, had followed Zeppelin's uphill struggle, +and at last, in 1902, came to his aid by writing a letter which ran:-- + +"Since your varied flights have been reported to me it is a great +pleasure to me to express my acknowledgment of your patience and your +labours, and the endurance with which you have pressed on through +manifold hindrances till success was near. The advantages of your system +have given your ship the greatest attainable speed and dirigibility, and +the important results you have obtained have produced an epoch-making +step forward in the construction of airships and leave laid down a +valuable basis for future experiments." + +This Imperial appreciation of what had been accomplished proved to be +the turning point in the inventor's fortunes. It stimulated financial +support, and the second airship was taken in hand. But misfortune still +pursued him. Accidents were of almost daily occurrence. Defects were +revealed here and weaknesses somewhere else. So soon as one trouble was +overcome another made itself manifest. The result was that the whole of +the money collected by his hard work was expended before the ship +could take to the air. A further crash and blasting of cherished hopes +appeared imminent, but at this moment another Royal personage came to +the inventor's aid. + +The King of Wurtemberg took a personal interest in his subject's uphill +struggle, and the Wurtemberg Government granted him the proceeds of a +lottery. With this money, and with what he succeeded in raising by hook +and by crook, and by mortgaging his remaining property, a round L20,000 +was obtained. With this capital a third ship was taken in hand, and +in 1905 it was launched. It was a distinct improvement upon its +predecessors. The airship was 414 feet in length by 38 feet in diameter, +was equipped with 17 gas balloons having an aggregate capacity of +367,000 cubic feet of hydrogen, was equipped with two 85 horse-power +motors driving four propellers, and displaced 9 tons. All the +imperfections incidental to the previous craft had been eliminated, +while the ship followed improved lines in its mechanical and structural +details. + +The trials with this vessel commenced on November 30th, 1905, but +ill-luck had not been eluded. The airship was moored upon a raft which +was to be towed out into the lake to enable the dirigible to ascend. +But something went wrong with the arrangements. A strong wind caught the +ungainly airship, she dipped her nose into the water, and as the motor +was set going she was driven deeper into the lake, the vessel only being +saved by hurried deflation. + +Six weeks were occupied in repairs, but another ascent was made +on January 17th, 1906. The trials were fairly satisfactory, but +inconclusive. One of the motors went wrong, and the longitudinal +stability was found to be indifferent. The vessel was brought down, and +was to be anchored, but the Fates ruled otherwise. A strong wind caught +her during the night and she was speedily reduced to indistinguishable +scrap. + +Despite catastrophe the inventor wrestled gamely with his project. The +lessons taught by one disaster were taken to heart, and arrangements +to prevent the recurrence thereof incorporated in the succeeding craft. +Unfortunately, however, as soon as one defect was remedied another +asserted itself. It was this persistent revelation of the unexpected +which caused another period of indifference towards his invention. +Probably nothing more would have been heard of the Zeppelin after this +last accident had it not been for the intervention of the Prussian +Government at the direct instigation of the Kaiser, who had now taken +Count Zeppelin under his wing. A State lottery was inaugurated, the +proceeds of which were handed over to the indefatigable inventor, +together with an assurance that if he could keep aloft 24 hours without +coming to earth in the meantime, and could cover 450 miles within +this period, the Government would repay the whole of the money he had +lavished upon his idea, and liquidate all the debts he had incurred in +connection therewith. + +Another craft was built, larger than its predecessors, and equipped with +two motors developing 170 horse-power. Upon completion it was submitted +to several preliminary flights, which were so eminently successful +that the inventor decided to make a trial trip under conditions closely +analogous to those imposed for the Government test. On June 20th, 1908, +at 8:26 a.m. the craft ascended and remained aloft for 12 hours, during +which time it made an encouraging circular tour. Flushed with this +success, the Count considered that the official award was within reach, +and that all his previous disasters and misfortunes were on the eve of +redemption. + +The crucial test was essayed on August 5th, 1908. Accompanied by twelve +observers the vessel ascended and travelled without incident for +eight hours. Then a slight mishap demanded attention, but was speedily +repaired, and was ignored officially as being too trivial to influence +the main issue. Victory appeared within measurable distance: the arduous +toil of many patient years was about to be rewarded. The airship was +within sight of home when it had to descend owing to the development +of another motor fault. But as it approached the ground, Nature, as if +infuriated at the conquest, rose up in rebellion. A sudden squall struck +the unwieldy monster. Within a few moments it became unmanageable, and +through some inscrutable cause, it caught fire, with the result that +within a few moments it was reduced to a tangled mass of metallic +framework. + +It was a catastrophe that would have completely vanquished many an +inventor, but the Count was saved the gall of defeat. His flight, which +was remarkable, inasmuch as he had covered 380 miles within 24 hours, +including two unavoidable descents, struck the Teuton imagination. The +seeds so carefully planted by the "Most High of Prussia" now bore fruit. +The German nation sympathised with the indomitable inventor, appreciated +his genius, and promptly poured forth a stream of subscriptions to +enable him to build another vessel. The intimation that other Powers had +approached the Count for the acquisition of his idea became known far +and wide, together with the circumstance that he had unequivocally +refused all offers. He was striving for the Fatherland, and his +unselfish patriotism appealed to one and all. Such an attitude deserved +hearty national appreciation, and the members of the great German public +emptied their pockets to such a degree that within a few weeks a sum of +L300,000 or $1,500,000 was voluntarily subscribed. + +All financial embarrassments and distresses were now completely removed +from the Count's mind. He could forge ahead untrammelled by anxiety and +worry. Another Zeppelin was built and it created a world's record. It +remained aloft for 38 hours, during which time it covered 690 miles, +and, although it came to grief upon alighting, by colliding with a +tree, the final incident passed unnoticed. Germany was in advance of +the world. It had an airship which could go anywhere, irrespective of +climatic conditions, and in true Teuton perspective the craft was viewed +from the military standpoint. Here was a means of obtaining the mastery +of the air: a formidable engine of invasion and aerial attack had been +perfected. Consequently the Grand Idea must be supported with unbounded +enthusiasm. The Count was hailed by his august master as "The greatest +German of the twentieth century," and in this appreciation the populace +wholeheartedly concurred. Whether such a panegyric from such an +auspicious quarter is praise indeed or the equivalent of complete +condemnation, history alone will be able to judge, but when one +reflects, at this moment, upon the achievements of this aircraft during +the present conflagration, the unprejudiced will be rather inclined +to hazard the opinion that Imperial Teuton praise is a synonym for +damnation. + +Although the Zeppelin was accepted as a perfect machine it has never +been possible to disperse the atmosphere of disaster with which it has +been enveloped from the first. Vessel after vessel has gone up in smoke +and flame: few craft of this type have enjoyed more than an evanescent +existence; and each successive catastrophe has proved more terrible than +its predecessor. But the Teutonic nation has been induced to pin its +whole faith on this airship, notwithstanding that the more levelheaded +engineers of other countries have always maintained the craft to be a +"mechanical monstrosity" condemned from its design and principles of +construction to disaster. Unshaken by this adverse criticism, Germany +rests assured that by means of its Zeppelins it will achieve that +universal supremacy which it is convinced is its Destiny. + +This blind child-like faith has been responsible for the establishment +and development of the Zeppelin factories. At Friedrichshafen the +facilities are adequate to produce two of these vessels per month, while +another factory of a similar capacity has been established at Berlin. +Unfortunately such big craft demand large docks to accommodate them, and +in turn a large structure of this character constitutes an easy mark +for hostile attack, as the raiding airmen of the Allies have proved very +convincingly. + +But the Zeppelin must not be under-rated. Magnificent performances have +been recorded by these vessels, such as the round 1,000 miles' trip in +1909, and several other equally brilliant feats since that date. It +is quite true that each astounding achievement has been attended by an +equally stupendous accident, but that is accepted as a mere incidental +detail by the faithful Teutonic nation. Many vivid prophecies of the +forthcoming flights by Zeppelin have been uttered, and it is quite +probable that more than one will be fulfilled, but success will be +attributable rather to accident than design. + +Although the Zeppelin is the main stake of the German people in matters +pertaining to aerial conquest, other types of airships have not been +ignored, as related in another chapter. They have been fostered upon a +smaller but equally effective scale. The semi-rigid Parseval and Gross +craft have met with whole-hearted support, since they have established +their value as vessels of the air, which is tantamount to the acceptance +of their military value. + +The Parseval is pronounced by experts to be the finest expression of +aeronautical engineering so far as Teuton effort is concerned. Certainly +it has placed many notable flights to its credit. The Gross airship +is an equally serviceable craft, its lines of design and construction +closely following those of the early French supple airships. There are +several other craft which have become more or less recognised by the +German nation as substantial units of war, such as the Ruthemberg, +Siemens-Schukert, and so forth, all of which have proved their +serviceability more or less conclusively. But in the somewhat +constricted Teuton mind the Zeppelin and the Zeppelin only represents +the ultima Thule of aerial navigation and the means for asserting the +universal character of Pan-Germanism as well as "Kultur." + + + +CHAPTER IV. AIRSHIPS OF WAR + +So much has been said and written concerning the Zeppelin airship, +particularly in its military aspect, that all other developments in +this field have sunk into insignificance so far as the general public is +concerned. The Zeppelin dirigible has come to be generally regarded as +the one and only form of practical lighter-than-air type of aircraft. +Moreover, the name has been driven home with such effect that it is +regarded as the generic term for all German airships. + +These are grievous fallacies. The Zeppelin is merely one of a variety of +types, even in Germany, although at the moment it probably ranks as +the solitary survivor of the rigid system of construction. At one time, +owing to the earnestness with which the advantages of this form of +design were discussed, and in view of the fact that the Zeppelin +certainly appeared to triumph when all other designs failed, Great +Britain was tempted to embrace the rigid form of construction. The +building of an immense vessel of this class was actively supported +and it was aptly christened the "May-fly." Opponents of the movement +tempered their emphatic condemnatory criticism so far as to remark that +it MAY FLY, but as events proved it never did. The colossal craft +broke its back before it ever ventured into the air, and this solitary +experience proving so disastrous, the rigid form of construction was +abandoned once and for all. The venture was not in vain; it brought home +to the British authorities more convincingly than anything else that +the Zeppelin was a mechanical monstrosity. The French never even +contemplated the construction of such a craft at that time, estimating +it at its true value, and the British failure certainly served to +support French antagonism to the idea. Subsequently, however, an attempt +at rigid construction was made in France with the "Spiess" airship, +mainly as a concession to public clamour. + +Even in Germany itself the defects of the Zeppelin were recognised and +a decided effort to eliminate them was made by Professor Schutte in +co-operation with a manufacturer of Mannheim named Lanz. The joint +product of their ambitions, the Schutte-Lanz, is declared to be superior +to the Zeppelin, but so far it has failed to justify any of the claims +of its designers. This vessel, which also favours the colossal, is +likewise of the rigid type, but realising the inherent dangers accruing +from the employment of metal for the framework, its constructors have +used wood, reinforced and strengthened where necessary by metallic +angle-iron, plates, and bracing; this utilisation of metal is, however, +carried out very sparingly. The first vessel of this class was a huge +failure, while subsequent craft have not proved much more successful. + +In fact, one of the largest German airships ever designed, L4, is, or +rather was, a Schutte-Lanz, with a capacity of 918,000 cubic feet, but +over 6,000 pounds lighter than a Zeppelin of almost similar dimensions. +I say "was" since L4 is no more. The pride of its creators evinced a +stronger preference for Davy Jones' Locker than its designed realm. Yet +several craft of this type have been built and have been mistaken for +Zeppelins owing to the similarity of the broad principles of design and +their huge dimensions. In one vital respect they are decidedly inferior +to their contemporary--they are not so speedy. + +The most successful of the German lighter-than-air machines are those +known respectively as the semi rigid and non-rigid types, the best +examples of which are the Gross and Parseval craft. Virtually they are +Teutonic editions of the successful French craft of identical design by +which they were anticipated. The Lebaudy is possibly the most famous of +the French efforts in this direction. The gas-bag has an asymmetrical +shape, and is pointed at both ends, although the prow is blunter or +rounder than the stem. The gas-bag comprises a single chamber for the +inflating agent, the distended shape of the envelope being sustained by +means of an air-ballonet. By varying the contents of the latter through +the agency of a pump the tension of the gas in the lifting envelope can +be maintained, and the shape of the inflated balloon preserved under all +conditions. + +Beneath the gas-bag is a long strengthened girder, and from this in turn +the car is suspended. It is the introduction of this rigid girder which +is responsible for the descriptive generic term of "semi-rigid." On the +other hand the "non-rigid" type may be roughly described as a pisciform +balloon fitted with propelling machinery, inasmuch as the car containing +the driving machinery is suspended from the balloon in the manner of +the car in the ordinary drifting vessel. So far as the French effort is +concerned the Bayard-Clement type is the best example of the non-rigid +system; it is represented in Germany by the Parseval class. + +The Gross airship has been definitely adopted as a military machine +by the German authorities, and figures in the "M" class. The "M-IV" +completed in 1913 is the largest of this type, and differs from its +prototypes in that it carries two cars, each fitted with motors, whereas +the earlier machines were equipped with a single gondola after the +French pattern. This vessel measures 320 feet in length, has a maximum +diameter of 44 1/2 feet, displaces 13 tons, and is fitted with motors +developing 450 horse-power, which is sufficient to give it a speed of +47 miles per hour. This vessel represents a huge advance upon its +predecessors of this design, inasmuch as the latter were about 245 feet +in length by 36 1/4 feet in diameter, and displaced only six tons, +while the single car was provided with a motor developing only 150 +horse-power, the speed being 28 miles per hour. Thus it will be seen +that a huge development has suddenly taken place, a result due no doubt +to the co-operation of the well-known engineer Basenach. The "M-IV" +is essentially an experiment and great secrecy has been maintained +in regard to the trials which have been carried out therewith, the +authorities merely vouchsafing the fact that the airship has proved +completely successful in every respect; conclusive testimony of this +is offered by the inclusion of the vessel in the active aerial fleet of +Germany. + +But it is the Parseval which is regarded as the finest type of airship +flying the German flag. This vessel is the product of slow evolution, +for it is admitted to be a power-driven balloon. Even the broad lines +of the latter are preserved, the shape being that of a cylinder with +rounded ends. It is the direct outcome of the "Drachen-Balloon," +perfected by Parseval and Siegsfeld, the captive balloon which is an +indispensable part of the German military equipment. + +The complete success of the suspension system in this captive balloon +prompted Parseval to continue his researches and experiments in regard +to the application of power to the vessel, so as to induce it to move +independently of the wind. The suspension system and the car are the +outstanding features of the craft. It is non-rigid in the strictest +interpretation of the term, although, owing to the incorporation of +the steadying hollow "mattress" (as it is called by its inventor), the +strength of the suspension system, and the substantial character of the +car, it conveys an impression of great solidity. The thinnest rope, +both manilla and steel, in the suspension system is as thick as a man's +finger, while the car, measuring 30 feet in length by 6 feet in width, +carried out in wood, is a striking example of the maximum of strength +with the minimum of weight, being as steady and as solid as a boat's +deck. The propellers are collapsible, although in the latest craft of +this class they are semi-rigid. + +The mechanical equipment is also interesting. There are two propellers, +and two motors, each nominally driving one propeller. But should one +motor break down, or motives of economy, such as husbanding of fuel, +render it advisable to run upon one engine, then the two propellers may +be driven by either of the motors. + +The inventor has perfected an ingenious, simple, and highly efficient +coupling device to attain this end, but to ensure that the propeller +output is of the maximum efficiency in relation to the engine, the pitch +of the propellers may be altered and even reversed while the engine is +running. When one motor only is being used, the pitch is lowered until +the propellers revolve at the speed which they would attain if both +engines were in operation. This adjustment of the propeller pitch to the +most economical engine revolutions is a distinctive characteristic, and +contributes to the efficiency and reliability of the Parseval dirigible +to a very pronounced degree. + +Steering in the vertical plane is also carried out upon distinctive +lines. There are no planes for vertical steering, but movement is +accomplished by tilting the craft and thus driving the gas from one end +of the balloon to the other. This is effected by the manipulation of the +air-ballonets, one of which is placed at the prow and stem of the gas +bag respectively. If it is desired to descend the gas is driven from the +forward to the after end of the envelope, merely by inflating the bow +ballonet with air by means of a pump placed in the car. If ascent is +required, the after-ballonet is inflated, thereby driving the gas to the +forward end of the balloon, the buoyancy of which is thus increased. +The outstanding feature of the "Drachen-Balloon" is incorporated in +the airship. This is the automatic operation of the safety valve on the +gas-bag directly by the air ballonets. If these ballonets empty owing +to the pressure of the gas within the envelope, a rope system disposed +within the balloon and connecting the ballonets and the gas-valve at the +top is stretched taut, thereby opening the gas-valve. In this manner the +gas-pressure becomes reduced until the ballonets are enabled to exercise +their intended function. This is a safety precaution of inestimable +value. + +The Parseval is probably the easiest dirigible to handle, inasmuch as it +involves no more skill or knowledge than that required for an ordinary +free balloon. Its movements in the vertical plane are not dissimilar +to those of the aeroplane, inasmuch as ascent and descent are normally +conducted in a "screwing" manner, the only exception being of course +in abrupt descent caused by the ripping of the emergency-valve. On one +occasion, it is stated, one of the latest machines of this type, +when conducting experimental flights, absolutely refused to descend, +producing infinite amusement both among the crowd and those on board. + +The development of the Parseval is directly attributable to the +influence and intimate interest of the Kaiser, and undoubtedly this +represents the wisest step he ever made in the realm of aeronautics. It +certainly has enabled the German military machine to become possessed of +a significant fleet of what may be described as a really efficient and +reliable type of dirigible. The exact number of military Parsevals in +commission is unknown, but there are several classes thereof, in the +nature of aerial cruisers and vedettes. + +The largest and most powerful class are those known as the B type, +measuring about 240 feet in length by 40 feet maximum diameter, +of 223,000 cubic feet capacity, and fitted with two motorsand two +propellers. This vessel carries about 10 passengers, can climb to a +maximum height of approximately 8,500 feet, and is capable of remaining +in the air for twenty hours upon a single fuel charge. While this is +the largest and most serviceable type of Parseval designed for +military duties, there is another, the A class, 200 feet in length with +accommodation for six passengers in addition to the crew of three, which +is capable of attaining a maximum altitude of 6,700 feet, and has an +endurance capacity of 15 hours. This class also is fitted with twin +propellers and motors. In addition there are the C and E classes, +carrying from four to eight passengers, while the vedettes are +represented by the D and F classes, which have a maximum altitude of +2,000 feet and can remain aloft for only five hours upon a single fuel +charge. These smaller vessels, however, have the advantage of requiring +only one or two men to handle them. The present military Parseval +dirigible is made in one of these five standardised classes, experience +having established their efficiency for the specified military services +for which they are built. In point of speed they compare favourably with +the latest types of Zeppelin, the speeds of the larger types ranging +from 32 to 48 miles per hour with a motor effort of 360 to 400 +horse-power. + +So far as the French airships of war are concerned, the fleet is +somewhat heterogeneous, although the non-rigid type prevails. The French +aerial navy is represented by the Bayard-Clement, Astra, Zodiac, and the +Government-built machines. Although the rigid type never has met with +favour in France, there is yet a solitary example of this system of +construction--the Spiess, which is 460 feet in length by 47 feet in +diameter and has a displacement of 20 tons. The semi-rigid craft are +represented by the Lebaudy type, the largest of which measures 293 feet +in length by 51 feet in diameter, and has a displacement of 10 tons. + +One may feel disposed to wonder why the French should be apparently +backward in this form of aerial craft, but this may be explained by the +fact that the era of experiment had not been concluded at the time war +was declared, with the result that it has been somewhat difficult to +determine which type would meet the military requirements of the country +to the best advantage. Moreover, the French military authorities evinced +a certain disposition to relegate the dirigible to a minor position, +convinced that it had been superseded by the heavier-than-air machine. +Taken on the whole, the French airship fleet is inferior to the German +in point of speed, if not numerically, but this deficiency is more than +counterbalanced by the skill and ability of the men manning their craft, +who certainly are superior to their contemporaries in Germany, combined +with the proved character of such craft as are in service. + +The same criticism may be said to apply to Great Britain. That +country was backward in matters pertaining to the airship, because its +experiments were carried out spasmodically while dependence was reposed +somewhat too much upon foreign effort. The British airships are small +and of low speed comparatively speaking. Here again it was the advance +of the aeroplane which was responsible for the manifestation of a +somewhat indifferent if not lethargic feeling towards the airship. +Undoubtedly the experiments carried out in Great Britain were somewhat +disappointing. The one and only attempt to out-Zeppelin the Zeppelin +resulted in disaster to the craft before she took to the air, while +the smaller craft carried out upon far less ambitious lines were +not inspiritingly successful. Latterly the non-rigid system has been +embraced exclusively, the craft being virtually mechanically driven +balloons. They have proved efficient and reliable so far as they go, but +it is the personal element in this instance also which has contributed +so materially to any successes achieved with them. + +But although Great Britain and France apparently lagged behind the +Germans, appreciable enterprise was manifested in another direction. +The airship was not absolutely abandoned: vigilance was maintained for +a superior type of craft. It was an instance of weighing the advantages +against the disadvantages of the existing types and then evolving for a +design which should possess the former without any of the latter. This +end appears to be achieved with the Astra type of dirigible, the story +of the development of which offers an interesting chapter in the annals +of aeronautics. + +In all lighter-than-air machines the resistance to the air offered +by the suspension ropes is considerable, and the reduction of this +resistance has proved one of the most perplexing problems in the +evolution of the dirigible. The air is broken up in such a manner by +the ropes that it is converted into a brake or drag with the inevitable +result that the speed undergoes a severe diminution. A full-rigged +airship such as the Parseval, for instance, may present a picturesque +appearance, but it is severely unscientific, inasmuch as if it were +possible to eliminateor to reduce the air-resistance offered by the +ropes, the speed efficiency might be raised by some sixty per cent and +that without any augmentation of the propelling effort. As a matter +of fact Zeppelin solved this vexatious problem unconsciously. In his +monster craft the resistance to the air is reduced to a remarkable +degree, which explains why these vessels, despite all their other +defects are able to show such a turn of speed. + +It was this feature of the Zeppelin which induced Great Britain to +build the May-fly and which likewise induced the French Government to +stimulate dirigible design and construction among native manufacturers, +at the same time, however, insisting that such craft should be equal at +least in speed to the Zeppelins. The response to this invitation was the +Spiess, which with its speed of 45 miles per hour ranked, until 1914, as +one of the fastest dirigibles in the French service. + +In the meantime a Spanish engineer, Senor Torres, had been quietly +working out a new idea. He realised the shortcomings of the prevailing +types of airships some eleven years ago, and unostentatiously and +painstakingly set out to eliminate them by the perfection of a new type +of craft. He perfected his idea, which was certainly novel, and then +sought the assistance of the Spanish Government. But his fatherland was +not adapted to the prosecution of the project. He strove to induce the +authorities to permit even a small vessel to be built, but in vain. He +then approached the French Astra Company. His ambition was to build a +vessel as large as the current Zeppelin, merely to emphasise the value +of his improvement upon a sufficiently large scale, and to enable +comparative data concerning the two designs to be obtained. But the +bogey of expense at first proved insuperable. However, the French +company, decided to give the invention a trial, and to this end a small +"vedette" of about 53,000 cubic feet displacement was built. + +Although an unpretentious little vessel, it certainly served to +emphasise the importance of the Torres idea. It was pitted against the +"Colonel Renard," the finest ship at that time in the French aerial +service, which had proved the fastest airship in commission, and +which also was a product of the Astra Company. But this fine craft was +completely outclassed by the puny Astra-Torres. + +The builders and the inventor were now additionally anxious to +illustrate more emphatically the features of this design and to build +a far larger vessel. The opportunity was offered by the British +Government, which had been following the experiments with the small +Astra-Torres in France. An order was given for a vessel of 282,500 +cubic feet displacement; in this instance it was ranged against another +formidable rival--the Parseval. But the latter also failed to hold its +own against the Spanish invention, inasmuch as the Astra-Torres built +for the British authorities exceeded a speed of 50 miles per hour in the +official tests. This vessel is still doing valuable duty, being attached +to the British air-service in France. + +The achievements of the British vessel were not lost upon the French +Government, which forthwith placed an order for a huge vessel of 812,200 +cubic feet capacity, equipped with motors developing 1,000 horse-power, +which it was confidently expected would enable a speed of 60 miles per +hour to be attained. Thus France would be able to meet the Germans upon +fairly level terms, inasmuch as the speed of the latest Zeppelins does +not exceed 60 miles per hour. So confident were the authorities that a +second order for an even larger vessel was placed before the first large +craft was completed. + +This latter vessel is larger than any Zeppelin yet built, seeing that +it displaces 38 tons, and is fitted with motors developing 1,000 +horse-power. It has recently been completed, and although the results +of the trials, as well as the dimensions of the craft have not been +published, it is well known that the speed has exceeded 60 miles per +hour, so that France now possesses the speediest dirigible in the world. + +The Torres invention has been described as wonderful, scientifically +perfect and extremely simple. The vessel belongs to the non-rigid class, +but the whole of the suspension system is placed within the gas-bag, so +that the air-resistance offered by ropes is virtually eliminated in its +entirety, for the simple reason that practically no ropes are placed +outside the envelope. The general principle of design may be gathered +from the accompanying diagram. It is as if three sausage-shaped +balloons were disposed pyramidally--two lying side by side with one +super-imposed, with the bags connected at the points where the circular +sections come into contact. Thus the external appearance of the envelope +is decidedly unusual, comprising three symmetrical ridges. At the points +where the three bags come into contact cloth bands are stretched across +the arcs, thereby forming a cord. The suspension system is attached to +the upper corners of the inverted triangle thus formed, and converges +in straight lines through the gas space. The bracing terminates in +collecting rings from which a short vertical cable extends downwards +through a special accordion sleeve to pass through the lower wall of the +envelope. These sleeves are of special design, the idea being to permit +the gas to escape under pressure arising from expansion and at the +same time to provide ample play for the cable which is necessary in a +flexible airship. + +This cable emerges from the envelope only at the point or points where +the car or cars is or are placed. In the British airship of this type +there is only one car, but the larger French vessels are equipped +with two cars placed tandem-wise. The vertical cable, after extending +downwards a certain distance, is divided, one rope being attached +to one, and the second to the other side of the car. The two-bladed +propellers are disposed on either side of the car, in each of which a +500 horse-power motor is placed. + +The Astra-Torres type of dirigible may be said to represent the latest +expression in airship design and construction. The invention has given +complete satisfaction, and has proved strikingly successful. The French +Government has completed arrangements for the acquisition of larger +and more powerful vessels of this design, being now in the position to +contest every step that is made by Germany in this field. The type has +also been embraced by the Russian military authorities. The Astra-Torres +airship has a rakish appearance, and although the lines of the gas-bag +are admitted to increase frictional resistance, this is regarded as a +minor defect, especially when the many advantages of the invention are +taken into consideration. + + + +CHAPTER V. GERMANY'S AERIAL DREADNOUGHT FLEET + +Although Germany, as compared with France, was relatively slow +to recognise the immense possibilities of aircraft, particularly +dirigibles, in the military sense, once the Zeppelin had received the +well-wishes of the Emperor William, Teuton activities were so pronounced +as to enable the leeway to be made up within a very short while. While +the Zeppelin commanded the greatest attention owing to the interesting +co-operation of the German Emperor, the other types met with official +and royal recognition and encouragement as already mentioned. France, +which had held premier position in regard to the aerial fleet of +dirigibles for so long, was completely out-classed, not only in +dimensions but also in speed, as well as radius of action and +strategical distribution of the aerial forces. + +The German nation forged ahead at a great pace and was able to establish +a distinct supremacy, at least on paper. In the light of recent events +it is apparent that the German military authorities realised that the +dawn of "The Day" was approaching rapidly, and that it behoved them to +be as fully prepared in the air as upon the land. It was immaterial that +the Zeppelin was the synonym for disaster. By standardisation its cost +could be reduced while construction could be expedited. Furthermore, +when the matter was regarded in its broadest aspect, the fact was +appreciated that forty Zeppelins could be built at the cost of one +super-Dreadnought, so that adequate allowance could be made for +accidents now and then, since a Zeppelin catastrophe, no matter how +complete it may be, is regarded by the Teuton as a mere incident +inseparable from progressive development. + +At the beginning of the year 1914 France relied upon being strengthened +by a round dozen new dirigibles. Seven of these were to be of 20,000 +cubic metres' capacity and possessed of a speed of 47 miles per hour. +While the existing fleet was numerically strong, this strength was more +apparent than real, for the simple reason that a large number of craft +were in dry-dock undergoing repair or overhaul while many of the units +were merely under test and could not be regarded therefore as in the +effective fleet. True, there were a certain number of private craft +which were liable to be commandeered when the occasion arose, but they +could not be considered as decided acquisitions for the simple reason +that many were purely experimental units. + +Aerial vessels, like their consorts upon the water, have been divided +into distinctive classes. Thus there are the aerial cruisers comprising +vessels exceeding 282,000 cubic feet in capacity; scouts which include +those varying between 176,600 and 282,000 cubic feet capacity; and +vedettes, which take in all the small or mosquito craft. At the end +of 1913, France possessed only four of the first-named craft in actual +commission and thus immediately available for war, these being the +Adjutant Vincenot, Adjutant Reau, Dupuy de Lome, and the Transaerien. +The first three are of 197,800 cubic feet. All, however, were privately +owned. + +On the other hand, Germany had no fewer than ten huge vessels, ranging +from 353,000 to 776,900 cubic feet capacity, three of which, the +Victoria Luise, Suchard, and Hansa, though owned privately, were +immediately available for war. Of these the largest was the Zeppelin +naval vessel "L-1" 525 feet in length, by 50 feet diameter, of 776,900 +cubic feet capacity, equipped with engines developing 510 horse-power, +and with a speed of 51.8 miles per hour. + +At the end of 1913 the effective aerial fleet of Germany comprised +twenty large craft, so far in advance of the French aerial cruisers as +to be worthy of the name bestowed upon them--"Aerial Dreadnoughts." This +merely represented the fleet available for immediate use and did not +include the four gigantic Suchard-Schutte craft, each of 847,500 cubic +feet, which were under construction, and which were being hurried +forward to come into commission early in 1914. + +But the most interesting factor, apart from the possession of such a +huge fleet of dirigible air-craft, was their distribution at strategical +points throughout the Empire as if in readiness for the coming combat. +They were literally dotted about the country. Adequate harbouring +facilities had been provided at Konigsberg, Berlin, Posen, Breslau, +Kiel, Hamburg, Wilhelmshaven, Dusseldorf, Cologne, Frankfort, Metz, +Mannheim, Strasburg, and other places, with elaborate headquarters, of +course, at Friedrichshafen upon Lake Constance. The Zeppelin workshops, +harbouring facilities, and testing grounds at the latter point had +undergone complete remodelling, while tools of the latest type had +been provided to facilitate the rapid construction and overhaul of the +monster Zeppelin dirigibles. Nothing had been left to chance; not an +item was perfunctorily completed. The whole organisation was perfect, +both in equipment and operation. Each of the above stations possessed +provision for an aerial Dreadnought as well as one or more aerial +cruisers, in addition to scouts or vedettes. + +Upon the outbreak of hostilities Germany's dirigible fleet was in a +condition of complete preparedness, was better organised, and better +equipped than that of any of her rivals. At the same time it constituted +more of a paper than a fighting array for reasons which I will +explain later. But there was another point which had escaped general +observation. Standardisation of parts and the installation of the +desired machinery had accomplished one greatly desired end--the +construction of new craft had been accelerated. Before the war an +interesting experiment was carried out to determine how speedily a +vessel could be built. The result proved that a dirigible of the most +powerful type could be completed within eight weeks and forthwith the +various constructional establishments were brought into line so as to +maintain this rate of building. + +The growth of the Zeppelin, although built upon disaster, has been +amazing. The craft of 1906 had a capacity of 430,000 cubic feet and a +speed of 36 miles per hour. In 1911 the creator of this type launched +a huge craft having a capacity of 627,000 cubic feet. In the meantime +speed had likewise been augmented by the use of more powerful motors +until 52 miles an hour was attained. But this by no means represented +the limit. The foregoing vessels had been designed for land service +purely and simply, but now the German authorities demanded similar craft +for naval use, possessed of high speed and greater radius of action. +Count Zeppelin rose to the occasion, and on October 7th, 1912, launched +at Friedrichshafen the monster craft "L-I," 525 feet in length, 50 feet +in diameter, of 776,900 cubic feet capacity, a displacement of 22 +tons and equipped with three sets of motors aggregating more than 500 +horse-power, and capable of imparting a speed of 52 miles per hour. + +The appearance of this craft was hailed with intense delight by the +German nation, while the naval department considered her to be a +wonderful acquisition, especially after the searching reliability trial. +In charge of Count Zeppelin and manned by a crew of 22 officers and men +together with nearly three tons of fuel--the fuel capacity conveys +some idea of her possible radius of action--she travelled from +Friedrichshafen to Johannisthal in 32 hours. On this remarkable journey +another point was established which was of far-reaching significance. +The vessel was equipped with wireless telegraphy and therewith she +kept in touch with the earth below throughout the journey, dropping and +picking up wireless stations as she progressed with complete facility. +This was a distinct achievement, inasmuch as the vessel having been +constructed especially for naval operations she would be able to keep +in touch with the warships below, guiding them unerringly during their +movement. + +The cross-country trip having proved so completely successful the +authorities were induced to believe that travelling over water would be +equally satisfactory. Accordingly the "L-I" was dispatched to the island +of Heligoland, the intention being to participate in naval manoeuvres +in order to provide some reliable data as to the value of these craft +operating in conjunction with warships. But in these tests German +ambition and pride received a check. The huge Zeppelin was manoeuvring +over the North Sea within easy reach of Heligoland, when she was caught +by one of those sudden storms peculiar to that stretch of salt water. In +a moment she was stricken helpless; her motive power was overwhelmed +by the blind forces of Nature. The wind caught her as it would a +soap-bubble and hurled her into the sea, precipitating the most +disastrous calamity in the annals of aeronautics, since not only was the +ship lost, but fifteen of her crew of 22 officers and men were drowned. + +The catastrophe created consternation in German aeronautical circles. +A searching inquiry was held to explain the disaster, but as usual it +failed to yield much material information. It is a curious circumstance, +but every successive Zeppelin disaster, and their number is legion, +has been attributable to a new cause. In this instance the accident was +additionally disturbing, inasmuch as the ship had been flying across +country continuously for about twelve months and had covered more miles +than any preceding craft of her type. No scientific explanation for the +disaster was forthcoming, but the commander of the vessel, who sank with +his ship, had previously ventured his personal opinion that the +vessel was over-loaded to meet the calls of ambition, was by no means +seaworthy, and that sooner or later she would be caught by a heavy +broadside wind and rendered helpless, or that she would make a headlong +dive to destruction. It is a significant fact that he never had any +faith in the airship, at least for sea duty, though in response to +official command he carried out his duties faithfully and with a blind +resignation to Fate. + +Meantime, owing to the success of the "L-I" in cross-country operations, +another and more powerful craft, the "L-II" had been taken in hand, and +this was constructed also for naval use. While shorter than her consort, +being only 487 feet over all, this vessel had a greater beam--55 feet. +This latter increase was decided because it was conceded to be an easier +matter to provide for greater beam than enhanced length in the existing +air-ship harbours. The "L-II" displaced 27 tons--five tons in excess of +her predecessor. In this vessel many innovations were introduced, such +as the provision of the passage-way connecting the cars within the hull, +instead of outside the latter as had hitherto been the practice, while +the three cars were placed more closely together than formerly. The +motors were of an improved type, giving an aggregate output of 900 +horse-power, and were divided into four separate units, housed in two +engine-rooms, the front car being a replica in every detail of the +navigating bridge of a warship. + +This vessel was regarded as a distinct improvement upon the "L-I," +although the latter could boast some great achievements. But her glory +was short-lived. In the course of the Government trials, while some 900 +feet aloft, the huge vessel suddenly exploded and was burned in the air, +a mass of broken and twisted metal-work falling to the ground. Of the +28 officers and men, including members of the Admiralty Board who were +conducting the official trials, all but one were killed outright, and +the solitary exception was so terribly burned as to survive the fall for +only a few hours. + +The accident was remarkable and demonstrated very convincingly that +although Count Zeppelin apparently had made huge strides in aerial +navigation through the passage of years, yet in reality he had made no +progress at all. He committed the identical error that characterised the +effort of Severo Pax ten years previously, and the disaster was directly +attributable to the self-same cause as that which overwhelmed the +Severo airship. The gas, escaping from the balloons housed in the hull, +collected in the confined passage-way communicating with the cars, came +into contact with a naked light, possibly the exhaust from the motors, +and instantly detonated with terrific force, blowing the airship to +fragments and setting fire to all the inflammable materials. + +In this airship Zeppelin committed an unpardonable blunder. He had +ignored the factor of "internal safety," and had deliberately flown in +the face of the official rule which had been laid down in France after +the Severo disaster, which absolutely forbade the inclusion of such +confined spaces as Zeppelin had incorporated. This catastrophe coming so +closely as it did upon the preceding disaster to the pride of the German +aerial fleet somewhat shook public confidence in these craft, while +aeronautical authorities of other countries described the Zeppelin more +vehemently than ever as a "mechanical monstrosity" and a "scientific +curiosity." + +The Zeppelin has come to be feared in a general manner, but this result +is due rather to stories sedulously circulated, and which may be easily +traced to Teutonic sources. Very few data of a reliable character have +been allowed to filter through official circles. We have been told +somewhat verbosely of what it can accomplish and of its high degree of +efficiency and speed. But can credence be placed in these statements? + +When Zeppelin IV made its unexpected descent at Luneville, and was +promptly seized by the French authorities, the German War office evinced +distinct signs of uneasiness. The reason was speedily forth coming. The +captain of the craft which had been captured forgot to destroy his +log and other records of data concerning the vessel which had been +scientifically collected during the journey. All this information +fell into the hands of the French military department, and it proved a +wondrous revelation. It enabled the French to value the Zeppelin at its +true worth, which was by no means comparable to the estimate based on +reports skilfully circulated for the benefit of the world at large. + +Recently the French military department permitted the results of their +expert official examination to be made public. From close investigation +of the log-book and the diagrams which had been prepared, it was found +that the maximum speed attained by Zeppelin IV during this momentous +flight was only 45 miles per hour! It was ascertained, moreover, that +the load was 10,560 pounds, and the ascensional effort 45,100 pounds. +The fuel consumption had averaged 297 pounds per hour, while the fuel +tanks carried sufficient for a flight of about seven hours. The airship +had attained a maximum height of about 6,230 feet, to reach which 6,600 +pounds of ballast had to be discarded. Moreover, it was proved that a +Zeppelin, if travelling under military conditions with full armament and +ammunition aboard, could carry sufficient fuel for only ten hours at the +utmost, during which, if the slightest head-wind prevailed, it could not +cover more than 340 miles on the one fuel charge. + +This information has certainly proved a revelation and has contributed +to the indifference with which the Parisians regard a Zeppelin raid. At +the outbreak of war the Zeppelin station nearest to Paris was at Metz, +but to make the raid from that point the airship was forced to cover +a round 500 miles. It is scarcely to be supposed that perfectly calm +weather would prevail during the whole period of the flight, so that +a raid would be attended by considerable risk. That this handicap was +recognised in German military circles is borne out by the fact that a +temporary Zeppelin hangar was established at a point considerably nearer +the French capital, for the purpose of enabling a raid to be carried out +with a greater possibility of success. + +The capture of Zeppelin IV revealed another important fact. The critical +flying height of the airship is between 3,300 and 4,000 feet. To attempt +a raid at such an altitude would be to court certain disaster, inasmuch +as the vessel would have to run the gauntlet of the whole of the French +artillery, which it is admitted has a maximum range exceeding the flying +altitude of the Zeppelin. That the above calculation is within reason is +supported by the statements of Count Zeppelin himself, who has declared +that his airships are useless at a height exceeding 5,000 feet. +Confirmatory evidence upon this point is offered by the raid upon the +British East Coast towns, when it is stated that the aircraft were +manoeuvring at a height not exceeding 2,000 feet. + + + +CHAPTER VI. THE MILITARY VALUE OF GERMANY'S AERIAL FLEET + +Although the Zeppelin undoubtedly has been over-rated by the forces to +which it is attached, at the same time it must not be under-estimated by +its detractors. Larger and more powerful vessels of this type have been, +and still are being, constructed, culminating, so far as is known, in +the "L-5," which is stated to have a capacity of about 1,000,000 cubic +feet, and to possess an average speed of 65 miles per hour. + +While it is generally maintained that the Zeppelins will prove +formidable in attack, greater reliance is being placed upon the +demoralising or terrifying effect which they are able to exercise. Owing +to the fact that from 3 to 5 tons of fuel--say 900 to 1,500 gallons of +gasoline or petrol--can be carried aboard, giving them a wide radius of +action, it is doubtful whether they could travel from Cologne to London +and back upon a single fuel charge, since such a raid would entail a +journey of about 600 miles. The latest types of this craft are said to +possess a high ascensional speed, which offers a distinct protection +against aeroplane attack. According to such official information as +has been vouchsafed, a Zeppelin, when hard pressed, is able to rise +vertically 3,500 feet in about three minutes. This is far in excess of +the ascensional speed of even the speediest aeroplane, of course, the +penalty for such a factor has to be paid: the loss of gas is appreciable +and may lead to the craft's ultimate undoing. At the same time, however, +it is able to maintain the superior position as compared with the +aeroplane for a considerable period: the upper reaches of the air are +its sanctuary. + +Nor must the nocturnal activities of the Zeppelin be overlooked. So far +as night operations by these vessels are concerned, little has leaked +out, so that the possibilities of the airship in this direction are +still somewhat hypothetical. The fact remains, however, that it is +night movements which perhaps are the most to be dreaded by the enemy. +According to official German sources of information the latest types of +Zeppelins are engined by "noiseless" motors. There is nothing remarkable +in this feature, since the modern motor-car virtually answers to this +description, although in this instance quietness is obtained for the +most part by recourse to the sleeve-valve engine. Still, the ordinary +Otto-cycle internal combustion engine can be rendered almost silent by +the utilisation of adequate muffling devices, which, in the Zeppelin, +are more possible of incorporation than in the aeroplane, because the +extra weight imposed by this acquisition is a minor consideration in +comparison with the lifting power of the vessel. + +Night operations, however, have not proved eminently successful. The +very darkness which protects the aerial prowler also serves a similar +purpose in connection with its prey. But aerial operations under the +cover of darkness are guided not so much by the glare of lights from +below as betrayal by sound. The difference between villages and cities +may be distinguished from aloft, say at 1,500 to 3,000 feet, by the hum +which life and movement emit, and this is the best guide to the aerial +scout or battleship. The German authorities have made a special study +of this peculiar problem, and have conducted innumerable tests upon the +darkest nights, when even the sheen of the moon has been unavailable, +for the express purpose of training the aerial navigators to discover +their position from the different sounds reaching them from below. In +other words, the corsair in the skies depends more upon compass and +sound than upon compass and vision when operating after dark. The +searchlights with which the Zeppelins are equipped are provided merely +for illuminating a supposed position. They are not brought into service +until the navigator concludes that he has arrived above the desired +point: the ray of light which is then projected is merely to assist the +crew in the discharge of the missiles of destruction. + +The Zeppelin, however, owing to its speed, both in the horizontal and +vertical planes, is essentially a unit for daylight operations. The +other airships which Germany possesses, and which for the most part are +of the non-rigid type, are condemned to daylight operations from +the character of their design. Owing to their low speeds they may be +dismissed as impossible aerial vessels for hazardous work and are not +regarded by the German authorities as all-round airships of war. + +Craft of the air are judged in Germany from the one standard only. This +may be a Teutonic failing, but it is quite in keeping with the Teutonic +spirit of militarism. Commercialism is a secondary factor. To the German +Emperor an airship is much what a new manufacturing process or machine +is to the American. Whereas the latter asks, "How much will it save +me on the dollar?" to the War Lord of Germany--and an airship +notwithstanding its other recommendatory features is judged solely from +this standpoint--the question is "What are its military qualifications?" + +When the semi-rigid airship "V-I" was brought before the notice of the +German military department the pressing point concerning its military +recommendations arose at once. The inventor had foreseen this issue and +was optimistic. Thereupon the authorities asked if the inventor were +prepared to justify his claims. The retort was positive. Forthwith the +Junkers decided to submit it to the test. + +This ship is of quite a distinctive type. It is an aerial cruiser, and +the inventor claims that it combines all the essential qualifications +of the Zeppelin and of the competitors of the latter, in addition to the +advantage of being capable of dissection, transportation in parts, and +rapid re-erection at any desired spot. The length of the vessel is about +270 feet; maximum diameter approximately 42 feet, and capacity about +300,000 cubic feet. The outstanding feature is a rigid keel-frame +forming a covered passage way below the envelope or gas-bag, combined +with easy access to all parts of the craft while under way, together +with an artificial stiffening which dispenses with the necessity of +attaching any additional cars. The frame is so designed that the load, +as well as the ballast and fuel tanks, may be distributed as desired, +and at the same time it ensures an advantageous disposition of the +steering mechanism, far removed from the centre of rotation at the +stern, without any overloading of the latter. + +The lifting part of the airship comprises a single gas bag fitted with +two ballonets provided to ensure the requisite gas-tension in the main +envelope, while at the same time permitting, in times of emergency, +a rapid change of altitude. Self-contained blowers contribute to the +preservation of the shape of the envelope, the blowers and the ballonets +being under the control of the pilot. Planes resembling Venetian blinds +facilitate vertical steering, while the suspension of the keel is +carried out in such a manner as to secure uniformity of weight upon the +gas bag. The propelling power comprises two sets of internal combustion +engines, each developing 130 horse-power, the transmission being through +rubber belting. The propellers, built of wood, make 350 revolutions per +minute, and are set as closely as possible to the centre of resistance. + +But the most salient characteristic of this machine is its portability. +It can be dismantled and transported by wagons to any desired spot, +the suspension frame being constructed in units, each of which is +sufficiently small to be accommodated in an ordinary vehicle. Upon +arrival the parts may be put together speedily and easily. The +authorities submitted the airship to exacting trials and were so +impressed by its characteristics and the claims of the inventor that +undoubtedly it will be brought into service during the present crisis. + +At the same time the whole faith of the German military staff so far +as airship operations are concerned, is pinned to the Zeppelin. +Notwithstanding its many drawbacks it is the vessel which will be used +for the invasion of Great Britain. Even the harbour question, which is +admitted to be somewhat acute, has been solved to a certain degree. +At strategical points permanent harbours or airship sheds have been +established. Seeing that the airships demand considerable skill in +docking and undocking, and that it is impossible to achieve these +operations against the wind, swinging sheds have been adopted. + +On water the practice is to anchor a floating harbour at one end, +leaving the structure to swing round with the wind. But on dry land such +a dock is impossible. Accordingly turntable sheds have been adopted. +The shed is mounted upon a double turn-table, there being two circular +tracks the one near the centre of the shed and the other towards its +extremities. The shed is mounted upon a centre pivot and wheels engaged +with these inner and outer tracks. In this manner the shed may be swung +round to the most favourable point of the compass according to the wind. + +In the field, however, such practices are impossible, and the issue +in this connection has been overcome by recourse to what may be termed +portable harbours. They resemble the tents of peripatetic circuses and +travelling exhibitions. There is a network of vertical steel members +which may be set with facility and speed and which are stayed by +means of wire guys. At the top of the outer vertical posts pulleys +are provided whereby the outer skin or canvas forming the walls may +be hauled into position, while at the apex of the roof further pulleys +ensure the proper placing of the roofing. The airship is able to enter +or leave from either end according to conditions. The material is +fireproofed as a precautionary measure, but at the same time the modern +aerial bomb is able to penetrate the roofing without any difficulty and +to explode against the airship anchored within. + +The one great objection to the Zeppelin harbour is the huge target it +offers to hostile attack, which, in the event of a vessel being moored +within, is inevitably serious. Thus, for instance, upon the occasion of +the air raids conducted by Lieutenant Collet and of Squadron +Commander Briggs and his colleagues at Dusseldorf and Friedrichshafen +respectively, little difficulty was experienced in destroying the +airships riding at anchor. The target offered by the shed is so +extensive that it would be scarcely possible for a flying enemy to miss +it. A bomb dropped from a reasonable height, say 500 feet, would be +almost certain to strike some part of the building, and a Zeppelin is +an easy vessel to destroy. The firing of one balloon is sufficient +to detonate the whole, for the simple reason that hydrogen gas is +continuously oozing through the bags in which it is contained. According +to a recent statement the Germans are said to be utilising an inert +or non-inflammable gas, equal in lifting power to hydrogen, for the +inflation of military craft, but scientific thought does not entertain +this statement with any degree of seriousness. No gas as light as +hydrogen and non-explosive is known to commerce. + +Will Germany invade Great Britain by air? This is the absorbing topic of +the moment--one which has created intense interest and a certain feeling +of alarm among the timorous. Although sporadic raids are considered +to be possible and likely to be carried out with a varying measure +of success--such as that made upon the British East Coast--eminent +authorities ridicule an invasion in force. The risk would be enormous, +although there is no doubt that Germany, which has always maintained +that an invasion of this character will be made, will be compelled to +essay such a task, in order to satisfy public opinion, and to justify +official statements. It is a moot point, however, whether the invaders +ever will succeed in making good their escape, unless Nature proves +exceptionally kind. + +The situation is best summed up in the unbiassed report of General +George P. Scriven, Chief Signal officer of the United States Army to the +U.S. Secretary of War. In this report, which deals exhaustively with the +history, construction and achievements of airships, such an invasion +is described as fantastic and impracticable. Writing on November 10th, +1914, the officer declares that "he is not prepared to recommend +the American Army to take up seriously the question of constructing +dirigibles, as they are not worth their cost as offensive machines, +while for reconnaissance or defence they are of far less value than +aeroplanes." In his words, "Dirigibles are seemingly useless in defence +against the aeroplane or gun-fire." + +In order to be able to make an invasion in force upon Great Britain's +cities extremely favourable weather must prevail, and the treacherous +nature of the weather conditions of the North Sea are known fully well +both to British and Teuton navigators. Seeing that the majority of the +Zeppelin pilots are drawn from the Navy and mercantile marine, and +thus are conversant with the peculiarities and characteristics of +this stretch of salt water, it is only logical to suppose that their +knowledge will exert a powerful influence in any such decision, the +recommendations of the meteorological savants not withstanding. + +When the Zeppelin pride of the German Navy "L-1" was hurled to +destruction by a typical North Sea squall, Captain Blew of the Victoria +Luise, a Zeppelin with many great achievements to her credit, whose +navigator was formerly in the Navy, and thus is familiar with the whole +issue, explained that this atmospheric liveliness of the North Sea +prevails for the most part in the latitude of Norway, but that it +frequently extends as far south as the gate of the Channel. He related +furthermore that the rain squalls are of tropical violence, while the +vertical thrusts of air are such that no dirigible as yet constructed +could ever hope to live in them. Under such conditions, he continued, +the gas is certain to cool intensely, and the hull must then become +waterlogged, not to mention the downward thrust of the rain. Under such +conditions buoyancy must be imperilled to such a degree as to demand the +jettisoning of every piece of ballast, fuel and other removable weight, +including even the steadying and vertical planes. When this has been +done, he pointed out, nothing is left with which to combat the upward +vertical thrusts of the air. To attempt to run before the wind is to +court positive disaster, as the wind is certain to gain the mastery. +Once the airship loses steering way and is rendered uncontrollable it +becomes the sport of the forces of Nature, with the result that +destruction is merely a matter of minutes, or even seconds. + +Every navigator who knows the North Sea will support these conclusions. +Squalls and blizzards in winter, and thunderstorms in summer, rise +with startling suddenness and rage with terrific destructive fury. +Such conditions must react against the attempt of an aerial invasion +in force, unless it be made in the character of the last throw by a +desperate gambler, with good fortune favouring the dash to a certain +degree. But lesser and more insignificant Zeppelin raids are likely +to be somewhat frequent, and to be made at every favourable climatic +opportunity. + + + +CHAPTER VII. AEROPLANES OF WAR + +Owing to the fertility of inventors and the resultant multiplicity of +designs it is impossible to describe every type of heavier-than-air +machine which has been submitted to the exacting requirements of +military duty. The variety is infinite and the salient fact has already +been established that many of the models which have proved reliable and +efficient under normal conditions are unsuited to military operations. +The early days of the war enabled those of doubtful value to be +eliminated, the result being that those machines which are now in +use represent the survival of the fittest. Experience has furthermore +emphasised the necessity of reducing the number of types to the absolute +minimum. This weeding-out process is being continued and there is no +doubt that by the time the war is concluded the number of approved types +of aeroplanes of military value will have been reduced to a score or +less. The inconveniences and disadvantages arising from the utilisation +of a wide variety of different types are manifold, the greatest being +the necessity of carrying a varied assortment of spare parts, and +confusion in the repair and overhauling shops. + +The methodical Teuton was the first to grasp the significance of these +drawbacks; he has accordingly carried standardisation to a high degree +of efficiency, as is shown in another chapter. At a later date France +appreciated the wisdom of the German practice, and within a short time +after the outbreak of hostilities promptly ruled out certain types of +machines which were regarded as unsuitable. In this instance the process +of elimination created considerable surprise, inasmuch as it involved an +embargo on the use of certain machines, which under peace conditions +had achieved an international reputation, and were held to represent the +finest expression of aeronautical science in France as far as aeroplane +developments are concerned. + +Possibly the German machine which is most familiar, by name, to the +general public is the Taube, or, as it is sometimes called, the Etrich +monoplane, from the circumstance that it was evolved by the Austrian +engineer Igo Etrich in collaboration with his colleague Wels. These two +experimenters embarked on the study of dynamic flight contemporaneously +with Maxim, Langley, Kress, and many other well-known pioneers, but it +was not until 1908 that their first practical machine was completed. +Its success was instantaneous, many notable flights being placed to its +credit, while some idea of the perfection of its design may be gathered +from the fact that the machine of to-day is substantially identical +with that used seven years ago, the alterations which have been effected +meanwhile being merely modifications in minor details. + +The design of this machine follows very closely the lines of a bird in +flight--hence its colloquial description, "Taube," or "dove." Indeed the +analogy to the bird is so close that the ribs of the frame resemble the +feathers of a bird. The supporting plane is shaped in the manner of +a bird's distended wing, and is tipped up at the rear ends to ensure +stability. The tail also resembles that of a bird very closely. + +This aeroplane, especially the latest type, is very speedy, and it has +proved extremely reliable. It is very sharp in turning and extremely +sensitive to its rudder, which renders it a first-class craft for +reconnoitring duty. The latest machines are fitted with motors +developing from 120 to 150 horse-power. + +The "Taube" commanded attention in Germany for the reason that it +indicated the first departure from the adherence to the French designs +which up to that time had been followed somewhat slavishly, owing to the +absence of native initiative. + +The individuality of character revealed in the "Taube" appealed to the +German instinct, with the result that the machine achieved a greater +reputation than might have been the case had it been pitted against +other types of essentially Teutonic origin. The Taube was subsequently +tested both in France and Great Britain, but failed to raise an equal +degree of enthusiasm, owing to the manifestation of certain defects +which marred its utility. This practical experience tended to prove that +the Taube, like the Zeppelin, possessed a local reputation somewhat of +the paper type. The Germans, however, were by no means disappointed by +such adverse criticism, but promptly set to work to eliminate defects +with a view to securing an all-round improvement. + +The most successful of these endeavours is represented in the +Taube-Rumpler aeroplane, which may be described as an improved edition +of Etrich's original idea. As a matter of fact the modifications were of +so slight, though important, a character that many machines generically +described as Taubes are in reality Rumplers, but the difference is +beyond detection by the ordinary and unpractised observer. + +In the Rumpler machine the wings, like those of the Taube, assume +broadly the form and shape of those of the pigeon or dove in flight. The +early Rumpler machines suffered from sluggish control, but in the later +types this defect has been overcome. In the early models the wings were +flexible, but in the present craft they are rigid, although fitted with +tips or ailerons. The supporting truss beneath the wings, which was such +an outstanding feature of its prototype, has been dispensed with, the +usual I-beam longitudinals being used in its stead. The latest machines +fitted with 100-120 horse-power Mercedes motors have a fine turn of +speed, possess an enhanced ascensional effort, and are far simpler to +control. + +Other German machines which are used in the military service are the +Gotha and the Albatross. The former is a monoplane, and here again +the influence of Etrich upon German aeroplane developments is strongly +manifested, the shape of the bird's wing being retained. In the Gotha +the truss which Etrich introduced is a prominent characteristic. The +Albatross is a biplane, but this craft has proved to be somewhat slow +and may be said to be confined to what might be described as the heavier +aerial military duties, where great endurance and reliability are +essential. As the war proceeds, doubtless Teuton ingenuity will +be responsible for the appearance of new types, as well as certain +modifications in the detail construction of the existing machines, but +there is every indication that the broad lines of Etrich's conception +will be retained in all monoplanes. + +There is one point in which Germany has excelled. Wood is not employed +in the construction of these heavier-than-air craft. Steel and the +lighter tough alloys are exclusively used. In this way the minimum of +weight consistent with the maximum of strength policy is carried +out. Moreover the manufacture of component parts is facilitated and +accelerated to a remarkable degree by the use of metal, while the +tasks of fitting and repairing are notably expedited by the practice of +standardisation. Germany is also manifesting commendable enterprise in +the perfection of light powerful motors for these dynamic machines. The +latest types of explosion-motors range from 100 to 150 horse-power; the +advantages of these are obvious. + +Upon the outbreak of hostilities the French possessed an enormous number +and variety of aeroplanes and this aerial fleet had been brought to +a high standard of organisation. The aerial fleet is sub-divided into +squadrons called "escadrilles," each of which comprises six machines and +pilots. These units are kept up to strength, wastage being made up from +reserves, so as to maintain the requisite homogeneity. + +But ere the war had been in progress many weeks an official order was +issued forbidding the employment of the Bleriot, Deperdussin, Nieuport, +and R.E.P. monoplanes. Those which received official approval included +the Caudron, Henry, and Maurice Farman, Morane-Saulnier, and Voisin +machines. + +This drastic order came somewhat as a thunderbolt, and the reason for +the decree has not been satisfactorily revealed. Suffice to say that in +one stroke the efficiency and numerical strength of the French aerial +navy were reduced very appreciably. For instance, it is stated that +there were thirty escadrilles of Bleriot monoplanes together with pilots +at the front, in addition to thirty mixed escadrilles of the other +prohibited types with their fliers. Moreover a round 33 escadrilles of +all the various types were in reserve. The effect of the military order +was to reduce the effective strength by no fewer than 558 aeroplanes. + +Seeing that the French aerial force was placed at a great disadvantage +numerically by this action, there seems to be ample justification for +the hostile criticism which the decree of prohibition aroused in certain +circles, especially when it is remembered that there was not an equal +number of the accepted machines available to take the place of those +which had been ruled out of court. One effect of this decree was to +throw some 400 expert aviators upon the waiting list for the simple +reason that machines were unavailable. Some of the best aviation skill +and knowledge which France possesses were affected by the order. It +is stated that accomplished aviators, such as Vedrines, were unable to +obtain machines. + +It will be seen that the ultimate effect of the French military decree +was to reduce the number of types to about four, each of which was +allotted a specific duty. But whereas three different bi-planes are on +the approved list there is only one monoplane--the Morane-Saulaier. +This machine, however, has a great turn of speed, and it is also able to +climb at a very fast pace. In these respects it is superior to the crack +craft of Germany, so that time after time the latter have refused battle +in the skies, and have hurried back to their lines. + +The Morane-Saulnier is the French mosquito craft of the air and like the +insect, it is avowedly aggressive. In fact, its duties are confined to +the work of chasing and bringing down the enemy, for which work its high +manoeuvring capacity is excellently adapted. Its aggressive armament +comprises a mitrailleuse. Unfortunately, however, the factory +responsible for the production of this machine is at present handicapped +by the limitations of its manufacturing plant, which when pushed to the +utmost extent cannot turn out more than about ten machines per week. No +doubt this deficiency will be remedied as the war proceeds by extension +of the works or by allotting orders to other establishments, but at the +time of the decree the manufacturing capacity was scarcely sufficient to +make good the wastage, which was somewhat heavy. + +As far as biplanes are concerned the Caudron is the fastest in flight +and is likewise extremely quick in manoeuvring. It is a very small +machine and is extremely light, but the fact that it can climb at the +rate of over 330 feet per minute is a distinct advantage in its favour. +It supplements the Morane-Saulnier monoplane in the specific duty of the +latter, while it is also employed for discovering the enemy's artillery +and communicating the range of the latter to the French and British +artillery. In this latter work it has played a very prominent part and +to it is due in no small measure that deadly accuracy of the artillery +of the Allies which has now become so famous. This applies especially +to those tactics, where the field artillery dashes up to a position, +discharges a number of rounds in rapid succession, or indulges in rafale +firing, and then limbering up, rushes away before the enemy can reply. + +As is well known the Farman biplanes possess high endurance qualities. +They can remain aloft for many hours at a stretch and are remarkably +reliable. Owing to these qualities they are utilised for prolonged and +searching reconnoitring duties such as strategical reconnaissances as +distinct from the hurried and tactical reconnaissances carried out by +fleeter machines. While they are not so speedy as the monoplanes of the +German military establishment, endurance in this instance is preferable +to pace. A thorough survey of the enemy's position over the whole of +his military zone, which stretches back for a distance of 30 miles or so +from the outer line of trenches, is of incalculable value to a commander +who is contemplating any decisive movement or who is somewhat in doubt +as to the precise character of his antagonist's tactics. + +The French aerial fleet has been particularly active in its work of +raiding hostile positions and submitting them to a fusillade of bombs +from the clouds. The machine which is allotted this specific task is +the Voisin biplane. This is due to the fact that this machine is able to +carry a great weight. It was speedily discovered that in bomb-raids +it is essential for an aeroplane to be able to carry a somewhat large +supply of missiles, owing to the high percentage of misses which attends +these operations. A raid by a machine capable of carrying only, +say, half-a-dozen projectiles, is virtually a waste of fuel, and +the endurance limitations of the fast machines reacts against their +profitable use in this work. On the other hand, the fact that the Voisin +machine is able to carry a large supply of bombs renders it an ideal +craft for this purpose; hence the official decision to confine it to +this work. + +So far as the British efforts in aerial work are concerned there is no +such display of rigid selection as characterises the practice of the +French and German military authorities. Britain's position in the air +has been extensively due to private enterprise, and this is still being +encouraged. Moreover at the beginning of the war Britain was numerically +far inferior both to her antagonist and to her ally. Consequently it was +a wise move to encourage the private manufacture of machines which had +already established their value. The consequence is that a variety +of machines figure in the British aerial navy. Private initiative is +excellently seconded by the Government manufacturing aeroplane factory, +while the training of pilots is likewise being carried out upon a +comprehensive scale. British manufacture may be divided into two broad +classes--the production of aeroplanes and of waterplanes respectively. +Although there is a diversity of types there is a conspicuous +homogeneity for the most part, as was evidenced by the British raid +carried out on February 11-12, when a fleet of 34 machines raided the +various German military centres established along the coast of Flanders. + +Considerable secrecy has been displayed by the British Government +concerning the types of machines that are being utilised, although +ample evidence exists from the producing activity of the various +establishments that all available types which have demonstrated their +reliability and efficiency are being turned to useful purpose. The Avro +and Sopwith warplanes with their very high speeds have proved remarkably +successful. + +So far as manufacturing is concerned the Royal Aerial Factory may be +said to constitute the back bone of the British aerial fleet. This +factory fulfils various purposes. It is not only engaged in the +manufacture of machines, and the development of aeroplanes for specific +duties, but also carries out the inspection and testing of machines +built by private firms. Every machine is submitted to an exacting test +before it is passed into the service. + +Three broad types of Government machines are manufactured at this +establishment. There is that designed essentially for scouting +operations, in which speed is the all-important factor and which is +of the tractor type. Another is the "Reconnoitring" machine +known officially as the "R.E." to-day, but formerly as the "B.E" +(Bleriot-Experimental), a considerable number of which are in +commission. + +This machine is also of the tractor type, carrying a pilot and an +observer, and has a maximum speed of 40-50 miles per hour. If required +it can further be fitted with an automatic gun for defence and attack. +The third craft is essentially a fighting machine. Owing to the +introduction of the machine-gun which is fixed in the prow, with the +marksman immediately behind it, the screw is placed at the rear. The +pilot has his seat behind the gunner. The outstanding feature of these +machines is the high factor of safety, which attribute has astonished +some of the foremost aviation experts in the world. + +Great Britain lagged behind her Continental rivals in the development +of the Fourth Arm, especially in matters pertaining to motive power. +For some time reliance was placed upon foreign light highspeed explosion +motors, but private enterprise was encouraged, with the result that +British Motors comparing favourably in every respect with the best +productions upon the Continent are now available. Development is still +proceeding, and there is every evidence that in the near future entire +reliance will be placed upon the native motor. + +Undoubtedly, as the war progresses, many valuable lessons will be +learned which will exercise an important bearing upon the design +and construction of warplanes. The ordeals to which the machines are +submitted in military duties are far more severe than any imposed by the +conditions of commerce. Accordingly there is every indication that +the conflict upon the Continent will represent a distinctive epoch in +aeroplane design and construction. Many problems still await solution, +such as the capacity to hover over a position, and it is quite possible +that these complex and baffling questions will be settled definitely +as the result of operations in the field. The aeroplane has reached a +certain stage of evolution: further progress is virtually impossible +unless something revolutionary is revealed, perfected, and brought to +the practical stage. + + + +CHAPTER VIII. SCOUTING FROM THE SKIES + +From the moment when human flight was lifted from the rut of experiment +to the field of practical application, many theories, interesting and +illuminating, concerning the utility of the Fourth Arm as a military +unit were advanced. The general consensus of expert opinion was that +the flying machine would be useful to glean information concerning the +movements of an enemy, rather than as a weapon of offence. + +The war is substantiating this argument very completely. Although +bomb-dropping is practised somewhat extensively, the results achieved +are rather moral than material in their effects. Here and there +startling successes have been recorded especially upon the British side, +but these triumphs are outnumbered by the failures in this direction, +and merely serve to emphasise the views of the theorists. + +The argument was also advanced that, in this particular work, the +aeroplane would prove more valuable than the dirigible, but actual +campaigning has proved conclusively that the dirigible and the +heavier-than-air machines have their respective fields of utility in the +capacity of scouts. In fact in the very earliest days of the war, +the British airships, though small and slow in movement, proved more +serviceable for this duty than their dynamic consorts. This result +was probably due to the fact that military strategy and tactics were +somewhat nonplussed by the appearance of this new factor. At the time +it was an entirely unknown quantity. It is true that aircraft had been +employed in the Balkan and the Italo-Ottoman campaigns, but upon such a +limited scale as to afford no comprehensive idea of their military value +and possibilities. + +The belligerents, therefore, were caught somewhat at a disadvantage, +and an appreciable period of time elapsed before the significance of +the aerial force could be appreciated, while means of counter acting +or nullifying its influences had to be evolved simultaneously, +and according to the exigencies of the moment. At all events, the +protagonists were somewhat loth to utilise the dirigible upon an +elaborate scale or in an aggressive manner. It was employed more after +the fashion of a captive balloon, being sent aloft from a point well +behind the front lines of the force to which it was attached, and +well out of the range of hostile guns. Its manoeuvres were somewhat +circumscribed, and were carried out at a safe distance from the enemy, +dependence being placed upon the advantages of an elevated position for +the gathering of information. + +But as the campaign progressed, the airships became more daring. Their +ability to soar to a great height offered them complete protection +against gun-fire, and accordingly sallies over the hostile lines were +carried out. But even here a certain hesitancy became manifest. This +was perfectly excusable, for the simple reason that the dirigible, above +all, is a fair-weather craft, and disasters, which had overtaken these +vessels time after time, rendered prudence imperative. Moreover, but +little was known of the range and destructiveness of anti-aircraft guns. + +In the duty of reconnoitring the dirigible possesses one great advantage +over its heavier-than-air rival. It can remain virtually stationary in +the air, the propellers revolving at just sufficient speed to off-set +the wind and tendencies to drift. In other words, it has the power of +hovering over a position, thereby enabling the observers to complete +their task carefully and with deliberation. + +On the other hand, the means of enabling an aeroplane to hover still +remain to be discovered. It must travel at a certain speed through the +air to maintain its dynamic equilibrium, and this speed is often too +high to enable the airman to complete his reconnaissance with sufficient +accuracy to be of value to the forces below. All that the aeroplane can +do is to circle above a certain position until the observer is satisfied +with the data he has collected. + +But hovering on the part of the dirigible is not without conspicuous +drawbacks. The work of observation cannot be conducted with any degree +of accuracy at an excessive altitude. Experience has proved that the +range of the latest types of anti-aircraft weapons is in excess of +anticipations. The result is that the airship is useless when hovering +beyond the zone of fire. The atmospheric haze, even in the clearest +weather, obstructs the observer's vision. The caprices of this obstacle +are extraordinary, as anyone who has indulged in ballooning knows fully +well. On a clear summer's day I have been able to see the ground beneath +with perfect distinctness from a height of 4,500 feet, yet when the +craft had ascended a further two or three hundred feet, the panorama was +blurred. A film of haze lies between the balloon and the ground beneath. +And the character of this haze is continually changing, so that the +aerial observer's task is rendered additionally difficult. Its effects +are particularly notice able when one attempts to photograph the view +unfolded below. Plate after plate may be exposed and nothing will be +revealed. Yet at a slightly lower altitude the plates may be exposed and +perfectly sharp and well-defined images will be obtained. + +Seeing that the photographic eye is keener and more searching than the +human organ of sight, it is obvious that this haze constitutes a very +formidable obstacle. German military observers, who have accompanied +the Zeppelins and Parsevals on numerous aerial journeys under varying +conditions of weather, have repeatedly drawn attention to this factor +and its caprices, and have not hesitated to venture the opinion that it +would interfere seriously with military aerial reconnaissances, and also +that it would tend to render such work extremely hazardous at times. + +When these conditions prevail the dirigible must carry out its work upon +the broad lines of the aeroplane. It must descend to the level where a +clear view of the ground may be obtained, and in the interests of safety +it has to keep on the move. To attempt to hover within 4,000 feet of +the ground is to court certain disaster, inasmuch as the vessel offers +a magnificent and steady target which the average gunner, equipped with +the latest sighting devices and the most recent types of guns, scarcely +could fail to hit. + +But the airman in the aeroplane is able to descend to a comparatively +low level in safety. The speed and mobility of his machine constitute +his protection. He can vary his altitude, perhaps only thirty or forty +feet, with ease and rapidity, and this erratic movement is more than +sufficient to perplex the marksmen below, although the airman is +endangered if a rafale is fired in such a manner as to cover a wide +zone. + +Although the aeroplane may travel rapidly it is not too fleet for a keen +observer who is skilled in his peculiar task. He may only gather a +rough idea of the disposition of troops, their movements, the lines +of communication, and other details which are indispensable to his +commander, but in the main the intelligence will be fairly accurate. +Undulating flight enables him to determine speedily the altitude at +which he is able to obtain the clearest views of the country beneath. +Moreover, owing to his speed he is able to complete his task in far less +time than his colleague operating in the dirigible, the result being +that the information placed at the disposal of his superior officers is +more to the moment, and accordingly of greater value. + +Reconnoitring by aeroplane may be divided into two broad categories, +which, though correlated to a certain degree, are distinctive, because +each constitutes a specific phase in military operations. They are known +respectively as "tactical" and "strategical" movements. The first is +somewhat limited in its scope as compared with the latter, and +has invariably to be carried out rapidly, whereas the strategical +reconnaissance may occupy several hours. + +The tactical reconnaissance concerns the corps or divisional commander +to which the warplane is attached, and consequently its task is confined +to the observation of the line immediately facing the particular corps +or division. The aviator does not necessarily penetrate beyond the lines +of the enemy, but, as a rule limits his flight to some distance from +his outermost defences. The airman must possess a quick eye, because +his especial duty is to note the disposition of the troops immediately +facing him, the placing of the artillery, and any local movements of the +forces that may be in progress. Consequently the aviator engaged on +this service may be absent from his lines for only a few minutes, +comparatively speaking; the intelligence he acquires must be speedily +communicated to the force to which he is attached, because it may +influence a local movement. + +The strategical reconnaissance, on the other hand, affects the whole +plan of campaign. The aviators told off for this duty are attached to +the staff of the Commander-in-Chief, and the work has to be carried out +upon a far more comprehensive and elaborate scale, while the airmen +are called upon to penetrate well into the hostile territory to a point +thirty, forty, or more miles beyond the outposts. + +The procedure is to instruct the flier either to carry out his +observations of the territory generally, or to report at length upon a +specified stretch of country. In the latter event he may fly to and +fro over the area in question until he has acquired all the data it is +possible to collect. His work not only comprises the general disposition +of troops, defences, placing of artillery, points where reserves are +being held, high-roads, railways, base camps, and so forth, but he is +also instructed to bring back as correct an idea as possible of what +the enemy proposes to do, so that his Commander-in-Chief may adjust +his moves accordingly. In order to perform this task with the requisite +degree of thoroughness it is often necessary for the airman to remain in +the air for several hours continuously, not returning, in fact, until he +has completed the allotted duty. + +The airman engaged in strategical aerial reconnaissance must possess, +above all things, what is known as a "military" eye concerning the +country he traverses. He must form tolerably correct estimates of the +forces beneath and their character. He must possess the ability to +read a map rapidly as he moves through the air and to note upon it all +information which is likely to be of service to the General Staff. +The ability to prepare military sketches rapidly and intelligibly is +a valuable attribute, and skill in aerial photography is a decidedly +useful acquisition. + +Such men must be of considerable stamina, inasmuch as great demands +are made upon their powers of endurance. Being aloft for several hours +imposes a severe tax upon the nervous system, while it must also be +borne in mind that all sorts and conditions of weather are likely to +be encountered, more particularly during the winter. Hail, rain, and +blizzards may be experienced in turn, while the extreme cold which often +prevails in the higher altitudes during the winter season is a +fearful enemy to combat. Often an airman upon his return from such a +reconnaissance has been discovered to be so numbed and dazed as a result +of the prolonged exposure, that considerable time has elapsed before +he has been sufficiently restored to set forth the results of his +observations in a coherent, intelligible manner for the benefit of the +General Staff. Under these circumstances it is not surprising that the +most skilful and experienced aviators are generally reserved for this +particular work. In addition to the natural accidents to which the +strategical aerial observer is exposed, the dangers arising from hostile +gun-fire must not be overlooked. He is manoeuvring the whole time +over the enemy's firing zone, where anti-aircraft weapons are disposed +strategically, and where every effort is made by artillery to bring him +down, or compel him to repair to such a height as to render observation +with any degree of accuracy well-nigh impossible. + +The methods practised by the German aerial scout vary widely, and are +governed in no small measure by the intrepidity and skill of the airman +himself. One practice is to proceed alone upon long flights over the +enemy's lines, penetrating just as far into hostile territory as the +pilot considers advisable, and keeping, of course, within the limits of +the radius of action of the machine, as represented by the fuel supply, +the while carefully taking mental stock of all that he observes below. +It is a kind of roving commission without any definite aim in view +beyond the collection of general intelligence. + +This work, while productive and valuable to a certain degree, is +attended with grave danger, as the German airmen have repeatedly found +to their cost. Success is influenced very materially by the accuracy +of the airman's judgment. A slight miscalculation of the velocity +and direction of the wind, or failure to detect any variations in the +climatic conditions, is sufficient to prove his undoing. German airmen +who essayed journeys of discovery in this manner, often failed to regain +their lines because they ventured too far, misjudged the speed of the +wind which was following them on the outward run, and ultimately were +forced to earth owing to the exhaustion of the fuel supply during the +homeward trip; the increased task imposed upon the motor, which had to +battle hard to make headway, caused the fuel consumption per mile to +exceed calculations. + +Then the venturesome airman cannot neglect another factor which is +adverse to his success. Hostile airmen lie in wait, and a fleet of +aeroplanes is kept ready for instant service. They permit the invader +to penetrate well into their territory and then ascend behind him to +cut off his retreat. True, the invader has the advantage of being on the +wing, while the ether is wide and deep, without any defined channels +of communication. But nine times out of ten the adventurous scout is +trapped. His chances of escape are slender, because his antagonists +dispose themselves strategically in the air. The invader outpaces one, +but in so doing comes within range of another. He is so harassed that he +either has to give fight, or, finding his retreat hopelessly cut off, +he makes a determined dash, trusting to his high speed to carry him +to safety. In these driving tactics the French and British airmen have +proved themselves adepts, more particularly the latter, as the chase +appeals to their sporting instincts. There is nothing so exhilarating as +a quarry who displays a determination to run the gauntlet. + +The roving Teuton scout was considerably in evidence in the early days +of the war, but two or three weeks' experience emphasised the sad fact +that, in aerial strategy, he was hopelessly outmatched by his opponents. +His advantage of speed was nullified by the superior tactical and +strategical acumen of his antagonists, the result being that the German +airman, who has merely been trained along certain lines, who is in +many cases nothing more than a cog-wheel in a machine, and who is +proverbially slow-witted, has concluded that he is no match for the +airmen of the Allies. He found from bitter experience that nothing +afforded the Anglo-French military aviators such keen delight as to lie +in wait for a "rover," and then to swoop into the air to round him up. + +The proportion of these individual scouts who were either brought down, +or only just succeeded in reaching safety within their own lines, and +who were able to exhibit serious wounds as evidence of the severity of +the aerial tussle, or the narrowness of the escape, has unnerved the +Teuton airmen as a body to a very considerable extent. Often, even when +an aeroplane descended within the German lines, it was found that the +roving airman had paid the penalty for his rashness with his life, so +that his journey had proved in vain, because all the intelligence he +had gained had died with him, or, if committed to paper, was so +unintelligible as to prove useless. + +It was the success of the British airmen in this particular field +of duty which was responsible for the momentous declaration in +Field-Marshal Sir John French's famous despatch:--"The British Flying +Corps has succeeded in establishing an individual ascendancy, which is +as serviceable to us as it is damaging to the enemy.... The enemy have +been less enterprising in their flights. Something in the direction of +the mastery of the air has already been gained." + +The methods of the British airmen are in vivid contrast to the +practice of the venturesome Teuton aerial rovers described above. While +individual flights are undertaken they are not of unknown duration or +mileage. The man is given a definite duty to perform and he ascends +merely to fulfil it, returning with the information at the earliest +possible moment. It is aerial scouting with a method. The intelligence +is required and obtained for a specific purpose, to govern a +contemplated move in the grim game of war. + +Even then the flight is often undertaken by two or more airmen for the +purpose of checking and counterchecking information gained, or to ensure +such data being brought back to headquarters, since it is quite possible +that one of the party may fall a victim to hostile fire. By operating +upon these lines there is very little likelihood of the mission +proving a complete failure. Even when raids upon certain places such as +Dusseldorf, Friedrichshafen or Cuxhaven are planned, complete dependence +is not placed on one individual. The machine is accompanied, so that +the possibility of the appointed task being consummated is transformed +almost into a certainty. + +The French flying men work upon broadly similar lines. Their fleet is +divided into small squadrons each numbering four, six, or more machines, +according to the nature of the contemplated task. Each airman is given +an area of territory which is to be reconnoitred thoroughly. In this way +perhaps one hundred or more miles of the enemy's front are searched for +information at one and the same time. The units of the squadron start +out, each taking the appointed direction according to the preconceived +plan, and each steering by the aid of compass and map. They are urged to +complete the work with all speed and to return to a secret rendezvous. + +Later the air is alive with the whirring of motors. The machines are +coming back and all converging to one point. They vol-plane to the earth +and gracefully settle down within a short distance of each other at the +rendezvous. The pilots collect and each relates the intelligence he has +gained. The data are collated and in this manner the General Staff is +able to learn exactly what is transpiring over a long stretch of the +hostile lines, and a considerable distance to the rear of his advance +works. Possibly five hundred square miles have been reconnoitred in +this manner. Troops have been massed here, lines of communication extend +somewhere else, while convoys are moving at a third place. But all has +been observed, and the commanding officer is in a position to re-arrange +his forces accordingly. It is a remarkable example of method in military +tactics and strategy, and conveys a striking idea of the degree to which +aerial operations have been organised. + +After due deliberation it is decided that the convoys shall be raided, +or that massed troops shall be thrown into confusion, if not dispersed. +The squadron is ordered to prepare for another aerial journey. The roads +along which the convoys are moving are indicated upon the map, or the +position of the massed troops in bivouac is similarly shown. The airmen +load their machines with a full charge of bombs. When all is ready the +leader ascends, followed in rapid succession by the other units, and +they whirr through the air in single file. It now becomes a grim game of +follow-my-leader. + +The leader detects the convoy, swoops down, suddenly launches his +missiles, and re-ascends. He does not deviate a foot from his path to +observe the effects of his discharge, as the succeeding aeroplane is +close behind him. If the leader has missed then the next airman may +correct his error. One after another the machines repeat the manoeuvre, +in precisely the same manner as the units of a battleship squadron +emulate the leading vessel when attacking the foe. The tactical +evolutions have been laid down, and there is rigid adherence thereto, +because only thereby may success be achieved. When the last war-plane +has completed its work, the leader swings round and repeats the dash +upon the foe. A hail of bullets may scream around the men in the air, +but one and all follow faithfully in the leader's trail. One or more +machines may fail in the attack, and may even meet with disaster, but +nothing interferes with the movements of the squadron as a whole. It is +the homogeneity of the attacking fleet which tells, and which undermines +the moral of the enemy, even if it does not wreak decisive material +devastation. The work accomplished to the best of their ability, the +airmen speed back to their lines in the same formation. + +At first sight reconnoitring from aloft may appear a simple operation, +but a little reflection will reveal the difficulties and arduousness of +the work. The observer, whether he be specially deputed, or whether +the work be placed in the hand of the pilot himself--in this event the +operation is rendered additionally trying, as he also has to attend to +his machine must keep his eyes glued to the ground beneath and at the +same time be able to read the configuration of the panorama revealed to +him. He must also keep in touch with his map and compass, so as to be +positive of his position and direction. He must be a first-class judge +of distances and heights. + +When flying rapidly at a height of 4,000 feet or more, the country below +appears as a perfect plane, or flat stretch, although as a matter of +fact it may be extremely undulating. Consequently, it is by no means a +simple matter to distinguish eminences and depressions, or to determine +the respective and relative heights of hills. + +If a rough sketch is required, the observer must be rapid in thought, +quick in determination, and facile with his pencil, as the machine, no +matter how it may be slowed down, is moving at a relatively high speed. +He must consult his map and compass frequently, since an airman who +loses his bearings is useless to his commander-in-chief. He must have +an eagle eye, so as to be able to search the country unfolded below, in +order to gather all the information which is likely to be of value to +his superior officers. He must be able to judge accurately the numbers +of troops arrayed beneath him, the lines of the defensive works, to +distinguish the defended from the dummy lines which are thrown up to +baffle him, and to detect instantly the movement of the troops and +the direction, as well as the roads, along which they are proceeding. +Reserves and their complement, artillery, railway-lines, roads, and +bridges, if any, over streams and railways must be noted--in short +he must obtain an eye photograph of the country he observes and grasp +exactly what is happening there. In winter, with the thermometer well +down, a blood-freezing wind blowing, wreaths of clouds drifting below +and obscuring vision for minutes at a time, the rain possibly pelting +down as if presaging a second deluge, the plight of the vigilant human +eye aloft is far from enviable. + +Upon the return of the machine to its base, the report must be prepared +without delay. The picture recorded by the eye has to be set down +clearly and intelligibly with the utmost speed. The requisite +indications must be made accurately upon the map. Nothing of importance +must be omitted: the most trivial detail is often of vital importance. + +A facile pencil is of inestimable value in such operations. While +aloft the observer does not trust to his memory or his eye picture, but +commits the essential factors to paper in the form of a code, or what +may perhaps be described more accurately as a shorthand pictorial +interpretation of the things he has witnessed. To the man in the street +such a record would be unintelligible, but it is pregnant with meaning, +and when worked out for the guidance of the superior officers is a mass +of invaluable detail. + +At times it so happens that the airman has not been able to complete +his duty within the time anticipated by those below. But he has gathered +certain information which he wishes to communicate without coming to +earth. Such data may be dropped from the clouds in the form of maps or +messages. Although wireless telegraphy is available for this purpose, +it suffers from certain drawbacks. If the enemy possesses an equipment +which is within range of that of the air-craft and the force to which +it belongs, communications may be nullified by the enemy throwing out +a continuous stream of useless signals which "jamb" the intelligence of +their opponents. + +If a message--written in code--or a map is to be dropped from aloft it +is enclosed within a special metallic cylinder, fitted with a vane tail +to ensure direction of flight when launched, and with a detonating head. +This is dropped overboard. When it strikes the ground the detonator +fires a charge which emits a report without damaging the message +container, and at the same time fires a combustible charge emitting +considerable smoke. The noise attracts anyone in the vicinity of the +spot where the message has fallen, while at the same time the clouds of +smoke guide one to the point and enable the cylinder to be recovered. +This device is extensively used by the German aviators, and has proved +highly serviceable; a similar contrivance is adopted by French airmen. + +There is one phase of aerial activity which remains to be demonstrated. +This is the utilisation of aerial craft by the defenders of a besieged +position such as a ring of fortifications or fortified city. The utility +of the Fourth Arm in this province has been the subject of considerable +speculation. Expert opinion maintains that the advantage in this +particular connection would rest with the besiegers. The latter would +be able to ascertain the character of the defences and the defending +gun-force, by means of the aerial scout, who would prove of inestimable +value in directing the fire of the besieging forces. + +On the other hand it is maintained that an aerial fleet would be useless +to the beleaguered. In the first place the latter would experience +grave difficulties in ascertaining the positions of the attacking +and fortress-reducing artillery, inasmuch as this could be masked +effectively, and it is thought that the aerial force of the besieged +would be speedily reduced to impotence, since it would be subjected to +an effective concentrated fire from the ring of besieging anti-aircraft +guns and other weapons. In other words, the theory prevails that an +aerial fleet, no matter how efficient, would be rendered ineffective for +the simple reason that it would be the initial object of the besieger's +attack. Possibly the stem test of experience will reveal the fallacy of +these contentions as emphatically as it has disproved others. But there +is one point upon which authorities are unanimous. If the artillery of +the investing forces is exposed and readily distinguishable, the aerial +forces of the beleaguered will bring about its speedy annihilation, as +the defensive artillery will be concentrated upon that of the besiegers. + + + +CHAPTER IX. THE AIRMAN AND ARTILLERY + +There is one field in which the airman has achieved distinctive +triumphs. This is in the guidance of artillery fire. The modern battle +depends first and foremost upon the fierce effectiveness of big-gun +assault, but to ensure this reliable direction is imperative. No force +has proved so invaluable for this purpose as the man of-the-air, and +consequently this is the province in which he has been exceptionally and +successfully active. + +It will be recalled that in the Japanese investiture of Port Arthur +during the Russo-Japanese war, thousands of lives were expended upon the +retention and assault of 203 Metre Hill. It was the most blood-stained +spot upon the whole of the Eastern Asiatic battlefield. General Nogi +threw thousands after thousands of his warriors against this rampart +while the Russians defended it no less resolutely. It was captured and +re-captured; in fact, the fighting round this eminence was so intense +that it appeared to the outsider to be more important to both sides than +even Port Arthur itself. + +Yet if General Nogi had been in the possession of a single aeroplane +or dirigible it is safe to assert that scarcely one hundred Japanese or +Russian soldiers would have met their fate upon this hill. Its value to +the Japanese lay in one sole factor. The Japanese heavy guns shelling +the harbour and the fleet it contained were posted upon the further +side of this eminence and the fire of these weapons was more or less +haphazard. No means of directing the artillery upon the vital points +were available; 203 Metre Hill interrupted the line of sight. The +Japanese thereupon resolved to capture the hill, while the Russians, +equally appreciative of the obstruction it offered to their enemy, as +valiantly strove to hold it. Once the hill was captured and the fire +of the Japanese guns could be directed, the fate of the fortress was +sealed. + +Similar conditions have prevailed during the present campaign, +especially in the western theatre of war, where the ruggedness of the +country has tended to render artillery fire ineffective and expensive +unless efficiently controlled. When the German Army attacked the line of +the British forces so vehemently and compelled the retreat at Mons, +the devastating fire of the enemy's artillery was directed almost +exclusively by their airmen, who hovered over the British lines, +indicating exactly the point where gun-fire could work the maximum +of havoc. The instant concentration of massed artillery fire upon +the indicated positions speedily rendered one position after another +untenable. + +The Germans maintained the upper hand until at last the aerial forces of +the British Expeditionary Army came into action. These airmen attacked +the Teuton aerial craft without the slightest hesitation, and in a +short while rendered cloudland absolutely unhealthy. The sequel +was interesting. As if suddenly blinded, the German artillery fire +immediately deteriorated. On the other hand, the British artillery, +now having the benefit of aerial guidance, was able to repay the +German onslaughts with interest, and speedily compelled that elaborate +digging-in of the infantry lines which has now become so characteristic +of the opposing forces. + +So far as the British lines are concerned the men in the trenches keep a +sharp look-out for hostile aeroplanes. The moment one is observed to +be advancing, all the men seclude themselves and maintain their +concealment. To do otherwise is to court a raking artillery outburst. +The German aeroplane, detecting the tendency of the trenches describes +in the air the location of the vulnerable spot and the precise +disposition by flying immediately above the line. Twice the manoeuvre +is repeated, the second movement evidently being in the character of a +check upon the first observation, and in accordance with instructions, +whereupon the Tommies, to quote their own words, "know they are in for +it!" Ere the aeroplane has completed the second manoeuvre the German +guns ring out. + +The facility with which artillery fire can be concentrated through the +medium of the aeroplane is amazing. In one instance, according to the +story related to me by an officer, "a number of our men were resting in +an open field immediately behind the second line of trenches, being in +fact the reserves intended for the relief of the front lines during the +following night. An aeroplane hove in sight. The men dropped their kits +and got under cover in an adjacent wood. The aeroplane was flying at a +great height and evidently laboured under the impression that the kits +were men. Twice it flew over the field in the usual manner, and then +the storm of shrapnel, 'Jack Johnsons' and other tokens from the Kaiser +rained upon the confined space. A round four hundred shells were dropped +into that field in the short period of ten minutes, and the range was +so accurate that no single shell fell outside the space. Had the men not +hurried to cover not one would have been left alive to tell the tale, +because every square foot of the land was searched through and through. +We laughed at the short-sightedness of the airman who had contributed +to such a waste of valuable shot and shell, but at the same time +appreciated the narrowness of our own escape." + +The above instance is by no means isolated. It has happened time after +time. The slightest sign of activity in a trench when a "Taube" is +overhead suffices to cause the trench to be blown to fragments, and time +after time the British soldiers have had to lie prone in their trenches +and suffer partial burial as an alternative to being riddled by +shrapnel. + +The method of ascertaining the range of the target from the indications +given by the aeroplane are of the simplest character. The German method +is for the aerial craft to fly over the position, and when in vertical +line therewith to discharge a handful of tinsel, which, in falling, +glitters in the sunlight, or to launch a smoking missile which answers +the same purpose as a projectile provided with a tracer. This smoke-ball +being dropped over the position leaves a trail of black or whitish smoke +according to the climatic conditions which prevail, the object being to +enable the signal to be picked up with the greatest facility. The height +at which the aerial craft is flying being known, a little triangulation +upon the part of the observer at the firing point enables him to +calculate the range and to have the guns laid accordingly. + +When the aerial craft has been entrusted with the especial duty of +directing artillery-fire, a system of communication between the aerial +observer and the officer in charge of the artillery is established, +conducted, of course, by code. In the British Army, signalling is both +visual and audible. In daylight visual signalling is carried out by +means of coloured flags or streamers and smoke-signals, while audible +communication is effected by means of a powerful horn working upon the +siren principle and similar to those used by automobiles. Both flags and +sound-signals, however, are restricted owing to the comparatively short +distances over which they can be read with any degree of accuracy. The +smoke-signal therefore appears to be the most satisfactory and reliable, +as the German airmen have proved conclusively, for the simple reason +that the trail of smoke may be picked up with comparative ease, even +at a distance, by means of field glasses. The tinsel too, is readily +distinguishable, particularly in bright weather, for the glittering +surface, catching the sun-light, acts some what in the manner of a +heliograph. + +The progress of the airman is followed by two officers at the base from +which he started. One is equipped with the director, while the +second takes the range. Directly this has been found as a result of +calculation, the guns are laid ready for firing. In those cases where +the enemy's artillery is concealed perhaps behind a hill, the airman is +of incalculable value, inasmuch as he is able to reveal a position which +otherwise would have to be found by considerable haphazard firing, and +which, even if followed by a captive balloon anchored above the firing +point, might resist correction. + +The accuracy of the airman's work in communicating the range has been +responsible for the high efficiency of the British and French artillery. +The latter, with the 75 millimetre quick-firing gun, is particularly +adapted to following up the results of the aeroplane's reconnaissance, +especially with the system of rafale fire, because the whole position +can be searched through and through within a minute or two. According +to information which has been given to me by our artillery officers, the +British system also has proved disastrous to the enemy. The practice +is to get the range as communicated by the aeroplane, to bring the +artillery into position speedily, to discharge salvo after salvo with +all speed for a few minutes, and then to wheel the artillery away before +any hostile fire can be returned. The celerity with which the British +artillery comes into, and goes out of, action has astonished even +our own authorities. This mobility is of unique value: it is taking +advantage of a somewhat slow-witted enemy with interest. By the time +the Germans have opened fire upon the point whence the British guns were +discharged, the latter have disappeared and are ready to let fly from +another point, some distance away, so that the hostile fire is abortive. +Mobility of such a character is decidedly unnerving and baffling even to +a quick-witted opponent. + +In his search for hostile artillery the airman runs grave risks and +displays remarkable resource. It is invariably decided, before he sets +out, that he shall always return to a certain altitude to communicate +signals. Time after time the guns of the enemy have been concealed +so cunningly from aerial observation as to pass unnoticed. This trait +became more pronounced as the campaigns of the Aisne progressed. +Accordingly the airman adopts a daring procedure. He swoops down over +suspicious places, where he thinks guns may be lurking, hoping that the +enemy will betray its presence. The ruse is invariably successful. The +airman makes a sudden dive towards the earth. The soldiers in hiding +below, who have become somewhat demoralised by the accuracy of the +British aerial bomb-throwers, have an attack of nerves. They open a +spirited fusillade in the hope of bringing the airman to earth. But +their very excitement contributes to his safety. The shots are fired +without careful aim and expend themselves harmlessly. Sweeping once more +upwards, the airman regains the pre-determined level, performs a certain +evolution in the air which warns the observer at his base that he has +made a discovery, and promptly drops his guiding signal directly over +the point from which he has drawn fire. + +Operations at night are conducted by means of coloured lights or an +electrical searchlight system. In the former instance three lights +are generally carried--white, red, and green--each of which has a +distinctive meaning. If reliance is placed upon the electric light +signalling lamp, then communications are in code. But night operations +are somewhat difficult and extremely dangerous, except when the elements +are propitious. There is the ground mist which blots everything from +sight, rendering reconnaissance purely speculative. But on a clear night +the airman is more likely to prove successful. He keeps a vigilant eye +upon all ground-lights and by close observation is able to determine +their significance. It is for this reason that no lights of any +description are permitted in the advance trenches. The striking of a +match may easily betray a position to the alert eye above. + +So far as the British Army is concerned a complete code is in operation +for communicating between aeroplanes and the ground at night. Very's +lights are used for this purpose, it being possible to distinguish the +respective colours at a distance of six miles and from an altitude of +2,000 feet. The lights are used both by the aeroplane and the battery of +artillery. + +The code is varied frequently, but the following conveys a rough idea of +how communication is carried out by this means under cover of darkness. +The aeroplane has located its objective and has returned to the +pre-arranged altitude. A red light is thrown by the airman. It indicates +that he is directly over the enemy's position. A similarly coloured +light is shown by the artillery officer, which intimates to the airman +that his signal has been observed and that the range has been taken. + +In observing the effects of artillery fire a code of signals is employed +between the airman and the artillery officer to indicate whether the +shot is "long" or "short," to the right or to the left of the mark, +while others intimate whether the fuse is correctly timed or otherwise. +It is necessary to change the code fairly frequently, not only lest +it should fall into the enemy's hands, but also to baffle the hostile +forces; otherwise, after a little experience, the latter would be able +to divine the significance of the signals, and, in anticipation of being +greeted with a warm fusillade, would complete hurried arrangements +to mitigate its effects, if not to vacate the position until the +bombardment had ceased. + +Sufficient experience has already been gathered, however, to prove the +salient fact that the airman is destined to play an important part +in the direction and control of artillery-fire. Already he has been +responsible for a re-arrangement of strategy and tactics. The man aloft +holds such a superior position as to defy subjugation; the alternative +is to render his work more difficult, if not absolutely impossible. + + + +CHAPTER X. BOMB-THROWING FROM AIR-CRAFT + +During the piping times of peace the utility of aircraft as weapons of +offence was discussed freely in an academic manner. It was urged +that the usefulness of such vessels in this particular field would +be restricted to bomb-throwing. So far these contentions have been +substantiated during the present campaign. At the same time it was +averred that even as a bomb-thrower the ship of the air would prove +an uncertain quantity, and that the results achieved would be quite +contrary to expectations. Here again theory has been supported by +practice, inasmuch as the damage wrought by bombs has been comparatively +insignificant. + +The Zeppelin raids upon Antwerp and Britain were a fiasco in the +military sense. The damage inflicted by the bombs was not at all in +proportion to the quantity of explosive used. True, in the case of +Antwerp, it demoralised the civilian population somewhat effectively, +which perhaps was the desired end, but the military results were nil. + +The Zeppelin, and indeed all dirigibles of large size, have one +advantage over aeroplanes. They are able to throw bombs of larger size +and charged with greater quantities of high explosive and shrapnel than +those which can be hurled from heavier-than-air machines. Thus it has +been stated that the largest Zeppelins can drop single charges exceeding +one ton in weight, but such a statement is not to be credited. + +The shell generally used by the Zeppelin measures about 47 inches in +length by 8 1/2 inches in diameter, and varies in weight from 200 to +242 pounds. Where destruction pure and simple is desired, the shell +is charged with a high explosive such as picric acid or T.N.T., the +colloquial abbreviation for the devastating agent scientifically known +as "Trinitrotoluene," the base of which, in common with all the high +explosives used by the different powers and variously known as lyddite, +melinite, cheddite, and so forth, is picric acid. Such a bomb, if it +strikes the objective, a building, for instance, fairly and squarely, +may inflict widespread material damage. + +On the other hand, where it is desired to scatter death, as well as +destruction, far and wide, an elaborate form of shrapnel shell is +utilised. The shell in addition to a bursting charge, contains bullets, +pieces of iron, and other metallic fragments. When the shell bursts, +their contents, together with the pieces of the shell which is likewise +broken up by the explosion, are hurled in all directions over a radius +of some 50 yards or more, according to the bursting charge. + +These shells are fired upon impact, a detonator exploding the main +charge. The detonator, comprising fulminate of mercury, is placed in +the head or tail of the missile. To secure perfect detonation and to +distribute the death-dealing contents evenly in all directions, it is +essential that the bomb should strike the ground almost at right +angles: otherwise the contents are hurled irregularly and perhaps in +one direction only. One great objection to the percussion system, as +the method of impact detonation is called, is that the damage may be +localised. A bomb launched from a height of say 1,000 feet attains +terrific velocity, due to the force of gravity in conjunction with its +own weight, in consonance with the law concerning a falling body, by the +time it reaches the ground. It buries itself to a certain depth before +bursting so that the forces of the explosion become somewhat muffled as +it were. A huge deep hole--a miniature volcano crater--is formed, +while all the glass in the immediate vicinity of the explosion may be +shattered by the concussion, and the walls of adjacent buildings be +bespattered with shrapnel. + +Although it is stated that an airship is able to drop a single missile +weighing one ton in weight, there has been no attempt to prove the +contention by practice. In all probability the heaviest shell launched +from a Zeppelin has not exceeded 300 pounds. There is one cogent reason +for such a belief. A bomb weighing one ton is equivalent to a similar +weight of ballast. If this were discarded suddenly the equilibrium of +the dirigible would be seriously disturbed--it would exert a tendency +to fly upwards at a rapid speed. It is doubtful whether the planes +controlling movement in the vertical plane would ever be able to +counteract this enormous vertical thrust. Something would have to submit +to the strain. Even if the dirigible displaced say 20 tons, and a bomb +weighing one ton were discharged, the weight of the balloon would be +decreased suddenly by approximately five per cent, so that it would +shoot upwards at an alarming speed, and some seconds would elapse before +control was regained. + +The method of launching bombs from airships varies considerably. Some +are released from a cradle, being tilted into position ready for firing, +while others are discharged from a tube somewhat reminiscent of that +used for firing torpedoes, with the exception that little or no +initial impetus is imparted to the missile; the velocity it attains is +essentially gravitational. + +The French favour the tube-launching method since thereby it is stated +to be possible to take more accurate aim. The objective is sighted and +the bomb launched at the critical moment. In some instances the French +employ an automatic detonator which corresponds in a certain measure to +the time-fuse of a shrapnel shell fired from a gun. + +The bomb-thrower reads the altitude of his airship as indicated by his +barometer or other recording instrument, and by means of a table at his +command ascertains in a moment the time which will elapse before the +bomb strikes the ground. The automatic detonator is set in motion and +the bomb released to explode approximately at the height to which it +is set. When it bursts the full force of the explosion is distributed +downwards and laterally. Owing to the difficulty of ensuring the +explosion of the bomb at the exact height desired, it is also made to +explode upon impact so as to make doubly sure of its efficacy. + +Firing timed bombs from aloft, however, is not free from excitement and +danger, as the experience of a French airman demonstrates. His dirigible +had been commanded to make a night-raid upon a railway station which was +a strategical junction for the movement of the enemy's troops. Although +the hostile searchlights were active, the airship contrived to slip +between the spokes of light without being observed. By descending to a +comparatively low altitude the pilot was able to pick up the objective. + +Three projectiles were discharged in rapid succession and then the +searchlights, being concentrated, struck the airship, revealing its +presence to the troops below. Instantly a spirited fusillade broke out. +The airmen, by throwing ballast and other portable articles overboard +pell-mell, rose rapidly, pursued by the hostile shells. + +In the upward travel the bomb-thrower decided to have a parting shot. +The airship was steadied momentarily to enable the range to be taken, +the automatic detonator was set going and the bomb slipped into the +launching tube. But for some reason or other the missile jambed. + +The situation was desperate. In a few seconds the bomb would burst and +shatter the airship. The bomb-thrower grabbed a tool and climbing into +the rigging below hacked away at the bomb-throwing tube until the whole +equipment was cut adrift and fell clear of the vessel. Almost instantly +there was a terrific explosion in mid-air. The blast of air caused the +vessel to roll and pitch in a disconcerting manner, but as the airman +permitted the craft to continue its upward course unchecked, she soon +steadied herself and was brought under control once more. + +The bomb carried by aeroplanes differs consider ably from that used by +dirigibles, is smaller and more convenient to handle, though considering +its weight and size it is remarkably destructive. In this instance +complete reliance is placed upon detonation by impact. The latest types +of British war-plane bombs have been made particularly formidable, those +employed in the "raids in force" ranging up to 95 pounds in weight. + +The type of bomb which has proved to be the most successful is +pear-shaped. The tail spindle is given an arrow-head shape, the vanes +being utilised to steady the downward flight of the missile. In falling +the bomb spins round, the rotating speed increasing as the projectile +gathers velocity. The vanes act as a guide, keeping the projectile in as +vertical a plane as possible, and ensuring that the rounded head shall +strike the ground. The earlier types of bombs were not fitted with these +vanes, the result being that sometimes they turned over and over as they +fell through the air, while more often than not they failed to explode +upon striking the ground. + +The method of launching the bomb also varies considerably, experience +not having indicated the most efficient method of consummating this +end. In some cases the bombs are carried in a cradle placed beneath the +aeroplane and launched merely by tilting them in a kind of sling, one by +one, to enable them to drop to the ground, this action being controlled +by means of a lever. In another instance they are dropped over the side +of the car by the pilot, the tail of the bomb being fitted with a swivel +and ring to facilitate the operation. Some of the French aviators favour +a still simpler method. The bomb is attached to a thread and lowered +over the side. At the critical moment it is released simply by severing +the thread. Such aeroplane bombs, however, constitute a menace to the +machine and to the pilot. Should the bomb be struck by hostile rifle or +shell fire while the machine is aloft, an explosion is probable; while +should the aero plane make an abrupt descent the missiles are likely to +be detonated. + +A bomb which circumvents this menace and which in fact will explode +only when it strikes the ground is that devised by Mr. Marten-Hale. +This projectile follows the usual pear-shape, and has a rotating tail to +preserve direction when in flight. The detonator is held away from the +main charge by a collar and ball-bearing which are held in place by the +projecting end of a screw-releasing spindle. When the bomb is dropped +the rotating tail causes the spindle to screw upwards until the +projection moves away from the steel balls, thereby allowing them to +fall inward when the collar and the detonator are released. In order to +bring about this action the bomb must have a fall of at least 200 feet. + +When the bomb strikes the ground the detonator falls down on the charge, +fires the latter, and thus brings about the bursting of the bomb. The +projectile is of the shrapnel type. It weighs 20 pounds complete, is +charged with some four pounds of T.N.T., and carries 340 steel balls, +which represent a weight of 5 3/4 pounds. + +The firing mechanism is extremely sensitive and the bomb will burst +upon impact with the hull of an airship, water, or soft soil. This +projectile, when discharged, speedily assumes the vertical position, so +that there is every probability that it will strike the ground +fairly and squarely, although at the same time such an impact is not +imperative, because it will explode even if the angle of incidence be +only 5 degrees. It is remarkably steady in its flight, the balancing and +the design of the tail frustrating completely any tendency to wobble or +to turn turtle while falling. + +Other types of missile may be used. For instance, incendiary bombs have +been thrown with success in certain instances. These bombs are similar +in shape to the shrapnel projectile, but are charged with petrol or some +other equally highly inflammable mixture, and fitted with a detonator. +When they strike the objective the bursting charge breaks up the shell, +releasing the contents, and simultaneously ignites the combustible. + +Another shell is the smoke-bomb, which, up to the present, has been used +only upon a restricted scale. This missile is charged with a certain +quantity of explosive to burst the shell, and a substance which, when +ignited, emits copious clouds of dense smoke. The scope of such a shell +is somewhat restricted, it is used only for the purpose of obstructing +hostile artillery fire. The shells are dropped in front of the artillery +position and the clouds of smoke which are emitted naturally inter fere +with the operations of the gunners. These bombs have also been used +with advantage to denote the position of concealed hostile artillery, +although their utility in this connection is somewhat uncertain, owing +to the difficulty of dropping the bomb so accurately as to enable the +range-finders to pick up the range. + +Dropping bombs from aloft appears to be a very simple operation, but +as a matter of fact it is an extremely difficult matter to strike the +target, especially from a high altitude. So far as the aeroplane is +concerned it is somewhat at a disadvantage as compared with the airship, +as the latter is able to hover over a position, and, if a spring-gun +is employed to impart an initial velocity to the missile, there is a +greater probability of the projectile striking the target provided it +has been well-aimed. But even then other conditions are likely to arise, +such as air-currents, which may swing the missile to one side of the +objective. Consequently adequate allowance has to be made for windage, +which is a very difficult factor to calculate from aloft. + +Bomb-dropping from an aeroplane is even more difficult. If for instance +the aeroplane is speeding along at 60 miles an hour, the bomb when +released will have a speed in the horizontal plane of 60 miles an hour, +because momentarily it is travelling at the speed of the aeroplane. +Consequently the shell will describe a curved trajectory, somewhat +similar to that shown in Fig. 7. + +On the other hand, if the aeroplane is travelling slowly, say at 20 +miles an hour, the curve of the trajectory will be flatter, and if a +head wind be prevailing it may even be swept backwards somewhat after it +has lost its forward momentum, and describe a trajectory similar to that +in Fig. 8. + +A bomb released from an altitude of 1000 feet seldom, if ever, makes +a bee-line for the earth, even if dropped from a stationary airship. +Accordingly, the airman has to release the bomb before he reaches the +target below. The determination of the critical moment for the release +is not easy, inasmuch as the airman has to take into his calculations +the speed of his machine, his altitude, and the direction and velocity +of the air-currents. + +The difficulty of aiming has been demonstrated upon several occasions at +aviation meetings and other similar gatherings. Monsieur Michelin, +who has done so much for aviation in France, offered a prize of +L1,00--$5,000--in 1912 for bomb-dropping from an aeroplane. The target +was a rectangular space marked out upon the ground, measuring 170 feet +long by 40 feet broad, and the missiles had to be dropped from a height +of 2,400 feet. The prize was won by the well-known American airman, +Lieutenant Riley E. Scott, formerly of the United States Army. He +dropped his bombs in groups of three. The first round fell clear of the +target, but eight of the remaining missiles fell within the area. + +In the German competition which was held at Gotha in September of the +same year the results were somewhat disappointing. Two targets were +provided. The one represented a military bivouac occupying a superficies +of 330 square feet, and the other a captive balloon resembling a +Zeppelin. The prizes offered were L500, L200, and L80--$2,500, $1,000 +and $400--respectively, and were awarded to those who made the greatest +number of hits. The conditions were by no means so onerous as those +imposed in the Michelin contest, inasmuch as the altitude limit was set +at 660 feet, while no machine was to descend within 165 feet. The first +competitor completely failed to hit the balloon. The second competitor +flying at 800 feet landed seven bombs within the square, but only one +other competitor succeeded in placing one bomb within the space. + +Bomb-dropping under the above conditions, however, is vastly dissimilar +from such work under the grim realities of war. The airman has to act +quickly, take his enemy by surprise, avail himself of any protective +covering which may exist, and incur great risks. The opposing forces are +overwhelmingly against him. The modern rifle, if fired vertically into +the air, will hurl the bullet to a height of about 5,000 feet, while +the weapons which have been designed to combat aircraft have a range of +10,000 feet or more. + +At the latter altitude aggressive tactics are useless. The airman is +unable to obtain a clear sharp view of the country beneath owing to the +interference offered to vision by atmospheric haze, even in the dearest +of weather. In order to obtain reasonable accuracy of aim the corsair +of the sky must fly at about 400 feet. In this respect, however, the +aeroplane is at a decided advantage, as compared with the dirigible. The +machine offers a considerably smaller target and moves with much greater +speed. Experience of the war has shown that to attempt to hurl bombs +from an extreme height is merely a waste of ammunition. True, they do a +certain amount of damage, but this is due to luck, not judgment. + +For success in aerial bomb operations the human element is mainly +responsible. The daring airman is likely to achieve the greatest +results, as events have proved, especially when his raid is sudden and +takes the enemy by surprise. The raids carried out by Marix, Collet, +Briggs, Babington, Sippe and many others have established this fact +incontrovertibly. In all these operations the airmen succeeded because +of their intrepidity and their decision to take advantage of cover, +otherwise a prevailing mist or low-lying clouds. Flight-Lieutenant +Collet approached the Zeppelin shed at Dusseldorf at an altitude of +6,000 feet. There was a bank of mist below, which he encountered at +1,500 feet. He traversed the depth of this layer and emerged therefrom +at a height of only 400 feet above the ground. His objective was barely +a quarter of a mile ahead. Travelling at high speed he launched his +bombs with what proved to be deadly precision, and disappeared +into cover almost before the enemy had grasped his intentions. +Lieutenant-Commander, now Flight-Commander, Marix was even more daring. +Apparently he had no mist in which to conceal himself but trusted almost +entirely to the speed of his machine, which probably at times notched 90 +miles per hour. Although his advent was detected and he was greeted with +a spirited fusillade he clung to his determined idea. He headed straight +for the Zeppelin shed, launched two bombs and swung into the higher +reaches of the air without a moment's hesitation. His aim was deadly, +since both bombs found their mark, and the Zeppelin docked within was +blown up. The intrepid airman experienced several narrow escapes, for +his aeroplane was struck twenty times, and one or two of the control +wires were cut by passing bullets. + +The raid carried out by Commanders Briggs and Babington in company with +Lieutenant Sippe upon the Zeppelin workshops at Friedrichshafen was even +more daring. Leaving the Allies' lines they ascended to an altitude of +4,500 feet, and at this height held to the pre-arranged course until +they encountered a mist, which while protecting them from the alert eyes +of the enemy below, was responsible for the separation of the raiders, +so that each was forced to act independently and to trust to the compass +to bring him out of the ordeal successfully. Lieutenant Sippe sighted +Lake Constance, and taking advantage of the mist lying low upon the +water, descended to such an extent that he found himself only a few feet +above the roofs of the houses. Swinging round to the Lake he descended +still lower until at last he was practically skimming the surface of the +Lake, since he flew at the amazingly low height of barely seven feet +off the water. There is no doubt that the noise of his motor was heard +plainly by the enemy, but the mist completely enveloped him, and +owing to the strange pranks that fog plays with sound deceived his +antagonists. + +At last, climbing above the bank of vapour, he found that he had +overshot the mark, so he turned quickly and sped backwards. At the same +time he discovered that he had been preceded by Commander Briggs, who +was bombarding the shed furiously, and who himself was the object of +a concentrated fire. Swooping down once more, Lieutenant Sippe turned, +rained his bombs upon the objective beneath, drawing fire upon himself, +but co-operating with Commander Babington, who had now reached the +scene, he manoeuvred above the works and continued the bombardment until +their ammunition was expended, when they sped home-wards under the +cover of the mist. Considering the intensity of the hostile fire, it +is surprising that the aeroplanes were not smashed to fragments. +Undoubtedly the high speed of the machines and the zigzagging courses +which were followed nonplussed the enemy. Commander Briggs was not +so fortunate as his colleagues; a bullet pierced his petrol tank, +compelling a hurried descent. + +The most amazing feature of these aerial raids has been the remarkably +low height at which the airmen have ventured to fly. While such a +procedure facilitates marksmanship it increases the hazards. The airmen +have to trust implicitly to the fleetness of their craft and to their +own nerve. Bearing in mind the vulnerability of the average aeroplane, +and the general absence of protective armouring against rifle fire at +almost point-blank range, it shows the important part which the human +element is compelled to play in bomb-dropping operations. + +Another missile which has been introduced by the French airmen, and +which is extremely deadly when hurled against dense masses of men, +is the steel arrow, or "flechette" as it is called. It is a fiendish +projectile consisting in reality of a pencil of solid polished steel, 4 +3/4 inches in length. The lower end has a sharp tapering point, 5/8ths +of an inch in length. For a distance of 1 1/8th of an inch above this +point the cylindrical form of the pencil is preserved, but for the +succeeding three inches to the upper end, the pencil is provided with +four equally spaced angle flanges or vanes. This flanging of the upper +end or tail ensures the arrow spinning rapidly as it falls through the +air, and at the same times preserves its vertical position during its +descent. The weight of the arrow is two-thirds of an ounce. + +The method of launching this fearsome projectile is ingenious. A hundred +or even more are packed in a vertical position in a special receptacle, +placed upon the floor of the aeroplane, preferably near the foot of the +pilot or observer. This receptacle is fitted with a bottom moving in the +manner of a trap-door, and is opened by pressing a lever. The aviator +has merely to depress this pedal with his foot, when the box is opened +and the whole of the contents are released. The fall at first is +somewhat erratic, but this is an advantage, as it enables the darts to +scatter and to cover a wide area. As the rotary motion of the arrows +increases during the fall, the direct line of flight becomes more +pronounced until at last they assume a vertical direction free from all +wobbling, so that when they alight upon the target they are quite plumb. + +When launched from a height they strike the objective with terrific +force, and will readily penetrate a soldier's helmet and skull. Indeed, +when released at a height of 4,000 feet they have been known to pierce a +mounted soldier's head, and pass vertically through his body and that +of his horse also. Time after time German soldiers have found themselves +pinned to the ground through the arrow striking and penetrating their +feet. Owing to the extremely light weight of the darts they can be +launched in batches of hundreds at a time, and in a promiscuous manner +when the objective is a massed body of infantry or cavalry, or a +transport convoy. They are extremely effective when thrown among horses +even from a comparatively low altitude, not so much from the fatalities +they produce, as from the fact that they precipitate a stampede among +the animals, which is generally sufficiently serious and frantic to +throw cavalry or a transport-train into wild confusion. + +Although aerial craft, when skilfully handled, have proved highly +successful as weapons of offence, the possibilities of such aggression +as yet are scarcely realised; aerial tactics are in their infancy. +Developments are moving rapidly. Great efforts are being centred upon +the evolution of more formidable missiles to be launched from the +clouds. The airman is destined to inspire far greater awe than at +present, to exercise a still more demoralising influence, and to work +infinitely more destruction. + + + +CHAPTER XI. ARMOURED AEROPLANES + +The stern test of war has served to reveal conclusively the fact that +aerial craft can be put out of action readily and effectively, when once +the marksman has picked up the range, whether the gunner be conducting +his operations with an anti-aircraft gun stationed upon the ground, +or from a hostile machine. It will be remembered that Flight-Commander +Briggs, on the occasion of the daring British raid upon the Zeppelin +sheds at Friedrichshafen, was brought to the ground by a bullet which +penetrated his fuel tank. Several other vessels, British, German, +French, and Russian alike, have been thrown out of action in a similar +manner, and invariably the craft which has been disabled suddenly in +this way has fallen precipitately to earth in the fatal headlong dive. + +Previous to the outbreak of hostilities there was considerable +divergence of opinion upon this subject. The general opinion was that +the outspread wings and the stays which constituted the weakest parts of +the structure were most susceptible to gun-fire, and thus were likely to +fail. But practice has proved that it is the driving mechanism which is +the most vulnerable part of the aeroplane. + +This vulnerability of the essential feature of the flying machine is a +decisive weakness, and exposes the aviator to a constant menace. It +may be quite true that less than one bullet in a thousand may hit the +machine, but when the lucky missile does find its billet its effect is +complete. The fact must not be overlooked that the gunners who work the +batteries of anti-aircraft guns are becoming more and more expert as a +result of practice, so that as time progresses and improved guns for +such duty are rendered available, the work of the aviator is likely to +become more dangerous and difficult. Experience has proved that the high +velocity gun of to-day is able to hurl its projectile or shell to an +extreme height--far greater than was previously considered possible--so +that considerable discretion has to be exercised by the airman, who +literally bears his life in his hands. + +Although elaborate trials were carried out upon the testing ranges with +the weapons devised especially for firing upon flying machines, captive +balloons being employed as targets, the data thus obtained were neither +conclusive nor illuminating. The actual experiences of airmen have given +us some very instructive facts upon this point for the first time. + +It was formerly held that the zone of fire that is to be considered as +a serious danger was within a height of about 4,500 feet. But this +estimate was well within the mark. Airmen have found that the modern +projectiles devised for this phase of operations are able to inflict +distinctly serious damage at an altitude of 9,000 feet. The shell itself +may have but little of its imparted velocity remaining at this altitude, +but it must be remembered that when the missile bursts, the contents +thereof are given an independent velocity, and a wide cone of +dispersion, which is quite sufficient to achieve the desired end, +inasmuch as the mechanism of the modern aeroplane and dirigible is +somewhat delicate. + +It was for this reason that the possibility of armouring the airship was +discussed seriously, and many interesting experiments in this field were +carried out. At the same time it was decided that the armouring +should be effected upon lines analogous to that prevailing in warship +engineering. The craft should not only be provided with defensive but +also with aggressive armament. This decision was not viewed with general +approbation. It was pointed out that questions of weight would arise, +especially in relation to the speed of the machine. Increased weight, +unless it were accompanied by a proportionate augmentation of power +in the motor, would react against the efficiency and utility of the +machine, would appreciably reduce its speed, and would affect its +climbing powers very adversely. In some quarters it was maintained +that as a result the machine would even prove unsuited to military +operations, inasmuch as high speed is the primary factor in these. + +Consequently it was decided by the foremost aviating experts that +machines would have to be classified and allotted to particular spheres +of work, just as warships are built in accordance with the special +duty which they are expected to perform. In reconnaissance, speed is +imperative, because such work in the air coincides with that of +the torpedo-boat or scout upon the seas. It is designed to acquire +information respecting the movements of the enemy, so as to assist the +heavier arms in the plan of campaign. On the other hand, the fighting +corsair of the skies might be likened to the cruiser or battleship. It +need not possess such a high turn of speed, but must be equipped with +hard-hitting powers and be protected against attacking fire. + +One attempt to secure the adequate protection against gun-fire from the +ground assumed the installation of bullet-proof steel plating, about one +fifth of an inch thick, below the tank and the motor respectively. +The disposition of the plating was such as to offer the minimum of +resistance to the air and yet to present a plane surface to the ground +below. So far as it went this protection was completely effective, but +it failed to armour the vital parts against lateral, cross and downward +fire while aloft. As the latter is more to be feared than the fire from +the ground, seeing that it may be directed at point blank range, this +was a decided defect and the armour was subsequently abandoned as +useless. + +The only effective method of achieving the desired end is to armour the +whole of the carriage or fuselage of the adroplane, and this was the +principle adopted by the Vickers Company. The Vickers military aeroplane +is essentially a military machine. It is built of steel throughout. +The skeleton of the machine is formed of an alloy which combines the +qualities of aluminium and steel to ensure toughness, strength, and +lightness. In fact, metal is employed liberally throughout, except in +connection with the wings, which follow the usual lines of construction. +The body of the car is sheathed with steel plating which is bullet proof +against rifle or even shrapnel fire. The car is designed to carry two +persons; the seats are therefore disposed tandem-wise, with the observer +or gunner occupying the front seat. + +The defensive armament is adequate for ordinary purposes. Being fitted +with a 100 horse-power motor, fairly high speeds are attainable, +although the velocity is not equal to that of machines constructed upon +conventional lines, inasmuch as there is an appreciable increase in +weight. + +The car is short and designed upon excellent stream lines, so that the +minimum of resistance to the air is offered, while at the same time the +balancing is perfect. The sides of the car are brought up high enough +to protect the aviators, only their heads being visible when they are +seated. The prow of the car follows the lines generally adopted in high +speed torpedo boat design; there is a sharp knife edge stem with an +enclosed fo'c's'le, the latter housing the gun. + +Another craft, designed for scouting operations, may be likened to +the mosquito craft of the seas. This machine, while a biplane like +the military aeroplane, is of lighter construction, everything +being sacrificed to speed in this instance. It is fitted with a 100 +horse-power motor and is designed to carry an observer if required. +There is no offensive armament, however. The fuel tank capacity, +moreover, is limited, being only sufficient for a two or three hours' +flight. While this is adequate for general reconnoitring, which for the +most part entails short high speed flights, there are occasions when +the Staff demands more prolonged observations conducted over a greater +radius. This requisition can be met by eliminating the observer, whose +duties in this instance must be assumed by the pilot, and substituting +in place of the former, a second fuel tank of sufficient capacity for a +flight of four or five hours, thereby bringing the term of action in the +air to about 6 1/4 hours. This machine travels at a very high speed and +is eminently adapted to its specific duty, but it is of limited service +for general purposes. + +The arming of an aeroplane, to enable it to defend itself against +hostile attack or to participate in raiding operations upon the aerial +fleet of the enemy, appears to be a simple task, but as a matter of +fact it is an undertaking beset with difficulties innumerable. This is +especially the case where the aeroplane is of the tractive type, that is +to say where the propellers are placed in the forefront of the machine +and in their revolution serve to draw the machine forward. All other +considerations must necessarily be sacrificed to the mounting of the +propeller. Consequently it is by no means easy to allot a position for +the installation of a gun, or if such should be found there is grave +risk of the angle of fire being severely restricted. In fact, in many +instances the mounting of a gun is out of the question: it becomes a +greater menace to the machine than to the enemy. + +The French aeronautical section of the military department devoted +considerable study to this subject, but found the problem almost +insurmount able. Monsieur Loiseau met with the greatest measure of +success, and his system is being practised in the present campaign. This +principle is essentially adapted to tractor aeroplanes. Forward of the +pilot a special position is reserved for the gunner. A special mounting +is provided towards the prow, and upon the upper face of the body of the +machine. The gun mounting is disposed in such a manner that it is able +to command a wide arc of fire in the vertical plane over the nose of the +machine and more particularly in the downward direction. + +The marksman is provided with a special seat, but when he comes into +action he has to stand to manipulate his weapon. The lower part of his +body is protected by a front shield of steel plate, a fifth of an inch +in thickness, while a light railing extending upon either side and +behind enables the gunner to maintain his position when the aeroplane is +banking and climbing. The machine gun, of the Hotchkiss type, is mounted +upon a swivel attached to a tripod, while the latter is built into the +bracing of the car, so as to ensure a fairly steady gun platform. + +While the gun in the hands of a trained marksman may be manipulated with +destructive effect, the drawbacks to the arrangement are obvious. The +gunner occupies a very exposed position, and, although the bullet-proof +shield serves to break the effects of wind when travelling at high +speed which renders the sighting and training of the weapon extremely +difficult, yet he offers a conspicuous target, more particularly when +the enemy is able to assume the upper position in the air as a result of +superior speed in travelling. The gun, however, may be elevated to about +60 degrees, which elevation may be accentuated by the inclination of the +aeroplane when climbing, while the facility with which the weapon may be +moved through the horizontal plane is distinctly favourable. + +But the aerial marksman suffers from one very pronounced defect: he has +a severely restricted survey of everything below, since his vision is +interrupted by the planes. The result is that an enemy who has lost +ascendancy of position is comparatively safe if he is able to fly +immediately below his adversary: the mitrailleuse of the latter cannot +be trained upon him. On the other hand the enemy, if equipped with +repeating rifles or automatic pistols, is able to inflict appreciable +damage upon the craft overhead, the difficulties of firing vertically +into the air notwithstanding. + +In the Vickers system, where the propeller is mounted behind the car, +the aeroplane thus operating upon the pusher principle, the nose of the +car is occupied by the arm, which is a rifle calibre machine gun fitted +upon a special mounting. The prow is provided with an embrasure for +the weapon and the latter is so installed as to command an angle of 30 +degrees on all sides of the longitudinal axis of the machine when +in flight. In this instance the marksman is provided with complete +protection on all sides, inasmuch as his position is in the prow, where +the hood of the fo'c's'le shields him from overhead attack. The gun +is protected by a special shield which moves with the gun barrel. This +shield is provided with mica windows, through which the gunner is able +to sight his arm, so that he is not inconvenienced in any way by the +wind draught. + +One shortcoming of such methods of arming an aeroplane will be observed. +Ahead firing only is possible; the weapon cannot be trained astern, +while similarly the line of fire on either broadside is severely +limited. This is one reason why the machine-gun armament of aerial craft +of the heavier-than-air type has not undergone extensive development. +In many instances the pilot and observer have expressed their preference +for repeating high velocity rifles over any form of fixed gun mounting, +and have recourse to the latter only when the conditions are extremely +favourable to its effective employment. + +Efforts are now being made to equip the military type of aeroplane with +both forward and astern firing guns. The urgency of astern fire has +been brought home very vividly. Suppose, for instance, two hostile +aeroplanes, A and B, are in the air. A has the advantage at first, but +B is speedier and rapidly overhauls A. During the whole period of the +overhauling movement the gun of B can be directed upon A, while the +latter, owing to the arc of training being limited to c d cannot reply. +Obviously in the running fight it would be to the advantage of B, +although the fleeter machine, to keep behind A (position 1), but the +latter is making towards its own lines. + +Under these circumstances A must be headed off, so B crowds on speed +to consummate this end. But in the overtaking process B renders his +gun-fire ineffective, inasmuch as B passes beyond the arc of his gun +which is represented by e f. But in so doing B comes within the firing +arc of A (position 9). To minimise this danger B ascends to a higher +level to obtain the paramount position. + +If, however, B were equipped with an astern gun the aeroplane A would +be within the fire of B when the forward gun of the latter could not +be used. Similarly if A were also fitted with an astern gun it would be +able to attack its pursuer the whole time B was to its rear and in +this event, if its gun-fire were superior, it would be able to keep +the latter to a safe distance, or compel B to manoeuvre into a superior +position, which would entail a certain loss of time. + +An astern firing gun would be valuable to B in another sense. Directly +it had passed A or brought the latter within the zone of its astern gun +it could maintain its fire at the most advantageous range, because owing +to its speed it would be able to dictate the distance over which shots +should be exchanged and if mounted with a superior weapon would be able +to keep beyond the range of A's guns while at the same time it would +keep A within range of its own gun and consequently rake the latter. In +the interests of self-preservation A would be compelled to change +its course; in fact, B would be able to drive it in any direction he +desired, as he would command A's movements by gun-fire. + +The value of combined ahead and astern firing has been appreciated, but +there is one difficulty which at the moment appears to be insuperable +the clearance of the propeller. At the moment astern-firing, if such it +may be called, is maintained by repeating rifles, but this armament +is not to be compared with machine-gun firing, as the latter with +its capacity to pour 400 to 600 shots a minute, is far more deadly, +particularly when the weapon is manipulated by a crack gunner. + +Up to the present the offensive armament of aeroplanes has been confined +to light machine guns such as the Hotchkiss, Berthier, Schwartlose, +and Maxim weapons. So far as the arming of aeroplanes is concerned the +indispensable condition is light weight. With airships this factor is +not so vital, the result being that some dirigibles are mounted with +guns, throwing one pound bursting shells, fitted either with delay +action or percussion fuses, the former for preference. These shells are +given a wide cone of dispersion. Experiments are also being made with a +gun similar to the pom-pom which proved so useful in South Africa, the +gun throwing small shells varying from four to eight ounces in weight at +high velocity and in rapid succession. While such missiles would not be +likely to inflict appreciable damage upon an armoured aeroplane, they +would nevertheless be disconcerting to the aviators subjected to +such fire, and in aerial combats the successful undermining of the +adversary's moral is of far greater importance than in land operations, +since immediately ascendancy in the artillery operations is attained the +final issue is a matter of moments. + +But the most devastating arm which has yet been contrived for aerial +operations is the light machine gun which has recently been perfected. +The one objective with this weapon is to disable the hostile aircraft's +machinery. It fires an armour piercing projectile which, striking the +motor of any aircraft, would instantly put the latter out of action. The +shell has a diameter of about.75 inch and weighs about four ounces. The +gun is a hybrid of the mitrailleuse and the French "Soixante-quinze," +combining the firing rapidity of the former with the recoil mechanism +of the latter. This missile has established its ability to penetrate +the defensive armouring of any aeroplane and the motor of the machine +at 1,000 yards' range. This offensive arm is now being manufactured, so +that it is likely to be seen in the near future as the main armament of +aeroplanes. + +At the moment widespread efforts are being made in the direction of +increasing the offensive efficiency of aircraft. It is one of the phases +of ingenuity which has been stimulated into activity as a result of the +war. + + + +CHAPTER XII. BATTLES IN THE AIR + +Ever since the days of Jules Verne no theme has proved so popular in +fiction as fighting in the air. It was a subject which lent itself to +vivid imagination and spirited picturesque portrayal. Discussion might +be provoked, but it inevitably proved abortive, inasmuch as there was a +complete absence of data based upon actual experience. The novelist +was without any theory: he avowedly depended upon the brilliance of his +imagination. The critic could only theorise, and no matter how dogmatic +his reasonings, they were certainly as unconvincing as those of the +object of his attack. + +But truth has proved stranger than fiction. The imaginative pictures +of the novelist have not only been fulfilled but surpassed, while the +theorising critic has been utterly confounded. Fighting in the air has +become so inseparable from the military operations of to-day that it +occurs with startling frequency. A contest between hostile aeroplanes, +hundreds of feet above the earth, is no longer regarded as a dramatic, +thrilling spectacle: it has become as matter-of-fact as a bayonet melee +between opposed forces of infantry. + +A duel in the clouds differs from any other form of encounter. It is +fought mercilessly: there can be no question of quarter or surrender. +The white flag is no protection, for the simple reason that science and +mechanical ingenuity have failed, so far, to devise a means of taking +an aeroplane in tow. The victor has no possible method of forcing the +vanquished to the ground in his own territory except driving. If such a +move be made there is the risk that the latter will take the advantage +of a critical opportunity to effect his escape, or to turn the tables. +For these reasons the fight is fought to a conclusive finish. + +To aspire to success in these combats waged in the trackless blue, +speed, initiative, and daring are essential. Success falls to the swift +in every instance. An aeroplane travelling at a high speed, and pursuing +an undulating or irregular trajectory is almost impossible to hit from +the ground, as sighting is so extremely difficult. Sighting from another +machine, which likewise is travelling rapidly, and pursuing an irregular +path, is far more so. Unless the attacker can approach relatively +closely to his enemy the possibility of hitting him is extremely remote. +Rifle or gun-fire must be absolutely point blank. + +When a marauding aeroplane is espied the attacking corsair immediately +struggles for the strategical position, which is above his adversary. To +fire upwards from one aeroplane at another is virtually impossible, +at least with any degree of accuracy. The marksman is at a hopeless +disadvantage. If the pilot be unaccompanied and entirely dependent upon +his own resources he cannot hope to fire vertically above him, for +the simple reason that in so doing he must relinquish control of his +machine. A rifle cannot possibly be sighted under such conditions, +inasmuch as it demands that the rifleman shall lean back so as to obtain +control of his weapon and to bring it to bear upon his objective. Even +if a long range Mauser or other automatic pistol of the latest type be +employed, two hands are necessary for firing purposes, more particularly +as, under such conditions, the machine, if not kept under control, is +apt to lurch and pitch disconcertingly. + +Even a colleague carried for the express purpose of aggression is +handicapped. If he has a machinegun, such as a Maxim or a mitrailleuse, +it is almost out of the question to train it vertically. Its useful +vertical training arc is probably limited to about 80 degrees, and +at this elevation the gunner has to assume an extremely uncomfortable +position, especially upon an aeroplane, where, under the best of +circumstances, he is somewhat cramped. + +On the other hand the man in the aeroplane above holds the dominating +position. He is immediately above his adversary and firing may be +carried out with facility. The conditions are wholly in his favour. +Sighting and firing downwards, even if absolutely vertically, imposes +the minimum physical effort, with the result that the marksman is able +to bring a steadier aim upon his adversary. Even if the machine be +carrying only the pilot, the latter is able to fire upon his enemy +without necessarily releasing control of his motor, even for a moment. + +If he is a skilled sharpshooter, and the exigencies demand, he can +level, sight, and fire his weapon with one hand, while under such +circumstances an automatic self-loading pistol can be trained upon the +objective with the greatest ease. If the warplane be carrying a second +person, acting as a gunner, the latter can maintain an effective rifle +fusillade, and, at the same time, manipulate his machine-gun with no +great effort, maintaining rifle fire until the pilot, by manoeuvring, +can enable the mitrailleuse or Maxim to be used to the greatest +advantage. + +Hence the wonderful display of tactical operations when two hostile +aeroplanes sight one another. The hunted at first endeavours to learn +the turn of speed which his antagonist commands. If the latter is +inferior, the pursued can either profit from his advantage and race away +to safety, or at once begin to manoeuvre for position. If he is made of +stern stuff, he attempts the latter feat without delay. The pursuer, if +he realises that he is out classed in pace, divines that his quarry will +start climbing if he intends to show fight, so he begins to climb also. + +Now success in this tactical move will accrue to the machine which +possesses the finest climbing powers, and here again, of course, +speed is certain to count. But, on the other hand, the prowess of the +aviator--the human element once more--must not be ignored. The war has +demonstrated very convincingly that the personal quality of the aviator +often becomes the decisive factor. + +A spirited contest in the air is one of the grimmest and most thrilling +spectacles possible to conceive, and it displays the skill of the +aviator in a striking manner. Daring sweeps, startling wheels, +breathless vol-planes, and remarkable climbs are carried out. One +wonders how the machine can possibly withstand the racking strains to +which it is subjected. The average aeroplane demands space in which +to describe a turn, and the wheel has to be manipulated carefully and +dexterously, an operation requiring considerable judgment on the part of +the helmsman. + +But in an aerial duel discretion is flung to the winds. The pilot +jambs his helm over in his keen struggle to gain the superior position, +causing the machine to groan and almost to heel over. The stem stresses +of war have served to reveal the perfection of the modern aeroplane +together with the remarkable strength of its construction. In one or two +instances, when a victor has come to earth, subsequent examination has +revealed the enormous strains to which the aeroplane has been subjected. +The machine has been distorted; wires have been broken--wires which have +succumbed to the enormous stresses which have been imposed and have +not been snapped by rifle fire. One well-known British airman, who was +formerly a daring automobilist, confided to me that a fight in the +air "is the finest reliability trial for an aeroplane that was ever +devised!" + +In these desperate struggles for aerial supremacy the one party +endeavours to bring his opponent well within the point-blank range of +his armament: the other on his part strives just as valiantly to keep +well out of reach. The latter knows fully well that his opponent is at +a serious disadvantage when beyond point-blank range, for the simple +reason that in sighting the rifle or automatic pistol, it is difficult, +if not impossible while aloft, to judge distances accurately, and to +make the correct allowances for windage. + +If, however, the dominating aviator is armed with a machine gun he +occupies the superior position, because he can pour a steady hail of +lead upon his enemy. The employment of such a weapon when the contest is +being waged over friendly territory has many drawbacks. Damage is likely +to be inflicted among innocent observers on the earth below; the airman +is likely to bombard his friends. For this very reason promiscuous +firing, in the hope of a lucky shot finding a billet in the hostile +machine, is not practised. Both parties appear to reserve their fire +until they have drawn within what may be described as fighting distance, +otherwise point blank range, which may be anything up to 300 yards. + +Some of the battles between the German and the French or British +aeroplanes have been waged with a total disregard of the consequences. +Both realise that one or the other must perish, and each is equally +determined to triumph. It is doubtful whether the animosity between the +opposing forces is manifested anywhere so acutely as in the air. In some +instances the combat has commenced at 300 feet or so above the +earth, and has been fought so desperately, the machines climbing and +endeavouring to outmanoeuvre each other, that an altitude of over 5,000 +feet has been attained before they have come to close grips. + +The French aviator is nimble, and impetuous: the German aviator is +daring, but slow in thought: the British airman is a master of strategy, +quick in thought, and prepared to risk anything to achieve his end. The +German airman is sent aloft to reconnoitre the enemy and to communicate +his information to his headquarters. That is his assigned duty and he +performs it mechanically, declining to fight, as the welfare of his +colleagues below is considered to be of more vital importance than his +personal superiority in an aerial contest. But if he is cornered he +fights with a terrible and fatalistic desperation. + +The bravery of the German airmen is appreciated by the Allies. The +French flying-man, with his traditional love for individual combat, +seeks and keenly enjoys a duel. The British airman regards such a +contest as a mere incident in the round of duty, but willingly accepts +the challenge when it is offered. It is this manifestation of what may +be described as acquiescence in any development that enabled the British +flying corps, although numerically inferior, to gain its mastery of the +air so unostentatiously and yet so completely. + +All things considered an aeroplane duel is regarded as a fairly equal +combat. But what of a duel between an aeroplane and a dirigible? Which +holds the advantage? This question has not been settled, at any rate +conclusively, but it is generally conceded that up to a certain point +the dirigible is superior. It certainly offers a huge and attractive +target, but rifle fire at its prominent gas-bag is not going to cause +much havoc. The punctures of the envelope may represent so many +vents through which the gas within may effect a gradual escape, but +considerable time must elapse before the effect of such a bombardment +becomes pronounced in its result, unless the gas-bag is absolutely +riddled with machine gun-fire, when descent must be accelerated. + +On the other hand, it is to be presumed that the dirigible is armed. +In this event it has a distinct advantage. It has a steady gun-platform +enabling the weapons of offence to be trained more easily and an +enhanced accuracy of fire to be obtained. In order to achieve success +it is practically imperative that an aeroplane should obtain a position +above the dirigible, but the latter can ascend in a much shorter space +of time, because its ascent is vertical, whereas the aeroplane +must describe a spiral in climbing. Under these circumstances it is +relatively easy for the airship to outmanoeuvre the aeroplane in the +vertical plane, and to hold the dominating position. + +But even should the aeroplane obtain the upper position it is not +regarded with fear. Some of the latest Zeppelins have a machine gun +mounted upon the upper surface of the envelope, which can be trained +through 360 degrees and elevated to about 80 degrees vertical. Owing to +the steady gun platform offered it holds command in gun-fire, so that +the aeroplane, unless the aviator is exceptionally daring, will not +venture within the range of the dirigible. It is stated, however, that +this upper gun has proved unsatisfactory, owing to the stresses and +strains imposed upon the framework of the envelope of the Zeppelin +during firing, and it has apparently been abandoned. The position, +however, is still available for a sniper or sharpshooter. + +The position in the sky between two such combatants is closely analogous +to that of a torpedo boat and a Dreadnought. The latter, so long as it +can keep the former at arm's, or rather gun's, distance is perfectly +safe. The torpedo boat can only aspire to harass its enemy by buzzing +around, hoping that a lucky opportunity will develop to enable it to +rush in and to launch its torpedo. It is the same with the aeroplane +when arrayed against a Zeppelin. It is the mosquito craft of the air. + +How then can a heavier-than-air machine triumph over the unwieldy +lighter-than-air antagonist? Two solutions are available. If it can +get above the dirigible the adroplane may bring about the dirigible's +destruction by the successful launch of a bomb. The detonation of the +latter would fire the hydrogen within the gas-bag or bags, in which +event the airship would fall to earth a tangled wreck. Even if the +airship were inflated with a non-inflammable gas--the Germans claim +that their Zeppelins now are so inflated--the damage wrought by the bomb +would be so severe as to destroy the airship's buoyancy, and it would be +forced to the ground. + +The alternative is very much more desperate. It involves ramming the +dirigible. This is undoubtedly possible owing to the speed and facile +control of the aeroplane, but whether the operation would be successful +remains to be proved. The aeroplane would be faced with such a +concentrated hostile fire as to menace its own existence--its forward +rush would be frustrated by the dirigible just as a naval vessel parries +the ramming tactics of an enemy by sinking the latter before she reaches +her target, while if it did crash into the hull of the dirigible, +tearing it to shreds, firing its gas, or destroying its equilibrium, +both protagonists would perish in the fatal dive to earth. For this +reason ramming in mid-air is not likely to be essayed except when the +situation is desperate. + +What happens when two aeroplanes meet in dire combat in mid-air and one +is vanquished? Does the unfortunate vessel drop to earth like a stone, +or does it descend steadily and reach the ground uninjured? So far as +actual experience has proved, either one of the foregoing contingencies +may happen. In one such duel the German aeroplane was observed to start +suddenly upon a vol-plane to the ground. Its descending flight carried +it beyond the lines of the Allies into the territory of its friends. +Both came to the conclusion that the aviator had effected his escape. +But subsequent investigation revealed the fact that a lucky bullet +from the Allies' aeroplane had lodged in the brain of the German pilot, +killing him instantly. At the moment when Death over took him the +aviator had set his plane for the descent to the ground, and the machine +came to earth in the manner of a glider. + +But in other instances the descent has been far more tragic. The +aeroplane, deprived of its motive power, has taken the deadly headlong +dive to earth. It has struck the ground with terrific violence, burying +its nose in the soil, showing incidentally that a flying machine is an +indifferent plough, and has shattered itself, the debris soaked with +the escaping fuel becoming ignited. In any event, after such a fall the +machine is certain to be a wreck. The motor may escape damage, in +which event it is salvaged, the machine subsequently being purposely +sacrificed to the flames, thereby rendering it no longer available +to the enemy even if captured. In many instances the hostile fire has +smashed some of the stays and wires, causing the aeroplane to lose its +equilibrium, and sending it to earth in the manner of the proverbial +stone, the aviators either being dashed to pieces or burned to death. + +What are the vulnerable parts of the aeroplane? While the deliberate +intention of either combatant is to put his antagonist hors de combat, +the disablement of the machine may be achieved without necessarily +killing or even seriously wounding the hostile airman. The prevailing +type of aeroplane is highly susceptible to derangement: it is like a +ship without armour plate protection. The objective of the antagonist is +the motor or the fuel-tank, the vital parts of the machine, as much as +the aviator seated within. + +A well-planted shot, which upsets the mechanism of the engine, or a +missile which perforates the fuel tank, thereby depriving the motor of +its sustenance, will ensure victory as conclusively as the death of the +aviator himself. Rifle fire can achieve either of these ends with little +difficulty. Apart from these two nerve-centres, bombardment is not +likely to effect the desired disablement, inasmuch as it cannot be +rendered completely effective. The wings may be riddled like a sieve, +but the equilibrium of the machine is not seriously imperilled thereby. +Even many of the stays may be shot away, but bearing in mind the slender +objective they offer, their destruction is likely to be due more to +luck than judgment. On the other hand, the motor and fuel tank of the +conventional machine offer attractive targets: both may be put out of +action readily, and the disablement of the motive power of an enemy's +craft, be it torpedo-boat, battleship, or aeroplane, immediately places +the same at the assailant's mercy. + +Nevertheless, of course, the disablement of the airman brings about +the desired end very effectively. It deprives the driving force of its +controlling hand; The aeroplane becomes like a ship without a rudder: a +vessel whose helmsman has been shot down. It is unmanageable, and likely +to become the sport of the element in which it moves. It is for this +reason that aviators have been urged to direct their fire upon the men +and mechanism of a dirigible in the effort to put it out of action. +An uncontrolled airship is more likely to meet with its doom than an +aeroplane. The latter will inevitably glide to earth, possibly damaging +itself seriously in the process, as events in the war have demonstrated, +but a helpless airship at once becomes the sport of the wind, and anyone +who has assisted, like myself, in the descent of a vessel charged with +gas and floating in the air, can appreciate the difficulties experienced +in landing. An uncontrolled Zeppelin, for instance, would inevitably +pile up in a tangled twisted ruin if forced to descend in the manner of +an ordinary balloon. Consequently the pilot of a dirigible realises to +the full the imperative urgency of keeping beyond the point-blank fire +of aerial mosquito craft. + +The assiduity with which British aviators are prepared to swarm to the +attack has been responsible for a display of commendable ingenuity +on the part of the German airman. Nature has provided some of its +creatures, such as the octopus, for instance, with the ways and means +of baffling its pursuers. It emits dense clouds of inky fluid when +disturbed, and is able to effect its escape under cover of this screen. + +The German aviator has emulated the octopus. He carries not only +explosive bombs but smoke balls as well. When he is pursued and he finds +himself in danger of being overtaken, the Teuton aviator ignites these +missiles and throws them overboard. The aeroplane becomes enveloped in +a cloud of thick impenetrable smoke. It is useless to fire haphazard +at the cloud, inasmuch as it does not necessarily cover the aviator. He +probably has dashed out of the cloud in such a way as to put the screen +between himself and his pursuer. + +In such tactics he has merely profited by a method which is practised +freely upon the water. The torpedo boat flotilla when in danger of being +overwhelmed by superior forces will throw off copious clouds of smoke. +Under this cover it is able to steal away, trusting to the speed of the +craft to carry them well beyond gunshot. The "smoke screen," as it is +called, is an accepted and extensively practised ruse in naval strategy, +and is now adopted by its mosquito colleagues of the air. + + + +CHAPTER XIII. TRICKS AND RUSES TO BAFFLE THE AIRMAN + +The airman has not been allowed to hold his undisputed sway in military +operations for long. Desperate situations demand drastic remedies and +already considerable and illuminating ingenuity is being displayed to +baffle and mislead the scout of the skies. + +It is a somewhat curious and noteworthy fact, that the Germans were +among the first to realise the scope of the airman's activities, and the +significance of their relation to the conveyance of intimate information +and the direction of artillery fire. Consequently, they now spare no +effort to convey illusory information, in the hope that the hostile +force may ultimately make a false move which may culminate in disaster. + +Thus, for instance, as much endeavour is bestowed upon the fashioning of +dummy trenches as upon the preparation of the actual lines of defence. +And every care will be taken to indicate that the former are strongly +held. The dug-outs are complete and at places are apparently cunningly +masked. If the airman is flying swiftly, he is likely to fail to +distinguish the dummy from the real trenches. To him the defences appear +to be far more elaborate and more strongly held than is the actual case. + +The advantage of this delusion is obvious when a retreat is being made. +It enables the enemy to withdraw his forces deliberately and in perfect +order, and to assume another and stronger position comparatively at +leisure. The difficulty of detecting the dummies is emphasised, inasmuch +as now, whenever the sound of an aeroplane is heard, or a glimpse +thereof is obtained, the men keep well down and out of sight. Not a sign +of movement is observable. For all the airman may know to the contrary, +the trenches may be completely empty, whereas, as a matter of fact, +they are throbbing with alert infantry, anxious for a struggle with the +enemy. + +This is one instance where the dirigible is superior to the aeroplane. +The latter can only keep circling round and round over the suspicious +position; the movement through the air interferes with close continuous +observation. On the other hand, the dirigible can maintain a stationary +position aloft for hours on end. Then the issue is resolved into a +contest of patience, with the advantage to the airman. The soldiers in +the trenches fret and fume under cover; confined concealment is irksome +and is a supreme test of the nerves. Unless the soldiers are made of +very stern stuff, physical endurance succumbs. Some rash act--apparently +very trivial--may be committed; it suffices for the vigilant +sentinel overhead. He detects the slender sign of life, forms his own +conclusions, and returns to his headquarters with the intelligence that +the enemy is playing "Brer Rabbit." + +It has also become increasingly difficult for the airman to gather +absolutely trustworthy data concerning the disposition and movement of +troops. Small columns are now strung out along the highways to convey +the impression that the moving troops are in far greater force than is +actually the case, while the main body is under the cover offered by +a friendly wood and is safe from detection. The rapidity with which +thousands of men are able to disappear when the word "Airman" is passed +round is astonishing. They vanish as completely and suddenly as +if swallowed by the earth or dissolved into thin air. They conceal +themselves under bushes, in ditches, lie prone under hedgerows, dart into +houses and outbuildings--in short, take every cover which is available, +no matter how slender it may seem, with baffling alacrity. The +attenuated column, however, is kept moving along the highway for the +express purpose of deceiving the airman. + +Advancing troops also are now urged to move forward under the shelter +of trees, even if the task entails marching in single or double file, to +escape the prying eyes of the man above. By keeping close to the line +of trunks, thus taking full advantage of the overhanging branches, and +marching in such a manner as to create little dust, it is possible to +escape the aerial scout. + +The concealment of cavalry, however, is somewhat difficult. An animal, +especially if he be unaccustomed to the noise of the aeroplane, +is likely to become startled, and to give vent to a frightened and +vociferous neighing which invariably provokes a hearty response from +his equine comrades. The sharp ear of the airman does not fail to +distinguish this sound above the music of his motor. Again, he has come +to regard all copses and stretches of undergrowth with suspicion. Such +may or may not harbour the enemy, but there is no risk in making an +investigation. He swoops down, and when a short distance above the +apparently innocent copse, circles round it two or three times. Still +undecided, he finally hurls a bomb. Its detonation invariably proves +effective. The horses stampede and the secret is out. Even foot +soldiers must be severely trained and experienced to resist the natural +inclination to break cover when such a missile is hurled into their +midst. + +Frequently a force, which has laboured under the impression that it is +safe from detection, has revealed its presence unwittingly and upon the +spur of the moment. If the men be steeled against the bomb attack, it +is almost impossible to resist the inclination to take a shot when the +airman, swooping down, ventures so temptingly near as to render him +an enticing target almost impossible to miss. As a rule, however, the +observer is on the alert for such a betrayal of a force's existence. +When the bomb fails to scatter the enemy, or the men are proof against +the temptation to fire a volley, a few rounds from the aeroplane's +machine gun often proves effective. If the copse indeed be empty no harm +is done, beyond the abortive expenditure of a few rounds of ammunition: +if it be occupied, the fruits of the manoeuvre are attractive. Cunning +is matched against cunning, and the struggle for supremacy in the art of +craftiness is keen. + +The French Flying Corps have had recourse to an ingenious ruse for +accomplishing two ends--the one to draw concealed artillery fire, and +the other to pre-occupy the airmen. Two German aerial scouts observed a +French machine flying at a somewhat venturesome height over their masked +artillery. Divining the reason for the hostile intrepidity they +gave chase. Circling round the French machine they assailed it with +machine-gun fire. The enemy appeared to take no notice but continued his +gradual descent in a steady line. + +Presently the German airmen, having drawn sufficiently near, observed +that the French aviator was inert. Had he been killed? Everything +pointed to such a conclusion, especially as they had raked the aeroplane +fore and aft with bullets. But still suspicious they continued their +circling movements, their attention so concentrated upon their quarry +that they had not observed another move. It was the crash of guns from +their masked artillery which broke in upon their absorption. Looking +round, they observed three French aeroplanes soaring around and above +them at high speed. Scarcely had they realised the situation before +a spirited mitraireuse fire was rained upon them. One of the German +aeroplanes was speedily disabled. Its fuel tank was riddled and it sank +rapidly, finally crashing to earth in the deadly dive head foremost, +and killing both its occupants in the fall. The second aeroplane hurried +away with its pilot wounded. In the excitement of the aerial melee the +first French aeroplane had been forgotten. It was now scarcely 100 feet +above the German artillery. A capture appeared to be imminent, but the +Germans received a rude surprise. Suddenly the aeroplane exploded and a +hail of shrapnel burst over the heads of the artillerymen. + +The circumstance was decidedly uncanny, but after two or three such +experiences of exploding aeroplanes the matter was explained. The +apparently helpless aeroplane was merely a glider, which, instead of +carrying a man, had a booby-trap aboard. + +It appears that the French airmen have found a use for the aeroplanes +which are considered unsafe for further use. The motor and propeller are +removed and the dummy of explosives is strapped into position. The +laden glider is then taken aloft by means of an airship, and in the +concealment of the clouds is released, the rudder being so set as to +ensure a gradual vol-plane towards the suspicious position below. The +explosive cargo is set with a time fuse, the arrangement being that the +contents will be detonated while the machine is near the ground, unless +this end is accelerated by a well-planted shell from an anti-aircraft +gun. The decoy glider is generally accompanied by one or two aeroplanes +under control, which keep under the cover of the clouds until the +hostile aviators have been drawn into the air, when they swoop down +to the attack. The raiders are fully aware that they are not likely to +become the target of fire from the ground, owing to the fact that the +enemy's artillery might hit its friends. Consequently the antagonistic +airmen are left to settle their own account. In the meantime the +dummy machine draws nearer to the ground to explode and to scatter its +death-dealing fragments of steel, iron, and bullets in all directions. + +Possibly in no other phase of warfare is subterfuge practised so +extensively as in the concealment of guns. The branches of trees +constitute the most complete protection and guns are placed in position +beneath a liberal cover of this character. The branches also offer a +screen for the artillerymen, who can lurk beneath this shelter until the +aeroplane has passed. To complete the illusion dummy guns fashioned +from tree trunks and the wheels of useless limbers are rigged up, and +partially hidden under branches, the idea being to convey the impression +to the man aloft that they are the actual artillery. + +The aerial scout observes the dummies beneath the sparse covering of +branches. Congratulating himself upon his sharp eyesight, he returns +to his base with the intelligence that he has found the enemy's guns +he indicates their position upon the map, and in some cases returns to +notify the position of the weapons by smoke-ball or tinsel, when they +are immediately subjected to a severe bombardment. He follows the +shell-fire and sees the arms put out of action. He returns to camp +satisfied with his exploit, oblivious of the smiles and laughter of the +hostile artillerymen, who have their guns safely in position and +well masked some distance away. The dummies are imperfectly concealed +purposely, so that they may be discovered by the aerial scout, while the +real guns are completely masked and ready to belch forth from another +point. In one or two cases the dummies have been rigged up in such a +manner as to convey the impression, when seen from aloft, that a whole +battery has been put out of action, barrels and wheels as well as broken +limbers strewing the ground in all directions. + +Moving masses of soldiers are also resorting to cunning in order to +mislead the airman or to escape his observation. At the battle of +Haelen, during which engagement the German warplanes were exceptionally +active, the Belgian soldiers covered their heads with bundles of wheat +snatched from the standing stooks, and under this cover lurked in a +field where the corn was still standing. From aloft their forms defied +detection: the improvised headgear completely covered them and blended +effectively with the surrounding wheat. In another instance the French +misled a German airman somewhat effectively. What appeared to be +cavalry was seen to be retreating along the country road, and the airman +returned hurriedly to report. A German squadron was dispatched in hasty +pursuit. But as it rounded a copse skirting the road it received a +murderous fire at close quarters, which decimated the ranks and sent the +survivors flying for their lives along the road up which they had ridden +so confidently. Had the aviator been in a position to observe the horses +more closely, he would have found that what appeared to be riders on +their backs were in reality sacks stuffed with straw, dressed in old +uniforms, and that a mere handful of men were driving the animals +forward. The cavalrymen had purposely dismounted and secreted themselves +in the wood in anticipation of such a pursuit as was made. + +While the Germans do not appear to be so enterprising in this form +of ingenuity they have not been idle. A French airman flying over the +Teuton lines observed the outermost trenches to be alive with men whose +helmets were distinctly visible. The airman reported his observations +and the trench was subjected to terrific shell fire. Subsequently +the French made a spirited charge, but to their dismay found that the +outermost German trench was occupied by dummies fashioned from all sorts +of materials and crowned with helmets! This ruse had enabled the German +lines to be withdrawn to another position in safety and comparatively at +leisure. + +Before war was declared the German military experts were emphasising +the importance of trees for masking troops and guns against aerial +observation. One of the foremost authorities upon military aviation +only a few months ago urged the German Military Staff to encourage the +planting of orchards, not for the purpose of benefiting agriculture or +in the interests of the farmers, but merely for military exigencies. + +He pointed to the extensive orchards which exist in Alsace-Lorraine +and Baden, the military covering value of which he had determined from +personal experience, having conducted aerial operations while military +were moving to and fro under the cover of the trees. He declared that +the cover was efficient and that under the circumstances the laying +out of extensive orchards in strategical places should be carried out +without any delay. This, he urged, was a national and not a private +obligation. He advocated the bestowal of subsidies on the farmers to +encourage the planting of fruit trees. He suggested that the trees +should be provided by the State, and given to all who were prepared to +plant them; that substantial prizes should be awarded to encourage the +rapid growth thereof, and that annual prizes should be awarded to the +man who would undertake their cultivation and pruning, not from the +fruit-yielding point of view, but for facilitating the movement of +troops beneath their dense branches. + +He even urged the military acquisition of suitable land and its +determined, skilful, and discreet exploitation by those who loved the +Fatherland. He emphasised the necessity for keeping such orchards +under military control, only vouchsafing sufficient powers to the local +authorities to ensure the desired consummation. He maintained that, if +the work were prosecuted upon the right lines and sufficient financial +assistance were given, the purpose in view could be achieved without +saddling the war department with any unremunerative or excessive burden. +He admitted that the process of raising fruit trees to the stage +when they would afford adequate cover would be tedious and somewhat +prolonged, but argued that the military advantages, such as enabling +troops to move below the welcome shelter with absolute freedom and +without physical fatigue, would be an ample compensation. + +The utility of such cover to artillery was another factor he did not +fail to emphasise. He dwelt seriously upon the difficulty of rendering +permanent gun emplacements and heavy artillery invisible to the airman +by resort to the usual type of gun shields. The latter may be located +with ease by alert airmen, whereas if the guns were under cover of fruit +trees they would be able to accomplish their deadly mission without +betraying their presence to the aerial scout. Moreover, by pruning the +trees in such a manner as to ensure free movement beneath, the artillery +would be able to advance without betraying the fact to the enemy. + +This authority vigorously insisted that the work should be carried out +without a moment's delay as it was vital to the Fatherland. In the +light of recent events, and the excellent cover which is offered by the +orchards of the territory he cited as an illustration of his contention, +such a disclosure is pregnant with meaning. It throws a new light upon +the thorough methods with which the Germans carried out their military +preparations, and incidentally shows that they were fully alive to +every possible development. Fruit-raising as a complement to military +operations may be a new line of discussion, but it serves to reveal the +German in his true light, ready for every contingency, and shows how +thoroughly he appreciates the danger from the man in the clouds. + + + +CHAPTER XIV. ANTI-AIRCRAFT GUNS. MOBILE WEAPONS. + +When the airship and the aeroplane became accepted units of warfare it +was only natural that efforts should be concentrated upon the evolution +of ways and means to compass their destruction or, at least, to restrict +their field of activity. But aircraft appeared to have an immense +advantage in combat. They possess virtually unlimited space in which to +manoeuvre, and are able to select the elevation from which to hurl their +missiles of destruction. + +There is another and even more important factor in their favour. A +projectile fired, or even dropped, from a height, say of 5,000 feet, +is favourably affected by the force of gravity, with the result that +it travels towards the earth with accumulating energy and strikes the +ground with decisive force. + +On the other hand, a missile discharged into space from a weapon on the +earth has to combat this action of gravity, which exercises a powerful +nullifying influence upon its flight and velocity, far in excess of +the mere resistance offered by the air. In other words, whereas the +projectile launched from aloft has the downward pull of the earth or +gravitational force in its favour, the shell fired from the ground in +the reverse direction has to contend against this downward pull and its +decelerating effect. + +At the time when aircraft entered the realms of warfare very little +was known concerning the altitudes to which projectiles could be +hurled deliberately. Certain conclusive information upon this point was +available in connection with heavy howitzer fire, based on calculations +of the respective angles at which the projectile rose into the air and +fell to the ground, and of the time the missile took to complete its +flight from the gun to the objective. But howitzer fire against aircraft +was a sheer impossibility: it was like using a six-inch gun to kill a +fly on a window pane at a thousand yards' range. Some years ago +certain experiments in aerial firing with a rifle were undertaken +in Switzerland. The weapon was set vertically muzzle upwards and +discharged. From the time which elapsed between the issue of the bullet +from the muzzle until it struck the earth it was possible to make +certain deductions, from which it was estimated that the bullet reached +an altitude of 600 feet or so. But this was merely conjecture. + +Consequently when artillerists entered upon the study of fighting +air-craft with small arms and light guns, they were compelled to +struggle in the dark to a very pronounced extent, and this darkness was +never satisfactorily dispelled until the present war, for the simple +reason that there were no means of getting conclusive information. The +German armament manufacturers endeavoured to solve the problem by using +smoking shells or missiles fitted with what are known as tracers. By +following the ascensional path of the projectiles as revealed by the +smoke it was possible to draw certain conclusions. But these were by no +means convincing or illuminating, as so many factors affected the issue. + +Despite the peculiar and complex difficulties associated with the +problem it was attacked some what boldly. In this trying field of +artillery research the prominent German armament manufacturers, Krupp +of Essen and Ehrhardt of Dusseldorf, played a leading part, the result +being that before the airship or the aeroplane was received within the +military fold, the anti-aircraft gun had been brought into the field +of applied science. The sudden levelling-up serves to illustrate the +enterprise of the Germans in this respect as well as their perspicacity +in connection with the military value of aircraft. + +Any gun we can hope to employ against aircraft with some degree of +success must fulfil special conditions, for it has to deal with a +difficult and elusive foe. Both the lighter-than-air and the heavier +than-air craft possess distinctive features and varying degrees of +mobility. Taking the first-named, the facility with which it can vary +its altitude is a disconcerting factor, and is perplexing to the most +skilful gunner, inasmuch as he is called upon to judge and change the +range suddenly. + +On the other hand, the artilleryman is favoured in certain directions. +The range of utility of the airship is severely limited. If its avowed +mission is reconnaissance and conclusive information concerning the +disposition of forces, artillery and so forth is required, experience +has proved that such work cannot be carried out satisfactorily or with +any degree of accuracy at a height exceeding 5,000 feet, and a distance +beyond six miles. But even under these circumstances the climatic +conditions must be extremely favourable. If the elements are +unpropitious the airship must venture nearer to its objective. These +data were not difficult to collect, inasmuch as they were more or +less available from the results of military observations with captive +balloons, the conditions being somewhat similar. With the ordinary +captive balloon it has been found that, in clear weather, a radius of +about 3 3/4 miles at the maximum elevation constitutes its range of +reliable utility. + +With the aeroplane, however, the conditions are very dissimilar. In the +first place the machine owing to its diminutive size as compared with +the airship, offers a small and inconspicuous target. Then there is +its high independent speed, which is far beyond that of the airship. +Furthermore its mobility is greater. It can wheel, turn sharply to the +right or to the left, and pursue an irregular undulating flight in the +horizontal plane, which renders it well nigh impossible for a gunner to +pick it up. The machine moves at a higher relative speed than that at +which the gun can be trained. It is the rapid and devious variation +which so baffles the gunner, who unless he be highly skilled and +patient, is apt to commence to fire wildly after striving for a few +moments, and in vain, to pick up the range; he trusts to luck or depends +upon blind-shooting, which invariably results in a waste of ammunition. + +A gun, to be of tangible destructive efficiency when directed against +aircraft, especially those depending upon the gas-bag for equilibrium, +must be of special design. It must be capable of firing at an angle only +a few degrees less than the absolute vertical, and in order to follow +the rapid and involved movements of its objective, must be so mobile +that it can be trained through a complete circle at any angle of +inclination less than its maximum. At the same time, if the weapon is +being used in field operations it must be mounted upon a carriage of +adequate mobility to enable it to follow the airship, and thereby keep +pace with the latter, so that the aerial craft may be sorely harassed if +not actually hit. The automobile is the obvious vehicle for this duty, +and it has accordingly been extensively used in this service. + +The automobile and the gun mounted thereon follow widely different +lines. Some vehicles are designed especially for this duty, while others +are improvisations, and be it noted, in passing, that many of the latter +have proved more serviceable than the former. Still, the first-named +is to be preferred, inasmuch as necessarily it is designed to meet the +all-round requirements imposed, and consequently is better able to +stand up to the intended work, whereas the extemporised vehicle is only +serviceable under favourable conditions. + +The Krupp Company has evolved many designs of anti-aircraft motor-driven +guns--"Archibalds" the British airmen term them with emphatic levity. +They are sturdily-built vehicles fitted with heavy motors, developing +from 40 to 50 horse-power, with the chassis not widely dissimilar from +that adopted for motor-omnibus traffic. Consequently, they are not +necessarily condemned to the high-roads, but within certain limits +are able to travel across country, i.e., upon fields or other level +expanses, where the soil is not unduly soft. + +But the very character of the problem rendered the evolution of the +vehicle a somewhat perplexing matter. There were many factors which had +to be taken into consideration, and it was possible to meet the imposed +requirements only within certain limits. In the first place, the weight +of the gun itself had to be kept down. It was obviously useless to +overload the chassis. Again, the weight of the projectile and its +velocity had to be borne in mind. A high velocity was imperative. +Accordingly, an initial velocity varying from 2,200 to 2,700 feet per +second, according to the calibre of the gun, was determined. + +Moreover, as mobility was an indispensable condition, the gun had to be +so mounted that it could be fired from the motor-car even if the +latter were travelling at high speed. This requirement entailed another +difficulty. The gun had to be mounted in such a manner as to enable the +gunner to train it easily and readily through the complete circle and +through its complete range of vertical inclination. As the result +of prolonged experiments it was ascertained that the most suitable +arrangement was a pedestal mounting, either within a turret or upon an +open deck. To meet the weight of the gun, as well as the strains and +stresses incidental to firing, the chassis was strengthened, especially +over the rear axle near which the mounting is placed. + +The heaviest gun of this type is the 10.5 centimetre (4 1/4-inch) +quick-firer, throwing a shell weighing nearly forty pounds, with an +initial velocity of 2,333 feet per second. This "Archibald" is totally +unprotected. The gun is mounted centrally upon the carriage over the +rear axle, and occupies the centre of the deck between the driver's seat +and that of the gun crew behind. The whole of the deck is clear, thereby +offering no obstruction to the gunner in training the weapon, while the +space may be widened by dropping down the wings of the vehicle. At the +rear is a seat to accommodate the gun crew, beneath which the ammunition +is stowed. When travelling and out of action, the gun lies horizontally, +the muzzle pointing from the rear of the car. + +To reduce the strains arising from firing, the arm is fitted with +what is known as the "differential recoil." Above the breach is an air +recuperator and a piston, while there is no hydraulic brake such as is +generally used. The compressor is kept under compression while the car +is travelling with the gun out of action, so that the arm is available +for instant firing. This is a departure from the general practice in +connection with such weapons. When the gun is loaded the bolt which +holds the compressor back is withdrawn, either by the hand for manual +firing, or by the action of the automatic closing of the breech when the +arm is being used as a quick-firer. In firing the gun is thrown forward +under the pressure of the released air which occurs at the moment of +discharge. The energy of the recoil brings the gun back and at the same +time recharges the compressed air reservoir. + +The gun is so mounted upon its pedestal as to enable a maximum vertical +inclination of 75 degrees to be obtained. The mounting system also +enables the weapon to be trained in any desired direction up to the +foregoing maximum elevation throughout a complete circle, and it can +be handled with ease and celerity. A smaller "Archibald" is the 7.5 +centimetre (3-inch gun) throwing a 14.3 pound shell at an initial +velocity of about 2,170 feet per second. + +The turret anti-aircraft gun carried upon a motor-car differs from the +foregoing very considerably. This is a protected arm. The gun of 7.1 +centimetres--approximately 2.75 inches--is mounted in the same manner +upon the car-deck and over the driving axle, but is enclosed within a +sheet steel turret, which is proof against rifle and machine-gun +fire. This turret resembles the conning-tower of a battleship, and is +sufficiently spacious to house the whole of the gun crew, the internal +diameter being about seven feet. Access to the turret is obtained +through a rear door. This gun has a maximum elevation of about 75 +degrees, while its operation and mechanism are similar to those of the +unprotected weapon. + +The vehicle itself is practically identical with the armoured motor-car, +which has played such an important part during the present campaign, the +driver being protected by a bullet-proof steel screen similar in design +to the ordinary glass wind-screen fitted to touring automobiles. This is +carried sufficiently high to offer complete protection to his head when +seated at the wheel, while through a small orifice in this shield he is +able to obtain a clear view of the road. The engine and its vital +parts are also adequately protected. The ammunition is carried in a +cupboard-like recess forming part of the driver's seat, encased in +bullet-proof steel sheeting with flap-doors. This device enables the +shells to be withdrawn readily from the side of the car and passed to +the crew within the turret. The caisson is of sufficient dimensions to +receive 69 shells. + +The Ehrhardt airship fighting ordnance is similarly adapted to motor-car +operations, one type being especially powerful. The whole of the vehicle +is encased in armour-plating impervious to rifle and machine-gun fire. +The driver is provided with a small orifice through which he is able to +obtain a clear uninterrupted view of the road ahead, while the armouring +over the tonneau is carried to a sufficient height to allow head-room to +the gun crew when standing at the gun. All four wheels are of the disk +type and fashioned from heavy sheet steel. The motor develops 40-50 +horse-power and, in one type, in order to mitigate the risk of +breakdown or disablement, all four wheels are driven. The gun, a small +quick-firer, is mounted on a pedestal in a projecting conning-tower. The +mounting is placed behind the driver's seat, and is trained and operated +from the tonneau. The maximum elevation is 75 degrees, and like the +gun carriage bearing the tube guide it can be moved through a complete +circle, being free to rotate in the fixed pivot jack to enable this end +to be attained. + +The foregoing may be said to represent the most powerful types of mobile +anti-aircraft weapons used by the Austro-German forces to-day. Arms of +similar design, roughly speaking, have also been introduced into the +French and Russian services. In addition many semi-armoured weapons +of this character are in operation, some specially built for the work, +while others have been improvised. In the semi-armoured motor-car the +carriage follows the usual lines; it has an open top, the armouring +comprising the body of the tonneau and the diskwheels, which are made of +light bullet-proof steel. Here again the prevailing practice is to mount +the gun as nearly above the rear axle as possible, and to work it from +the tonneau. The maximum elevation is also 75 degrees, with training +throughout the entire circle. + +Another type comprises a very light machine gun of rifle calibre, and +this is intended for attachment to an ordinary motor car. There is a +pedestal mounting which can be set within the tonneau, while the weapon +is pivoted in an outrigger, the latter being free to rotate in its pivot +jack. This arrangement enables the arm to cover a wide range, while it +also admits of training through an extensive angle of elevation. + +The Allied forces improvised travelling anti-aircraft offences by +mounting the latest types of Vickers, Hotchkiss, and other machine guns +in armoured motor cars. Some of these have the domed turret form, with +the gun projecting through the roof, while others are protected against +hostile attack from the side only, the carriage being panelled with +bullet-proof steel sheeting. While such weapons are useful, inasmuch as +they can maintain a hot fire ranging up to 750 shots per minute, they +are not to be compared with the "Archibalds," which are able to throw +heavy shrapnel and incendiary shells, and have a vertical range of about +6,000 to 8,000 feet. + +The improvised motor-gun has not proved a complete success, except +in those instances when the hostile aircraft has ventured to approach +somewhat closely to the ground. The more formidable weapons cannot be +mounted upon ordinary vehicles, inasmuch as the increase in weight, +which is appreciable, impairs the efficiency of the vehicle, and at the +same time enhances the possibility of breakdown at a critical moment. +For such arms a special and substantial chassis is imperative, while the +motive power and gearing must be adapted to the circumstances. + +Motor-mounted anti-aircraft weapons, however, have not proved an +unqualified success. The fact that the vehicles are condemned to the +high roads, or at least to comparatively smooth and level ground, +constitutes a severe handicap. Again, when travelling at high speed, and +this is essential when pursuing a fast aeroplane, the accurate laying +of the weapon is extremely difficult, owing to the oscillation of the +vehicle itself, especially if the road surface is in a bad condition. +The sighting arrangements are of a wonderfully complete character, as +described elsewhere, but the irregular rolling movement arising from +high speed is a nullifying quantity. It is tolerably easy for the +aircraft, especially an aeroplane, to evade successful pursuit, either +by rising to an elevation beyond the range of the gun, or by carrying +out baffling evolutions such as irregular undulating flight, wheeling, +and climbing. According to the reports of the British and French airmen +the "Archibald" has failed to establish the glowing reputation which was +anticipated, for the simple reason that, unless it has a clear straight +road and can maintain its high speed, it can easily be out-distanced by +the fleet human bird. + +The motor-car suffers from another serious disability. It cannot +manoeuvre with sufficient celerity. For instance, if it is necessary to +turn round in a narrow lane, valuable time is lost in the process, and +this the airman turns to account. In hilly country it is at a still +greater disadvantage, the inclines, gradients, and sinuosities of the +roads restricting its effectiveness very pronouncedly. It must also be +remembered that, relatively speaking, the "Archibald" offers a better +target to the airman than the aeroplane offers to the man behind the +anti-aircraft gun on the motor below. A few well-placed bombs are +sufficient to induce the pursuers to cease their activities. Even if the +missiles fail to strike the motor-car itself they can wreak disaster in +directly by rendering the road impassable or dangerous to negotiate +at high speed. On the whole therefore, the "Archibald" is a greatly +exaggerated weapon of offence against aircraft, and, so far as is known, +has failed to fulfil expectations. In fact, the Germans have practically +abandoned the idea of using it in the manner of a pursuing arm; they +work the weapon as a fixture, depending upon the car merely as a +means of moving it from point to point. Thus, in reality, it has been +converted into a light field-piece, and may almost be included in the +category of fixed weapons for combating aerial operations. + + + +CHAPTER XV. ANTI-AIRCRAFT GUNS. IMMOBILE WEAPONS + +The immobile anti-aircraft gun, as distinct from that attached to a +travelling carriage such as a motor-car, may be subdivided into two +classes. The one is the fixed arm which cannot be moved readily, mounted +upon a permanent emplacement; the other is the field-piece which, while +fired from a stationary position, may be moved from point to point +upon a suitable carriage. The distinction has its parallel in ordinary +artillery, the first-named weapon coinciding with the heavy siege +gun, which is built into and forms part and parcel of the defensive or +offensive scheme, while the second is analogous to the field artillery, +which may be wheeled from position to position. + +In this phase of artillery the Germans led the way, for the simple +reason that they recognised the military value of aerial navigation +years in advance of their contemporaries. Again, in this field the +Krupp Organisation has played a prominent part. It embarked upon actual +construction of weapons while its rivals in other countries were content +to prepare their drawings, which were filed against "The Day." But it +must not be thought that because the German manufacturers of armaments +were ahead of their contemporaries they dominated the situation. Far +from it. Their competitors in the market of destruction were every whit +as keen, as ingenious, and as enterprising. Kruppism saw a commercial +opportunity to profit from advertisement and seized it: its rivals were +content to work in secret upon paper, to keep pace with the trend of +thought, and to perfect their organisations so as to be ready for the +crisis when it developed. + +The first Krupp anti-aircraft field-piece was a 6.5 centimetre (2 9/16 +inch) arm. It possessed many interesting features, the most salient of +which was the design of the axle of the carriage. The rigid axle for +the two wheels was replaced by an axle made in two sections, and +joined together in the form of a universal coupling, so that each +wheel virtually possessed its own axle, or rather half-axle. This was +connected with the cradle of the gun in such a manner that the wheels +were laterally pivoted thereon. + +The result is that each axle can be turned forward together with its +wheel, and thus the wheels have their rims brought into line to form an +arc of a circle, of which the rear end of the spade of the gun carriage +constitutes the centre. This acts as a pivot, about which the gun can +be turned, the pair of wheels forming the runners for the achievement of +this movement. The setting of the weapon in the firing position or its +reversion to the travelling position can be easily and speedily effected +merely by the rotation of a handwheel and gearing. + +With this gun a maximum elevation of 60 degrees is possible, owing to +the trunnions being carried well behind the breech in combination with +the system of long steady recoil. The balancing spring which encloses +the elevating screw is contained in a protected box. The recoil brake, +together with the spring recuperator, follows the usual Krupp practice +in connection with ordinary field pieces, as does also the automatic +breech-closing and firing mechanism. In fact there is no pronounced +deviation from the prevailing Krupp system, and only such modifications +as are necessary to adapt the arm to its special duty. When the gun +is elevated to high angles the shell, after insertion the breech is +prevented from slipping out by means of a special device, so that the +proper and automatic closing of the breech is not impaired in any way. + +In such an arm as this, which is designed essentially for high-angle +firing, the sighting and training facilities require to be carried +out upon special lines, inasmuch as the objective is necessarily at a +considerable altitude above the horizon of the gun. In other words, in +firing at a high inclination, distance between the gun and the target +cannot be utilised directly for the back sight. On the other hand, it is +essential that in proportion as the angle from the horizontal increases, +the back sight should be lowered progressively in a manner corresponding +to the distance. + +To assist the range-finder in his task of sighting it is necessary that +he should be provided with firing tables set out in a convenient form, +which, in conjunction with the telemeter, serve to facilitate training +for each successive round. In this way it is possible to pick up the +range quickly and to keep the objective in the line of fire until it +either has been put hors de combat, or has succeeded in retiring beyond +the range of the gun. + +The sighting arrangements of these Krupp anti-aircraft guns are carried +out upon these lines. Beneath the barrel of the back-sight is an +observing glass with an eye-piece for the artillerist, while above +and behind the observing glass is another eye-piece, to be used in +conjunction with the manipulation of the back-sight. The eye-piece +of the observation glass is so made that it can be turned through a +vertical plane in proportion as the angle of fire increases in relation +to the horizontal. The determination of the distance from the objective +and from the corresponding back-sight as well as the observation of +the altitude is carried out with the aid of the telemeter. This again +carries an observation glass fitted with an eye-piece which can +be turned in the vertical plane in the same manner as that of the +fore-sight. By means of this ingenious sighting device it is possible to +ascertain the range and angle of fire very easily and speedily. + +The weight of the special Krupp anti-aircraft field-piece, exclusive +of the protecting shield, is approximately identical with that of the +ordinary light artillery field-piece. It throws a shell weighing 8.8 +pounds with an initial velocity of about 2,066 feet per second. + +Although the German armament manufacturers were among the first to enter +the field with an anti-aircraft gun of this character they were speedily +followed by the French, who devised a superior weapon. In fact, the +latter represented such a decisive advance that the German artillerists +did not hesitate to appropriate their improvements in sundry essential +details, and to incorporate them with their own weapons. This applies +especially to the differential recoil system which is utilised in the +small anti-aircraft guns now mounted upon the roofs of high buildings +of cities throughout Germany for the express purpose of repelling aerial +attack. + +The French system is admitted by the leading artillery technicians of +the world to be the finest which has ever been designed, its remarkable +success being due to the fact that it takes advantage of the laws of +Nature. In this system the gun is drawn back upon its cradle preparatory +to firing. In some instances the barrel is compressed against a spring, +but in the more modern guns it is forced to rest against a cushion of +compressed air contained within a cylinder. When first bringing the +gun into action, the barrel is brought into the preliminary position by +manually compressing the air or spring by means of a lever. Thereafter +the gun works automatically. When the gun is fired the barrel is +released and it flies forward. At a critical point in its forward travel +the charge is fired and the projectile speeds on its way. The kick or +recoil serves to arrest the forward movement of the barrel and finally +drives it back again against the strong spring or cushion of compressed +air within the cylinder to its normal position, when it is ready for the +introduction of the next shell. + +The outstanding feature of this system is that the projectile is given +a higher initial velocity than is possible with the barrel held rigid at +the moment of discharge, because the shell is already travelling at the +moment of firing. + +The fixed anti-aircraft guns such as are stationed upon eminences and +buildings are of the quick firing type, the object being to hurl +a steady, continuous stream of missiles upon the swiftly moving +aeroplane. Some of the weapons throw a one-pound shell and are closely +similar to the pom-pom which proved so effective during the South +African war. Machine guns also have been extensively adopted for this +duty by all the combatants, their range of approximately 2,000 yards and +rapidity of fire being distinctly valuable when hostile aircraft descend +to an altitude which brings them within the range of the weapon. + +The greatest difficulty in connection with this phase of artillery, +however, is not so much the evolution of a serviceable and efficient +type of gun, as the determination of the type of projectile which +is likely to be most effective. While shrapnel is employed somewhat +extensively it has not proved completely satisfactory. It is +difficult to set the timing fuse even after the range has been found +approximately, which in itself is no easy matter when the aircraft is +moving rapidly and irregularly, but reliance is placed thereon in the +hope that the machine may happen to be within the cone of dispersion +when the shell bursts, and that one or more of the pieces of projectile +and bullets may chance to penetrate either the body of the airman or a +vital part of the mechanism. + +It is this uncertainty which has led to a preference for a direct +missile such as the bullet discharged from a machine gun. A stream of +missiles, even of rifle calibre, maintained at the rate of some 400 +shots per minute is certain to be more effective, provided range and aim +are correct, than shrapnel. But the ordinary rifle-bullet, unless the +objective is within very close range, is not likely to cause much harm, +at least not to the mechanism of the aerial vessel. + +It is for this reason that greater attention is being devoted, +especially by the French artillerists, to the Chevalier anti-aircraft +gun, a weapon perfected by a Swiss technician resident in Great Britain. +It projects a formidable missile which in fact is an armour-piercing +bullet 1/2- to 3/4-inch in diameter. It is designed for use with an +automatic machinegun, which the inventor has devised more or less upon +the well-known French system. The bullet has a high velocity--about +2,500 feet per second--and a maximum range of 6,000 to 8,000 feet at +the maximum elevation. Should such a missile strike the motor or other +mechanism of the vessel it would wreak widespread havoc, and probably +cause the machine to come to earth. This arm has been designed for the +express purpose of disabling the aeroplane, and not for the subjugation +of the airman, which is a minor consideration, inasmuch as he is +condemned to a descent when his craft receives a mortal wound. + +Attempts have been and still are being made to adapt an explosive +projectile to this gun, but so far the measure of success achieved has +not proved very promising. There are immense difficulties connected +with the design of an explosive shell of this class, charged with a +high explosive, especially in connection with the timing. So far as +dependence upon percussive detonation is concerned there is practically +no difficulty. Should such a missile strike, say, the motor of an +aeroplane, or even the hull of the craft itself, the latter would be +practically destroyed. But all things considered, it is concluded that +more successful results are likely to be achieved by the armour-piercing +bullet striking the mechanism than by an explosive projectile. + +The Krupp company fully realised the difficulties pertaining to the +projectile problem in attacks upon aerial craft. So far as dirigibles +are concerned shrapnel is practically useless, inasmuch as even should +the bag be riddled by the flying fragments, little effective damage +would be wrought--the craft would be able to regain its haven. +Accordingly efforts were concentrated upon the perfection of two new +types of projectiles, both of which were directed more particularly +against the dirigible. The one is the incendiary shell--obus +fumigene--while the other is a shell, the contents of which, upon coming +into contact with the gas contained within the gas-bag, set up certain +chemical reactions which precipitate an explosion and fire. + +The incendiary shells are charged with a certain compound which is +ignited by means of a fuse during its flight. This fuse arrangement +coincides very closely with that attached to ordinary shrapnel, inasmuch +as the timing may be set to induce ignition at different periods, such +as either at the moment it leaves the gun, before, or when it strikes +the envelope of the dirigible. The shell is fitted with a "tracer," +that is to say, upon becoming ignited it leaves a trail of smoke, +corresponding with the trail of a rocket, so that its passage through +the air may be followed with facility. This shell, however, was designed +to fulfil a dual. Not only will it fire the gaseous contents out of the +dirigible, but it has an explosive effect upon striking an incombustible +portion of the aircraft, such as the machinery, propellers or car, when +it will cause sufficient damage to throw the craft out of action. + +The elaborate trials which were carried out with the obus fumigene +certainly were spectacular so as they went. Two small spherical +balloons, 10 feet in diameter, and attached to 1,000 feet of cable, were +sent aloft. The anti-aircraft guns themselves were placed about 5,100 +feet distant. Owing to the inclement weather the balloons were unable +to attain a height of more than 200 feet in a direct vertical line above +the ground. The guns were trained and fired, but the one balloon was +not hit until the second round, while the third escaped injury until the +fifth round. When struck they collapsed instantly. Though the test was +not particularly conclusive, and afforded no reliable data, one point +was ascertained--the trail of smoke emitted by the shell enabled its +trajectory to be followed with ease. Upon the conclusion of these +trials, which were the most successful recorded, quick-firing tests +in the horizontal plane were carried out. The best performance in this +instance was the discharge of five rounds in eight seconds. In this +instance the paths of the projectiles were simple and easy to follow, +the flight of the shell being observed until it fell some 18,670 feet +away. But the Krupp firm have found that trials upon the testing ground +with a captive balloon differ very materially from stern tests in the +field of actual warfare. Practically nothing has been heard of the two +projectiles during this war, as they have proved an absolute failure. + +Some months ago the world was startled by the announcement that the +leading German armament firm had acquired the whole of the interest in +an aerial torpedo which had been evolved by the Swedish artillerist, +Gustave Unge, and it was predicted that in the next war widespread havoc +would be wrought therewith. Remarkable claims were advanced for this +projectile, the foremost being that it would travel for a considerable +distance through the air and alight upon the objective with infallible +accuracy. The torpedo in question was subjected to exacting tests in +Great Britain, which failed to substantiate all the claims which were +advanced, and it is significant to observe that little has been heard +of it during the present conflict. It is urged in certain technical +quarters, however, that the aerial torpedo will prove to be the most +successful projectile that can be used against aircraft. I shall deal +with this question in a later chapter. + +During the early days of the war anti-aircraft artillery appeared to +be a much overrated arm. The successes placed to its credit were +insignificant. This was due to the artillerymen being unfamiliar with +the new arm, and the conditions which prevail when firing into space. +Since actual practice became possible great advances in marksmanship +have been recorded, and the accuracy of such fire to-day is striking. +Fortunately the airman possesses the advantage. He can manoeuvre beyond +the range of the hostile weapons. At the moment 10,000 feet represents +the extreme altitude to which projectiles can be hurled from the arms +of this character which are now in use, and they lack destructiveness at +that range, for their velocity is virtually expended. + +Picking up the range is still as difficult as ever. The practice +followed by the Germans serves to indicate the Teuton thoroughness of +method in attacking such problems even if success does not ensue. The +favourite German principle of disposing anti-aircraft artillery is to +divide the territory to be protected into equilateral triangles, the +sides of which have a length of about six miles or less, according to +the maximum effective range of the pieces at an elevation of 23 1/2 +degrees. + +The guns are disposed at the corners of the triangles as indicated +in Figs. 13-14. Taking the one triangle as an example, the method of +picking up the range may be explained as follows. The several guns at +the comers of the triangle, each of which can be trained through the +360 degrees in the horizontal plane, are in telephonic touch with an +observer O stationed some distance away. The airman A enters the area +of the triangle. The observer takes the range and communicates with the +gunner B, who fires his weapon. The shell bursts at 1 emitting a red +flame and smoke. The observer notes the altitude and relative position +of the explosion in regard to the aircraft, while gunner B himself +observes whether the shell has burst to the right or to the left of the +objective and corrects accordingly. The observer commands C to fire, +and another shell is launched which emits a yellow flame and smoke. It +bursts at 2 according to the observer, while gunner C also notes +whether it is to the right or to the left of the target and corrects +accordingly. Now gunner D receives the command to fire and the shell +which explodes at 3 throws off a white flame and smoke. Gunner D +likewise observes whether there is any deviation to right or left of +the target and corrects in a similar manner. From the sum of the three +rounds the observer corrects the altitude, completes his calculations, +and communicates his instructions for correction to the three gunners, +who now merely train their weapons for altitude. The objective is to +induce the shells hurled from the three corners of the triangle to burst +at a common point 4, which is considered to be the most critical spot +for the aviator. The fire is then practically concentrated from the +three weapons upon the apex of a triangular cone which is held to bring +the machine within the danger zone. + +This method of finding the range is carried out quickly--two or three +seconds being occupied in the task. In the early days of the war the +German anti-aircraft artillerymen proved sadly deficient in this work, +but practice improved their fire to a marvellous degree, with the result +that at the moment it is dangerous for an aviator to essay his task +within an altitude of 6,000 feet, which is the range of the average +anti-aircraft gun. + +The country occupied by a belligerent is divided up in this manner +into a series of triangles. For instance, a machine entering hostile +territory from the east, enters the triangle A-B-C, and consequently +comes within the range of the guns posted at the comers of the triangle. +Directly he crosses the line B-C and enters the adjacent triangle he +passes beyond the range of gun A but comes within the range of the gun +posted at D, and while within the triangular area is under fire from the +guns B-C-D. He turns and crosses the line A-C, but in so doing enters +another triangle A-C-E, and comes range of the gun posted at E. + +The accompanying diagram represents an area of country divided up into +such triangle and the position of the guns, while the circle round the +latter indicate the training arc of the weapons, each of which is a +complete circle, in the horizontal plane. The dotted line represents +the aviator's line of flight, and it will be seen that no matter how he +twists and turns he is always within the danger zone while flying over +hostile territory. The moment he outdistances one gun he comes within +range of another. + +The safety of the aviator under these circumstances depends upon his +maintaining an altitude exceeding the range of the guns below, the most +powerful of which have a range of 8,000 to 10,000 feet, or on speed +combined with rapid twisting and turning, or erratic undulating flight, +rendering it extremely difficult for the gun-layer to follow his path +with sufficient celerity to ensure accurate firing. + +At altitudes ranging between 4,000 and 6,000 feet the aeroplane comes +within the range of rifle and machine-gun firing. The former, however, +unless discharged in volleys with the shots covering a wide area, is not +particularly dangerous, inasmuch as the odds are overwhelmingly against +the rifleman. He is not accustomed to following and firing upon a +rapidly moving objective, the result being that ninety-nine times out +of a hundred he fails to register a hit. On the other hand the advantage +accruing from machine-gun fire is, that owing to the continuous stream +of bullets projected, there is a greater possibility of the gun being +trained upon the objective and putting it hors de combat. + +But, taking all things into consideration, and notwithstanding the +achievements of the artillerist, the advantages are overwhelmingly +on the side of the aviator. When one reflects upon the total sum of +aircraft which have been brought to earth during the present campaign, +it will be realised that the number of prizes is insignificant in +comparison with the quantity of ammunition expended. + + + +CHAPTER XVI. MINING THE AIR + +While the anti-aircraft gun represents the only force which has +been brought to the practical stage for repelling aerial attack, and +incidentally is the sole offensive weapon which has established its +effectiveness, many other schemes have been devised and suggested to +consummate these ends. While some of these schemes are wildly fantastic, +others are feasible within certain limitations, as for instance when +directed against dirigibles. + +It has been argued that the atmosphere is akin to the salt seas; that +an aerial vessel in its particular element is confronted with dangers +identical with those prevailing among the waters of the earth. But such +an analogy is fallacious: there is no more similarity between the air +and the ocean than there is between an airship and a man-of-war. The +waters of the earth conceal from sight innumerable obstructions, such as +rocks, shoals, sandbanks, and other dangers which cannot by any means be +readily detected. + +But no such impediments are encountered in the ether. The craft of the +air is virtually a free age in the three dimensions. It can go whither +it will without let or hindrance so long as the mechanical agencies of +man are able to cope with the influences of Nature. It can ascend to +a height which is out of all proportion to the depth to which the +submarine can descend in safety. It is a matter of current knowledge +that a submarine cannot sink to a depth of more than 250 feet: an aerial +vessel is able to ascend to 5,000, 8,000, or even 10,000 feet above the +earth, and the higher the altitude it attains the greater is its degree +of safety. The limit of ascension is governed merely by the physical +capacities of those who are responsible for the aerial vessel's +movement. + +It is for this reason that the defensive measures which are practised in +the waters of the earth are inapplicable to the atmosphere. Movement +by, or in, water is governed by the depth of channels, and these may be +rendered impassable or dangerous to negotiate by the planting of mines. +A passing ship or submarine may circumvent these explosive obstructions, +but such a successful manoeuvre is generally a matter of good luck. So +far as submarines are concerned the fact must not be over looked +that movements in the sea are carried out under blind conditions: the +navigator is unable to see where he is going; the optic faculty is +rendered nugatory. Contrast the disability of the submarine with the +privileges of its consort in the air. The latter is able to profit from +vision. The aerial navigator is able to see every inch of his way, at +least during daylight. When darkness falls he is condemned to the same +helplessness as his confrere in the waters below. + +A well-known British authority upon aviation suggested that advantage +should be taken of this disability, and that the air should be mined +during periods of darkness and fog to secure protection against +aerial invasion. At first sight the proposal appears to be absolutely +grotesque, but a little reflection will suffice to demonstrate its +possibilities when the area to be defended is comparatively limited. The +suggestion merely proposes to profit from one defect of the dirigible. +The latter, when bent upon a daring expedition, naturally prefers to +make a bee-line towards its objective: fuel considerations as a matter +of fact compel it to do so. Consequently it is possible, within certain +limits, to anticipate the route which an invading craft will follow: the +course is practically as obvious as if the vessel were condemned to a +narrow lane marked out by sign-posts. Moreover, if approaching under +cover of night or during thick weather, it will metaphorically "hug the +ground." To attempt to complete its task at a great height is to court +failure, as the range of vision is necessarily so limited. + +Under these circumstances the mining of the air could be carried out +upon the obvious approaches to a threatened area. The mines, comprising +large charges of high-explosive and combustible material, would be +attached to small captive balloons similar to the "sounding balloons" +which are so much used by meteorologists in operations for sounding the +upper strata of the atmosphere. These pilot balloons would be captive, +their thin wires being wound upon winches planted at close intervals +along the coast-line. The balloon-mines themselves would be sent to +varying heights, ranging from 1,000 to 5,000 feet, and with several +attached to each cable, the disposition of the mines in the air in +such an irregular manner being in fact closely similar to the practice +adopted in the mining of a channel for protection against submarines and +hostile ships. + +The suggestion is that these mines should be sent aloft at dusk or upon +the approach of thick and foggy weather, and should be wound in at dawn +or when the atmosphere cleared, inasmuch as in fine weather the floating +aerial menace would be readily detected by the pilot of a dirigible, and +would be carefully avoided. If the network were sufficiently intricate +it would not be easy for an airship travelling at night or in foggy +weather to steer clear of danger, for the wires holding the balloons +captive would be difficult to distinguish. + +The mines would depend upon detonators to complete their work, and here +again they would bear a close resemblance to sea-mines. By looping the +mines their deadliness could be increased. The unsuspicious airship, +advancing under cover of darkness or thick weather, might foul one of +the wires, and, driving forward, would tend to pull one or more mines +against itself. Under the force of the impact, no matter how gentle, or +slight, one or more of the detonating levers would be moved, causing the +mine to explode, thus bursting the lifting bag of the vessel, and firing +its gaseous contents. An alternative method, especially when a cable +carried only a single mine, would be to wind in the captive balloon +directly the wire was fouled by an invading aerial craft, the process +being continued until the mine was brought against the vessel and +thereby detonated. + +Another proposed mining method differs materially in its application. In +this instance it is suggested that the mines should be sent aloft, but +should not be of the contact type, and should not be fired by impact +detonators, but that dependence should be placed rather upon the +disturbing forces of a severe concussion in the air. The mines would +be floating aloft, and the advance of the airship would be detected. The +elevation of the mines in the vicinity of the invading craft would be +known, while the altitude of the airship in relation thereto could be +calculated. Then, it is proposed that a mine within d certain radius +of the approaching craft, and, of course, below it, should be fired +electrically from the ground. It is maintained that if the charge were +sufficiently heavy and an adequate sheet of flame were produced as a +result of the ignition, an airship within a hundred yards thereof would +be imperilled seriously, while the other mines would also be fired, +communicating ignition from one to the other. The equilibrium of the +airship is so delicate that it can be readily upset, and taking into +account the facts that gas is always exuding from the bag, and that +hydrogen has a tendency to spread somewhat in the manner of oil upon +water, it is argued that the gas would be ignited, and would bring about +the explosion of the airship. + +Another method has even been advocated. It is averred in authoritative +circles that when the aerial invasion in force of Great Britain is +attempted, the Zeppelins will advance under the cover of clouds. Also +that the craft will make for one objective--London. Doubtless advantage +will be taken of clouds, inasmuch as they will extend a measure of +protection to the craft, and will probably enable the invading fleet +to elude the vigilance of the aeroplane scouts and patrols. Under these +circumstances it is suggested that balloon-mines should be sent aloft +and be concealed in the clouds. It would be impossible to detect the +wires holding them captive, so that the precise location of the lurking +danger would not be divined by the invader. Of course, the chances are +that the invading airship would unconsciously miss the mines; on the +other hand the possibilities are equally great that it would blunder +into one of these traps and be blown to atoms. + +An English airman has recently suggested a means of mining invading +Zeppelins which differs completely from the foregoing proposals. His +idea is that aeroplanes should be equipped with small mines of the +contact type, charged with high explosives, and that the latter should +be lowered from the aeroplane and be trawled through the atmosphere. As +an illustration I will suppose that a hostile aircraft is sighted by a +patrolling aeroplane. The pilot's companion in the latter immediately +prepares his aerial mine, fixing the detonator, and attaching the mine +to the wire. The latter is then dropped overboard, the wire being paid +out from a winch until it has descended to the level of the hostile +craft. The airman now manoeuvres in the air circling about the airship, +dragging his mine behind him, and endeavouring to throw it across or +to bring it into contact with the airship below. Naturally the latter, +directly it observed the airman's object, would endeavour to elude the +pursuing trawling mine, either by crowding on speed or by rising to a +greater altitude. The aeroplane, however, would have the advantage both +in point of speed and powers of climbing, while there is no doubt that +the sight of the mine swinging in the air would exert a decisive moral +effect upon those in the airship. + +Attempts to render the mine harmless by discharging it prematurely with +the aid of rifle and machine-gun fire would, of course, be made by the +crew of the airship, but the trawling mine would prove a very difficult +target to strike. If such a missile were used against an airship of the +proportions of a Zeppelin the mine would inevitably be trawled across +the vessel sooner or later. Once the airship had been fouled, the +aviator would merely have to drive ahead, dragging the wire and its +charge across the gas-bag until at last one of the contact levers of the +mine was moved by being dragged against some part of the vessel, when +the mine would be exploded. In such operations the aviator would run a +certain risk, as he would be more or less above the airship, and to a +certain degree within the zone of the ultimate explosion. But there is +no doubt that he would succeed in his "fishing" exploit within a very +short time. + +This ingenious scheme has already been tested upon a small scale and has +been found effective, the trawling bomb being drawn across its target +and fired by contact within a few minutes. The experiment seems to prove +that it would be simpler and more effectual to attack a hostile aircraft +such as a Zeppelin in this manner than to drop free bombs at random. +Moreover, we cannot doubt that the sight of a mine containing even ten +or twelve pounds of high explosive dangling at the end of a wire would +precipitate a retreat on the part of an airship more speedily than any +other combative expedient. + +The advocate of this mine-trawling method, who is a well-known aviator, +anticipates no difficulty in manoeuvring a mine weighing 30 pounds at +the end of 300 feet of fine wire. Success depends in a great measure on +the skill of the aviator in maintaining a constant tension upon the line +until it falls across its objective. + +The process calls for a certain manifestation of skill in manoeuvring +the aeroplane in relation to the airship, judgment of distance, and +ability to operate the aeroplane speedily. The rapid ascensional +capability of the airship, as compared with that of the aeroplane, is a +disadvantage, but on the other hand, the superior mobility and speed of +the aeroplane would tell decisively for success. + +Among the many wonders which the Krupp organisation is stated to have +perfected, and which it is claimed will create considerable surprise, is +the aerial torpedo. Many of the Krupp claims are wildly chimerical, +as events have already proved, but there is no doubt that considerable +effort has been expended upon this latest missile, for which the firm is +said to have paid the inventor upwards of L25,000--$125,000. Curiously +enough the projectile was perfected within gunshot of the British +aerodrome of Hendon and is stated to have been offered to the British +Government at the time, and to have met with a chilling reception. One +fact, however, is well established. The inventor went to Germany, and +submitted his idea to Krupp, by whom it was tested without delay. Upon +the completion of the purchase, the great armament manufacturers did not +fail to publish broadcast the fact that they had acquired a mysterious +new terror of the skies. That was some three years ago, and in the +interval the cleverest brains of the German firm have been steadily +devoting their time and energies to the improvement of the missile, the +first appearance of which was recorded, in a somewhat hazy manner, in +the closing days of December. + +While the exact mechanism of this missile is a secret, the governing +principles of its design and operation are known to a select few +technicians in this country. Strange to say, the projectile was designed +in the first instance in the interests of peace and humanity, but while +engaged upon his experiments the inventor suddenly concluded that it +would be a more profitable asset if devoted to the grim game of war. At +the time the military significance of the airship and the aeroplane +were becoming apparent; hence the sudden diversion of the idea into a +destructive channel. + +This aerial torpedo is a small missile carrying a charge of high +explosive, such as trinitrotoluene, and depends for its detonation upon +impact or a time fuse. It is launched into the air from a cradle in the +manner of the ordinary torpedo, but the initial velocity is low. The +torpedo is fitted with its own motive power, which comes automatically +into action as the missile climbs into the air. This self-contained +energy is so devised that the maximum power is attained before the +missile has lost the velocity imparted in the first instance, the result +being that it is able to continue its flight in a horizontal direction +from the moment it attains the highest point in its trajectory, which is +naturally varied according to requirements. But there is no secret +about the means of propulsion. The body is charged with a slow-burning +combustible, in the manner of the ordinary rocket, whereby it is given a +rapid rotary motion. + +Furthermore it is stated to be fitted with a small gyroscope in the +manner of the torpedo used in the seas, for the purpose of maintaining +direction during flight, but upon this point there is considerable +divergence of opinion among technicians, the general idea being that +the torpedo depends upon an application of the principle of the ordinary +rocket rather than upon a small engine such as is fitted to the ordinary +torpedo. The employment of a slow combustible ensures the maintenance +of the missile in the air for a period exceeding that of the ordinary +shell. It is claimed by the Germans that this projectile will keep aloft +for half-an-hour or more, but this is a phantasy. Its maintenance of +flight is merely a matter of minutes. + +The belated appearance of this much-lauded projectile and its restricted +use suggest that it is unreliable, and perhaps no more effective than +the aerial torpedo which appeared in the United States during the +Spanish-American War, and proved a complete failure. An effective and +reliable means of combating or frustrating a dirigible attack, other +than by gun-fire or resort to the drastic remedy of ramming the enemy, +has yet to be devised. + + + +CHAPTER XVII. WIRELESS IN AVIATION + +In a previous chapter the various methods of signalling between the +ground and the airman aloft have been described. Seeing that wireless +telegraphy has made such enormous strides and has advanced to such a +degree of perfection, one naturally would conclude that it constitutes +an ideal system of communication under such conditions in military +operations. + +But this is not the case. Wireless is utilised only to a very limited +extent. This is due to two causes. The one is of a technical, the other +of a strategical character. + +The uninitiated, bearing in mind the comparative ease with which +wireless installations may be established at a relatively small expense, +would not unreasonably think that no serious difficulties of a technical +character could arise: at least none which would defy solution. But +these difficulties exist in two or three different fields, each of which +is peculiarly complex and demands individual treatment. + +In the first place, there is the weight of the necessary installation. +In the case of the dirigible this may be a secondary consideration, +but with the aeroplane it is a matter of primary and vital importance. +Again, under present conditions, the noise of the motor is apt to render +the intelligent deciphering of messages while aloft a matter of extreme +difficulty, especially as these are communicated in code. The engine +noise might be effectively overcome by the use of a muffler such as, +is used with automobiles, but then there is the further difficulty of +vibration. + +This problem is being attacked in an ingenious manner. It is proposed to +substitute for audible signals visual interpretations, by the aid of an +electric lamp, the fluctuations in which would correspond to the dots +and dashes of the Morse code. Thus the airman would read his messages by +sight instead of by sound. + +This method, however, is quite in its infancy, and although attractive +in theory and fascinating as a laboratory experiment or when conducted +under experimental conditions, it has not proved reliable or effective +in aeronautical operations. But at the same time it indicates a +promising line of research and development. + +Then there are the problems of weight and the aerial. So far as present +knowledge goes, the most satisfactory form of aerial yet exploited is +that known as the trailing wire. From 300 to 700 feet of wire are coiled +upon a reel, and when aloft this wire is paid out so that it hangs below +the aeroplane. As a matter of fact, when the machine is travelling at +high speed it trails horizontally astern, but this is immaterial. One +investigator, who strongly disapproves of the trailing aerial, has +carried out experiments with a network of wires laid upon and attached +to the surface of the aeroplane's wings. But the trailing wire is +generally preferred, and certainly up to the present has proved more +satisfactory. + +The greatest obstacle, however, is the necessary apparatus. The average +aeroplane designed for military duty is already loaded to the maximum. +As a rule it carries the pilot and an observer, and invariably includes +a light arm for defence against an aerial enemy, together with an +adequate supply of ammunition, while unless short sharp flights are to +be made, the fuel supply represents an appreciable load. Under these +circumstances the item of weight is a vital consideration. It must be +kept within a limit of 100 pounds, and the less the equipment weighs the +more satisfactory it is likely to prove, other things being equal. + +The two most successful systems yet exploited are the Dubilier and the +Rouget. The former is an American invention, the latter is of French +origin. Both have been tested by the British Military Aeronautical +Department, and the French authorities have subjected the French system +to rigorous trials. Both systems, within their limitations, have proved +satisfactory. + +The outstanding feature of the Dubilier system is the production of sine +waves of musical frequency from continuous current, thus dispensing +with the rotary converter. The operating principle is the obtaining of +a series of unidirectional impulses by a condenser discharge, the +pulsating currents following one another at regular intervals at a +frequency of 500 impulses per second, which may be augmented up to 1,000 +impulses per second. The complete weight of such an apparatus is 40 +pounds; the electric generator, which is no larger than the motor used +for driving the ordinary table ventilating fan, accounts for 16 pounds +of this total. Under test at sea, upon the deck of a ship, a range of +250 miles has been obtained. The British Government carried out a series +of experiments with this system, using a small plant weighing about 30 +pounds, with which communication was maintained up to about 20 miles. + +In the French system the Reuget transmitter is employed. The apparatus, +including the dynamo, which is extremely small, weighs in all 70 pounds. +A small alternator of 200 watts and 100 volts is coupled direct to the +aeroplane motor, a new clutch coupler being employed for this purpose. +By means of a small transformer the voltage is raised to 30,000 volts, +at which the condenser is charged. In this instance the musical spark +method is employed. + +The whole of the high tension wiring is placed within a small space +so as not to endanger the pilot, while the transformer is hermetically +sealed in a box with paraffin. The aerial comprises a trailing wire 100 +feet in length, which, however, can be wound in upon its reel within 15 +seconds. This reeled antenna, moreover, is fitted with a safety device +whereby the wire can be cut adrift in the event of an accident befalling +the aeroplane and necessitating an abrupt descent. With this apparatus +the French authorities have been able to maintain communication over a +distance of 30 miles. + +In maintaining ethereal communication with aeroplanes, however, a +portable or mobile station upon the ground is requisite, and this +station must be within the radius of the aerial transmitter, if +messages are to be received from aloft with any degree of accuracy and +reliability. Thus it will be recognised that the land station is as +important as the aeroplane equipment, and demands similar consideration. + +A wide variety of systems have been employed to meet these conditions. +There is the travelling automobile station, in which the installation +is mounted upon a motor-car. In this instance the whole equipment is +carried upon a single vehicle, while the antenna is stowed upon the roof +and can be raised or lowered within a few seconds. If motor traction is +unavailable, then animal haulage may be employed, but in this instance +the installation is divided between two vehicles, one carrying the +transmitting and receiving apparatus and the generating plant, the other +the fuel supplies and the aerial, together with spare parts. + +The motive power is supplied by a small air cooled petrol or gasoline +motor developing eight horse-power, and coupled direct to a 2-kilo watt +alternator. At one end of the shaft of the latter the disk discharger is +mounted, its function being to break up the train of waves into groups +of waves, so as to impart a musical sound to the note produced in the +receiver. A flexible cable transmits the electric current from the +generator to the wagon containing the instruments. The aerial is built +up of masts carried in sections. + +The Germans employ a mobile apparatus which is very similar, but in +this instance the mast is telescopic. When closed it occupies but little +space. By turning the winch handle the mast is extended, and can be +carried to any height up to a maximum of about 100 feet. The capacity +of these mobile stations varies within wide limits, the range of the +largest and most powerful installations being about 200 miles. The +disadvantage of these systems, however, is that they are condemned to +territories where the ground at the utmost is gently undulating, and +where there are roads on which four-wheeled vehicles can travel. + +For operation in hilly districts, where only trails are to be found, +the Marconi Company, has perfected what may be described as "pack" and +"knapsack" installations respectively. In the first named the whole of +the installation is mounted upon the backs of four horses. The first +carries the generator set, the second the transmitting instruments, the +third the receiving equipment, and the fourth the detachable mast and +stays. + +The generator is carried upon the horse's saddle, and is fitted with a +pair of legs on each side. On one side of the saddle is mounted a +small highspeed explosion motor, while on the opposite side, in axial +alignment with the motor, is a small dynamo. When it is desired to +erect the installation the saddle carrying this set is removed from the +horse's back and placed upon the ground, the legs acting as the support. +A length of shaft is then slipped into sockets at the inner ends of the +motor and dynamo shafts respectively, thus coupling them directly, while +the current is transmitted through a short length of flexible cable to +the instruments. The mast itself is made in lengths of about four feet, +which are slipped together in the manner of the sections of a fishing +rod, and erected, being supported by means of wire guys. In this manner +an antenna from 40 to 50 feet in height may be obtained. + +The feature of this set is its compactness, the equal division of the +sections of the installation, and the celerity with which the station +may be set up and dismantled in extremely mountainous country such as +the Vosges, where it is even difficult for a pack-horse to climb to +commanding or suitable positions, there is still another set which has +been perfected by the Marconi Company. This is the "knapsack" set, +in which the whole of the installation, necessarily light, small, +and compact, is divided among four men, and carried in the manner of +knapsacks upon their backs. Although necessarily of limited radius, +such an installation is adequate for communication within the restricted +range of air-craft. + +Greater difficulties have to be overcome in the mounting of a wireless +installation upon a dirigible. When the Zeppelin was finally accepted +by the German Government, the military authorities emphasised the great +part which wireless telegraphy was destined to play in connection with +such craft. But have these anticipations been fulfilled? By no means, as +a little reflection will suffice to prove. + +In the first place, a wireless outfit is about the most dangerous piece +of equipment which could be carried by such a craft as the Zeppelin +unless it is exceptionally well protected. As is well known the rigidity +of this type of airship is dependent upon a large and complicated +network of aluminium, which constitutes the frame. Such a huge mass +of metal constitutes an excellent collector of electricity from the +atmosphere; it becomes charged to the maximum with electricity. + +In this manner a formidable contributory source of danger to the airship +is formed. In fact, this was the reason why "Z-IV" vanished suddenly in +smoke and flame upon falling foul of the branches of trees during +its descent. At the time the Zeppelin was a highly charged electrical +machine or battery as it were, insulated by the surrounding air. +Directly the airship touched the trees a short circuit was established, +and the resultant spark sufficed to fire the gas, which is continuously +exuding from the gas bags. + +After this accident minute calculations were made and it was ascertained +that a potential difference of no less than 100,00 volts existed between +the framework of the dirigible and the trees. This tension sufficed +to produce a spark 4 inches in length. It is not surprising that the +establishment of the electric equilibrium by contact with the trees, +which produced such a spark should fire the hydrogen inflation charge. +In fact the heat generated was so intense that the aluminium metallic +framework was fused. The measurements which were made proved that the +gas was consumed within 15 seconds and the envelope destroyed within 20 +seconds. + +As a result of this disaster endeavours were made to persuade Count +Zeppelin to abandon the use of aluminium for the framework of his +balloon but they were fruitless, a result no doubt due to the fact that +the inventor of the airship of this name has but a superficial +knowledge of the various sciences which bear upon aeronautics, and fully +illustrates the truth of the old adage that "a little learning is a +dangerous thing." Count Zeppelin continues to work upon his original +lines, but the danger of his system of construction was not lost upon +another German investigator, Professor Schiitte, who forthwith embarked +upon the construction of another rigid system, similar to that of +Zeppelin, at Lanz. In this vessel aluminium was completely abandoned in +favour of a framework of ash and poplar. + +The fact that the aluminium constituted a dangerous collector of +electricity rendered the installation of wireless upon the Zeppelin not +only perilous but difficult. Very serious disturbances of an electrical +nature were set up, with the result that wireless communication between +the travelling dirigible and the ground below was rendered extremely +uncertain. In fact, it has never yet been possible to communicate over +distances exceeding about 150 miles. Apart from this defect, the danger +of operating the wireless is obvious, and it is generally believed in +technical circles that the majority of the Zeppelin disasters from fire +have been directly attributable to this, especially those disasters +which have occurred when the vessel has suddenly exploded before coming +into contact with terrestrial obstructions. + +In the later vessels of this type the wireless installation is housed +in a well insulated compartment. This insulation has been carried, to +an extreme degree, which indicates that at last the authorities have +recognised the serious menace that wireless offers to the safety of the +craft, with the result that every protective device to avoid disaster +from this cause has been freely adopted. + +The fact that it is not possible to maintain communication over a +distance exceeding some 20 miles is a severe handicap to the progressive +development of wireless telegraphy in this field. It is a totally +inadequate radius when the operations of the present war are borne in +mind. A round journey of 200, or even more miles is considered a +mere jaunt; it is the long distance flight which counts, and which +contributes to the value of an airman's observations. The general +impression is that the fighting line or zone comprises merely two or +three successive stretches of trenches and other defences, representing +a belt five miles or so in width, but this is a fallacy. The fighting +zone is at least 20 miles in width; that is to say, the occupied +territory in which vital movements take place represents a distance of +20 miles from the foremost line of trenches to the extreme rear, and +then comes the secondary zone, which may be a further 10 miles or +more in depth. Consequently the airman must fly at least 30 miles in +a bee-line to cover the transverse belt of the enemy's field of +operations. Upon the German and Russian sides this zone is of far +greater depth, ranging up to 50 miles or so in width. In these +circumstances the difficulties of ethereal communication 'twixt air and +earth may be realised under the present limitations of radius from which +it is possible to transmit. + +But there are reasons still more cogent to explain why wireless +telegraphy has not been used upon a more extensive scale during the +present campaign. Wireless communication is not secretive. In other +words, its messages may be picked up by friend and foe alike with +equal facility. True, the messages are sent in code, which may be +unintelligible to the enemy. In this event the opponent endeavours to +render the communications undecipherable to one and all by what is known +as "jambing." That is to say, he sends out an aimless string of +signals for the purpose of confusing senders and receivers, and this +is continued without cessation and at a rapid rate. The result is that +messages become blurred and undecipherable. + +But there is another danger attending the use of wireless upon the +battlefield. The fact that the stations are of limited range is well +known to the opposing forces, and they are equally well aware of the +fact that aerial craft cannot communicate over long distances. For +instance, A sends his airmen aloft and conversation begins between the +clouds and the ground. Presently the receivers of B begin to record +faint signals. They fluctuate in intensity, but within a few seconds B +gathers that an aeroplane is aloft and communicating with its base. By +the aid of the field telephone B gets into touch with his whole string +of wireless stations and orders a keen look-out and a listening ear to +ascertain whether they have heard the same signals. Some report that the +signals are quite distinct and growing louder, while others declare that +the signals are growing fainter and intermittent. In this manner B is +able to deduce in which direction the aeroplane is flying. Thus if those +to the east report that signals are growing stronger, while the stations +on the west state that they are diminishing, it is obvious that the +aeroplane is flying west to east, and vice versa when the west hears +more plainly at the expense of the east. If, however, both should report +that signals are growing stronger, then it is obvious that the aircraft +is advancing directly towards them. + +It was this ability to deduce direction from the sound of the signals +which led to the location of the Zeppelin which came down at Luneville +some months previous to the war, and which threatened to develop into a +diplomatic incident of serious importance. The French wireless stations +running south-east to north-west were vigilant, and the outer station on +the north-west side picked up the Zeppelin's conversation. It maintained +a discreet silence, but communicated by telephone to its colleagues +behind. + +Presently No. 2 station came within range, followed by Nos. 3, 4, 5, 6, +and so on in turn. Thus the track of the Zeppelin was dogged silently +through the air by its wireless conversation as easily and as positively +as if its flight had been followed by the naked eye. The Zeppelin +travellers were quite ignorant of this action upon the part of the +French and were surprised when they were rounded-up to learn that they +had been tracked so ruthlessly. Every message which the wireless of the +Zeppelin had transmitted had been received and filed by the French. + +Under these circumstances it is doubtful whether wireless telegraphy +between aircraft and the forces beneath will be adopted extensively +during the present campaign. Of course, should some radical improvement +be perfected, whereby communication may be rendered absolutely +secretive, while no intimation is conveyed to the enemy that ethereal +conversation is in progress, then the whole situation will be changed, +and there may be remarkable developments. + + + +CHAPTER XVIII. AIRCRAFT AND NAVAL OPERATIONS + +When once the flying machine had indicated its possibilities in +connection with land operations it was only natural that endeavours +should be made to adapt it to the more rigorous requirements of the +naval service. But the conditions are so vastly dissimilar that only a +meagre measure of success has been recorded. Bomb-throwing from +aloft upon the decks of battleships appeals vividly to the popular +imagination, and the widespread destruction which may be caused by +dropping such an agent down the funnel of a vessel into the boiler-room +is a favourite theme among writers of fiction and artists. But hitting +such an objective while it is tearing at high speed through the water, +from a height of several thousand feet is a vastly different task from +throwing sticks and balls at an Aunt Sally on terra firma: the target is +so small and elusive. + +Practically it is impossible to employ the flying machine, whether it +be a dirigible or an aeroplane, in this field. Many factors militate +against such an application. In the first place there is a very wide +difference between dry land and a stretch of water as an area over which +to manoeuvre. So far as the land is concerned descent is practicable at +any time and almost anywhere. But an attempt to descend upon the open +sea even when the latter is as calm as the proverbial mill-pond is +fraught with considerable danger. The air-currents immediately above the +water differ radically from those prevailing above the surface of +the land. Solar radiation also plays a very vital part. In fact the +dirigible dare not venture to make such a landing even if it be provided +with floats. The chances are a thousand to one that the cars will become +water-logged, rendering re-ascent a matter of extreme difficulty, if not +absolutely impossible. On the other hand, the aeroplane when equipped +with floats, is able to alight upon the water, and to rest thereon for +a time. It may even take in a new supply of fuel if the elements be +propitious, and may be able to re-ascend, but the occasions are rare +when such operations can be carried out successfully. + +In operations over water the airman is confronted with one serious +danger--the risk of losing his bearings and his way. For instance, many +attempts have been made to cross the North Sea by aeroplane, but only +one has proved successful so far. The intrepid aviator did succeed in +passing from the shore of Britain to the coast of Scandinavia. Many +people suppose that because an airman is equipped with a compass he must +be able to find his way, but this is a fallacy. The aviator is in the +same plight as a mariner who is compelled from circumstances to rely +upon his compass alone, and who is debarred by inclement weather from +deciding his precise position by taking the sun. A ship ploughing the +waters has to contend against the action of cross currents, the speed +of which varies considerably, as well as adverse winds. Unless absolute +correction for these influences can be made the ship will wander +considerably from its course. The airman is placed in a worse position. +He has no means of determining the direction and velocity of the +currents prevailing in the atmosphere, and his compass cannot give him +any help in this connection, because it merely indicates direction. + +Unless the airman has some means of determining his position, such as +landmarks, he fails to realise the fact that he is drifting, or, even +if he becomes aware of this fact, it is by no means a simple +straightforward matter for him to make adequate allowance for the +factor. Side-drift is the aviator's greatest enemy. It cannot be +determined with any degree of accuracy. If the compass were an +infallible guide the airman would be able to complete a given journey +in dense fog just as easily as in clear weather. It is the action of the +cross currents and the unconscious drift which render movement in the +air during fog as impracticable with safety as manoeuvring through the +water under similar conditions. More than one bold and skilful aviator +has essayed the crossing of the English Channel and, being overtaken by +fog, has failed to make the opposite coast. His compass has given him +the proper direction, but the side-drift has proved his undoing, with +the result that he has missed his objective. + +The fickle character of the winds over the water, especially over such +expanses as the North Sea, constitutes another and seriously adverse +factor. Storms, squalls, gales, and, in winter, blizzards, spring up +with magical suddenness, and are so severe that no aircraft could hope +to live in them. But such visitations are more to be dreaded by the +lighter-than-air than by the heavier-than-air machines. The former +offers a considerable area of resistance to the tempest and is caught up +by the whirlwind before the pilot fully grasps the significant chance +of the natural phenomenon. Once a dirigible is swept out of the hands of +its pilot its doom is sealed. + +On the other hand, the speed attainable by the aeroplane constitutes its +safety. It can run before the wind, and meantime can climb steadily and +rapidly to a higher altitude, until at last it enters a contrary wind or +even a tolerably quiescent atmosphere. Even if it encounters the tempest +head on there is no immediate danger if the aviator keep cool. This +fact has been established times out of number and the airman has been +sufficiently skilful and quick-witted to succeed in frustrating the +destructive tactics of his natural enemy. + +Only a short while ago in France, British airmen who went aloft in a +gale found the latter too strong for them. Although the machine was +driven full speed ahead it was forced backwards at the rate of 10 miles +per hour because the independent speed of the aeroplane was less +than the velocity of the wind. But a dirigible has never succeeded +in weathering a gale; its bulk, area, and weight, combined with its +relatively slow movement, are against it, with the result that it is +hurled to destruction. All things considered, the dirigible is regarded +as an impracticable acquisition to a fleet, except in the eyes of the +Germans, who have been induced to place implicit reliance upon their +monsters. The gullible Teuton public confidently believes that their +Dreadnoughts of the air will complete the destruction of the British +fleet, but responsible persons know full well that they will not play +such a part, but must be reserved for scouting. Hitherto, in naval +operations, mosquito water-craft, such as torpedo-boats, have been +employed in this service. But these swift vessels suffer from one +serious disability. The range of vision is necessarily limited, and a +slight mist hanging over the water blinds them; the enemy may even pass +within half-a-mile of them and escape detection. + +The Zeppelin from its position 1,000 feet or more above the water, in +clear weather, has a tremendous range of vision; the horizon is about 40 +miles distant, as compared with approximately 8 miles in the case of the +torpedo-boat. Of course an object, such as a battleship, may be detected +at a far greater range. Consequently the German naval programme is to +send the Zeppelin a certain distance ahead of the battleship squadron. +The dirigible from its coign of vantage would be able to sight a hostile +squadron if it were within visual range and would communicate the fact +to the commander of the fleet below. The latter would decide his course +according to information received; thus he would be enabled to elude +his enemy, or, if the tidings received from the aerial scout should +be favourable, to dispose his vessels in the most favourable array for +attack. + +The German code of naval tactics does not foreshadow the use of +dirigible aircraft as vessels of attack. Scouting is the primary and +indeed the only useful duty of the dirigible, although it is quite +possible that the aerial craft might participate in a subsequent naval +engagement, as, indeed, has been the case. Its participation, however, +would be governed entirely by climatic conditions. The fact that +the dirigible is a weak unit of attack in naval operations is fully +appreciated by all the belligerents. + +The picture of a sky "black with Zeppelins" may appeal to the popular +imagination, and may induce the uninitiated to cherish the belief that +such an array would strike terror into the hearts of the foe, but the +naval authorities are well aware that no material advantage would accrue +from such a force. In the first place they would constitute an ideal +target for the enemy's vessels. They would be compelled to draw within +range in order to render their own attack effective, and promiscuous +shooting from below would probably achieve the desired end. One or +more of the hostile aircraft would be hit within a short while. Such +disasters would undoubtedly throw the aerial fleet into confusion, +and possibly might interfere with the tactical developments of its own +friends upon the water below. + +The shells hurled from the Zeppelins would probably inflict but little +damage upon the warships beneath. Let it be conceded that they weigh +about 500 pounds, which is two-thirds of the weight of the projectile +hurled from the Krupp 128-centimetre howitzer. Such a missile would have +but little destructive effect if dropped from a height of 1,000 feet. +To achieve a result commensurate with that of the 28-centimetre howitzer +the airship would have to launch the missile from a height of about +7,000 feet. To take aim from such an altitude is impossible, especially +at a rapidly moving target such as a battle-cruiser. + +The fact must not be forgotten that Count Zeppelin himself has expressed +the opinion, the result of careful and prolonged experiments, that his +craft is practically useless at a height exceeding 5,000 feet. Another +point must not be overlooked. In a spirited naval engagement the +combatants would speedily be obliterated from the view of those aloft by +the thick pall of smoke--the combination of gun-fire and emission from +the furnaces and a blind attack would be just as likely to damage friend +as foe. + +Even if the aircraft ventured to descend as low as 5,000 feet it would +be faced with another adverse influence. The discharge of the heavy +battleship guns would bring about such an agitation of the air above as +to imperil the delicate equilibrium of an airship. Nor must one overlook +the circumstance that in such an engagement the Zeppelins would become +the prey of hostile aeroplanes. The latter, being swifter and nimbler, +would harry the cumbersome and slow-moving dirigible in the manner of +a dog baiting a bear to such a degree that the dirigible would be +compelled to sheer off to secure its own safety. Desperate bravery and +grim determination may be magnificent physical attributes, ut they +would have to be superhuman to face the stinging recurrent attacks of +mosquito-aeroplanes. + +The limitations of the Zeppelin, and in fact of all dirigible aircraft, +were emphasised upon the occasion of the British aerial raid upon +Cuxhaven. Two Zeppelins bravely put out to overwhelm the cruisers and +torpedo boats which accompanied and supported the British sea-planes, +but when confronted with well-placed firing from the guns of the vessels +below they quickly decided that discretion was the better part of valour +and drew off. In naval operations the aeroplane is a far more formidable +foe, although here again there are many limitations. The first and most +serious is the severely limited radius of action. The aeroplane motor is +a hungry engine, while the fuel capacity of the tank is restricted. The +German military authorities speedily realised the significance of this +factor and its bearing upon useful operations, and forth with carried +out elaborate endurance tests. In numerable flights were made with the +express purpose of determining how long a machine could remain in the +air upon a single fuel supply. + +The results of these flights were collated and the achievements of each +machine in this direction carefully analysed, a mean average drawn +up, and then pigeon-holed. The results were kept secret, only the more +sensational records being published to the world. As the policy of +standardisation in the construction of aeroplanes was adopted the radius +of action of each type became established. It is true that variations +of this factor even among vessels exactly similar in every respect are +inevitable, but it was possible to establish a reliable mean average for +general guidance. + +The archives of the Berlin military department are crowded with facts +and figures relating to this particular essential, so that the radius of +action, that is the mileage upon a single fuel charge, of any class and +type of machine may be ascertained in a moment. The consequence is that +the military authorities are able to decide the type of aeroplane which +is best suited to a certain projected task. According to the dossier +in the pigeon-hole, wherein the results of the type are filed, the +aeroplane will be able to go so far, and upon arriving at that point +will be able to accomplish so much work, and then be able to return +home. Consequently it is dispatched upon the especial duty without any +feeling of uncertainty. + +Unfortunately, these experimental processes were too methodical to prove +reliable. The endurance data were prepared from tests carried out in +the aerodrome and from cross-country trials accomplished under ideal or +fair-weather conditions. The result is that calculations have been often +upset somewhat rudely by weather conditions of a totally unexpected +character, which bring home vividly the striking difference between +theory and practice. + +The British and French aviation authorities have not adopted such +methodical standardisation or rule of thumb inferences, but rather +have fostered individual enterprise and initiative. This stimulation of +research has been responsible for the creation of a type of aeroplane +specially adapted to naval service, and generically known as the water +plane, the outstanding point of difference from the aeroplane being the +substitution of canoes or floats for the wheeled chassis peculiar to +the land machine. The flier is sturdily built, while the floats are +sufficiently substantial to support the craft upon the water in calm +weather. Perhaps it was the insular situation of the British nation +which was responsible for this trend of development, because so far as +Britain is concerned the sea-going aeroplane is in dispensable. But the +salient fact remains that to-day the waterplane service of Great Britain +is the most efficient in the world, the craft being speedy, designed and +built to meet the rough weather conditions which are experienced around +these islands, and ideal vessels for patrol and raiding duties. + +So far as the British practice is concerned the waterplane is designed +to operate in conjunction with, and not apart from, the Navy. It has +been made the eyes of the Navy in the strictest interpretation of the +term. In any such combination the great difficulty is the establishment +of what may be termed a mobile base, inasmuch as the waterplane must +move with the fleet. This end has been achieved by the evolution of +a means of carrying a waterplane upon, and launching it from, a +battleship, if necessary. + +For this purpose a docking cradle or way has been provided aft where +the aeroplane may be housed until the moment arrives for its employment. +Several vessels have been devoted to this nursing duty and are known as +parent ships to the waterplane service. All that is requisite when the +time arrives for the use of the seaplane is to lift it bodily by derrick +or crane from its cradle and to lower it upon the water. It will be +remembered that the American naval authorities made an experiment with a +scheme for directly launching the warplane from the deck of a battleship +in the orthodox, as well as offering it a spot upon which to alight upon +returning from a flight, while Wing-Commander Samson, R.N., D.S.O., the +famous British airman, repeated the experiment by flying from a similar +launching way installed upon H.M.S. Hibernia. But this practice has many +shortcomings. So far as the British and French navies are concerned, the +former process is preferred. Again, when the waterplane returns from a +flight it is admitted that it is simpler, quicker, and safer for it to +settle upon the water near the parent ship and to be lifted on board. + +As a sea-scout the waterplane is overwhelmingly superior to the +dirigible as events have conclusively proved. Its greater mobility and +speed stand it in excellent stead because it is able to cover a +larger area within a shorter space of time than its huge and unwieldy +contemporary. Furthermore, it is a difficult target to hit and +accordingly is not so likely to be brought down by hostile fire. There +is another point in its favour. The experience of the war has proved +that the numerically inferior enemy prefers to carry out his naval +operations under the cover of the mist and haze which settle upon the +water, and yet are of sufficient depth to conceal his identity and +composition. Such mists as a rule comprise a relatively thin bank of +low-lying vapour, which while enveloping the surface of the water in an +impenetrable pall, yet permits the mast-heads of the vessels to stand +out clearly, although they cannot be detected from the water-level +or even from the control and fighting tops of a warship. A scouting +waterplane, however, is able to observe them and note their movement, +and accordingly can collect useful information concerning the apparent +composition of the hidden force, the course it is following, its +travelling speed, and so forth, which it can convey immediately to its +friends. + +The aeroplane has established its value in another manner. Coal-burning +vessels when moving at any pronounced speed invariably throw off large +quantities of smoke, which may be detected easily from above, even when +the vessels themselves are completely hidden in the mist. It was this +circumstance which revealed the presence of the British squadron in the +affair of the Bight of Heligoland. + +The German airman on patrol duty from the adjacent base on the island of +Heligoland detected the presence of this smoke, above the low-lying bank +of fog, although there were no other visible signs of any vessels. Fully +cognisant of the fact that the German Fleet was at anchor in a safe +place he naturally divined that the smoke proceeded from a hostile +squadron, evidently bent upon a raid. He returned to his headquarters, +conveyed the intelligence he had collected to his superior officers, +upon receipt of which a German cruiser squadron was sent out and engaged +the British vessels to its own discomfiture. But for the airman's +vigilance and smartness there is no doubt that the British squadron +would have accomplished a great coup. + +This incident, however, served to reveal that the aerial scout is prone +to suffer from over-keenness and to collect only a partial amount +of information. Upon this occasion the German watchman detected the +presence of the British torpedo-boat and light cruiser force. Had +he continued his investigations and made a wider sweep he would have +discovered the proximity of the British battle-cruiser squadron +which routed the German force, the latter having acted on incomplete +information. + +While the low-lying sea-fog is the navigator's worst enemy, it is the +airman's greatest friend and protection. It not only preserves him +against visual discovery from below, but is an excellent insulator +of sound, so that his whereabouts is not betrayed by the noise of his +motor. It is of in calculable value in another way. When a fog prevails +the sea is generally as smooth as the pro verbial mirror, enabling the +waterplanes to be brought up under cover to a suitable point from which +they may be dispatched. Upon their release by climbing to a height of a +few hundred feet the airmen are able to reach a clear atmosphere, where +by means of the compass it is possible to advance in approximately the +desired direction, safe from discovery from below owing to the fog. +If they are "spotted" they can dive into its friendly depths, complete +their work, and make for the parent ship. + +Low-lying sea-fogs are favourable to aerial raids provided the scout is +able to catch sight of the upper parts of landmarks to enable him to +be sure of the correctness of his line of flight-in cases where +the distance is very short compass direction is sufficiently +reliable-because the bank of vapour not only constitutes a perfect +screen, but serves as a blanket to the motor exhaust, if not completely, +at least sufficiently to mislead those below. Fogs, as every mariner +will testify, play strange tricks with the transmission of sound. Hence, +although those on the vessels below might detect a slight hum, it might +possibly be so faint as to convey the impression that the aviator was +miles away, when, as a matter of fact, he was directly overhead. This +confusion arising from sound aberration is a useful protection in +itself, as it tends to lure a naval force lying in or moving through the +fog into a false sense of security. + +The development of the submarine revealed the incontrovertible fact +that this arm would play a prominent part in future operations upon the +water: a presage which has been adequately fulfilled during the +present conflict. The instinct of self-preservation at once provoked +a discussion of the most effective ways and means of disguising its +whereabouts when it travels submerged. To this end the German naval +authorities conducted a series of elaborate and interesting experiments +off the island of Heligoland. As is well known, when one is directly +above a stretch of shallow water, the bottom of the latter can be seen +quite distinctly. Consequently, it was decided to employ aerial craft +as detectives. Both the aeroplane and the dirigible took part in these +experiments, being flown at varying heights, while the submarine was +maneouvred at different depths immediately below. The sum of these +investigations proved conclusively that a submarine may be detected from +aloft when moving at a depth of from 30 to 40 feet. The outline of the +submerged craft is certainly somewhat blurred, but nevertheless it is +sufficiently distinct to enable its identity to be determined really +against the background or bottom of the sea. To combat this detection +from an aerial position it will be necessary inter alia to evolve a +more harmonious or protective colour-scheme for the submarine. Their +investigations were responsible for the inauguration of the elaborate +German aerial patrol of harbours, the base for such aerial operations +being established upon the island of Heligoland. + +So far the stern test of war as applied to the science of aeronautics +has emphasised the fact that as a naval unit the dirigible is a complete +failure. Whether experience will bring about a modification of these +views time alone will show, but it is certain that existing principles +of design will have to undergo a radical revision to achieve any notable +results. The aeroplane alone has proved successful in this domain, and +it is upon this type of aerial craft that dependence will have to be +placed. + + + +CHAPTER XIX. THE NAVIES of THE AIR + +Less than three years ago the momentous and spectacular race among +the Powers of Europe for the supremacy of the air began. At first the +struggle was confined to two rivals--France and Germany--but as time +progressed and the importance of aerial fleets was recognised, other +nations, notably Great Britain, entered the field. + +Germany obtained an advantage. Experiment and research were taken up at +a point which had been reached by French effort; further experiments and +researches were carried out in German circles with secret and feverish +haste, with the result that within a short time a pronounced degree of +efficiency according to German ideals had been attained. The degree of +perfection achieved was not regarded with mere academic interest; it +marked the parting of the ways: the point where scientific endeavour +commanded practical appreciation by turning the success of the laboratory +and aerodrome into the channel of commercial manufacture. In other +words, systematic and wholesale production was undertaken upon an +extensive scale. The component parts were standardised and arrangements +were completed with various establishments possessed of the most +suitable machinery to perfect a programme for turning out aeronautical +requirements in a steady, continuous stream from the moment the crisis +developed. + +The wisdom of completing these arrangements in anticipation is now +apparent. Upon the outbreak of hostilities many German establishments +devoted to the production of articles required in the infinite +ramifications of commerce found themselves deprived of their markets, +but there was no risk that their large plants would be brought to a +standstill: the Government ordered the manufacture of aeroplane parts +and motors upon an extensive scale. In this manner not only were +the industrial establishments kept going, but their production of +aeronautical requirements relieved those organisations devoted to the +manufacture of armaments, so that the whole resources and facilities of +these could be concentrated upon the supply of munitions of war. + +In France the air-fleet, although extensive upon the outbreak of war, +was somewhat heterogeneous. Experiment was still being pursued: no type +had met with definite official recognition, the result being that +no arrangements had been completed for the production of one or more +standard types upon an elaborate scale comparable with that maintained +by Germany. In fact some six months after the outbreak of war there was +an appreciable lack of precision on this point in French military. +Many of the types which had established their success were forbidden by +military decree as mentioned in a previous chapter, while manufacturing +arrangements were still somewhat chaotic. + +Great Britain was still more backward in the new movement. But this +state of affairs was in a measure due to the division of the Fourth Arm +among the two services. A well-organised Government manufactory for +the production of aeroplanes and other aircraft necessities had been +established, while the private manufacturers had completed preparations +for wholesale production. But it was not until the Admiralty accepted +responsibility for the aerial service that work was essayed in grim +earnest. + +The allocation of the aerial responsibilities of Great Britain to +the Admiralty was a wise move. Experience has revealed the advantages +accruing from the perfection of homogeneous squadrons upon the water, +that is to say groups of ships which are virtually sister-craft of +identical speed, armament, and so on, thus enabling the whole to act +together as a complete effective unit. As this plan had proved so +successful upon the water, the Admiralty decided to apply it to the +fleet designed for service in the air above. + +At the time this plan of campaign was definitely settled Great Britain +as an aerial power was a long way behind her most formidable rival, but +strenuous efforts were made to reduce the handicap, and within a +short while the greater part of this leeway had been made up. Upon the +outbreak of war Great Britain undoubtedly was inferior to Germany +in point of numbers of aircraft, but the latter Power was completely +outclassed in efficiency, and from the point of view of PERSONNEL. The +British had developed the waterplane as an essential auxiliary to naval +operations, and here was in advance of her rival, who had practically +neglected this line of experiment and evolution, resting secure in the +assurance of her advisers that the huge dirigibles would be adequate for +all exigencies on the water. + +Indeed, when war was declared, all the Powers were found more or less +wanting so far as their aerial fleets were concerned. If Germany's huge +aerial navy had been in readiness for instant service when she invaded +Belgium, she would have overcome that little country's resistance in a +far shorter time and with much less waste of life. It was the Belgians +who first brought home to the belligerents the prominent part that +aircraft were destined to play in war, and the military possibilities of +the aeroplane. True, the Belgians had a very small aerial navy, but +it was put to work without delay and accomplished magnificent results, +ascertaining the German positions and dispositions with unerring +accuracy and incredible ease, and thus enabling the commander of the +Belgian Army to dispose his relatively tiny force to the best advantage, +and to offer the most effective resistance. + +Great Britain's aerial navy, while likewise some what small, was also +ready for instant service. The British Expeditionary force was supported +by a very efficient aerial fleet, the majority of the vessels forming +which flew across the Channel at high speed to the British headquarters +in France so as to be available directly military preparations were +begun, and the value of this support proved to be inestimable, since it +speedily demoralised the numerically superior enemy. + +France, like Germany, was somewhat dilatory, but this was attributable +rather to the time occupied in the mobilisation of the Fourth Arm than +to lack of energy. There were a round 1,500 aeroplanes ostensibly +ready for service, in addition to some 26 dirigibles. But the fleet +was somewhat scattered, while many of the craft were not immediately +available, being in the shops or in dock for repairs and overhaul. +During the period of mobilisation the so-called standing military force +was augmented by about 500 machines which were acquired from private +owners. The aeroplane factories were also, overhauled and re-organised +so as to be in a position to remedy the inevitable wastage, but these +organisation efforts were somewhat handicapped by the shortage of labour +arising from the call to arms. France, moreover, imperilled her aerial +strength by forbidding the use of 558 machines which were ready for +service. + +Germany's aerial fleet was of similar proportions to that of her Gallic +neighbour, but curiously enough, and in strange contrast, there appeared +to be a lack of readiness in this ramification of the Teuton +war machine. The military establishment possessed about 1,000 +machines--active and reserve--of which it is estimated 700 were +available for instant service. During the period of mobilisation a +further 450 machines were added to the fleet, drawn for the most +part from private owners. So far as the dirigibles were concerned 14 +Zeppelins were ready for duty, while others were under construction +or undergoing overhaul and repair. A few other types were also in +commission or acquired during mobilisation, bringing the dirigible force +to 40 machines all told. + +But the greatest surprise was probably offered by Russia. Very little +was known concerning Russian activities in this particular field, +although it was stated that large orders for machines had been placed +with various foreign manufactories. Certain factories also had been +established within the Empire, although the character of their work and +its results and achievements were concealed from prying eyes. In Russia, +however, an appreciable number of private aeroplanes were in operation, +and these, of course, were placed at the disposal of the authorities the +moment the crisis developed. + +The British and French aeroplane manufacturers had been busy upon +Russian orders for many months previous to the outbreak of hostilities, +while heavy shipments of component parts had been made, the assembling +and completion of the machines being carried out in the country. It is +generally believed that upon the outbreak of war Russia had a fleet of +800 aeroplanes in hand, of which total 150 were contributed from private +sources. Even the dirigible had not been overlooked, there being nearly +20 of these craft attached to the Russian Army, although for the most +part they are small vessels. + +In comparison with the foregoing large aerial navies, that of Great +Britain appeared to be puny. At the moment Great Britain possesses about +500 machines, of which about 200 are waterplanes. In addition, according +to the Secretary of the Admiralty, 15 dirigibles should be in service. +Private enterprise is supported by the Government, which maintains a +factory for the manufacture of these craft. + +During the two years preceding the outbreak of war the various Powers +grew remarkably reticent concerning the composition and enlargement of +their respective aerial fleets. No official figures were published. +But at the same time it is a well-known fact that during the year 1913 +France augmented her flying force by no fewer than 544 aeroplanes. +Germany was no less energetic, the military acquisition in this branch, +and during the self-same year, approaching 700 machines according to the +semi-official reports published in that country. + +The arrangements concluded for the manufacture of additional craft +during the war are equally remarkable. The principal factory in Germany, +(now devoting its energies to the production of these craft, although in +happier days its normal complement of 4,000 men were responsible for +the production of another commercial article) possesses facilities for +turning out 30 complete aeroplanes per week, according to the statement +of its managing director. But it is averred that this statement is +purposely misleading, inasmuch as during the first fortnight of the +campaign it was producing over 50 aeroplanes per week. It must be +remembered that Germany is responsible for the supply of the majority of +such craft for the Austrian armies, that country purchasing these vessels +in large numbers, because in the early days of the conflict it was +notoriously weak in this arm. Since the declaration of war strenuous +efforts have been made to remedy this state of affairs, particularly +upon the unexpected revelation of Russia's aerial strength. + +It is computed that upon the outbreak of war the various Powers were in +the position to show an aggregate of 4,980 aircraft of all descriptions, +both for active service and reserve. This is a colossal fleet, but it +serves to convey in a graphic manner the importance attached to the +adrial vessel by the respective belligerents. So far as Germany is +concerned she is sorely in need of additional machines. Her fleet of the +air has lost its formidable character, owing to the fact that it has to +be divided between two frontiers, while she has been further weakened by +the enormous lengths of the two battle-fronts. + +Russia has been able to concentrate her aerial force, which has proved +of incalculable value to the Grand Duke Nicholas, who has expressed his +appreciation of the services rendered by his fliers. The French likewise +have been favoured by Fortune in this respect. Their aerial navy is +likewise concentrated upon a single frontier, although a pronounced +proportion has been reserved for service upon the Mediterranean +sea-board for co-operation with the fleet. France suffers, however, to +a certain degree from the length of her battle-line, which is over 200 +miles in length. The French aerial fleet has been particularly active +in the Vosges and the Argonne, where the difficult, mountainous, and +densely wooded country has rendered other systems of observation of +the enemy's movements a matter of extreme difficulty. The Germans have +laboured under a similar handicap in this territory, and have likewise +been compelled to centre a considerable proportion of their aerial fleet +upon this corner of the extended battlefield. + +It is in this region that the greatest wastage has been manifest. I +have been informed by one correspondent who is fighting in this sternly +contested area, that at one time a daily loss of ten German machines +was a fair average, while highwater mark was reached, so far as his own +observations and ability to glean information were concerned by the loss +of 19 machines during a single day. The French wastage, while not so +heavy upon the average, has been considerable at times. + +The term wastage is somewhat misleading, if not erroneous. It does not +necessarily imply the total loss of a machine, such as its descent +upon hostile territory, but includes damage to machines, no matter how +slight, landing within their own lines. In the difficult country of the +Vosges many aeroplanes have come to earth somewhat heavily, and have +suffered such damage as to render them inoperative, compelling their +removal from the effective list until they have undergone complete +overhaul or reconstruction. Upon occasions this wastage has been so +pronounced that the French aviators, including some of the foremost +fliers serving with the forces, have been without a machine and have +been compelled to wait their turn. + +I am informed that one day four machines, returning from a +reconnaissance in force, crashed successively to the ground, and each +had to be hauled away to the repair sheds, necessitating withdrawal +from service for several days. Unfortunately the French, owing to their +decision to rule out certain machines as unsuited to military service, +have not yet perfected their organisation for making good this wastage, +although latterly it has been appreciably reduced by greater care among +the aviators in handling their vessels. + +The fast vessels of the French aerial fleet have proved exceptionally +valuable. With these craft speeds of 95 and 100 miles or more per hour +have been attained under favourable conditions, and pace has proved +distinctly advantageous, inasmuch as it gives the French aviators a +superiority of about 40 per cent over the average German machine. It +was the activity and daring of the French fliers upon these high speed +machines which induced the German airmen to change their tactics. +Individual effort and isolated raiding operations were abandoned in +favour of what might be described as combined or squadron attack. Six +or eight machines advancing together towards the French lines somewhat +nonplussed these fleet French mosquito craft, and to a certain degree +nullified their superiority in pace. Speed was discounted, for the +simple reason that the enemy when so massed evinced a disposition to +fight and to follow harassing tactics when one of the slowest French +machines ventured into the air. + +It is interesting to observe that aerial operations, now that they are +being conducted upon what may be termed methodical lines as distinct +from corsair movements, are following the broad fundamental principles +of naval tactics. Homogeneous squadrons, that is, squadrons composed +of vessels of similar type and armament, put out and follow roughly +the "single line ahead" formation. Upon sighting the enemy there is the +manoeuvring for position advantage which must accrue to the speedier +protagonist. One then, witnesses what might almost be described as an +application of the process of capping the line or "crossing the 'T.'" +This tends to throw the slower squadron into confusion by bending it +back upon itself, meanwhile exposing it to a demoralizing fire. + +The analogy is not precisely correct but sufficiently so to indicate +that aerial battles will be fought much upon the same lines, as +engagements between vessels upon the water. If the manoeuvres accomplish +nothing beyond breaking up and scattering the foe, the result is +satisfactory in as much as in this event it is possible to exert a +driving tendency and to force him back upon the lines of the superior +force, when the scattered vessels may be brought within the zone of +spirited fire from the ground. + +Attacks in force are more likely to prove successful than individual +raiding tactics, as recent events upon the battlefield of Europe have +demonstrated more or less convincingly. An attack in force is likely to +cause the defenders upon the ground beneath to lose their heads and to +fire wildly and at random, with the result that the airmen may achieve +their object with but little damage to themselves. This method of +attacking in force was essayed for the first time by the British aerial +fleet, which perhaps is not surprising, seeing that the machines are +manned and the operations supervised by officers who have excelled in +naval training, and who are skilled in such movements. + +No doubt this practice, combined with the daring of the British +aviators, contributed very materially to the utter demoralisation of the +German aerial forces, and was responsible for that hesitancy to attack +a position in the vicinity of the British craft which became so manifest +in the course of a few weeks after the outbreak of hostilities. + +One of the foremost military experts of the United States, who passed +some time in the fighting zone, expressed his opinion that the +British aerial force is the most efficient among the belligerents when +considered as a unit, the French flier being described by the same +authority as most effective when acting individually, owing to personal +intrepidity. As a scout the French aviator is probably unequalled, +because he is quick to perceive and to collect the data required, and +when provided with a fast machine is remarkably nimble and venturesome +in the air. The British aviators, however, work as a whole, and in the +particular phases where such tactics are profitable have established +incontestable superiority. At first the German aerial force appeared +to possess no settled system of operation. Individual effort was +pronounced, but it lacked method. The Germans have, however, profited +from the lessons taught by their antagonists, and now are emulating +their tactics, but owing to their imperfect training and knowledge the +results they achieve appear to be negligible. + +The dirigible still remains an unknown quantity in these activities, +although strange to relate, in the early days of the war, the work +accomplished by the British craft, despite their comparatively low speed +and small dimensions, excelled in value that achieved by the +warplanes. This was particularly noticeable in matters pertaining to +reconnaissance, more especially at night, when the British vessels often +remained for hours together in the air, manoeuvring over the hostile +lines, and gathering invaluable information as to the disposition and +movements of the opposing forces. + +But it is probably in connection with naval operations that the British +aerial fleet excels. The waterplanes have established their supremacy +over the naval dirigible in a striking manner. British endeavour +fostered the waterplane movement and has carried it to a high degree +of perfection. The waterplane is not primarily designed to perform long +flights, although such may be carried out if the exigencies demand. The +practice of deputing certain vessels to art as "parent ships" to a +covey of waterplanes has proved as successful in practice, as in theory. +Again, the arrangements for conveying these machines by such means to a +rendezvous, and there putting them into the water to complete a certain +duty, have been triumphantly vindicated. At the time this idea was +embraced it met with a certain degree of hostile criticism: it was +argued that the association of the two fighting, machines would tend +towards confusion, and impair the efficiency of both. + +Practice has refuted this theory. The British aerial raids upon Cuxhaven +and other places would have been impossible, and probably valueless as +an effective move, but for the fact that it was possible to release the +machines from a certain point upon the open sea, within easy reach of +the cooperating naval squadron. True, the latter was exposed to hostile +attack from submarines, but as results proved this was easy to repel. +The aircraft were enabled to return to their base, as represented by the +rendezvous, to be picked up, and to communicate the intelligence gained +from their flight to the authorities in a shorter period of time than +would have been possible under any other circumstances, while the risk +to the airmen was proportionately reduced. + +The fact that the belligerents have built up such huge aerial navies +conclusively proves that the military value of the Fourth Arm has been +fully appreciated. From the results so far achieved there is every +indication that activity in this direction will be increased rather than +diminished. + + + + + +End of the Project Gutenberg EBook of Aeroplanes and Dirigibles of War, by +Frederick A. Talbot + +*** END OF THIS PROJECT GUTENBERG EBOOK AEROPLANES AND DIRIGIBLES OF WAR *** + +***** This file should be named 793.txt or 793.zip ***** +This and all associated files of various formats will be found in: + http://www.gutenberg.org/7/9/793/ + + + +Updated editions will replace the previous one--the old editions +will be renamed. + +Creating the works from public domain print editions means that no +one owns a United States copyright in these works, so the Foundation +(and you!) can copy and distribute it in the United States without +permission and without paying copyright royalties. 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