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diff --git a/old/aadow10.txt b/old/aadow10.txt new file mode 100644 index 0000000..2024a8e --- /dev/null +++ b/old/aadow10.txt @@ -0,0 +1,6998 @@ +The Project Gutenberg Etext of Aeroplanes and Dirigibles of War +by Frederick A. Talbot + + +Copyright laws are changing all over the world, be sure to check +the copyright laws for your country before posting these files!! + +Please take a look at the important information in this header. +We encourage you to keep this file on your own disk, keeping an +electronic path open for the next readers. Do not remove this. + + +**Welcome To The World of Free Plain Vanilla Electronic Texts** + +**Etexts Readable By Both Humans and By Computers, Since 1971** + +*These Etexts Prepared By Hundreds of Volunteers and Donations* + +Information on contacting Project Gutenberg to get Etexts, and +further information is included below. We need your donations. + + +Aeroplanes and Dirigibles of War + +by Frederick A. 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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 employ ment 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 thecountry, 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 ex tremely 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 thelatter 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 heavierthan-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, +thisvessel 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 +uncontrollableit 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 effec tiveness +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 +roundto 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 becommg 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 +tandemwise, 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 +almostimpossible 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, especiauy 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 infficted 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 pedestalin 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 theprevailing 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 insertioin 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, con tinuous 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 reahsed 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 5,1OO 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 firmhave found that trials upon the testing ground with +a captive balloon differ very materially from sterntests 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 aoft, 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 humanty, 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 cornmunication 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 Lun6ville 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 ts 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 suf ficiently +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. Consequentiy, 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 com +manded 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 +fomidable 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 eeperiment 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 Austnan 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 apprecably 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 Etext of Aeroplanes and Dirigibles of War + diff --git a/old/aadow10.zip b/old/aadow10.zip Binary files differnew file mode 100644 index 0000000..adb5e60 --- /dev/null +++ b/old/aadow10.zip |