Night bombing, necessitated by the fact that by day a large machine heavily laden with bombs was an easy prey to the fighting scout, came into prominence in 1916, increasing in intensity up to the end of the war; and raids into Germany recommenced. Early in 1918 these raids included the bombing of Maintz, Stuttgart, Coblentz, Cologne, and Metz. Machines sometimes dropped their bombs from heights of about 12,000 feet and at other times descended to within 200 feet of their objectives.

Contact Patrol.

Contact patrol, the name given to the direct co-operation of aircraft with troops on the ground, was first extensively practised at the Battle of the Somme, though experiments in this direction had been made in 1915, messages being dropped at the Battle of Neuve Chapelle at pre-arranged points.

The main objects of contact patrols were to assist the telephone (which was frequently cut by shellfire), to keep the various headquarters informed of the progress of their troops during the attack, so also saving them from the possibility of coming under the fire of their own artillery, to report on enemy positions, to transmit messages from the troops engaged to the headquarters of their units, to attack ground formations, and to co-operate with tanks. A system of red flares on the floor of the trenches was used to mark the disposition of the troops, and aircraft communicated their information by means of signalling lamps, wireless and message-bags.

During the German retreat of 1917 contact patrols attacked enemy foundations from 100 feet and in some cases landed behind the enemy lines to obtain information. The skill of low-flying pilots in taking cover by flying behind woods, houses, etc., became increasingly important. The fact that 62,673 rounds of ammunition were fired from the air against enemy ground targets between November 20th and 26th, 1917, and 163,567 between March 13th and 18th, 1918, indicates the rapid development of this form of aircraft action, the effect of which was frequently more deadly than bombing.

Two of many protagonists of contact patrol were Pretyman and Bishop. On one occasion the latter, in attacking an aerodrome at about 50 feet, riddled the officers' and men's quarters with bullets, put two or three machines on the ground out of action, and three in succession as they got into the air. Another interesting example of contact patrol work occurred in 1917 when a pilot flew his machine at a low altitude over the enemy trenches, and he and his observer attracted the attention of the Germans by firing their machine guns and Verey lights. The Germans were so busy with the aeroplane that they had their backs turned to the front line and our infantry were able to cross no-man's land without any artillery preparation, take prisoners and bomb dug-outs.

An article in the Cologne Gazette showed what the Germans thought of low "strafing."

"The operations" (i.e. of June 7th, 1917), it says, "were prefaced by innumerable enemy airmen, who, at the beginning of the preparation for the attack, appeared like a swarm of locusts and swamped the front. They also work on cunningly calculated methods. Their habit is to work in three layers—one quite high, one in the middle, and the third quite low. The English who fly lowest show an immense insolence; they came down to 200 metres and shot at our troops with their machine guns, which are specially adapted to this purpose."

Armour was first employed as a result of Shephard finding at Maubeuge a bullet lodged in the seat of his leather suit. Thin sheets of steel were at once cut out and placed in the wickerwork seats of aeroplanes. This primitive protection developed into the armoured machine mentioned later, which was about to make its appearance at the Armistice.

I may mention here the "special duty" flights, which consisted in establishing secret communication between our Intelligence Branch and agents in the territory occupied by the Germans. Agents, mostly French and Belgian, were carried by aeroplane over the enemy lines and landed there. This work was started in 1914.

Fighting.

At the beginning of the war it became obvious that it was not only the duty of aircraft to obtain information but also to prevent enemy aircraft crossing our lines. In addition to the reconnaissance machine, and in order to make its work possible, a machine designed purely for fighting was required. In August, 1914, the aeroplane's armament consisted simply of rifle, or carbine, and revolver, but our pilots nevertheless attacked hostile machines whenever the opportunity occurred. The first German machine to fly over us was at Maubeuge on August 22nd, 1914, and, though fighting on an extensive scale did not take place until 1916, as early as August 25th, 1914, there were three encounters in the air in which two enemy machines were driven down. One interesting report of an early fight is that between a B.E. and a German machine on December 20th, 1914.

"A German aeroplane with one passenger and pilot being encountered over Poperinghe, we followed to Morbecque and then to Armentieres. The passenger of the B.E. fired 40 rounds from his rifle and the German passenger replied with some rounds from his revolver. The B.E. crossed the bows of the German machine to permit the pilot to use his revolver. The German switched off and dived below the B.E., and is believed to have landed somewhere north-west of Lille."

Another instance of the early air combats was when Holt, single-handed, and armed only with a rifle, lashed to a strut of his machine, attacked ten Germans near Dunkirk, causing them to drop their bombs in the field and make off to their own lines.

We managed to bring down a number of German machines, mainly by rifle fire (five had already been brought down by September 7th, 1914), but our great difficulty early in the war was to get the enemy into action, and, although during October and November, 1914, there was a certain amount of fighting, as a rule the German when attacked made for his own lines and the protection of his anti-aircraft guns. This, though offensive carried to the extent of wastefulness of life is equally bad, was a serious mistake in all ways from his point of view, entailing as it did a tendency for the confidence of the troops and the morale of the air service to be undermined from the outset. The error was rectified, but only temporarily, at the Somme.

As the specialized duties of aircraft increased, the Corps machines engaged in them needed protection and it was realized that the best method of protection was the development of the air offensive. This was rendered possible by the adaptation of the machine gun to the aeroplane. Early in 1915 the invention of the "synchronizing gear" enabled a machine gun to fire through the propeller, and by the end of 1915 fighting in the air became the general rule. The first squadron, No. 24, composed purely of fighting machines, took its place on the Western Front in February, 1916, and gradually Wings were attached to Armies solely for fighting and the protection of Corps machines. During the long months of the Battle of the Somme, for instance, when, though the Royal Flying Corps dominated the air, the Germans put up a strenuous opposition, bombing machines were protected by fighting patrols in formation on the far side of the points attacked. The rapidity with which fighting in the air developed is shown by the fact that at the end of 1916 twenty new fighting squadrons were asked for on the Western Front; the establishment was increased to twenty-four machines per squadron, and by the end of the war even night-fighting squadrons were operating with considerable success and, had the war continued, would have proved a very important factor in air warfare.

The development of aerobatics, air fighting, and formation tactics brought many airmen into prominence. For example Albert Ball, who ascribed his successes to keen application to aerial gunnery; J. B. McCudden, the first man to bring four hostile machines down in a day; and Trollope, who later on brought down six. Hawker met his death fighting von Richthofen, who describes the fight in his book The Red Air Fighter as follows:—

"Soon I discovered that I was not fighting a beginner. He had not the slightest intention to break off the fight.... The gallant fellow was full of pluck, and when we had got down to 3,000 feet he merrily waved to me as if to say, 'Well, how do you do?'... The circles which we made round one another were so narrow that their diameter was probably not more than 250 or 300 feet.... At that time his first bullets were flying round me, as up to then neither of us had been able to do any shooting."

At 300 feet Hawker was compelled to fly in a zig-zag course to avoid bullets from the ground and this enabled Richthofen to dive on his tail from a distance of 150 feet.

This indicates a heavy disadvantage under which our aircraft laboured in all their work on the Western Front. The prevailing westerly wind which, while it assisted the enemy in his homeward flight, made it very difficult for a British machine, perhaps damaged by anti-aircraft fire, to make its way—still under fire—to its base.

I cannot leave the subject of air fighting without giving one or two more examples. One which comes to mind is that of five British machines attacking twenty-five of the enemy. One of ours gliding down with its engine stopped and being attacked by two Germans was saved by another British one attacking and driving off the two enemy. The result of the combat was five German machines destroyed and four driven down out of control, whilst all of ours returned safely. Another example, that of Barker who, whilst destroying an enemy two-seater, was wounded from below by another German machine and fell some distance in a spin. Recovering, he found himself surrounded by fifteen Fokkers, two of which he attacked indecisively but shot down a third in flames. Whilst doing this he was again wounded, again fainted, again fell, again recovered control and again, being attacked by a large formation, shot down an enemy in flames. A bullet now shattered his left elbow and, fainting a third time, he fell several thousand feet, where he was again attacked, and thinking his machine had been set on fire he tried, as he thought in a final effort, to ram a Fokker, but instead drove it down on fire! Barker was by this time without the use of both legs and an arm. Diving to a few thousand feet of the ground he again found his retreat barred by eight of the enemy, but these he was able to shake off after short bursts of fire and he returned a few feet above the ground to our lines.

Though at the beginning our machines were rather better than either the French or German, it was the marked superiority of our pilots which gave us the greatest advantage. We should have been superior even had the machines been exchanged.

CO-OPERATION WITH THE NAVY.

We have seen that the functions of co-operation with the Navy—Coast defence and Fleet assistance—were very complicated, and that at the outbreak of war the splendid pilots and excellent equipment of the R.N.A.S. were not so highly organized and were wanting in cohesion, but that the R.N.A.S. had advanced further than the Royal Flying Corps in specialized technical development. In the earlier part of the war, in addition to its main duties, the R.N.A.S. ventured in many directions, many of them of considerable value to the Army, as, for instance, at Antwerp.

Coast Defence, Patrol and Convoy Work.

Immediately war broke out a system of coastal patrols was established between the Humber and the Thames Estuary and over the Channel—the latter serving as an escort to the Expeditionary Force crossing to France. Patrols were at first, through limitations of equipment, mainly confined to the Home coast, but, as the war went on and machines improved, they were rapidly extended, especially in connection with the detection and destruction of submarines; reconnaissances were carried out over the enemy's shores, and in 1918 there were forty-three flights of seaplanes, thirty flights of aeroplanes, together with flying boats and airships, operating from, and communicating with, an ever-increasing number of shore stations. Not only was anti-submarine work carried out in the vicinity of the coast, but organized hunts were made for submarines, ships were convoyed on the high seas, shipping routes were protected, and action was taken to bar the passage of submarines through narrow channels. This was effected by an intensive system of combining and interlocking patrols, and by maintaining, in close co-operation with surface craft, a protective barrage across suitable stretches of water, such as the Straits of Dover.

Airships from the beginning, when patrols operated from Kingsnorth during the crossing of the Expeditionary Force to France, proved particularly useful for escort, in addition to patrol work, and twenty-seven small airships, known as the S.S. type, were completed in 1915. In 1916 the Coastal type with a longer range was designed and constructed and new airship bases were established.

Fleet Assistance, Reconnaissance, Spotting for Ships' Guns.

The successful use of Drachen kite-balloons borne in ships at the Dardanelles led to their extensive development. Up to about May, 1915, when the vessels to which they were attached could stand in close to shore and overlook the enemy's positions from a distance of three or four thousand yards, a large amount of spotting of great value was carried out by these balloons for ships at Gallipoli, but when the Turks brought long-range guns into position, kite-balloon vessels were obliged to lie out beyond 11,000 yards and their services were rendered comparatively slight for this purpose. From 1916, however, they were towed by merchant auxiliaries and light cruisers to spot submarines, observers communicating with the patrol ship by means of telephone. One of the most wonderful sights I have ever seen was from the observer's basket of the kite-balloon let up from S.S. "Manica" in June, 1915. We were spotting for the guns of H.M.S. "Lord Nelson" bombarding Chanak. The sky and sea were a marvellous blue and visibility excellent, the peninsula, where steady firing was going on all the time, lay below us, the Straits, with their ships and boats, the Asiatic shore gradually disappearing in a golden haze, the Gulf of Xeros, the Marmora, and behind one the islands of the AEgean affording a perfect background. No one who was at the Dardanelles, however vivid the horrors and the heat and dust and flies, will forget the beauty of the scene, especially at sunset, and it was seen at its best from the basket of a kite-balloon.

The ever-increasing assistance rendered by aircraft to surface vessels in crippling Germany's submarine campaign is shown by the fact that in 1915 ten submarines were attacked from the air and in 1918 126 were sighted and 93 attacked. Nor was the principle forgotten in countering the submarine menace that offence is the best defence, and among the many duties of R.N.A.S. aircraft, based on Dunkirk from the early days of the war, were anti-submarine patrols along the Belgian coast and the bombing of hostile submarine bases, such as Bruges.

As in the case of the Army Corps observation machines, fighting scouts became necessary for the protection of patrols and to counter the enemy's efforts at raids and sea reconnaissance, and the considerable amount of experiment in air fighting which the R.N.A.S. had made before the war bore useful fruit.

For the immediate protection of the Grand Fleet seaplane and aeroplane bases were established at Scapa Flow and Thurso at the beginning of the war, but, owing to damage from a gale in November, 1914, aircraft operations with the Fleet were carried out from the seaplane carrier "Campania." The problem of using carriers with the Fleet had not been seriously tackled before the war, and though experiments were strenuously carried out, and there were fourteen carrier ships in commission in 1918, and a seaplane carrier operated with the Battle Cruiser Squadron at Jutland, the use of aircraft in this way did not become very efficient. One of the chief difficulties was limitation in size, and consequently in radius of action, of aircraft employed from carriers or the decks of battleships. The total number of aeroplanes and seaplanes allotted to the Grand Fleet in 1918 was 350.

Seaplane carriers occasionally co-operated with fighting ships. For instance in October, 1915, a fast carrier at the Dardanelles accompanied ships detailed for the bombardment of Dedeagatch, and her seaplanes not only co-operated in spotting but also made a valuable reconnaissance of the Bulgarian coast and railway. But as a rule fighting and reconnaissance aircraft had mainly to work from shore bases. To assist in this direction, units were sent overseas to be nearer their sphere of action, as, for instance, the R.N.A.S. squadrons stationed at Dunkirk which, besides general reconnaissance, helped the Navy to keep open the Straits of Dover, carried out bombing raids against German bases and dockyards, such as Ostend, Zeebrugge, and Bruges, and co-operated with monitors in the bombardment of the Belgian coast. The development of a long-range seaplane or flying boat was also taken in hand, though an efficient type was not produced until the last year of the war.

As with the Army, an important part of naval aircraft duties was spotting for gunfire; and likewise single-seater fighters were required for the protection of our own aircraft, for preventing enemy aircraft reconnaissance, for attacking the enemy's fleet and protecting our own. The use of offensive patrols steadily increased during the war.

Bombing.

I have already referred to bombing and mentioned the attack on Dusseldorf as an instance of the work done. Bombing raids had always been looked on with favour by the R.N.A.S. and were used throughout the war as a means of countering hostile aircraft operations from bases in Belgium. One of the first successful raids was that against the Friedrichshaven Zeppelin works by three Avro machines, which flew 250 miles over enemy country on November 21st, 1914. Another noteworthy example was the attempted raid against Cuxhaven on Christmas Day, 1914, carried out by seaplanes, which were still in an experimental stage, and three carriers escorted by naval units. Powerful machines for bombing purposes were ordered and bombs of greatly increased size and gear for dropping them were designed.

Torpedo Attack.

The impetus given to bombing helped forward another use of naval aircraft: torpedo attack. This is likely to develop in the future into one of the most important uses of aircraft in naval operations, but during the war it was never given an objective by the German fleet. In May, 1915, two Sunbeam Short machines were embarked in the "Ben-my-Chree" for operations at Gallipoli, and it was in this theatre that for the first time in history ships were sunk by torpedoes released from aircraft. I shall never forget the night when we steamed silently up the narrow Gulf of Xeros and lay waiting to release our seaplanes in the still darkness of the early morning. The machines were lowered noiselessly into the water, and, their engines started, flew across the narrow neck of Bulair under fire from the old Turkish line; then, reaching the northern end of the Dardanelles at dawn, they descended low (one machine actually landed on the water and discharged its torpedo), sank their targets, and returned. In addition to the possibility of submarine attack, the Gulf of Xeros is so narrow that our ship could have been hit by the cross fire of field guns. It was a very fine performance and, although during many years I have spent anxious hours hoping for the distant purr of a safe returning machine, I have never been happier than when after a long wait our seaplanes were again quickly raised on board. The only torpedo machine employed at the Battle of Jutland was a Sunbeam fitted with a 14-inch torpedo, and it was not until just before the Armistice that a squadron of torpedo aircraft was ready for operations with the Grand Fleet.

The Germans also tried to develop the use of torpedo-carrying seaplanes and, as with their submarines, had the advantage over us of a vast number of targets close to hand in our North Sea and Channel shipping, but fortunately the British fighting scouts were able to destroy several of their machines before they had done much damage.

HOME DEFENCE.

At the beginning of the war the R.N.A.S. assumed responsibility for the defence of Great Britain against attacks by hostile aircraft, and a scheme for the defence of London and other large towns was entrusted to an anti-aircraft section of the Admiralty Air Department. Its resources, however, consisting of a few unsuitable and widely scattered aeroplanes, some 1 pdr. pom-poms with searchlights manned by a special corps, were inadequate and it was fortunate that only three small daylight aeroplane raids, mainly for reconnaissance, were made during 1914—the first German machine to visit England dropping a bomb near Dover on December 21st.

Night Flying and Night Fighting.

In spite of continuous action by the R.N.A.S. against German airship bases in Belgium, there were in 1915 nineteen airship and eight aeroplane raids—one by night—over England, and, although the new and powerful Zeppelin L.Z.38, which attacked London on May 31st, was destroyed by an aeroplane counter-attack in its shed near Brussels, no real counter measures were evolved until 1916, when Home Defence was taken over by the War Office. During that year a Home Defence Squadron of B.E.2c's, rapidly expanded to a Wing, was formed; and the systematic training of night pilots, the standardization of night-flying equipment and armament, and the lighting of aerodromes, was taken in hand. A continuous aeroplane and searchlight barrage with night landing grounds was gradually formed between Dover and the Forth; the wireless signals employed to assist Zeppelins in finding their way were intercepted, thus enabling our rapidly improving fighting machines to pick up and attack raiding airships; and the constant attacks to which airship sheds were exposed in Belgium, caused their withdrawal to positions further inland and increased their distance from England. During 1916 there were twenty-two raids by airships, six of which were destroyed, the first being brought down in September at Cuffley by Leefe Robinson. Thenceforward airship raids declined, the destruction of the majority of the largest and latest which raided England on October 19th, 1917, sealing their fate.

On the other hand, aeroplane daylight and night raids on London, the first of which occurred in November, 1916, increased in number and strength with the object, in addition to the destruction of material and civilian morale, of forcing upon us the unsound retention at home of a considerable air defence force. The largest of these attacks was made by seventeen aeroplanes at midday on June 13th, 1917, but, the Zeppelin danger nullified, counter measures to meet the new menace were gradually evolved. New squadrons were raised and the number of home defence squadrons was raised to fourteen service and eight night training squadrons; a Northern Home Defence Wing was formed at York; and the Home Defence Group became the 6th Brigade. The first night aeroplane raid occurred in September, and the systematic training of night-fighting pilots on scout machines was hurried on. Separate zones for aeroplanes, guns and searchlights—the latter provided with sound locators—forming an outer barrage, were instituted, and aprons, supported by kite-balloons, formed a protective barrage up to 8,000 feet. A system of wireless and ground telephonic communication was improvised for plotting the course of attacking aircraft and thus enabling squadron commanders to concentrate machines at the point of attack. By 1918 the night-fighting aeroplane, assisted by these means, had countered the night-bombing aeroplane. At first, this had been the result of the retention of a large number of fighting aircraft and a complete organization at home.

Meanwhile, night fighting, especially the protection of night bombers by fighting machines, had become of paramount importance on the Western Front. The chief feature of activity in September, 1918, was the successful co-operation between searchlights in the forward areas and No. 151 night-fighting squadron. This was the first night-fighting squadron, trained by the 6th Brigade, to be sent to France. It was proposed to send four more such squadrons and thus form a first line of offensive defence which would react on hostile raids over England. Thus once again the old doctrine was gradually observed that offence is the only true defence, and that purely defensive measures, however efficient, by keeping men and material from the vital point, are necessarily expensive out of all proportion to their effectiveness. Both the Germans and ourselves made the initial mistake of organizing large local defence systems partly to placate public opinion. During the German offensive of 1918 a further development of night fighting took place in the bombing and low strafing of enemy troops and unlighted transport with the aid of flares.

THE MACHINE AND ENGINE.

Turning now to the machine and engine, the Military Trials held in 1912, when the Royal Flying Corps was started, represented the first organized effort to assist the evolution of service aeroplanes in this country and a brief comparison will be useful to show the performance of the average machines and engines of that date, at the beginning, and at the end of the war, and of civil machines of to-day.

At the Military Competitions of 1912, of the eight types—Avro, B.E., Bristol, Cody, Bleriot, Deperdussin, Hanriot, and M. Farman—the first four were British, though only the Avro had a British engine, and the last four French, fitted with French engines. The average horse-power was about 83, the average maximum speed 67, and the minimum 50 miles per hour; the climb to 1,000 feet was effected in 4-1/2 minutes with an average load of 640 lb., which included pilot, fuel for four hours and useful load. The loading per square foot was, for biplanes, about 4-1/2, and, for monoplanes, 6 lb.

On the outbreak of war, and until the end of 1914, of the ten types in use—Avro, B.E., Bristol, Sopwith, Vickers, M. Farman, H. Farman, Caudron, Morane, and Voisin—five were British and five were French and all were fitted with French engines. The average horse-power was still about 83, but the average maximum speed had risen to 74, and the minimum had fallen to 41 miles per hour. The load averaged 609 lb.

A remarkable advance in machine and engine construction is shown by referring to the tables for 1918. At the Armistice of the twelve types—Avro, Bristol Fighter, Sopwith Snipe, S.E. 5a, de Havilland 4 and 9a, Vickers Vimy, Handley Page O/400 and V/1,500, Fairey Seaplane 3c, F. 2 A. and F. 5—all were British and, except the de Havilland 9a, which had an American engine, were fitted with engines of British manufacture. The F. 2 A., and F. 5, were twin-engined, while one, the Handley Page V/1,500, was equipped with four engines. The average horse-power was per engine, 344, and per machine, 516; the average maximum speed 111, and the minimum 53-1/2 miles per hour, the climb to 6,500 feet was carried out in 13 minutes and to 10,000 feet in 24 minutes with an average load, including fuel for 5-1/2 hours, of 2,742 lb. The average ceiling was 15,500 feet; the loading per square foot about 8 lb.

The years following the Armistice have witnessed the conversion of military machines and the development of new designs for commercial purposes. In 1921 there were thirteen types fitted with British engines: Avro, Bristol, de Havilland 4, 16 and 18, Vickers Vimy, Handley Page O/400 and W. 8, B.A.T., Westland, Fairey, Supermarine and Vickers Amphibians. No British machine had a foreign engine. The Vickers Vimy, Handley Page O/400 and W. 8, which had a passenger-carrying capacity of 15, were twin-engined. The average horse-power was per engine, 387, and per machine, 474; the average maximum speed 114, and the minimum 49, miles per hour. With an average load of 2,467 lb., including fuel for 4-1/2 hours, 19 minutes was required for a climb to 10,000 feet. The average loading per square foot was about 13 lb., and the average ceiling 15,793 feet.

Before the war, in addition to the Royal Aircraft Factory, there were only eight firms engaged, on a very small scale, in the manufacture of aircraft in England, and an aero engine industry hardly existed. Until 1916, the greater proportion of our machines, and almost all our engines, were French, and we were very dependent upon France for the replacement of our heavy losses in material. By the end of the war the bulk of our material was of British design and construction, though there was still a certain number of British built engines of French design. One American engine—the Liberty—was also employed. The fact that in October, 1918, the Royal Air Force had 22,171 machines and 37,702 engines on charge, and that during the ten months January to October the output of machines had been 26,685 and of engines 29,561, gives some idea of the enormous growth in production.

In the first few months of the war it was not possible to progress far with new inventions or improvements. Fortunately, our Aircraft Factory had evolved in the B.E. a machine of considerable stability which in this respect compared favourably with German machines, and was well adapted to its work of reconnaissance.

Technical progress during the war often unfortunately involved the loss of valuable lives, as for instance those of Professor Hopkinson and Busk, to both of whom heavy debts of gratitude are owed, but gradually obstacle after obstacle, problem after problem, was successfully tackled by our designers and constructors. With a view to enlarging the field of observation, staggered planes were introduced in the B.E.2c. This machine also proved that it was possible to calculate the degree of stability and thus paved the way for the design of aeroplanes with indifference to stability and increased man[oe]uvrability for fighting purposes, or with great inherent stability for bombing. During 1915 the B.E.2c was used for all purposes, but the extra loading involved by the increasing use of aeroplanes for bombing and fighting caused a decrease in the rate of speed and climb, and our aeroplanes were temporarily inferior in fighting power to the Fokker.

The necessity of preventing the enemy obtaining information soon led to the development of air fighting. At the beginning of the war the sole armament of aeroplanes was the rifle or revolver. The machine gun soon followed, but its use in tractor machines was impracticable on account of the danger of hitting the airscrew. The first "fighters" were therefore two-seater pushers, such as the "Short-horn" Maurice Farmans which, though not designed for fighting, and too slow to chase enemy aircraft, were the first to be fitted with Lewis guns, and F.E.'s, the first machine designed specifically for fighting, with the machine-gun operator in front of the pilot. These "pusher" fighters had an excellent field of view and fire forwards, but suffered from lack of speed and a large "blind" area to the rear. On the other hand, the single-seater tractors were potentially the superior fighters, and in order to protect the blades of the airscrew the French were the first to use deflector blades on them in tractor machines.

Our early single-seater tractors were fitted with a Lewis gun fixed so as to fire over or at the side of the airscrew and actuated by a bowden wire, the most efficient, though not the most numerous, fighting machines at the end of 1915 being the Bristol Scouts.

By the Summer of 1916, however, we had adapted the "synchronizing gear" to our machine guns, enabling them to be fired through the propeller; while aircraft engines developed much greater power and full allowance was made for all equipment carried. From that time the development of our single-seater fighters was steadily progressive. One of the first of these was the Sopwith "Pup," which had a speed of 106-1/2 miles an hour at 6,500 feet, climbed 10,000 feet in just over 14 minutes, and could attain a ceiling of 17,500 feet. In 1917 appeared the Sopwith "Camel," a typical example of this type, which was simple, stable, easily controllable and possessed two guns. It had a speed of 121 miles an hour at 10,000 feet, to which height it could climb in under 10-1/2 minutes, and a ceiling of 23,000 feet. The Martinsyde F.4, embodying further improvements, was not ready in time for active service.

While the single-seater tractor was developing for purely offensive action, the two-seater fighter, of which the field of view, man[oe]uvrability and general performance were being improved, retained its utility as a reconnaissance machine. In 1916 the "pusher" type was superseded by the Sopwith "1-1/2 Strutter" armed with a synchronized Vickers gun, which for its 130 horse-power was never surpassed. The pilot was close to the engine and had a good view of the ground, while the gunner was placed behind him with a rotary Lewis gun turret. Early in 1917 these qualities were further developed in the Bristol Fighter.

With the advent of these improved types the B.E.2c was relegated to the work of artillery co-operation, until superseded by the B.E.2e. Towards the end of 1916 appeared the R.E.8 with a Vickers synchronized gun and a Lewis gun, which after many vicissitudes became the standard machine for artillery work.

Systematic bombing was practised by nearly all types of machines, but real accuracy was never obtained. Thus, the B.E.2c was first used in formations, but with a full load of bombs it could not carry an observer, and its moderate speed left it an easy prey to hostile fighters. Early in 1916 appeared the Martinsyde single-seater bomber with an endurance of 4-1/2 hours, and in 1917 the D.H.4 which was much used for day-bombing. The F.E.2b pusher, discarded as a fighting machine, became the principal night-bomber.

It was comparatively late in the war before special bombing machines were evolved. They were then divided into day-bombers and night-bombers, the D.H.9 and 9a machines being typical of the former and the Handley Page of 1917—a large twin-engine aeroplane, the first really effective night-bomber, of considerable carrying power but low performance—of the latter. By November 8th, 1918, two super-Handley Pages were ready to start to Berlin. They possessed a maximum range of 1,100 miles, a crew of seven, four 350 horse-power Rolls-Royce engines, arranged in pairs, a tractor and a pusher in tandem on either side of the machine, and, as they would be compelled to fly both by night and day, a gun defence system. The D.H.10a and the Vickers Vimy, for day and night bombing respectively, were also being produced at the date of the Armistice.

In the early days of the war an aeroplane had little to fear above 4,000 feet. With the improvement of the anti-aircraft gun there was, by the end of the war, no immunity at 20,000 feet. Very low flying for attack was, however, being rapidly developed, and would have proved of great effect in 1919. The aeroplane used for this purpose was the single-seater fighter, and the Sopwith "Salamander," with two guns, a speed of 125 miles an hour, and 650 lb. of armoured plates, was about to make its appearance at the Armistice.

I have previously mentioned how dependent the improvement of design and performance of aircraft has been upon the less simple and tardier development of the engine. The invention of the light motor made aviation possible, and development has synchronized with the evolution of lighter, more powerful and more reliable engines. One of the most difficult problems still confronting us is the production of a cheap, high-powered and reliable engine, but the existence at the end of the war of machines weighing 15 tons indicates the progress achieved, while British engines of 600 horse-power are now in use, and one of 1,000 horse-power will shortly be available.

TACTICS AND THE STRATEGIC AIR OFFENSIVE.

During the war there were three concurrent movements in process: the ratios of the various forms of air tactics were constantly changing, and the components of our air forces varied in accordance with the development of reconnaissance, artillery co-operation, bombing and fighting. Secondly, their total strength was increasing rapidly; and, thirdly, it was increasing relatively faster than the Army or Navy.

It was an evident and logical development and in accord with the shortage of national man power and the consequent tendency to a reduction in the strength of the Army, that, the necessary uses of aircraft with the Army and Navy being ensured, any available margin of air power should be employed on an independent basis for definite strategic purposes. The difficulty was to arrive at an agreement as to the minimum tactical and grand tactical requirements of the Army and Navy. The British Army was not alone in asserting that there was no minimum and that it wanted every available airman, and agreed with the French that anything which it could temporarily spare should be lent to the French Army. It was argued that the Armies could as easily and better arrange for strategic bombing. Fortunately in 1918, when I was Chief of the Air Staff, we managed to secure a margin and formed the Independent Air Force in June of that year. It was, of course, understood that, in the event of either the British or French Armies being hard put to it, the Independent Air Force could temporarily come to their direct assistance and act in close co-operation with them.

In 1915 in accordance with the old doctrine that offence is the best defence, the surest method of protecting specialized machines on the battle front was found to be in the attack of enemy aircraft by fighting machines. In 1918 it was decided that raids on the centres of German war industry would not only cripple the enemy's output of material essential to victory, but also relieve the pressure on the Western Front, the vital point of the war. The Germans had had the same intention in the many raids which started over Dover on December 21st, 1914.

Long-range bombing had, however, been carried out spasmodically before 1918. In addition to its taste for bombing in general, the Royal Naval Air Service were keenly bent from the outset on long-range bombing in particular. The question of forming an Allied squadron to bomb German munition factories was first raised in 1915 at one of the monthly meetings between the French and British Aviation departments; and in February, 1916, a small squadron of Sopwith "1-1/2 Strutters" was formed at Detling for the purpose of bombing Essen and Dusseldorf from England, but the Army in France, being short of machines, asked that they should be sent to the front, and therefore the scheme did not mature; neither, for similar reasons, did one for the co-operation in 1916 of British and French bombing squadrons, operating from Luxeuil.

It was not until October, 1917, that the first striking force, consisting of three squadrons, was formed under the Army with Ochey as its base. It was mainly used in raids against the ironworks in the Alsace-Lorraine Basin and the chemical industry in the neighbourhood of Mannheim. As I have said, a definite offensive policy by means of an independent strategic force was later decided upon, and the "Independent" Air Force was brought into existence. It originally comprised two day-bomber and two night-bomber squadrons. During the summer additional squadrons were allotted to it, including D.H.9's and Handley Pages. Day-bombing squadrons had to fight their way to objectives in close formation, and the problems connected with navigation, calculation of petrol supply, action of wind and ceiling, were all accentuated. Casualties were heavy, with the result that a squadron of Fighters, composed of Sopwith "Camels," was incorporated for the purpose of protection. Thus we see the beginnings of an air fleet analogous to the naval fleet with its capital ships and protective craft.

The main objectives were the centre of the chemical industry at Mannheim and Frankfort; the iron and steel works at Briey and Longwy and the Saar Basin; the machine shops in the Westphalian district and the magneto works at Stuttgart; the submarine bases at Wilhelmshaven, Bremerhaven, Cuxhaven, and Hamburg, and the accumulator factories at Hagen and Berlin.

It will be seen from a map that three of the main industrial centres were situated near the west frontier of Germany; and, therefore, one portion of the striking force was based at Ochey, which lies within a few miles of the Saar Basin, within 180 miles of Essen, and within 150 miles of Frankfurt. Another portion was based on Norfolk, where a group of super-Handley Page machines were established for the specific purpose of attacking Berlin, a distance of 540 miles, and the naval bases within 400 miles. It was obvious that though aircraft from England would have to cover greater distances, they would not expose themselves to the strong hostile defences in rear of the battle front.

Three instances of the Independent Air Force's action may be cited. On the night of August 21st/22nd, two Handley Page machines dropped over one ton of bombs on Cologne Station, the raid occupying seven hours. On the night of August 25th/26th two Handley Pages attacked the Badische Aniline und Soda Fabrik of Mannheim; bombs were dropped from a height of 200 feet, direct hits being obtained in every case; and the machines then remained over the town, which they swept with machine-gun fire. On August 12th the first attack was made on Frankfurt by twelve D.H.4 day-bombers, every machine reaching the objective and returning safely in spite of being attacked, over Mannheim and throughout the return journey, by some forty hostile fighters.

During the five months of its existence the Independent Air Force dropped 550 tons of bombs, 160 by day and 390 by night. Of these 200 tons were dropped on aerodromes, largely by the short-distance F.E.2b's, as a result of which, hostile attacks on Allied aerodromes became practically negligible. Theoretically, machines of the Independent Air Force should not have been utilized for attacking purely military objectives in the Army zone, such as aerodromes, and their co-operation with the Army for this purpose shows that their true role was either not appreciated or not favoured by the French and other Commands.

There is ample testimony to the spirit of demoralization which pervaded the civil population of the towns attacked.

"My eyes won't keep open whilst I am writing," reads one captured letter. "In the night twice into the cellar and then again this morning. One feels as if one were no longer a human being. One air raid after another. In my opinion this is no longer war but murder. Finally, in time, one becomes horribly cold, and one is daily, nay, hourly, prepared for the worst." "Yesterday afternoon," says another, "it rained so much and was so cloudy that no one thought it was possible for them to come. It is horrible; one has no rest day or night."

Although, for reasons into which it is not necessary to enter here, only a comparatively small percentage of the efforts of the Independent Force were directed against the industrial targets for which the force had been created, yet by the end of the war the strategic conception of air power was bearing fruit, and the Air Ministry had in hand measures for bombing which would have gone far to shatter German munitionment. The defence measures forced upon the Germans within their own country were reacting on their offensive action at the front, which was at the same time denuded of fighting aircraft at various points to meet the menace of our strategic force at Ochey.

ORGANIZATION.

As in peace on a small, so in war on a large scale, the history of the organization of aircraft, while we were fighting for our national existence and competing with similar enemy expansion, is one of continuous development, of decentralization of command and co-ordination of duties. Headquarters, the Squadron and the Aircraft Park, as originally conceived in peace, though subject to variations in size, remained the basis of our organization. For instance, the original eighteen machines of our squadron were increased to twenty-four for single-seater fighters and reduced to six in the case of the super-Handley Page bombers. The four squadrons originally operated directly under Headquarters, were soon allocated to Corps for tactical reconnaissance and artillery co-operation, while a unit remained at Headquarters for strategical and long-distance reconnaissance and a few special duties. The next step was in November, 1914, when two Wings, composed originally of two, and later, of five squadrons each, were formed, R.F.C. Headquarters retaining one squadron and the wireless flight for G.H.Q. requirements. The Wing Headquarters co-ordinated the work of the squadrons which were allocated to Army Corps.

A further development, in 1916, was the formation for each of the three Armies of a Brigade, consisting of two Wings and an Aircraft Park. One—the Corps Wing—carried out artillery co-operation and close reconnaissance (including photography) with Army Corps, the other—the Army Wing—carried out more distant reconnaissance and fighting patrols under Army Headquarters. Our air superiority at the Battle of the Somme in 1916 led us to expect German counter-measures in 1917, and our programme for the following winter contemplated a proportion of two fighting squadrons to each Corps Squadron. By 1917 there were five British Armies in France and Belgium and our air forces were increased to provide a Brigade for each of the two new Armies. The Headquarters of the flying force in the field (except in the case of the Independent Air Force, which was responsible to the Supreme War Council and the Air Ministry in London) remained attached to G.H.Q. throughout the war.

The main difficulty in the higher organization was the lack of co-operation between the Royal Flying Corps and the Royal Naval Air Service and their competition for the supply of men and machines—the demands of both being urgent and insatiable. As a first step to overcome this, an Air Board was formed in May, 1916, to discuss general air policy, especially the combined operation of the Naval and Military Air Services, to make recommendations on the types of machines required by each, and to co-ordinate the supply of material. The Air Board was an improvement, but not a remedy, and, therefore, in 1917 it was decided to form an Air Ministry responsible for war aviation in all its branches and to amalgamate the Naval and Military Air Services as the Royal Air Force. This was carried into effect early in 1918, with Lord Rothermere as Secretary of State for Air with a seat in the Cabinet, and the air became the third service of the Crown, with an independent Government department permeated with a knowledge of air navigation, machinery, and weather, and closely allied to the industrial world for the initiation, guidance, and active supervision of research and experimental work.

I will mention later some of the many arguments for and against the retention of an independent Air Ministry and autonomous Air Force in peace. The amalgamation was certainly advantageous in war. It effected the correlation of a number of hitherto independent services according to a uniform policy and prevented overlapping by centralizing administration. Under single control it was possible to carry out, on a carefully co-ordinated plan, recruiting and training, to supply men and material, to organize air power according to the strategic situation in each of the various theatres of war, and to form the correct ratio between the air forces in the field and the reserves in training at home. The difficulty was that the amalgamation had to be carried out during the most intensive period of air effort, but by the end of the war most of these objects had been attained without jeopardizing the close co-operation with the Army and Navy. Co-operation with the Naval and General Staffs and with naval and military formations was, in fact, improved, independent action was beginning to bear fruit, and we possessed an Air Force without rival.



CHAPTER III

PEACE

THE FUTURE OF AERIAL DEFENCE.

In the evolution of aviation during the war the conclusion has been reached that the most remarkable lines of development at the Armistice were in the direction of ground and night fighting, torpedo attack and long-range bombing, exemplifying respectively the three spheres of air operations—military co-operation, naval co-operation, and the strategic use of aircraft. It must be remembered that this progress in tactics and strategy, in the machine, and the airman's skill, was made in the short period of four years, and that every war has started with a great advance in scientific knowledge, accumulated during peace, over that obtaining at the close of the previous war. We may therefore assume, provided the danger is averted of a retrograde movement from recent scientific methods to pre-war conditions—sabres, bayonets, and guns—that by the outbreak of another war on a large scale, which we hope may never occur, the knowledge of Service aeronautics will have increased immeasurably since 1918, and may be, not a contributory, but a decisive factor in securing victory.

The period since the Armistice has been employed in the reduction and consolidation of the Royal Air Force. In England the cadre system has been adopted, while abroad the greatest concentration of effort is aimed at, with Egypt, at present the most important strategic point in the Imperial air system, as the centre of activity. Iraq is being handed over to the control of the Royal Air Force, whose share in the policing of overseas possessions is likely usefully to grow provided any tendency to the concurrent building up of a large ground organization is withstood. The advantages of aircraft for "garrison" duties lie, under suitable geographical conditions, in their swift action and wide range, their economy, and, during disturbances their capacity for constant pressure against the enemy without fear of retaliation. One of the main problems is at present that of personnel. Service flying is restricted to comparatively young men, and therefore the majority of officers can only be commissioned for short periods. For this reason the experiment is being made of taking officers direct from civil life on short engagements, and at the same time endeavouring to ensure, by technical and general education, that the Royal Air Force shall not become a blind-alley occupation.

Though it is difficult to foretell on what lines aircraft will develop for any one purpose, as in the past, the problem of military co-operation will perhaps be less complex than that of co-operation with the Navy. It will probably consist of improvements along the lines already indicated, such as increased range, speed, climb, man[oe]uvrability, offensive armament, armour, the assistance of tank and anti-tank action, and the utilization of gas. Fighting will undoubtedly take place at very high altitudes to keep the enemy's fighting machines away from the zone of operations—necessitating the development of the single-seater so as to increase climb and man[oe]uvrability, and obtain, if possible, a speed of 200 miles an hour at 30,000 feet. Cavalry, unless retained, as I think they should be, in the form of mounted machine-gunners, will, I think, disappear in European warfare, but infantry will remain, and it will be the object of aircraft to assist their advance by reconnaissance, ground attack, artillery and tank co-operation, and the destruction of the enemy's supplies and communications. In this connection ground tactics and air tactics must develop pari passu and commanders of Corps and Armies must work out during peace training the fullest schemes for the most intimate co-operation between air and land forces.

The future of naval co-operation is a difficult problem, more especially as there was no major naval engagement after Jutland in which aircraft could be used, and consequently we have little to go on in estimating their practical value in direct co-operation with the fleet. It is impossible at present to judge between the conflicting opinions as to the future of the capital ship, but it is certain that aviation will materially modify naval tactics and construction. Coast defence, reconnaissance, anti-submarine work, escort, and the bombing of enemy bases, will doubtless continue and develop with ever-increasing machinery and equipment; but torpedo attack by aircraft may reach a point where the very existence of opposing fleets may be endangered. It is already questionable whether a battleship could survive an attack launched by even a small force of this mobile arm.

As was the case during the war, the action of aircraft at sea is restricted by range, the difficulty being to find the mean between the opposing conditions of radius of flight and limitation in the size of aircraft imposed by the deck-space of "carriers," but there is reason to suppose that on the one hand engines will be so improved as to afford a sufficient radius of action to comparatively small aircraft, while, on the other, devices will be found to economize deck-space.

Fleets operating near the enemy's coast will be vulnerable from land aircraft bases, and thus close blockade will be rendered increasingly difficult. The possibility of gas attack on enemy bases from the air in co-operation with submarines and of effecting a blockade by this means must be envisaged.

Since the Armistice the operational work of the Royal Air Force on behalf of the Navy has been conducted under the auspices of the Admiralty. Improvements have been made in large flying boats and amphibians, especially with a view to facilitating their landing on "carriers" and the decks of battleships. There has also been considerable progress in the construction and use of torpedo aircraft.

The war lasted long enough to prove the effect of the strategic offensive by air. In spite of the dictates of humanity, it cannot be eliminated. It is true that modern war is inimical to the progress of mankind and brings only less suffering to the victors than to the vanquished. To ensure peace should therefore be our ideal. But a great war once joined is to-day a war of peoples. Not only armies in the field, but men, women, and even children at home, are concentrated on the single purpose of defeating the enemy, and armies, navies, and air forces are dependent upon the application to work, the output of war supplies, and, above all, the morale of the civil population. Just as gas was used notwithstanding the Hague Convention, so air war, in spite of any and every international agreement to the contrary, will be carried into the enemy's country, his industries will be destroyed, his nerve centres shattered, his food supply disorganized, and the will power of the nation as a whole shaken. Formidable as is the prospect of this type of air warfare, it will become still more terrible with the advent of new scientific methods of life-destruction, such as chemical and bacterial attack on great industrial and political centres. Various proposals, such as the control of the air effort, service and civil, of all countries by the League of Nations, and even the complete elimination of aviation, have been put forward as a means of avoiding the horrors of aerial warfare and its appurtenances, but they are untenable, and any power wishing and able to sweep them aside will undoubtedly do so.

A future war, as I see it, will begin something after this manner, provided either side possesses large air forces. Huge day and night bombers will assemble at the declaration of war to penetrate into the enemy's country for the attack of his centres of population, his mobilization zones, his arsenals, harbours, strategic railways, shipping and rolling stock. Corps and Army squadrons will concentrate in formation to accompany the armies to the front; reconnaissance and fighting patrols will scatter in all directions from coastal air bases to discover the enemy's concentrations and cover our own; the fleet, whatever its nature, will emerge with its complement of reconnaissance and protective machines and torpedo aircraft for direct action against the enemy's fleet. A few fighting defence units will remain behind.

But it must not be imagined that these functions will be carried out unopposed. Local battles in the air will occur between fighting machines for the protection of specialized machines, while the main air forces in large formations will concentrate independently to produce, if possible, a shattering blow on the enemy and obtain from the outset a supremacy in the air comparable to our supremacy on the sea in the last war.

In mobilization the time factor is all-important. Our national history has been one of extraordinary good fortune in this respect, but the margin allowable for luck is becoming very narrow and, whereas in 1914 it was some twenty days between the declaration of war and the exchange of the first shots, in the next war the air battle may be joined within as many hours, and an air attack launched almost simultaneously with the declaration of war. In modern war the mobilization period tends to shorten, and every effort will be made towards its further reduction, since mobilizing armies are particularly vulnerable from air attack.

CIVIL AVIATION AS A FACTOR IN NATIONAL SECURITY.

The picture I have drawn may appear highly coloured for the reason that no country is likely for some time to possess sufficiently large air forces to obtain a decisive victory, or at any rate an uncontested superiority, at the outbreak of war. Though in air, as in every other form of warfare, attack is more effective than defence, we cannot afford to keep our air forces up to war strength in peace any more than our Army or Navy.

The problem, from a military point of view, is therefore to ensure an adequate reserve and to maintain our capacity for expansion to meet emergencies. The number of units maintained at war establishment should be the absolute minimum for safety and of the type immediately required on mobilization, i.e. long-range bombing and naval reconnaissance squadrons. The remainder should be in cadre form. We can, of course, maintain a fixed number of machines and pilots in reserve for every one on the active list, but, although some such system is necessary, on a large scale it is open to many and serious objections. First of all, even on a cadre basis, it means keeping inactive at considerable cost a number of machines which may never be used and which, however carefully stored, quickly deteriorate. Knowledge of aeronautics is still slender and improvements are made so continuously that machines may become obsolete within a few months. Moreover, the growth of service aviation in peace must tend to become artificial and conventional rather than natural, and this will react on design and construction, which will be cramped, both technically and financially, within the limits imposed by service requirements.

It is obvious therefore that the capacity of the construction industry to expand cannot be fostered by service aviation alone; furthermore, in the event of another war of attrition, expansion will be more essential than any amount of machine reserve power immediately available, and in the event of a war of short duration that power will win which has the greatest preponderance of machines, service or civil, fit to take the air. The asphyxiation of a large enemy city, if within range, can be done by night-flying commercial machines, and it would require a defending force of great numerical superiority for its successful defence.

Whether, therefore, from this point of view, or others, which I will mention later, another solution must be found, and this lies in the development of civil aviation. An analogy in the Navy and the Mercantile Marine has long been apparent. "Sea power," says Mahan, "is based upon a flourishing industry." Substitute "air" for "sea" and the analogy is still true. The Navy owed its origin to our mercantile enterprise and to-day it depends upon the Mercantile Marine for its reserve power of men and material. In the same way must air power be built up on commercial air supremacy. If we accept Mahan, or the dictum of any other great naval or military historian or strategist, a service air force by itself is not air power, and after a brief if brilliant flash must wither if reserves are not immediately at hand. A large commercial air fleet will provide, not only a reserve of men and machines, but it will keep in existence an aircraft industry, with its designing and constructional staffs, capable of quick and wide expansion in emergency; and such an industry will not be employed on the design of contrivances for use in a possible war, but on meeting the practical requirements of everyday air transport and navigation.

Thus a natural, practical and healthy, as opposed to a stereotyped and artificial, growth will be ensured. Our naval supremacy is largely attributable to the interest which the people as a whole have traditionally taken in naval policy; in other words, to the fact that we are a seafaring nation. Similarly air supremacy can only be secured if the air-sense of the man in the street is fostered, and aviation is not confined to military operations, but becomes a part of everyday life. At the present time commercial aviation is far too small to play the part of reservoir to the Royal Air Force—an object which must constitute one of the principal claims for support of the nucleus already in existence.

CIVIL AVIATION AS AN INSTRUMENT OF IMPERIAL PROGRESS.

Civil aviation, however, has not only an indirect military, but, with its superiority in speed over other means of transport, a direct commercial utility. The nation which first substitutes aircraft for other means of transport will be more than half-way towards the supremacy of the air. Moreover, as the Roman Empire was built upon its roads and as the foundations of the British Empire have hitherto rested upon its shipping, as steam, the cable and wireless have each in turn been harnessed to the work of speeding up communications, so to-day, with the opening of a new era of Imperial co-operation and consultation, this new means of transport by air, with a speed hitherto undreamed of, must be utilized for communication and commerce between the various portions of the Empire.

A comparison of the French and British attitudes towards civil aviation clearly demonstrates the two policies I have mentioned. Both France and England grant subsidies—France the very much larger sum—but the great difference lies in the objects aimed at. French policy is fostering civil aviation as a part of its military policy and, a portion of the subsidy being given to machines fulfilling service requirements, there is a strong tendency for French civil aviation to be military air power camouflaged. British policy, on the other hand, should aim at fostering civil aviation primarily as a commercial concern and believes that air commerce is the basis of air power as a whole. We are prepared to face the tendency of military and civil machines to diverge if that divergence is essential to the commercial machine.

An alternative to the British policy of maintaining a small air force and fostering commercial aviation as a reserve is the Canadian plan of a small air force training school and a civil Government flying service with such objects as forest patrol, survey and coastguard duties, the work being carried out on repayment for Government departments, provincial governments and private corporations. The former method, allowing of independent commercial expansion, is better suited to British mentality and requirements, but its success will depend on a genuine endeavour to make commercial aviation the real and vital basis of our air power. Experience in commercial operation cannot be gained by the exploitation of air routes or the carriage of mails or passengers under Service auspices. It is only by running transport services, as far as possible under private management, that operational data can be obtained, economies effected, and the design of strictly commercial machines improved.

To sum up. Military air supremacy can best be assured by the intensive development of industrial air organization for commercial purposes. The conception of civil aviation as the mainstay of air power as a whole is right. Service aviation is bound by technical and financial limits; its scope confined to the requirements of war. Civil aviation, on the other hand, opens out a prospect of productive expansion. The steady growth of the Continental services is already beginning to demonstrate the importance of air transport.

FINANCIAL AND ECONOMIC PROBLEMS.

The commercial exploitation of air transport is passing through a period of experiment, and suffering in the general war reaction from the incapacity of the public to think of aviation except as a fighting service. The machines hitherto used on the lines to and on the Continent are principally converted war machines, and to transform military into commercial craft and to use them as such is of small assistance to civil aviation, which requires reliable, economic machines as one of the basic conditions of its financial success. The cost of running an air transport service is considerable. Depreciation is one heavy item of expenditure. New machines must be evolved suitable to the requirements of mail, passenger and freight transport, but, in the present state of financial stringency, capital is not forthcoming for experiment unless there is every promise of a safe return. Then there are the expenses involved in general ground organization, maintenance, fuel, insurance, etc. The question is how can we carry on until the really economic type of commercial machine is evolved. It will never be evolved unless there is continuous flying and a continuous demand for new and improved machines for commercial work. To meet this in France, the Government came forward with a liberal grant of subsidies which have now been increased and placed on a more favourable basis, permitting of a very considerable reduction in the fares for transport by air. The British Government has also granted a subsidy for British firms operating on the cross-Channel routes, which it is hoped will place them before long on a sound, self-supporting, commercial basis. Part of this subsidy is allocated to assist transport companies in obtaining the latest type of commercial machines on a hire purchase system. With a few services properly supported by the State we shall pull through the experimental period of civil aviation.

The services to the Continent, although the distance is on the short side for the merits of air transport to be properly demonstrated, effect a considerable saving in time, and it is certain that the amount of mail, especially parcels, carried on these routes will continue to increase and lead to the eventual adoption of normal rates for air postage. An extension of the use of aircraft as the regular means of carrying mails will be of great assistance in the development of air transport. Aircraft revolutionize the speed of intercommunication by letter, and banks and financial houses will gradually realize that large savings can be made by utilizing air mails for the transaction of business. A difficulty lies in the fact that the area of the British Isles is not very favourable for an extensive air mail service, which can only operate by day, since by the existing means of transport mails are carried during the out-of-business hours and can generally reach their destination in a night, while the distances to Paris and Brussels are too short to afford outstanding advantage.

Lastly, we require public support and a spirit of confidence in the air. This can only be secured by increased reliability, reduction of charges and keeping the public informed of the progress made. It is the nature of man to distrust new departures. He disliked the introduction of mechanical devices into the Lancashire weaving mills. He scoffed at the steamship and railway. To-day he is inclined to treat as premature the serious exploitation of the air. In spite of the great decrease of accidents, in spite of the increased comfort of air travel, in spite of increased regularity, the average person is slow to realize that the communication of the busy man of the future will be by air. The majority of the business world is too conservative to make general use of the opportunities offered by aircraft for the quick transmission of its correspondence, while, though speed must be paid for, the high fares hitherto charged have deterred the general public from substituting the aeroplane for the train or boat. The running costs represented by these fares are being materially reduced as a more economic machine is evolved, and the reduction of fares which helps to place competition with foreign subsidized services and with the older forms of transport on more equal terms must for a time depend upon the assistance of Government grants.

WEATHER CONDITIONS AND NIGHT FLYING.

The safety of the machine and the reliability of an air service largely depend on accurate weather forecasts. In order to co-ordinate the meteorological work of the country as a whole, and for the special assistance of aviation, the Meteorological Services of Great Britain have been amalgamated under the Department of Civil Aviation, and, working in close co-operation with the Communications Branch of the Department, have made improvements in the rapid collection and distribution of meteorological information for all purposes. In addition to the forecasts issued four times daily, collective reports are issued hourly by wireless from the London terminal aerodrome at Croydon and copies are distributed to transport companies and others concerned.

A feature of meteorology which is often overlooked is its economic value. By making use of a knowledge of the wind at different heights, aircraft can complete journeys more quickly than would otherwise be possible, and thereby save their own fuel and their passengers' time. This will be specially useful in the tropics where the regularity of the surface winds has its counterpart in the upper air, but even in Europe time-tables can be drawn up with due attention to the favourable and unfavourable effect of prevailing winds. The planning of airship routes in particular, must be considered in close connection with this aspect of weather conditions.

To-day, however, the aeroplane may be considered as an "all-weather" craft, save for mist and fog—the enemies of all transport and particularly to that of the air—to which unfortunately England is particularly liable during the winter. Experiments have been carried out on the dispersal of fog, the illumination of aerodromes by fog-piercing lights, and instruments to record the exact position of the aeroplane and its height above the ground, but success has not yet been achieved.

Similar to the problems of flying and landing in mist and fog is that of night flying. Until night flying is practicable, only half the value of the aeroplane's speed is obtainable, since other transport services run continuously day and night. Further, as machines become rapidly obsolete owing to technical progress, it is essential that they should be in use for the greatest number of hours during their life. Much has been done in the lighting and marking of aerodromes and in the equipment of aeroplanes with wireless telephone and direction-finding apparatus.

It may here be mentioned that there are two methods of obtaining the position of aircraft by means of wireless telegraphy, known as direction-finding and position-finding. Direction-finding is effected by means of two coils set at right angles in the aircraft, by means of which the bearing of a transmitting ground station with reference to the aircraft's compass can be taken. When two or more bearings on different ground stations, whose position is known, have been obtained, a "cut" or "fix" of the aircraft is obtained. The position-finding system consists of two or more ground stations fitted with apparatus capable of taking bearings with respect to true north and connected by direct telephone line. The aircraft calls up by wireless one of these stations, requests her position and then makes a series of signals for about half a minute. The stations take the aircraft's bearings, plot its position, and transmit the information to the aircraft. Wireless direction and position-finding, as well as wireless telephony, have on several occasions proved their value to navigation, but in spite of instances of successful night flying, developments have not been such as to render night services practicable.

Marine experience has been a valuable guide, but aerial illumination has entailed many new problems of its own—the distribution of light through very wide angles, the installation of light and powerful lamps in aircraft, the elimination of shadows and the prevention of dazzle, the provision of apparatus to indicate the strength and direction of the wind, and the like.

Very shortly the first organized and equipped night-flying route will be available; that between London and Lympne on the Continental air highway. The Boulogne-Paris section will probably be ready a little later. There will be four lighthouses on the English section, of which two will be automatic, requiring no attention for twelve months at a time. These, and many other, facilities will much assist the progressive establishment of services during the hours of darkness, and will provide valuable data for the establishment of other night-flying routes. There is no real difficulty given a reasonably clear atmosphere.

ORGANIZATION.

I have mentioned the broad lines on which the organization of the air services was built up before and during the war. We have seen that the initial foundations and framework remained and bore the great systematic structural development which was gradually required. In August, 1914, there were some 240 officers, 1800 men and 200 machines; in November, 1918, 30,000 officers, 170,000 men, and 22,000 machines, all of them better and of a higher performance than those of 1914. Our casualties during the war were about 18,000; air formations had been active in some fifteen theatres of operations; 8,000 enemy machines and 300 observation balloons had been destroyed; some three-quarters of a million photographs taken over hostile country, and 12,000,000 rounds had been fired from the air at ground targets. At Home two organizations had expanded independently from the same seed until, impeding one another's growth, their trunks had joined and a single and improved tree was the result.

This is the only country where a unified air service has been adopted. In war the arrangement was successful. Against its continuance in peace the Army and Navy urge that, with the best of wills, there is a great difference between having an integral branch of a service to work with other services and having to deal with an independent organization, and argue increased cost, duplication, competition and disjointed action. There is no doubt that the liaison of the General, Naval and Air Staffs must be closened, and if co-operation with the senior services was really becoming less satisfactory, a return to the old system should be considered amongst other alternatives, but I do not think that it should be so. It must also be remembered that, although air co-operation is vital to naval and military operations, it is fortunately unlikely that there will be another war for a long time and, meanwhile, the growing essential, independent strategic action would be irretrievably impaired by the reabsorption of the Air into the Army and Navy.

On the other hand, even apart from supply, such a reversion would also cause much duplication, e.g. training. The solution and the correct and logical outcome of the unification of the Air service is the close grouping of the three arms in a Ministry of Defence, and this, even in face of the obvious practical difficulties, should be adopted and co-ordination thus increased step by step. Apart from Supply, some of the services in which this could be effected are the medical, education, chaplains, mobilization stores, transport, works and buildings, accounting, communications, ordnance and national factories. A modified scheme might also be studied in which, under a Ministry of Defence, the Army and Navy each had tactical air units of seconded personnel for artillery co-operation, spotting and reconnaissance, and the Air Ministry dealt with supply, research, initial training and reserves, civil aviation and an independent air force.

One of many good examples of the necessity of co-ordination is afforded by the position of the aircraft supply services at the beginning of the war and their development. We have already seen that there were some eight private firms manufacturing aircraft in a small way and there was practically speaking no engine industry at all. For the Royal Flying Corps, the War Office had relied largely on the Royal Aircraft Factory, and, although the methods of control adopted had many advantages, there was in them a tendency to retard private enterprise and development. The Admiralty, on the other hand, had assisted by dealing almost entirely with firms for Royal Naval Air Service supply. The conditions in France fortunately were very much better than those in this country, and for the first year or two French factories helped us out with both machines and engines. By the end of the war we had the largest and most efficient aircraft industry in the world. There were no less than seventy-six great factories turning out vast numbers of complete aeroplanes, in addition to thirty-three manufacturing complete engines and over 3,000 turning out spares and equipment. Such expansion is not possible within a few weeks, it took a long time to arrive at this position, and it causes one very seriously to think what would have happened had France not been our ally, and points the moral which has been mentioned of the necessity for a thriving aircraft and engine industry in peace. During the war Germany also had a very large number of firms engaged on this work.

THE MACHINE AND ENGINE.

The general differences between service and civil requirements in aircraft fall under the headings of ceiling, load and speed. For service purposes very much higher ceiling and greater climb and speed are required and the design is much affected by the condensed nature of the load. For peace purposes, besides the primary advantage of speed which the air has over other forms of transport, regularity must be ensured and the correct ratio between speed, duration and load-carrying power determined. Great ceiling, man[oe]uvrability and climb are not required.

However great the speed and load, there is no value in air transport, whether for passengers or mails or goods, unless it is safe and also compares favourably from an economic point of view with the older methods. Without these the public cannot be expected to utilize air transport, nor is there any inducement to surrender mails and freight for carriage by air. Every endeavour compatible with economy is made, as far as the equipment of aerodromes and the organization of the routes are concerned, to render air navigation as safe as possible, yet, though both safety and economy of running have been improved, much remains to be done. Safety depends largely on engine reliability, fire prevention and the capacity of the machine to land in small spaces.

Though neither roads nor rails have to be laid and aircraft possess the great advantages of mobility and point to point transit, the initiation and maintenance of an air service is a very complex and costly matter. The utilization of converted war machines is no longer sufficient and those specially designed for commercial work are beginning to make their appearance. Such are the Handley Page W.8, the Vickers, the D.H.18 and 34, and the Bristol 10-seater.

The first two are twin-engine and the last three single-engine machines. Opinions differ as to the relative advantages of the twin and single-engine type. The first and running costs of the single engine are lower, but the twin has greater power and carrying capacity, while most pilots prefer to have a surplus of power over and above that required for normal flight. For these reasons, and because of the psychological effect on insurance companies and on passengers, the twin engine will probably remain in use for large commercial machines, until long-lived and economic engines of more than 500 horse-power are available. On the other hand, where extra power is not required, the twin-engine is not safer than the single-engine machine; no existing twin-engine commercial aeroplane can maintain its height and land safely with only one engine running. Experiments have been made, especially in Germany, on the multi-engined machine with all the engines in the fuselage, but its advantages have so far been counterbalanced by loss of efficiency due to transmission gearing and shaft drives to the propellers and the vibration and weight of the gearing.

High-powered engines are very expensive to run and every effort has therefore to be made by aerodynamic efficiency to carry more useful load with less horse-power. Improvement is being made in this direction; thus the D.H.18 carries eight passengers at 56 horse-power per passenger, the D.H.32 is designed for the same number at 45 horse-power each, and the D.H.34 for ten passengers at 45 horse-power each.

The two best German commercial machines, the Junkers and the Fokker, have a comparatively low horse-power and a low fuel load, but greater attention has been paid to the design of the machines, which are monoplanes with cantilever wings, offering less resistance to the air than our biplanes. One of the most difficult problems is to evolve a high-lift wing which does not impair the aircraft's speed in the air. For commercial machines we must aim at the largest possible commercial load, the smallest possible fuel load and, consequently, an engine which uses fuel economically and, conversely, a lighter fuel. The development of the engine is receiving constant attention, as are also various safety devices, among which may be mentioned those guarding against fire and those varying the lift of wings so as to lower the landing speed and thus decrease the dangers attendant upon forced landings.

In addition to the high initial cost of machines and engines, their maintenance also requires the greatest care. Detailed investigation must be made into all serious accidents. This is now compulsory under the new Air Navigation Act, and the fitness of pilots is ensured by periodical medical examination.

Apart from the weather, the safety of an aircraft depends upon its engine, and perhaps even more upon the installation and accessibility of engines and their adjuncts, such as the petrol, oil, water and ignition systems. During the earlier stages of the war the average life of an engine before complete overhaul was necessary was, of stationary engines, from 50 to 60 hours, and of rotary engines, about 15 hours. To-day these figures stand at 200 hours and upwards and from 50 to 60 hours respectively. For commercial purposes this must be further increased to 300-500 hours as a normal working period.

There are two schools of thought with regard to the efficiency, reliability and the economy of engines. One school advocates using a light power plant per horse-power, run normally at about half its maximum; the other favours a plant of greater weight, more solid construction and greater efficiency, running at nearly its full horse-power. The former is more expensive in primary cost and upkeep, but allows a higher performance and provides reserve horse-power for emergency; the latter is cheaper, but involves a certain risk owing to lack of surplus power. We have hitherto shown a tendency to adopt the former method, the Germans the latter. For commercial purposes a compromise will probably be found to be best.

Apart from the initial outlay on "air stock," the maintenance, overhead, fuel, insurance and depreciation charges are very heavy. These are much affected by such items as simplicity of design, strength against wear and tear, ease of assembly and interchangeability of parts, easily removable engines, increase in durability by the use of metal construction for parts of the machine and the propeller, the elimination of rubber joints, substitution of air for water cooling, facilities for loading and unloading in a commercial machine, simple and efficient navigational instruments and self-starter. Every improvement, however small, will assist to reduce running costs. Then revenue must be increased and the comfort of passengers, as, for instance, ventilation, warmth, luggage capacity and, more than all, a reduction of noise has to be carefully considered or they will not travel a second time by air. An effective engine silencer is at last well on the way. It is obvious what a great advantage this attainment will be both for service and civil purposes. Roughly speaking, a high-powered engine without a silencer is audible at a distance of some seven miles and at a height of 13,000 feet at night time, though these distances are reduced by about a third by day when normal ground noises exist. The bulk of noise is caused by the exhaust, the propeller and mechanical noises in the engine.

I cannot leave this subject without emphasizing the value of research, both abstract and concrete. But, though it is the keystone of progress, its results must largely depend on the amount of flying done. It is clear that for economic reasons new designs can only thoroughly be tried out by commercial use, and therefore again that real progress is dependent on commercial activity.

The advance of civil aviation is bound to be slower than was that of war aviation. But, as war experience improved old and evolved new types, so will peace requirements and experience shape the type and design of aircraft and engine best suited to its purposes. Although a good deal has under the circumstances already been achieved in peace, much remains to be done. Gradually, however, with a modicum of research, improvements in the factors already mentioned and the reduction of initial cost and maintenance expenses, air transport for mails, passengers and goods will take its place as a normal commercial public utility service, and the increased speed of communication will assist in the general development of trade.

AIR SERVICES: BRITISH, CONTINENTAL AND IMPERIAL.

International civil flying commenced officially on August 26th, 1919, and gradually expanded, both in the United Kingdom and on the Continent, especially during the summer of 1920. France, aided by considerable subsidies, conducted services from Paris to London, Brussels and Strasburg, from Toulouse to Montpelier and across Spain to Casablanca in Morocco; Belgium, from Brussels to London and Paris; Holland, from Amsterdam to London; Germany, in spite of the restrictions placed upon her, entered the field as a competitor and her aircraft flew regularly from Berlin to Copenhagen and Bremen, and from Bremen to Amsterdam. On the American Continent, the United States Post Office ran mail services from New York to Washington, Chicago, and San Francisco, with extensions from Chicago, St. Paul, Minneapolis, and St. Louis.

For reasons which I shall give, there were no internal services in the United Kingdom, but there were four companies operating air lines from London to Paris, one of which held the contract for the carriage of mails. There were also air mail services between London and Brussels and Amsterdam. The mileage flown and the number of passengers and the weight of goods carried were considerable, while the number of letters steadily increased, especially on the Amsterdam service; and an efficiency of 76 per cent., 94 per cent., and 84 per cent. was obtained on the London-Paris, London-Brussels, and London-Amsterdam services respectively.

It must be remembered that these results were obtained without any direct assistance on the part of the State, such as was given by the French Government to air-transport companies in the form of subsidies. British economic policy is traditionally opposed to subsidies, believing that enterprise can be healthily built up on private initiative. Therefore, until 1921 civil aviation had to content itself with the indirect assistance of the State, which consisted mainly in the adjustment of international flying; the laying-out and equipment of aerodromes on the air routes; the provision of wireless communication and meteorological information; research and the collection and issue of general information concerning aviation.

This indirect assistance, however, proved inadequate to maintain the progress achieved during 1920, and therefore the maintenance of air services by means of temporary direct financial assistance had to be arranged.

I have already pointed out the difficulty against which commercial aviation has to contend in regard to the geographical features and position of the United Kingdom. Its comparatively small size, the propinquity of industrial centres, our efficient day and night express railway services, especially those running north and south, lessen the value of aircraft's superior speed and militate against the operation of successful internal air services. Possible exceptions might include amphibian services between London and Dublin, accelerating the delivery of mails five or six hours; between Glasgow and Belfast, where the Clyde and the harbour of Belfast could be used as terminals; or between London and the Channel Islands. I may point out in parenthesis that the development of alighting stations on rivers passing through the centres of towns is important, as a great deal of time is at present wasted in reaching the aerodromes necessarily situated some miles outside large centres of population.

Our immediate opportunities of development near home are therefore afforded by the air services to Paris, Brussels, and Amsterdam; but even here the saving in time is not great, and our position is unfavourable compared to that of the United States, where the Post Office saves two days in the delivery of mails by air between New York and San Francisco; or compared to that of Germany, where Berlin is within a 350-mile radius of Copenhagen, Cologne, Munich, Warsaw, and Vienna, which is itself in an advantageous situation as the junction for a South European system extending to the Balkan States and the Near East.

The ultimate use of the air, however, is not exemplified by a few passengers flying daily between London and the Continent any more than by a few squadrons of fighting craft. In a decade or two overhead transit will become the main factor in the express delivery of passengers, mails, and goods. It is the one means left to the Empire of speeding up world-communication to an extent as yet unrealized. For the price of a battleship a route to Australia could be organized, the value of which would be beyond computation.

The British Empire as a whole offers vast fields for expansion. In Africa, Canada, and Australia are found the great distances suitable to the operation of aircraft, the wide undeveloped areas through which air transport may prove more economic than the construction of railways, and the trans-oceanic routes over which travel by steamship has reached, and in many cases passed, its economic maximum speed. Air transport, careless whether the route be over land or sea, unhampered by foreign frontiers, gives the Empire precisely those essential powers of direct, supple, and speedy intercommunication which ship and rail have already shown us to be vital.

Here again the geographical position of England presents a difficult problem. England is divided from the rest of the Empire by a wide expanse, either of ocean or foreign territory. Egypt, the starting-point for air routes to India, Australia, and South Africa, may be described as the centre of a circle of which England is on the circumference; and it may be some years before an aeroplane can complete the journey between England and Egypt with only Malta as a stopping-place.

The future of long-distance oceanic air routes may depend upon the airship. Lighter-than-air craft, mainly for reasons of cost and vulnerability, did not receive such an impetus from the war as did the aeroplane, but the modern airship has claims for use over distances exceeding 1,000 miles. It can fly by night with even greater ease than by day; fog is no deterrent; engine trouble does not bring it down; and it can take advantage of prevailing winds. It would reduce the sea journey from England to Karachi from 22 to 5 days; from England to Johannesburg from 21 to 7 days; and from England to Perth from 32 to 10-1/2 days. Its achievements have already been considerable. In November, 1917, the German L.57 flew from Constantinople to East Africa and back—a distance of 4,000 miles—in 96 hours; in June, 1919, the R.34 flew from East Fortune to Danzig and back in 57 hours; and in July it crossed the Atlantic, was moored out in America for four days, and returned, a total distance of 8,000 miles, in the flying time of 108 hours for the outward and 75 hours for the homeward journey.

Before and during the war Germany gained wide experience in the design, construction, and handling of airships. It is probable that as soon as the peace terms and financial position permit she will begin to establish this form of transport on a commercial basis. In accordance with the Peace Treaty, and the Ultimatum of the London Conference of 1921, the construction of aircraft of all kinds is at present forbidden, but Germany is fostering airship development by the means left at her disposal. Her scientists are probing the constructional problems connected with large airships, while efforts are being made, by financial and other assistance, to maintain her technical staffs and airship bases in existence. At the same time German commercial interests are negotiating with foreign countries with a view to the development of airships abroad, and plans are being discussed for an airship service between Spain and Argentina.

The United States, France, and Italy are all interesting themselves, either financially or constructionally, in the future of airship development.

In Great Britain we have made great strides, particularly in the construction of small types, and our practical air experience in lighter-than-air craft, during the war, is the greatest in the world. With a view to carrying out the experiments necessary further to demonstrate the capacity of airships for commercial long-distance flights, a few months ago the Department of Civil Aviation took over all airship material surplus to service requirements. The main object was to test the practicability and value of mooring airships to a mast. Up to the present, a principal factor militating against the economic operation of airships has been the large and expensive personnel required for handling them on the ground, especially in stormy weather. The mooring-mast experiments have had considerable success and airships have been moored in high winds and over long periods with the assistance of a very small personnel.

The Government has decided, however, though recognizing their potentialities for speeding up communications between the various Dominions and the Mother Country, that the operation of airships cannot be carried out by the State on account of the present financial position.

Recognizing the limitations of Home services and those to the Continent, it was for the purpose of directing attention to the Imperial aspect of civil aviation that the great demonstration flights were organized in which Alcock flew the Atlantic in a Vickers "Vimy," Scott crossed to the United States and back in the R.34, Ross-Smith flew from England to Australia, and van Ryneveld from London to the Cape.

These flights necessitated, too, considerable ground organization in laying out aerodromes, as the following report on one in Africa vividly illustrates: "If aerodromes are left unattended for one year," it says, "practically all the work would have to be undertaken afresh, particularly in Rhodesia. The growth of vegetation is enormous, especially during the rains, and grass will grow to a height of eleven feet in six months; and trees stumped two feet below the surface will throw out suckers and replant themselves within a month after the rains have started.... It is most important that rough drains should be traced.... I have just started planting Doub grass. This grass gives an ideal surface for landing, kills other grasses, and possesses deep interlacing roots which will bind the entire surface of the aerodromes, making it permanent and free from washaways and the formation of sluits."

The demonstration flights, however, showed what could, rather than what should, be done, and what we look for to-day is the inception of practical undertakings, however small, in the various portions of the Empire. The most important of these is the service contemplated between Egypt and India; another instance is afforded by the West Indies, which suffer from the lack of inter-island communications, both for mails and passengers, and this could be partially rectified by an air service employing seaplanes or amphibians for the Leeward and Windward Islands and the Bahamas, and between the Bahamas and the American Continent, where an American company is actually conducting a service. Another project, given up owing to recent disturbances, was one for a flying-boat service on the Nile. Services are also being considered from Malta to Italy, Geraldton to Derby in Western Australia, Sydney to Adelaide and Brisbane, and Melbourne to Hobart in Tasmania. Canadian activity takes the form of work carried out by Government-owned civil machines in connection with forest patrol, photographic survey, exploration, anti-smuggling patrols, etc. It would be a great advantage if railway and steamship companies seriously considered the value of supplementing their services by air.