Something must be said of the machines which flew to France. Experience at manœuvres had favoured the factory B.E. 2 biplane; of the other types most in use the Henri Farman had been found fatiguing to fly, and the Maurice Farman was too slow. Accordingly, in the winter of 1913-14 Lieutenant-Colonel F. H. Sykes had urged the gradual substitution of B.E. machines for the Farmans. Major W. S. Brancker, writing for the Director-General of Military Aeronautics, objected to this proposal on the ground that until a satisfactory type of fighting aeroplane should be evolved, the Henri Farman was the only machine that could mount weapons effectively; and further, that a slow machine had some advantages for observation. The first of these objections was not fully met until firing through the airscrew was introduced; the second was for a long time an accepted idea. The war was to prove that a slow machine, exposed to armed attack, cannot live in the air. The battle of the machines ended, for the time, in compromise. It was judged important that the Flying Corps should have four squadrons ready for war by the spring of 1914, and large changes would have caused delay. In the event, at the date of mobilization, No. 2 Squadron and No. 4 Squadron were furnished throughout with B.E. 2 machines; No. 3 Squadron made use of Blériots and Henri Farmans, and No. 5 of Henri Farmans, Avros, and B.E. 8's. A single type of machine for a single squadron is a thing to be desired; the squadron is easier for the pilots and the mechanics to handle; but in the early days of the war there was no formation flying; each machine did its work alone, so that uniformity was of less importance.

When the Flying Corps arrived in France they were received by the French with enthusiasm, and had their full share of the hospitality of those days. The officers were treated as honoured guests; the men with the transport were greeted by crowds of villagers, who at all their stopping-places pressed on them bottles of wine, bunches of flowers, fruit, and eggs. At Amiens the transport and machines were parked outside the town, without cover, and the officers were billeted at the 'Hôtel du Rhin' and elsewhere. The hardships of the war were yet to come. Lieutenant B. H. Barrington-Kennett, with his mind always set on the task before them, remarks: 'There seemed to be a general misunderstanding amongst the troops as to the length of time during which rations have to last. They were apt to eat what they wanted at one meal and then throw the remainder away. R.F.C. peace training does not encourage economy with food, as the men are financially well off, and can always buy food and drink in the villages.'

On Sunday, the 16th of August, the headquarters of the Flying Corps, the aeroplanes of Nos. 2, 3, and 4 Squadrons, and the transport of Nos. 3 and 4 Squadrons moved from Amiens to Maubeuge. Second Lieutenant E. W. C. Perry and his mechanic, H. E. Parfitt, of No. 3 Squadron, who were flying a B.E. 8 machine (familiarly known as a 'bloater'), crashed over the aerodrome at Amiens; the machine caught fire, and both were killed. There was another accident on the 18th, when the aeroplanes and transport of No. 5 Squadron followed. Second Lieutenant R. R. Smith-Barry and Corporal F. Geard, also flying a B.E. 8 machine, crashed at Péronne; the officer broke several bones, and the corporal was killed. Three of these machines in all were flown over at the beginning; they had been allotted to the Aircraft Park, and were taken on charge of the squadrons in the field to fill vacancies caused by mishaps. The third of them was the machine flown over by Captain G. I. Carmichael.

At Maubeuge the French authorities gave all the help they could, providing blankets and straw for the troops. The Flying Corps were now in the war zone, but for the first two or three days the conditions were those of peace. They saw nothing of the British army till one evening British troops marched through Maubeuge on their way to Mons. 'We were rather sorry they had come,' says Wing Commander P. B. Joubert de la Ferté, 'because up till that moment we had only been fired on by the French whenever we flew. Now we were fired on by French and English.... To this day I can remember the roar of musketry that greeted two of our machines as they left the aerodrome and crossed the main Maubeuge-Mons road, along which a British column was proceeding.' To guard against incidents like this the Flying Corps, while stationed at Maubeuge, turned to, and by working all night painted a Union Jack in the form of a shield on the under-side of the lower planes of all the machines.

While the Flying Corps remained at Maubeuge and began to carry out reconnaissances over Belgium, the little British army had moved up north to Mons, where it first met the enemy. By the 22nd of August it was in position, on a front of some twenty-five miles, the First Army Corps holding a line from Harmignies to Peissant on the east, the Second Army Corps holding Mons and the canal that runs from Mons to Condé on the west. On the right of the British the Fifth French Army, under General Lanrezac, was coming up to the line of the river Sambre.

The original German plan was broad and simple. The main striking force was to march through Belgium and Luxembourg into France. Its advance was to be a wheel pivoting on Thionville. Count von Schlieffen, who had vacated the appointment of Chief of the General Staff in 1906, had prepared this plan. He maintained that if the advance of a strong right wing, marching on Paris through Belgium, were firmly persisted in, it would draw the bulk of the French forces away from their eastern fortress positions to the neighbourhood of Paris, and that there the decisive battle would be fought. His successor, von Moltke, believed that the French, on the outbreak of war, would at once deliver a strong offensive in Lorraine and so would themselves come into the open, away from the bastion of the eastern fortresses. He must be prepared, he thought, to fight the decisive battle either on his left wing in Lorraine, or on his right wing near Paris, or, in short, at any point that the initial operations of the French should determine. This was not the conception of Count von Schlieffen, who had intended to impose his will on the campaign and to make the enemy conform to his movements. When he was on his death-bed in 1913, his thoughts were fixed on the war. 'It must come to a fight,' were the last words he was heard to mutter, 'only give me a strong right wing.' Von Moltke, though he did not absolutely weaken the right wing, weakened it relatively, by using most of the newly formed divisions of the German army for strengthening the left wing.

The French, when the war came, delivered their offensive in Alsace and Lorraine as had been expected, but not in the strength that had been expected. They were held up, and retired, not without loss, to strong defensive positions covering Épinal and Nancy. Meantime, the advance of the German armies through Belgium was met by a French offensive in the Ardennes, which also failed, whereupon General Joffre ordered a retreat on the whole front, and began to move some of his forces westward, to prepare for the battle in front of Paris.

The successes won by the German left wing and centre against a yielding and retreating enemy were mistaken by the German high command for decisive actions, which they were not. The French armies which had been driven back on the Lorraine front rapidly recovered, and on the 25th of August delivered a brilliant counter-offensive, inflicting heavy losses on the Germans, and in effect upsetting all the German plans. The indecision which marked the movements of the German right wing through northern France had its origin in von Moltke's modifications of von Schlieffen's plans and in the readiness of the Germans to believe that the war was virtually won.[4]

The heroic stand made by the Belgians at Liége purchased invaluable time for the preparations of the Allies. When, on the 17th of August, the last fort of Liége fell, the great wheel of the German northern armies began to revolve. Its pace was to be regulated by the pace of the armies nearest to its circumference; that is to say, the First Army, under von Kluck, and the Second Army, under von Bülow. Three divisions of cavalry were to advance against the line Antwerp-Brussels-Charleroi, moving westward across Belgium in order to discover whether a Belgian army was still in being, whether the British had landed any troops, and whether French forces were moving up into northern Belgium. The Belgian army retired within the defensive lines of Antwerp, and by the 20th of August Brussels was in the hands of the enemy. By the 22nd, von Bülow's army had entered Charleroi and was crossing the Sambre. The repulse of the French centre in the Ardennes left the British army and the French Fifth Army completely isolated on the front Mons-Charleroi. The French Fifth Army began to retreat. On Sunday morning, the 23rd of August, von Kluck's army came into action against the British position at Mons.

The British army had taken up its position in high hopes. It was not a British defeat which began the retreat from Mons, and the troops were not well pleased when they were ordered to retire. But the retreat was inevitable, and the most that the British could do was by rearguard actions to put a brake upon the speed of the advancing enemy until such time as they should be able to form up again in the Allied line and assail him. Much depended on their power to gain information concerning the movements of the enemy, so that they might know their own dangers and opportunities. Von Kluck had at first no definite news of the whereabouts of the British army. As late as the 20th of August the German Supreme Command had issued a communication to the German armies stating that 'a disembarkation of British Forces at Boulogne and their employment from the direction of Lille must be taken into account. It is the opinion here, however, that a landing on a big scale has not yet taken place.' General von Zwehl, Commander of the Seventh Reserve Corps, writing in September 1919, tells how the Germans had no reliable information concerning the British expeditionary force. 'It was only on the 22nd of August,' he says, 'that an English cavalry squadron was heard of at Casteau, six miles north-east of Mons, and an aeroplane of the English fifth flying squadron was shot down that had gone up from Maubeuge. The presence of the English in front was thus established, although nothing as regards their strength.' The first news that reached General von Kluck of the presence of the British forces came to him from a British, not from a German, aeroplane.

The first aerial reconnaissances by the Royal Flying Corps were carried out on Wednesday, the 19th of August, by Captain P. B. Joubert de la Ferté of No. 3 Squadron, in a Blériot, and Lieutenant G. W. Mapplebeck of No. 4 Squadron, in a B.E. They started at 9.30 a.m., and flew without observers. Captain Joubert de la Ferté was to reconnoitre Nivelles-Genappe in order to report what Belgian forces were in that neighbourhood; Lieutenant Mapplebeck was to find out whether enemy cavalry were still in force in the neighbourhood of Gembloux. The machines were to fly together as far as Nivelles, 'so that if one was obliged to descend the other could report its whereabouts'. The machines lost their way and lost each other. Lieutenant Mapplebeck eventually found himself over a large town which he failed to recognize as Brussels. Later he picked up his position at Ottignies, and soon found Gembloux, where he could see only a small body of cavalry moving in a south-easterly direction. After leaving Gembloux he was enveloped in cloud for some miles, came down to 300 feet over Namur, followed the Sambre, missed Maubeuge, and landed near Le Cateau, whence he flew back to the aerodrome at Maubeuge. He had been away from 9.30 a.m. to 12.0 midday. Captain Joubert de la Ferté, whose machine was slower than Lieutenant Mapplebeck's, attempted to steer by compass through the banks of cloud, and after two hours of wandering landed at Tournai. He made inquiries concerning the Belgian army, but nothing was known of them. He left Tournai at 12.15 p.m., lost his way again, and at 2.0 p.m. landed at Courtrai. Here he was told by the gendarmerie that the headquarters of the Belgian flying corps was at Louvain. He left Courtrai at 3.0 p.m. and passed over Ath, Hal, Braine l'Alleud, Nivelles, returning to Maubeuge at 5.30 p.m. He reported occasional trains in the main stations and pickets on the roads to Brussels.

On the 20th Major C. A. H. Longcroft, with Captain U. J. D. Bourke as observer, reconnoitred as far as Louvain and reported a force of all arms moving south-west through Tervueren, and another force moving into Wavre. They also saw an aerodrome just east of Louvain with seven machines on the ground. Lieutenant E. R. L. Corballis, who, with Captain G. E. Todd, flew over the area Nivelles-Hal-Enghien, reported that there was no sign of troops and that all bridges in the area appeared to be intact. The German flood was spreading but was still some distance away. On the following day (an important day of enemy movements) the weather in the morning was too foggy for observation, and in the afternoon was rainy and misty. Three reconnaissances which were made in the afternoon showed that the country immediately in front of the British was very quiet, but in the wood one mile south of Nivelles Lieutenant Corballis reported a large body of cavalry with some guns and infantry (this was later identified as the German 9th Cavalry Division), and another body of infantry moving south on Charleroi. At Pont-à-Celles on the Charleroi canal, south of Nivelles, three villages were seen to be burning.

On the 22nd there were twelve reconnaissances which revealed the presence of large bodies of troops moving in the direction of the British front, and did much to dissipate the fog of war. The first machine to return came in soon after eleven. This was piloted by Captain G. S. Shephard, with Lieutenant I. M. Bonham-Carter as observer. They had landed at Beaumont (about twelve miles east of Maubeuge) for petrol. Here they were informed that French cavalry had encountered German infantry north of the Sambre canal on the previous afternoon, and had had to fall back. The next machine to return came in at 11.50 a.m. with a wounded observer, Sergeant-Major D. S. Jillings of No. 2 Squadron. He was the first British soldier to be wounded in an aeroplane, and this casualty seemed to bring the German armies nearer than a dozen unmolested reconnaissances could have done. The machine, piloted by Lieutenant M. W. Noel, had come under heavy rifle fire first of all at Ollignies, south-east of Lessines, and then, after passing over a cavalry regiment just south-west of Ghislenghien, had been met with rifle and machine-gun fire. Frequent rifle fire was encountered all the way back to Ath, and just south-east of Ath, over Maffle, Sergeant-Major Jillings had been wounded in the leg by a rifle bullet. Confirmation of the presence of large bodies of enemy in this area came from Captain L. E. O. Charlton flying as observer with Second Lieutenant V. H. N. Wadham. They started at 10.0 a.m. and passed over Charleroi, Gembloux, and Brussels without seeing any large movements, but reported that the northern part of Charleroi and many other towns and villages in that area were burning. From Brussels they went on towards Grammont, and landed at Moerbeke, two miles south-east of Grammont, to make inquiries. Here they received information which hastened their departure. They learnt that a force of 5,000 Germans was in Grammont, that cavalry and cyclists were in Lessines, and that cavalry were expected from Enghien to arrive in Ath that evening. When passing over Bassilly, about half-way between Ath and Enghien, they were fired on by enemy troops which they estimated at the strength of an infantry brigade, and they drew further fire from patrols in Ath. They came in with their information at 1.10 p.m.; Lieutenant W. H. C. Mansfield just before this had reported large bodies moving into Enghien and Soignies. Afternoon reconnaissances added little that was new except that there were cavalry and infantry in the area north of the Mons-Condé canal, and cavalry as far west as Peruwelz.

The most important reconnaissance of the day is unfortunately not recorded in the war diary. The value of the report when it came in was recognized at once, and Brigadier-General Sir David Henderson took it personally to General Headquarters. It stated that a long column, whose strength was estimated to be that of an army corps, was moving westward on the Brussels-Ninove road. At Ninove the column continued south-west towards Grammont. This was von Kluck's Second Corps, and the report seemed to show an attempt at an enveloping movement. The same report confirmed what had already been seen, the presence of enemy troops moving along the great Chaussée on Soignies. This column was taking advantage of the trees on either side of the road to shield its movements. This was the first day on which a machine failed to return from over enemy territory. Lieutenants V. Waterfall and C. G. G. Bayly, of No. 5 Squadron, started on a reconnaissance in an Avro at 10.16 a.m. and next day were reported missing. It was the bringing down of this machine, no doubt, which gave the Germans their first assurance of the presence of the British forces. The observer's report, so far as he had written it, was picked up near the wreckage of the machine by some Belgian peasants, and eventually found its way to the War Office in London.

Sir John French on the evening of the 22nd held a conference at Le Cateau, whereat the position of the Germans, so far as it was then known, was explained and discussed. At the close of the conference Sir John stated that owing to the retreat of the French Fifth Army, the British offensive would not take place. A request from General Lanrezac arrived at 11.0 p.m., asking for offensive action against the German right flank, which was pressing him back from the Sambre. This could not be undertaken, but Sir John French promised to remain in his position for twenty-four hours.

In his book, A Staff Officer's Scrap Book, Sir Ian Hamilton, who was attached to the Japanese army during the Russo-Japanese War, has the following entry: 'The Russians are sending up balloons to our front, and in front of the Twelfth Division. Judging by manœuvres and South African experiences, they should now obtain a lot of misleading intelligence.' Observation from the air, when the war broke out, had still to prove its worth. The Royal Flying Corps, though confident of its own ability, was a new and untried arm. In the early reports there are occasional inaccuracies. Some of the early observers, among those who were hastily enrolled to bring newly formed squadrons up to strength, had not much military knowledge, and were not practised in reading the appearances of things seen from the air. At the time of the battles of Ypres, 1914, observers of No. 6 Squadron, which had prepared itself in hot haste for foreign service, mistook long patches of tar on macadamized roads for troops on the move, and the shadows cast by the gravestones in a churchyard for a military bivouac. Mistakes like these, though they were not very many, naturally made commanding officers shy of trusting implicitly to reports from the air. Yet the early reports of the first four squadrons did show without any possibility of mistake how formidable the German movements were.

Sir John French remained at Mons and was led into fighting a battle in a perilous position against much superior forces. The air reports of the 22nd had given some hints of the success of von Bülow's army in crossing the Sambre, had indicated a possible enveloping movement from the direction of Grammont, and had revealed something of the strength of the enemy troops on the British front. On the following day the attack began on the position at Mons, and pilots and observers were flying over and behind the battle-field looking for enemy movements, and locating enemy batteries.

On the 24th the retreat was in progress. As early as the morning of the 23rd the Royal Flying Corps had begun to shift its quarters from Maubeuge to Le Cateau. The transport and machines of No. 3 Squadron moved southward on that day, and on the 24th headquarters and other squadrons also moved to Le Cateau. 'We slept,' says Major Maurice Baring, 'and when I say we I mean dozens of pilots, fully dressed in a barn, on the top of, and underneath, an enormous load of straw.... Everybody was quite cheerful, especially the pilots.' On the afternoon of the 25th they moved again to St.-Quentin. The rapidity of the retreat put a heavy strain upon the headquarters of the Royal Flying Corps, which had to travel before the retreating army, to select an old aerodrome or to make a new one almost every day, and in the brief hours between arrival and departure to carry on all the complicated and delicate business of ministering to the needs of the squadrons. The places occupied by headquarters during the retreat were as follows:

• Sunday, 16th August Maubeuge.
• Monday, 24th August Le Cateau.
• Tuesday, 25th August St.-Quentin.
• Wednesday, 26th August La Fère.
• Friday, 28th August Compiègne.
• Sunday, 30th August Senlis.
• Monday, 31st August Juilly.
• Wednesday, 2nd September Serris.
• Thursday, 3rd September Touquin.
• Friday, 4th September Melun.

In some of these places regular aerodromes were available, in others a landing-ground had to be improvised. Sometimes officers of headquarters would be sent on a long way ahead in motor-cars to select a landing-ground, while another officer in a motor-car was detailed to guide the transport. This he did by taking with him a small number of men and dropping them one by one at the partings of the ways. When the route was very complicated, these guides became so many that they had to be carried in a transport lorry. The transport drivers were not as yet skilled in the art of map-reading, and to lose the transport would have left the Flying Corps helpless. Sometimes the officers who selected the landing-ground moved with the transport, and made their choice when the transport reached its destination. The only recognized French aerodromes which were used by the Royal Flying Corps during the retreat were those at Compiègne, Senlis, and Melun.

Whilst the aerodromes were changing almost daily, the officers carried on reconnaissance, sometimes starting out not knowing whether their aerodrome would be in British or enemy hands by the time they should return. On the 24th, whilst the squadrons were moving from Maubeuge to Le Cateau, the enemy advance as seen from the air looked menacing enough. Captain G. S. Shephard and Lieutenant I. M. Bonham-Carter were watching von Kluck's right wing soon after 4.0 a.m. They returned at six o'clock with news of extensive movement about Ath and Leuze. They reported a broken column nearly ten miles long with its head pointing at Peruwelz. The column branched off the main Ath-Tournai road at Leuze. This was part of von Kluck's Second Corps, and its line of march would take it to the west of the extreme western flank of the British army. The news was not reassuring. Captain H. C. Jackson as observer with Lieutenant E. L. Conran went up at 8.30 a.m. and came back at 12.30 p.m. with information of long enemy columns moving from Grammont through Lessines into La Hamaide and further troops on the Ath-Leuze road. They had flown as far as Ninove and Alost, but found the country there clear. On returning over Lessines at 11.30 a.m. they saw three German aeroplanes on the ground; they dropped a bomb overboard, but missed.

In the evening of the 24th, the first day of the retreat, the position was on the whole not unsatisfactory. The British Fifth Division had not only defended six miles of front, but with the aid of the cavalry and the 19th Infantry Brigade had met and beaten off von Kluck's enveloping attack. But that attack was soon renewed. On the following morning a heavy movement of German troops southward from Marchiennes, with cavalry, guns, and transport, was reported at six o'clock. Marchiennes is almost midway between Valenciennes and Douai, to the west of the British line of retreat. This moving line of troops continued southward through Somain for a distance of about five miles, and then bent in a south-easterly direction, pointing straight at Le Cateau, until it reached Bouchain, where there were mounted and dismounted troops extending over three miles. But Le Cateau was not the objective of these troops. General von Kluck believed that the next stand of the British army, after Mons, would be made on a position running east and west through Bavai, and resting its right on the fortress of Maubeuge. The troops seen at Bouchain were intended to envelop it and take it in the rear. Meantime the British army, having escaped the lure of Maubeuge, was continuing its painful march southward on both sides of the Forest of Mormal; and the claw that was extended to catch it closed upon air.

These movements of von Kluck's army on the 25th were influenced by his own air reports, which appear to have misled him. The army order issued by him from Soignies at 8.30 p.m. on the night of the 24th assumed that the British army would accept battle on the line Maubeuge-Bavai-Valenciennes. Von Kluck was very hopeful. 'The outflanking of the left of the British Army,' he says, 'on the assumption that it remained in position, appeared to be guaranteed.' An important air report which reached him at 1.0 a.m. on the 25th led him to suspect that the British were withdrawing on Maubeuge. Speaking of this report, he says: 'Enemy columns of all arms were in retreat on the roads Bellignies-Bavai, La Flamengrie-Bavai, and Gommegnies-Bavai. The direction in which the movement was being made beyond Bavai had not yet been determined; nevertheless, the army commander began to suspect that the British were withdrawing on Maubeuge.' He sent out orders in great haste by motor-car for the army to advance in a more southerly direction. At 9.0 a.m. however, a new air report came as a surprise. Long British columns of all arms were moving from Bavai along the Roman road to Le Cateau, and numerous small columns, single companies, batteries, squadrons, and cars were crossing the Selle, north and south of Solesmes. 'The enemy was marching in an almost opposite direction to what was supposed earlier in the morning.' A fresh order was at once sent out to attack the British and bring them to a standstill. Von Kluck does not quote these air reports. But he says enough to show that he was misled chiefly by his own preconceptions. Hope told a flattering tale, and he seems to have been possessed by the idea that the British army would be tempted into the fortress of Maubeuge.

The whole body of information which on any one day was obtained from the reconnaissances of the Royal Flying Corps could be set out in detail only by quoting all the reports in full. That would be too cumbrous a method of writing history. The reports contain much that is comparatively insignificant. But the reader of this book may desire to know exactly what an air report is like, and his curiosity shall be gratified. Here is the report, of no special tactical significance, but full of incident, of a long air reconnaissance made by Lieutenant G. F. Pretyman and Major L. B. Boyd-Moss in a machine of No. 3 Squadron, on the day of the battle of Le Cateau:

The machine, it will be seen, dropped a bomb on a park of transport vehicles, was fired at by howitzers, and was brought down by heavy infantry fire. A more dreaded enemy here makes an early appearance—the prevailing westerly wind. This wind was the heaviest trial for pilots during years on the western front; it made it easy to get at the enemy and difficult to get away from him; the road to safety always, while the west wind was blowing, lay uphill.

On this same day—the day of the battle of Le Cateau—the First Army Corps under Sir Douglas Haig was delayed, and failed to reach its appointed position in touch with the Second Army Corps. Lieutenant A. E. Borton and Lieutenant F. G. Small were dispatched from headquarters in a machine of No. 5 Squadron to 'find Sir Douglas Haig'. With them went Lieutenant D. S. Lewis in a B.E. machine fitted with wireless apparatus. He was to report by wireless when Sir Douglas Haig was found. Lieutenants Borton and Small in their Henri Farman, being unable to find a suitable landing-ground in the rear of the First Army Corps, landed between the firing lines in a field protected by a rise in the ground from the direct fire of the enemy. With the aid of a cavalry patrol they succeeded in delivering their message to Sir Douglas Haig, after which they returned to their machine, started up the engine, and flew away in the presence of two Uhlans, who had just ridden into the field. Meantime, Lieutenant Lewis, to whom they were unable to signal, lost touch with them; he circled in the air for an hour under fire, and returned with one shell splinter and four bullet-holes in his machine, and with one of his hands grazed by a bullet. Captain L. E. O. Charlton was also sent at 11.30 a.m. to report to General Smith-Dorrien at Bertry. 'I found him', he says, 'in considerable anxiety as to his left about Haucourt and Selvigny. Having been on that flank at 9.30 a.m., I was able to reassure him as to its safety, and made another ascent to confirm my previous reconnaissance. During the reconnaissance I was able to report that the enemy had made no progress, though their shell-fire had increased. I was sent up again to examine the right about Le Cateau, and on reporting at 2.45 p.m. the General told me that the Fifth Division had been unable to withstand a most determined artillery attack, and had come back. He added that he had no doubt he would succeed in getting them back somehow, and requested me to inform Sir Archibald Murray. I left at 3.0 p.m. and reported to General Headquarters as ordered.'

General Smith-Dorrien did succeed in getting them back. The stand made at Le Cateau was a great fight against odds; and the part played in the battle by the Royal Flying Corps seems a little thing when it is compared with the gallant resistance of the infantry. But British machines were flying over the enemy, under fire, within full view of the British army, and some British officers who took part in the battle have described how the sight of our aeroplanes above them raised the spirits of the troops and gave them a feeling of security.

Copies of the original reports made out by observers before and during the retreat from Mons are preserved in the war diary of headquarters, Royal Flying Corps. It is not possible to say when each of these reports reached General Headquarters; they were sent in as soon as possible after the machines landed—some of them at once by telephone. When the reports are systematically mapped out, day by day, they give a fairly accurate picture of the German advance and throw light on the German plans. General von Kluck speaks more than once of driving the British army before him, but the complete map of the German movements, as they were reported day by day from the air, shows that his predominant idea was to envelop them. Always the crab-like claw is seen extended to the west and beginning to close in on the line of the British retreat; always the British army is already at a point farther south on the line, out of the reach of the claw. When with swollen and blistered feet and half asleep on the march, the patient British soldier carried on, he was doing more to defeat the Germans than he could have done if his dearest wish had been granted and he had been allowed to make a desperate stand. It is a wonderful army that can suffer the long depression and fatigue of such a retreat and yet keep its fighting quality unimpaired.

Von Kluck's advance after the battle of Le Cateau was directed to the south-west. Speaking of the situation on the 28th. of August, he says, 'The occupation of the Somme area marked the conclusion of the fighting with the British Army for the time being. In spite of the great efforts of the First Army the British had escaped the repeated attempts to envelop them. They continued their retreat southwards.' On the same day the headquarters of the German army propounded a new task. 'The left wing of the main French forces', they wrote, 'is retreating in a southerly and south-westerly direction in front of the victorious Second and Third Armies. It appears to be of decisive importance to find the flank of this force, whether retreating or in position, force it away from Paris, and outflank it. Compared with this new objective the attempt to force the British Army away from the coast is of minor importance.'

The German Supreme Command were giving most of their attention to the operations on their left wing, where the Fifth and Sixth German Armies were converging for the attack on Nancy, which town, when it fell, was to witness the triumphal entry of the German Emperor. Meantime, the French, trusting to the strength of their eastern fortifications, were rapidly taking troops away from their eastern armies to form a new French army, the Sixth, which was to operate to the north of Paris and was to take part in the counter-offensive against the German First and Second Armies. This was unknown to the German Command, who thought that victory lay within the grasp of their eastern armies.

On the evening of the 30th of August General von Kluck received wireless messages from the headquarters of the Second Army reporting a decisive victory, and asking the First Army to wheel inwards towards the line La Fere-Laon in order to gain the full advantages of the victory. General von Kluck replied that the First Army had wheeled round towards the Oise and would advance on the 31st by Compiègne and Noyon to exploit the success of the Second Army. This was the much-discussed wheeling movement, or swerve, which was discovered by the British from the air. Von Kluck had been ordered by the German Supreme Command on the 28th to continue his march towards the Lower Seine. Now, in response to von Bülow's request, he wheeled his army south-eastwards towards the Oise. The German Supreme Command was informed of this, and replied, 'The movement begun by the First Army is in accordance with the wishes of the Supreme Command'. The Royal Flying Corps reports of the 31st of August gave to the British Command the first intimation of what was happening. Here is one of them: