It was at Mons in the third week of the Great War. The grey-green German hordes had overwhelmed the greater part of Belgium and were sweeping down into France whose people and military establishment were all unprepared for attack from that quarter. For days the little British army of perhaps 100,000 men, that forlorn hope which the Germans scornfully called "contemptible," but which man for man probably numbered more veteran fighters than any similar unit on either side, had been stoutly holding back the enemy's right wing and fighting for the delay that alone could save Paris. At Mons they had halted, hoping that here was the spot to administer to von Kluck, beating upon their front, the final check. The hope was futile. Looking back upon the day with knowledge of what General French's army faced—a knowledge largely denied to him—it seems that the British escape from annihilation was miraculous. And indeed it was due to a modern miracle—the conquest of the air by man in the development of the airplane.

General French was outnumbered and in danger of being flanked on his left flank. His right he thought safe, for it was in contact with the French line which extended eastward along the bank of the Somme to where the dark fortress of Namur frowned on the steeps formed by the junction of that river with the Meuse. At that point the French line bent to the south following the course of the latter river.

Namur was expected to hold out for weeks. Its defence lasted but three days! As a matter of fact it did not delay the oncoming Germans a day, for they invested it and drove past in their fierce assault upon Joffre's lines. Enormously outnumbered, the French were broken and forced to retreat. They left General French's right flank in the air, exposed to envelopment by von Kluck who was already reaching around the left flank. The German troops were ample in number to surround the British, cut them off from all support, and crush or capture them all. This indeed they were preparing to do while General French, owing to some mischance never yet explained, was holding his ground utterly without knowledge that his allies had already retired leaving his flank without protection.

When that fatal information arrived belatedly at the British headquarters it seemed like a death warrant. The right of the line had already been exposed for more than half-a-day. It was inexplicable that it had not already been attacked. It was unbelievable that the attack would not fall the next moment. But how would it be delivered and where, and what force would the enemy bring to it? Was von Kluck lulling the British into a false sense of security by leaving the exposed flank unmenaced while he gained their rear and cut off their retreat? Questions such as these demanded immediate answer. Ten years before the most dashing scouts would have clattered off to the front and would have required a day, perhaps more, to complete the necessary reconnaissance. But though of all nations, except of course the utterly negligent United States, Great Britain had least developed her aviation corps, there were attached to General French's headquarters enough airmen to meet this need. In a few minutes after the disquieting news arrived the beat of the propellers rose above the din of the battlefield and the airplanes appeared above the enemy's lines. An hour or two sufficed to gather the necessary facts, the fliers returned to headquarters, and immediately the retreat was begun.

It was a beaten army that plodded back to the line of the Marne. Its retreat at times narrowly approached a rout. But the army was not crushed, annihilated. It remained a coherent, serviceable part of the allied line in the successful action speedily fought along the Marne. But had it not been for the presence of the airmen the British expeditionary force would have been wiped out then and there.

The battle of Mons gave the soldiers a legend which still persists—that of the ghostly English bowmen of the time of Edward the Black Prince who came back from their graves to save that field for England and for France. Thousands of simple souls believe that legend to-day. But it is no whit more unbelievable than the story of an army saved by a handful of men flying thousands of feet above the field would have been had it been told of a battle in our Civil War. The world has believed in ghosts for centuries and the Archers of Mons are the legitimate successors of the Great Twin Brethren at the Battle of Lake Regillus. But CÆsar, Napoleon, perhaps the elder von Moltke himself would have scoffed at the idea that men could turn themselves into birds to spy out the enemy's dispositions and save a sorely menaced army. When this war has passed into history it will be recognized that its greatest contributions to military science have been the development and the use of aircraft and submarines. There have, of course, been other features in the method of waging war which have been novel either in themselves, or in the gigantic scale upon which they have been employed. There is, for example, nothing new about trench warfare. The American who desires to satisfy himself about that need only to visit the Military Park at Vicksburg, or the country about Petersburg or Richmond, to recognize that even fifty years ago our soldiers understood the art of sheltering themselves from bullet and shrapnel in the bosom of Mother Earth. The trench warfare in Flanders, the Argonne, and around Verdun has been novel only in the degree to which it has been developed and perfected. Concrete-lined trenches, with spacious and well-furnished bomb-proofs, with phonographs, printing presses, and occasional dramatic performances for lightening the soldiers' lot present an impressive elaboration of the muddy ditches of Virginia and Mississippi. Yet after all the boys of Grant and Lee had the essentials of trench warfare well in mind half a century before Germany, France, and England came to grips on the long line from the North Sea to the Vosges.

Asphyxiating gas, whether liberated from a shell, or released along a trench front to roll slowly down before a wind upon its defenders, was a novelty of this war. But in some degree it was merely a development of the "stinkpot" which the Chinese have employed for years. So too the tear-bomb, or lachrymatory bomb, which painfully irritated the eyes of all in its neighbourhood when it burst, filling them with tears and making the soldiers practically helpless in the presence of a swift attack. These two weapons of offence, and particularly the first, because of the frightful and long-continuing agony it inflicts upon its victims, fascinated the observer, and awakened the bitter protests of those who held that an issue at war might be determined by civilized nations without recourse to engines of death and anguish more barbaric than any known to the red Indians, or the most savage tribes of Asia. Neither of these devices, nor for that matter the cognate one of fire spurted like a liquid from a hose upon a shrinking enemy, can be shown to have had any appreciable effect upon the fortunes of any great battle. Each, as soon as employed by any one belligerent, was quickly seized by the adversary, and the respiratory mask followed fast upon the appearance of the chlorine gas. Whatever the outcome of the gigantic conflict may be, no one will claim that any of these devices had contributed greatly to the result.

But the airplane revolutionized warfare on land. The submarine has made an almost equal revolution in naval warfare.

Had the airplane been known in the days of our Civil War some of its most picturesque figures would have never risen to eminence or at least would have had to win their places in history by efforts of an entirely different sort. There is no place left in modern military tactics for the dashing cavalry scout of the type of Sheridan, Custer, Fitz Lee, or Forrest. The airplane, soaring high above the lines of the enemy, brings back to headquarters in a few hours information that in the old times took a detachment of cavalry days to gather. The "screen of cavalry" that in bygone campaigns commanders used to mask their movements no longer screens nor masks. A general moves with perfect knowledge that his enemy's aircraft will report to their headquarters his roads, his strength, and his probable destination as soon as his vanguard is off. During the Federal advance upon Richmond, Stonewall Jackson, most brilliant of the generals of that war, repeatedly slipped away from the Federal front, away from the spot where the Federal commanders confidently supposed him to be, and was found days later in the Valley of the Shenandoah, threatening Washington or menacing the Union rear and its communications. The war was definitely prolonged by this Confederate dash and elusiveness—none of which would have been possible had the Union forces possessed an aviation corps.

It is yet to be shown conclusively that as offensive engines aircraft have any great value. The tendency of the military authorities of every side to minimize the damage they have suffered makes any positive conclusion on this subject difficult and dangerous at this moment. The airplane by day or the Zeppelin by night appears swiftly and mysteriously, drops its bombs from a height of several thousand feet, and takes its certain flight through the boundless sky to safety. The aggressor cannot tell whether his bombs have found a fitting target. He reports flaming buildings left behind him, but whether they are munition factories, theatres, or primary schools filled with little children he cannot tell. Nor does he know how quickly the flames were extinguished, or the amount of damage done. The British boast of successful air raids upon Cuxhaven, Zeebrugge, Essen, and Friedrichshaven. But if we take German official reports we must be convinced that the damage done was negligible in its relation to the progress of the war. In their turn the Germans brag mightily of the deeds of their Zeppelins over London, and smaller British towns. But the sum and substance of their accomplishment, according to the British reports, has been the slaughter and mutilation of a number of civilians—mostly women and children—and the bloody destruction of many humble working-class homes.

At this writing, December, 1917, it is not recorded that any battleship, munition factory, any headquarters, great government building, or fortress has been destroyed or seriously injured by the activities of aircraft of either type. This lack of precise information may be due to the censor rather than to any lack of great deeds on the part of airmen. We do know of successful attacks on submarines, though the military authorities are chary about giving out the facts. But as scouts, messengers, and guides for hidden batteries attacking unseen targets, aviators have compelled the rewriting of the rules of military strategy. About this time, however, it became apparent that the belligerents intended to develop the battleplanes. Particularly was this true of the Allies. The great measure of success won by the German submarines and the apparent impossibility of coping adequately with those weapons of death once they had reached the open sea, led the British and the Americans to consider the possibility of destroying them in their bases and destroying the bases as well. But Kiel and Wilhelmshaven were too heavily defended to make an attack by sea seem at all practicable. The lesser ports of Zeebrugge and Ostend had been successfully raided from the air and made practically useless as submarine bases. Discussion therefore was strong of making like raids with heavier machines carrying heavier guns and dropping more destructive bombs upon the two chief lurking places of the submarines. While no conclusion had been reached as to this strategy at the time of the publication of this book, both nations were busy building larger aircraft probably for use in such an attack.

The submarine has exerted upon the progress of the war an influence even more dominant than that of aircraft. It has been a positive force both offensive and defensive. It has been Germany's only potent weapon for bringing home to the British the privations and want which war entails upon a civilian population, and at the same time guarding the German people from the fullest result of the British blockade. It is no overstatement to declare that but for the German submarines the war would have ended in the victory of the Allies in 1916.

We may hark back to our own Civil War for an illustration of the crushing power of a superior navy not qualified by any serviceable weapon in the hands of the weaker power.

Historians have very generally failed to ascribe to the Federal blockade of Confederate ports its proportionate influence on the outcome of that war. The Confederates had no navy. Their few naval vessels were mere commerce destroyers, fleeing the ships of the United States navy and preying upon unarmed merchantmen. With what was rapidly developed into the most powerful navy the world had ever seen, the United States Government from the very beginning of the war locked the Confederate States in a wall of iron. None might pass going in or out, except by stealth and at the peril of property and life. Outside the harbour of every seaport in the control of the Confederates the blockading men-of-war lurked awaiting the blockade runners. Their vigilance was often eluded, of course, yet nevertheless the number of cargoes that slipped through was painfully inadequate to meet the needs of the fenced-in States. Clothing, medicines, articles of necessary household use were denied to civilians. Cannon, rifles, saltpetre, and other munitions of war were withheld from the Confederate armies. While the ports of the North were bustling with foreign trade, grass grew on the cobble-stoned streets along the waterfronts of Charleston and Savannah. Slow starvation aided the constant pounding of the Northern armies in reducing the South to subjection.

Had the Confederacy possessed but a few submarines of modern type this situation could not have persisted. Then, as to-day, neutral nations were eager to trade with both belligerents. There were then more neutrals whose interests would have compelled the observance of the laws of blockade, which in the present war are flagrantly violated by all belligerents with impunity. A submarine raid which would have sunk or driven away the blockading fleet at the entrance to a single harbour would have resulted in opening that harbour to the unrestricted uses of neutral ships until the blockade could be re-established and formal notice given to all powers—a formality which in those days, prior to the existence of cables, would have entailed weeks, perhaps months, of delay.

How serious such an interruption to the blockade was then considered was shown by the trepidation of the Union naval authorities over the first victories of the Merrimac prior to the providential arrival of the Monitor in Hampton Roads. It was then thought that the Confederate ram would go straight to Wilmington, Charleston, and Savannah, destroy or drive away the blockaders, and open the Confederacy to the trade of the world.

Even then men dreamed of submarines, as indeed they have since the days of the American Revolution. Of the slow development of that engine of war to its present effectiveness we shall speak more fully in later chapters. Enough now to say that had the Confederacy possessed boats of the U-53 type the story of our Civil War might have had a different ending. The device which the Allies have adopted to-day of blockading a port or ports by posting their ships several hundred miles away would have found no toleration among neutrals none too friendly to the United States, and vastly stronger in proportion to the power of this nation than all the neutrals to-day are to the strength of the Allies.

Victory in the Clouds.
Painting by John E. Whiting.