What the results might have been if the full weight of the massed attack could have been prepared without detection and flung on our lines without warning is hard to say; but there is every chance that our first line at least might have been broken into and swamped by the sheer weight of numbers.  That, clearly, is what the Germans had intended, and from the number of men employed it is evident that they meant to push to the full any chance our breaking line gave them to reoccupy and hold fast a considerable portion of the ground they had lost.  It is said that three to four full divisions were used.  If that is correct, it is certain that the German army was minus three to four effective divisions when the attack withdrew, that a good half of the men in them would never fight again.  The attack lost its first great advantage in losing the element of surprise.  The bulk of the troops would have been moved into position in the hours of darkness.  That wood, in all probability, was filled with men by night.  The only daylight movement attempted would have been the cautious filling of the trenches, the pouring in of the long gray-coated lines along the communication trenches, all keeping well down and under cover.  Under the elaborate system of deep trenches, fire-, and support-, communication- and approach-trenches running back for miles to emerge only behind houses or hill or wood, it is surprising how large a mass of men can be pushed into the forward trenches without any disclosure of movement to the enemy.  Scores of thousands of men may be packed away waiting motionless for the word, more thousands may be pouring slowly up the communication ways, and still more thousands standing ready a mile or two behind the lines; and yet to any eye looking from the enemy’s side the country is empty and still, and bare of life as a swept barn.  Even the all-seeing airmen can be cheated, and see nothing but the usual quiet countryside, the tangled crisscross of trenches, looking from above like so many wriggling lines of thin white braid with a black cord-center, the neat dolls’ toy-houses and streets of the villages, the straight, broad ribbon of the Route Nationale, all still and lifeless, except for an odd cart or two on the high road, a few dotted figures in the village streets.  Below the flying-men the packed thousands are crouched still to earth.  At the sound of the engine’s drone, at sight of the wheeling shape, square miles of country stiffen to immobility, men scurry under cover of wall or bush, the long, moving lines in the trenches halt and sink down and hang their heads (next to movement the light dots of upturned, staring faces are the quickest and surest betrayal of the earth-men to the air-men), the open roads are emptied of men into the ditches and under the trees.  For civilized man, in his latest art of war, has gone back to be taught one more simple lesson by the beasts of the field and birds of the air; the armed hosts are hushed and stilled by the passing air-machine, exactly as the finches and field-mice of hedgerow and ditch and field are frozen to stillness by the shadow of a hovering hawk, the beat of its passing wing.