My eyes were glued to my glasses, but they shook in my hands so that I could scarcely see.  I bit my lip to steady myself, but they still wavered.  From time to time I glanced at my watch.  Eight minutes gone—­ten—­seventeen.  If only the planes would come into sight!  Even the certainty of failure would be better than this harrowing doubt.  They should be back by now unless they had swung north across the salient, or unless the miracle of miracles—­

Then came the distant yapping of an anti-aircraft gun, caught up the next second by others, while smoke patches studded the distant blue sky.  The clouds were banking in mid-heaven, but to the west there was a big clear space now woolly with shrapnel bursts.  I counted them mechanically—­one—­three—­five—­nine—­with despair beginning to take the place of my anxiety.  My hands were steady now, and through the glasses I saw the enemy.

Five attenuated shapes rode high above the bombardment, now sharp against the blue, now lost in a film of vapour.  They were coming back, serenely, contemptuously, having seen all they wanted.

The quiet was gone now and the din was monstrous.  Anti-aircraft guns, singly and in groups, were firing from every side.  As I watched it seemed a futile waste of ammunition.  The enemy didn’t give a tinker’s curse for it . . .  But surely there was one down.  I could only count four now.  No, there was the fifth coming out of a cloud.  In ten minutes they would be all over the line.  I fairly stamped in my vexation.  Those guns were no more use than a sick headache.  Oh, where in God’s name were our own planes?

At that moment they came, streaking down into sight, four fighting-scouts with the sun glinting on their wings and burnishing their metal cowls.  I saw clearly the rings of red, white, and blue.  Before their downward drive the enemy instantly spread out.

I was watching with bare eyes now, and I wanted companionship, for the time of waiting was over.  Automatically I must have run down the knoll, for the next I knew I was staring at the heavens with Archie by my side.  The combatants seemed to couple instinctively.  Diving, wheeling, climbing, a pair would drop out of the melee or disappear behind a cloud.  Even at that height I could hear the methodical rat-tat-tat of the machine-guns.  Then there was a sudden flare and wisp of smoke.  A plane sank, turning and twisting, to earth.

‘Hun!’ said Archie, who had his glasses on it.

Almost immediately another followed.  This time the pilot recovered himself, while still a thousand feet from the ground, and started gliding for the enemy lines.  Then he wavered, plunged sickeningly, and fell headlong into the wood behind La Bruyere.

Farther east, almost over the front trenches, a two-seater Albatross and a British pilot were having a desperate tussle.  The bombardment had stopped, and from where we stood every movement could be followed.  First one, then another, climbed uppermost and dived back, swooped out and wheeled in again, so that the two planes seemed to clear each other only by inches.  Then it looked as if they closed and interlocked.  I expected to see both go crashing, when suddenly the wings of one seemed to shrivel up, and the machine dropped like a stone.