I was conjecturing in a feverish sort of way how far we had been from the trenches and if that shrapnel line had been bursting over them, or if the enemy, spotting a base of some kind, had begun to shell it, when growing out of the air there approached a sound. Scarcely audible at first, like the faint whining of the wind, gathering its frenzy, now whistling, screaming, shrieking, I heard somewhere near in the void, the song of a shell. And when writing on the observer's table, I was trying to jot down how it felt, I heard another, nearer it seemed, and the pencil fell from my fingers, rolling down until it stopped by the ledge while I sat staring at it and trying not to think what might have occurred had we been a few seconds faster or the shell a few seconds slower. And then I felt myself slide forward in the seat and I knew that the machine was diving down. There was no danger, I felt; of course the aviator was all right, No shrapnel had burst near us but then, we might have been within rifle range. No! Absurd! Yet I quickly glanced over my shoulder and felt centuries younger when I saw the smile on Hals' solemn face. And then, as unexpectedly as it had begun, the downward bolt ceased. Hals was rattling the celluloid screen. It dawned on me that he wanted to tell me something. I leaned back and he leaned forward. I could hear him but faintly although he shouted. "Those shells were on the same elevation as we, or we could not have heard them. So I dove." And there they were screaming their death song overhead now, although I could no longer hear them. We flew towards a yellow château and then once more began to climb. Of course we were out of the path of the shells, but Hals had not then known that we were in the line of howitzers. The minutes passed, and slowly I admitted that the danger was over. A stinging pain, moreover, was settling above my eyes, and what I might have put down to the quick breathing of excitement, I realized now to be the gasping of the lungs in a rarified atmosphere. High indeed we were climbing, for the earth seemed to shrink and its many colors to blend themselves in a vague tinting suffusion of purple and gold, the veil of a dream.