We stopped at a gap in the firs and walked to the brink of the plateau.  Just under us lay a rock-rimmed lake.  More zig-zag earthworks surmounted it on all sides, and on the nearest shore was the branched roofing of another great mule-shelter.  We were looking down at the spot to which the night-caravans of the Chasseurs Alpins descend to distribute supplies to the fighting line.

“Who goes there?  Attention!  You’re in sight of the lines!” a voice called out from the firs, and our companion signed to us to move back.  We had been rather too conspicuously facing the German batteries on the opposite slope, and our presence might have drawn their fire on an artillery observation post installed near by.  We retreated hurriedly and unpacked our luncheon-basket on the more sheltered side of the ridge.  As we sat there in the grass, swept by a great mountain breeze full of the scent of thyme and myrtle, while the flutter of birds, the hum of insects, the still and busy life of the hills went on all about us in the sunshine, the pressure of the encircling line of death grew more intolerably real.  It is not in the mud and jokes and every-day activities of the trenches that one most feels the damnable insanity of war; it is where it lurks like a mythical monster in scenes to which the mind has always turned for rest.

We had not yet made the whole tour of the mountain-top; and after luncheon we rode over to a point where a long narrow yoke connects it with a spur projecting directly above the German lines.  We left our mules in hiding and walked along the yoke, a mere knife-edge of rock rimmed with dwarf vegetation.  Suddenly we heard an explosion behind us:  one of the batteries we had passed on the way up was giving tongue.  The German lines roared back and for twenty minutes the exchange of invective thundered on.  The firing was almost incessant; it seemed as if a great arch of steel were being built up above us in the crystal air.  And we could follow each curve of sound from its incipience to its final crash in the trenches.  There were four distinct phases:  the sharp bang from the cannon, the long furious howl overhead, the dispersed and spreading noise of the shell’s explosion, and then the roll of its reverberation from cliff to cliff.  This is what we heard as we crouched in the lee of the firs:  what we saw when we looked out between them was only an occasional burst of white smoke and red flame from one hillside, and on the opposite one, a minute later, a brown geyser of dust.

Presently a deluge of rain descended on us, driving us back to our mules, and down the nearest mountain-trail through rivers of mud.  It rained all the way:  rained in such floods and cataracts that the very rocks of the mountain seemed to dissolve and turn into mud.  As we slid down through it we met strings of Chasseurs Alpins coming up, splashed to the waist with wet red clay, and leading pack-mules so coated with it that they looked like studio models from which