As we tramped along towards St. Julien our attention was attracted to a greenish yellow smoke ascending from the part of the line occupied by the French. We wondered what the smoke was coming from. Half a mile up the road we seated ourselves on a disused trench and lit cigarettes, while I began to read a home letter which I had found at Brielen.
An aeroplane flying low overhead dropped some fire-balls. Immediately a violent artillery cannonade began. Looking towards the French line we saw this yellowish green cloud rising on a front of at least three miles and drifting at a height of perhaps a hundred feet towards us.
"That must be the poison gas that we have heard vague rumours about," I remarked to the Captain. The gas rose in great clouds as if it had been poured from nozzles, expanding as it ascended; here and there brown clouds seemed to be mixed with the general yellowish green ones. "It looks like chlorine," I said, "and I bet it is." The Captain agreed that it probably was.
The cannonade increased in intensity. About five minutes after it began a hoarse whistle, increasing to a roar like that of a railroad train, passed overhead. "For Ypres," we ejaculated, and looking back we saw a cloud as big as a church rise up from that ill-fated city, followed by the sound of the explosion of a fifteen-inch shell. Thereafter these great shells succeeded one another at regular intervals, each one followed by the great black cloud in Ypres.
The bombardment grew in intensity. Over in a field not two hundred yards away numerous coal boxes exploded, throwing up columns of mud and water like so many geysers. General Alderson and General Burstall of the Canadian Division came hurrying up the road and paused for a moment to shake hands, and to remark that the Germans appeared to be making a heavy attack upon the French. We wondered whether they would get back to their headquarters or not.
Shells of various calibres, whistling and screaming, flew over our heads from German batteries as well as from our own batteries replying to them. The air seemed to be full of shells flying in all directions. The gas cloud gradually grew less dense, but the bombardment redoubled in violence as battery after battery joined in the angry chorus.
Across the fields we could see guns drawn by galloping horses taking up new positions. One such gun had taken a position not three hundred yards away from us when a German shell lit apparently not twenty feet away from it; that gun was moved with despatch into another position.
Occasionally we imagined that we could hear heavy rifle and machine gun fire, but the din was too great to distinguish much detail. The common expression used on the front, "Hell let loose," was the only term at all descriptive of the scene.
Streaking across the fields towards us came a dog. On closer view he appeared to be a nondescript sort of dog of no particular family or breeding. But he was bent on one purpose, and that seemed to be to put as great a distance as possible between himself and the Germans. He had been gassed, and had evidently been the first to get out of the trenches. Loping along at a gait that he could, if necessary, maintain for hours, he fled by with tail between his legs, tongue hanging out and ears well back. And as he passed he gave us a look which plainly said, "Silly fools to stand there when you could get out; just wait there and you will get yours." And on he went, doubtless galloping into the German lines on the opposite side of the salient.
By this time our eyes had begun to run water, and became bloodshot. The fumes of the gas which had reached us irritated our throats and lungs, and made us cough. We decided that this gas was chiefly chlorine, with perhaps an admixture of bromine, but that there was probably something else present responsible for the irritation of our eyes.