For the remainder of 1916 the boche treated us with gradually increasing numbers of Green Cross Shell. His tactics, too, got a bit better--I mean for him--for he began to make more concentrated bombardments on particular targets. Possibly this was because of special orders that were issued on the subject. One of these was by General von Buelow to the artillery of his army, in which he said: “There have been many instances of Green Cross Shell being fired in small quantities. This is a waste of ammunition, as with all gas shell good effects are only obtained by using them in large quantities. The firing of small quantities of gas shell has also the disadvantage that the enemy is practiced in the use of his anti-gas appliances and attains a higher degree of gas preparedness. For this reason the effect produced by larger quantities will be reduced.” This showed the increasing interest in the use of gas shell taken by the German General Staff, and heavier and more concentrated bombardments based on the above orders became more frequent. One of these, brought off in unusual circumstances, occurred at Arras in December, 1916. I say “unusual” because the weather was so cold at the time that the Green Cross liquid did not evaporate so quickly as usual but hung about in some places for long periods. The bombardment occurred at night and about three thousand shell must have been fired into one corner of the town--in fact, all round the old gateway through which the whole of the transport from the St. Pol road would have to pass. The surrounding houses and cellars got filled with gas, and in such billets, especially where shell had actually burst inside a room, the liquid soaked into the walls and floors and only evaporated the next morning when the air grew warmer. A lot of men were gassed in this manner on the following day, as they naturally thought the gas had vanished, and were gradually overcome as things warmed up. In the open, gas disappeared more at its usual rate, though it hung about all during the bombardment and for several hours after, thus forcing men in the neighbourhood to wear respirators for long periods. Some of these men, overcome by fatigue, actually slept in their respirators. I think this was the first time I had heard of its being done, though it has been done often enough since.