The enemy patrols that poked through the Polygon Wood at daybreak on the 4th, and discovered the British retirement to a line further west, must indeed have been surprised. The fighting of the previous ten days had cost the Allies over thirty square miles of ground and more than 20,000 casualties, but the British Army had undoubtedly gained in morale, nevertheless. Colonials and Territorials, as well as old line regiments filled with new reserve men, had fought shoulder to shoulder with the veterans of Le Cateau and the Aisne, every unit gaining strength unconsciously as each contingent rose in the other's estimation. Mutual admiration and mutual confidence had welded the Army all the more closely together. On a call at 5th Corps Headquarters at Abele, west of Poperinghe, I saw a couple of what appeared to be divers' helmets. These were loaded into a car, with a good-sized roll of rubber tubing and a homely pair of bellows attached to each of the grotesque pieces of headgear. Curious, I asked a "Q" officer, standing near by, just how this paraphernalia was to be used. "People get strange ideas about fighting gas," he said. "These outfits were designed and forwarded to us to be sent up front, so up front I am sending them. They are provided to allow some of our men, say about 3 in every 10,000, so far as present supply goes, to stay in the gas-filled trenches while some pals with the bellows pump good air to them through a few hundred feet of hose. "If the gas area should be of considerable extent the chap with the bellows would soon be pumping chlorine into his fellow-Tommy, and die pumping at that, or else take to the woods and let the diver himself get what air he could find. "Many accidents might befall the tube. A Hun might sit on it. I hate to think of myself, squatting in a trench with one of those things over my head, praying for air, with the bellows man pumping his heart out trying to get ozone through a rubber tube on top of which some fat Boche had plumped, while he potted away at one or the other of us. "A shell, too, would have an interesting time with such a tube. Imagine the chap in the helmet hollering, 'Pump away, you lazy beggar, I'm not getting enough air to keep a flea alive,' and all the good old oxygen pouring out of a jagged hole in the bally pipe, hundreds of feet from him. "Then, suppose a man, coming up before daylight, got his foot caught in that length of tube," he continued enthusiastically--but I realised I had started something I couldn't stop, and fled.