The most important feature of this long tour was the appearance of American troops. The 30th Division of the American Expeditionary Force had been attached to the 49th and 33rd Divisions for instruction. This division was recruited entirely from North and South Carolina and Tennessee. Some of its companies boasted continuity from units of the Confederate Army in the American Civil War, and many of the officers and men were descendants of those who had fought under Lee and Jackson; indeed, the Intelligence Officer of one of the regiments of this division was a grandson of General Robert E. Lee. Physically the men were very fine, and the standard of education among them was very high. They were mostly recruited from agricultural districts, and were magnificent rifle shots. During the tour many officers and other ranks--or, as they are called in the American Army, “enlisted men”--were attached to the Battalion for instruction in trench duties. They proved themselves very keen to learn, and the Battalion got on well with them. On July 15th the Battalion went back for its second period of rest at Siege Camp. After eight days it went into brigade reserve to the Right Sector. But the same night, before the relief was carried out, the men were engaged in an operation of, to them, an entirely new type. This operation was always known as Scheme B. It was a cloud gas discharge, and was to be carried out as follows:-- 1. Nine light railway trains, each consisting of seven trucks, all loaded with gas cylinders, were to be brought up to Austral Dump by light engines. Here they were to be taken over by the Battalion, six men to a truck, and pushed out into No Man’s Land in front of White Chateau, along an old light railway which ran there. 2. The men were then to withdraw into the support line, and the gas from all the cylinders was to be discharged simultaneously by a system of detonators, exploded electrically. 3. When sufficient time had been allowed for the gas to clear, the men were to go out again and push the trucks back to Austral Dump, where they would be taken charge of by the light railway men again. The Battalion’s part in the operation sounded simple, but it was to prove far otherwise.