All the Reconnaissance Officers and the Tank Staff who had to frequent the line wore non-committal burberries and discreet tin hats; one well-known Staff Officer even went to the length of affecting blue glasses; in fact, in the matter of disguise the line was only drawn at ginger whiskers. The cars they came in had their distinguishing badges taken off, and their drivers were carefully primed with cock-and-bull stories with which to explain their presence. Staff and Reconnaissance Officers slunk about, above all avoiding Headquarters and those other social centres which etiquette enjoins must be first called upon by all who visit other people’s trenches. Friends were stealthily avoided, and a curious jumble of assorted and obvious lies was gradually put into circulation. At the Lyceum the villain conducts his affairs in this sort of way without arousing the least suspicion in any one, but in real life, and particularly in the line where a look-out must constantly be kept for spies, such conduct is apt to cause remark. Before Cambrai embarrassing situations frequently arose which could be elucidated only by the drawing aside of some justly indignant Commanding Officer for a few minutes’ whispered conversation. At the 1st Brigade Headquarters in Arras there was a locked room with “No admittance” written large upon the door. Here were ostentatiously hung spoof maps of other topical districts and a profusion of plans lay spread about. The Reconnaissance Officer always hoped that this room was duly ransacked by the “unauthorised person,” for whose visit he had taken such pains to prepare. One more precaution was most carefully observed in the line itself. Exactly the amount of artillery fire to which the enemy was accustomed must be continued, and from guns of the calibre which he expected. It was considered that more or less shooting, or the use of guns to which he was not accustomed, would be sure to alarm him. For more than a week before the battle there was no rain. Low, creeping mists screened our movements and made it almost impossible that the enemy should have seen us from the air. But the time was, nevertheless, an anxious one. On the night of the 18th-19th the enemy raided our line and captured some of our men. We were uncertain how much these men knew, and how much information they would give under examination. If under prompt examination they gave away the gist of our plans the enemy would have twenty-four hours in which to bring up reserves. There was, however, nothing to be done except to await the event. There was yet one other particular in which the Battle of Cambrai was to differ from other battles. In modern warfare the place of the General commanding any considerable body of troops is almost invariably in the rear at some point where communications are good and whence he can effectively control his reserves.