The Marshal postponed the attack for another day. Rumor gave the reason that the French Fourth Army was not ready; possibly the real reason, or at least a contributory reason, was in the canniness of such an old hand at offensives as Marshal Foch. Ours was a new army under enormous pressure. Veteran armies were always asking, at the last moment, for more time in which to complete their preparations before attacking. Possibly the Marshal had set the 25th as the date with a view to forcing our effort under spur of the calendar, while he looked forward to granting the inevitable request for delay. At all events the respite was most welcome. Our staff had time for further conferences and attention to their arrangements for supplies, and our combat troops a breathing spell which gave their officers another day in which to study the positions they were to storm. When I considered all the digging necessary for making the gun positions, or had even a cursory view of the parks of divisional transport, of the reserves crowded in villages and woods, of the ammunition trains, and of the busy corps and division headquarters, I wondered if it were possible that the Germans could not have been apprised that a concentration was in progress. Not only did pocket lamps flash like fireflies from the hands of those who used them thoughtlessly, but despite precautions careless drivers turned on motor lights, and some rolling kitchen was bound to let out a flare of sparks, while the locomotives running in and out at railheads showed streams of flames from their stacks, and here and there fires were unwittingly started. An aviator riding the night, as he surveyed the shadowy landscape, could not miss these manifestations of activity. If he shut off his engine he might hear above the low thunder of transport the roar of the tanks advancing into position, of the heavy caterpillar tractors drawing big guns. When the air was clear and the wind favorable, the increasing volume of sound directed toward the front must have been borne to sharp ears on the other side of No Man's Land. All this I may mention again, without reference to observations by spies within our lines.