A division with all its artillery, machine-guns, and transport is a ponderous column in movement, with every part having its regulation place. One day in one set of villages and the next in another, the communication of orders and requirements down through all the branches is difficult, and the more so when you are short of dispatch riders, and there is a limit to what can be done over the field telephone. The unexpected demand for wires for our second great offensive must not find the signal corps unprepared; or a people as dependent on telephones and telegraph as we are, and so accustomed to having them materialize on request, would have been helpless in making war. The deepest tactical concern was, of course, the coördination of the artillery with the infantry advance. It is only a difference of a hundred yards' range, as we all know, between putting your shells among your own men instead of the enemy's. Reliable communication from the infantry to the aviator and his reliable report of his observations to the artillery and infantry is one of the complicated features in that team-play, which, in the game of death, needs all the finesse of professional baseball, a secret service, and a political machine, plus the requisite poise, despite poor food and short hours of sleep, for worthily leading men in battle. Some divisions that went into this action had not yet received their artillery; or again their artillery arrived from the training camp, where the guns had just been received, barely in time to go into position, so that an inexperienced artillery commander reported to an inexperienced division commander with whom he had never served. There were batteries without horses, which the horses of other batteries pulled into position after they had brought up their own. Battery commanders received their table of barrages and their objectives of fire, and, without registering, had to trust to observation by men untried in battle or by aviators who had never before observed in a big operation. Aviators had been trained to expect the infantry to put out panels, and they might say that the infantry did not show their panels, while the infantry would deny the charge. Such things had happened before. They would happen this time. They happen to the most veteran of armies, whose long experience, however, may have an excellent substitute in other qualities which we had in plenitude, as we shall see.