The ground plan of my three-day trip was planned to give me a condensed view of all the component parts of a French army of five army corps, or about 200,000 men, from the rear up to the front trench. We accordingly began with the Motor Transport Repair Corps, situated in Epernay, consisting of 1,000 men and 14 officers, including 3 doctors. It kept in up-to-the-minute running order the 1,500 motor vehicles of the army corps which occupied the front 20 miles before us. The Captain who showed us around had been technical supervisor of the Rochet-Schneider Auto Company and had, together with all the other mechanical experts, been mobilized directly into the present work. He answered my surprise at the number of soldiers employed in these peaceful labors by explaining that two soldiers at work in the rear for every three soldiers fighting was the regular formula. Epernay, being the centre of the champagne industry, most of the military repair garages had been located in the great wine storehouses. It was odd to see soldiers repainting grim wire-cutting autos rubbing elbows with peasant women busily wrapping gold-foil round the heads of fat quarts of famous vintages. "Yes, they work together," smiled the Captain; "and it is not so incongruous as it looks. For the champagne was a good ally of ours during the battle of the Marne. It made enough casualties among the Boches to have an appreciable effect on the course of the battle. When we chased them out of here the broken bottles looked as though there were no more champagne left in the world. But as a matter of fact, so enormous are the quantities stored hereabouts that the German inroads were relatively slight." It was remarkable how much we were able to crowd into an hour's inspection. Great meat-lorries, each carrying enough fresh carcasses to stock a city butcher-shop, secured ventilation yet guarded their contents against flies by close-meshed steel netting instead of solid sides. But to protect the meat from dust science had had to bow to nature, for to the netting in its turn were attached pine boughs which admitted air while excluding dust more efficiently than any artificial contrivance. Enormous repair-lorries were each a perambulating garage fully equipped with machinery for repairing broken parts or making new ones. Some of these lorries ran on their own power. Others were towed along by a big motor. In either case they made their own power to run their repair machinery, and their own brilliant electric light by which to work at night. They had almost hermetically sealed curtains to keep the light from leaking out, for in mobile war they are often called upon to do their work in sight and range of the enemy. But the trench warfare has rooted them to the spot for a weary time. "But wait!" said the Captain. "When the advance begins just watch us keep up with the procession."