The structural organization of the corps, as it existed at the close of the war, consisted of General Tank Headquarters, with 15 officers and 60 men; Army Tank Headquarters (one for each field army), with 7 officers and 27 men; Brigade Headquarters, 4 officers and 47 men; a Heavy Battalion, with a strength of 68 officers and 778 men; a Light Battalion, consisting of 20 officers and 375 men; a repair and salvage company, 4 officers and 146 men; a Depot Company, 4 officers and 138 men. To each Army Tank Headquarters were assigned 5 brigades, each brigade being composed of 3 battalions, 1 heavy and 2 light, and 1 repair and salvage company. A battalion consists of three companies, each company having three platoons. As five fighting-tanks are assigned to each platoon, it will thus be seen that a field army has 675 tanks at its disposal. The commissioned and enlisted personnel of the Tank Corps was of as high an average, both mentally and physically, as any organization in the army, not even excepting the Air Service. About 65 per cent of the corps were technically trained men—engineers and machinists—while the remaining 35 per cent was composed of business and professional men, farmers, cow-punchers, college undergraduates, and soldiers of fortune. They came from every section of every State in the Union. Their versatility was denoted by the pipings of their overseas caps—blue, red, and yellow—which denoted that they combined the functions of infantry, artillery, and cavalry. Several other colors might appropriately have been added, however, for the tank men were as familiar with Browning, Lewis, and Vickers as the machine-gunners, they knew as much about gas-engines as the Motor Transport Corps, they were as competent to make repairs as the men of the Ordnance Department, and in action they took as many risks as the youngsters on whose breasts were embroidered the silver wings. They were as keen as razors and as hard as nails. They were, to use the phraseology of the plains, fairly “rarin’ to go,” and they were ready and anxious to fight at the drop of the hat. In fact, that was why they joined the Tank Corps—because they believed it offered more opportunities for Boche-killing than any other branch of the service.