Ambulance train.This photograph shows to what a state of perfection, in drill and equipment, the ambulance service of the Union armies had been brought by April, 1863. The castle on the ambulance curtains indicates the Engineer Corps. The little vignette below the larger photograph shows the train unharnessed and at rest. Starting with a medical department scarcely adequate for eleven thousand men in time of peace, the ambulance service was ultimately increased, developed, and organized into a vast administrative medico-military machine, working smoothly in all its ramifications and meeting efficiently the needs of a force aggregating, at one time, nearly a million men, exposed to the fire of an able opponent, and very often compelled to operate under unfavorable conditions and amid unhealthful surroundings. The department brought order out of chaos, health from disease, and surcease from suffering, in a manner and to a degree previously unparalleled. Its achievements must challenge the admiration of medical men for all time.