He invariably kept the Reserve Army Corps, as well as the Cavalry and Artillery Reserve, in his own hands, for decisive action at the crucial moment of the battle. These Army Corps were soon imitated by Prussia after 1806, by Austria before 1809, and by Russia by 1812, and became the permanent organization of the first two nations down to this day; but it was not definitely adopted by Russia until the close of the nineteenth century. In the Civil War in the United States both sides adopted Army Corps, which the size of their armies rendered desirable. STRENGTH OF ARMY CORPS The strength of Napoleon’s Army Corps was very variable. In the Grande Armée it was at first 2 or 3 Divisions of 2 or 3 Brigades, with 1 Cavalry Division, or from 19,000 to 30,000 in all. The Cavalry Corps was of 20,000 with 2 Horse Artillery Batteries. In later campaigns the Army Corps grew larger, and their strength varied with the quality of their Commander. In 1809 they were of 30,000 to 40,000 men, and one was of 4 Divisions with 60,000. In 1812 the French Corps varied from 30,000 to 70,000, the largest having 5 Divisions; but the Corps of the foreign allies were less than 25,000 strong. There were four Cavalry Corps, each of 28 Squadrons of Light Cavalry, 16 of Cuirassiers, and 16 of Dragoons. In 1813 the French Corps varied from 20,000 to 50,000, and the Cavalry Corps from 10,000 to 16,000. In 1815 the Corps were from 16,000 to 24,000 strong, and the Cavalry Corps was in 4 Divisions. Throughout these campaigns most of the Army Corps had a Cavalry Division attached to them. Since Napoleon’s time the organization of the French Army has been on similar lines. In the war with Austria in 1859 the Army Corps had 2 Divisions, each of 2 Brigades, or 18 to 20 Battalions, with 40 to 56 guns. In 1870 the Army Corps were of 3 Divisions with a Light Cavalry Division of 2 Brigades. Those commanded by a Marshal had 4 Divisions and a Cavalry Division of 4 Brigades. The Artillery with each Division consisted of 3 Field Batteries and 1 of Mitrailleuses; the Corps Artillery of 5 Batteries. As in Napoleon’s armies, there were Reserve Divisions of Heavy Cavalry, comprising 2 Brigades of 2 Regiments, with 2 Batteries of Horse Artillery. One evil of this organization was that the Light Cavalry Divisions kept close to their Army Corps, and the distant reconnoitring for the whole army fell to the Reserve Heavy Divisions, which were unsuited to this duty, and were often kept actually in reserve. PRUSSIAN ORGANIZATION IN THE NINETEENTH CENTURY