The Divisional organization was introduced just before the campaign of Jena in 1806, when the Division had 10 to 12 Battalions, 15 Squadrons, and 24 to 30 guns. By 1813, in the War of Liberation, Army Corps of 4 Brigades had replaced the Division. The Brigade was a mixed one of all Arms, and comprised 2 Regiments, or 6 Battalions, and 1 Battalion of Grenadiers formed by massing the Grenadier Companies of the Battalions. There were allotted to the Brigades 3 Regiments of Cavalry and 2 Batteries of 8 guns each. In 1815, in the Waterloo campaign, we find a similar organization, but the Brigades were of 3 Regiments, and dearth of Cavalry and Artillery only allowed 2 Squadrons, and 1 Battery of 8 guns, for each Brigade. The mistake of the Prussian organization in the Napoleonic Wars was that the whole of the Cavalry and Artillery were split up among the Brigades, and there was no body of either to oppose the massed Horse and guns of Napoleon’s Reserve, which he threw into action at the crucial moment with overpowering effect. This error was corrected, and after Waterloo the Army Corps comprised 3 Divisions which represented the old Brigades, and a Cavalry Division of 2 Brigades of 2 Regiments each, with 2 Horse Artillery Batteries. In 1853 the Army Corps was organized in its modern shape in 2 Divisions, of 2 Brigades, of 2 Regiments, with 1 Cavalry Regiment; but it had only 4 Batteries, or 32 guns, with each Division, and no Corps Artillery. In 1860 the Field Batteries, which had until then 8 guns, were reduced to their present strength of 6 guns. The experience gained in 1866 caused considerable modification in organization to be made before the war of 1870 broke out. The Reserve Artillery was abolished, and divided among the Army Corps, thus forming “Corps Artillery” of 7 Batteries. The 5th Squadron of Cavalry was made into a depôt, and Regiments took the field in 1870 with 4 Squadrons only, as at present. The Reserve Cavalry was abolished, and Cavalry Divisions formed. These were attached, not to Army Corps as in France, but to Armies, being intended for reconnaissance far to the front. Of recent years the Corps Artillery has been abolished, and the Batteries comprising it are distributed among the two Divisions, so as to increase the co-operation of the Artillery with the Infantry. PROPORTIONS OF THE ARMS CAVALRY AND INFANTRY In the sixteenth century the Horse outnumbered the Foot, but in the Thirty Years’ War they were roughly equal. In the English Civil War, and later in the seventeenth century, the Infantry began to outnumber the Cavalry, and in the eighteenth century the proportion of Foot to Horse rose, till it was in the proportion of 3, or even 4 to 1, and in the Napoleonic Wars, of 6 or 8 to 1.