The month of April was occupied by General Kuroki in the steady concentration of his troops and in the collection of war material. Pontoons were conveyed to the front in readiness for the operation of forcing the river; heavy guns were transported over the Korean roads with, in the circumstances, really marvelous rapidity; and masses of cavalry and infantry arrived at Wiju every day. By the end of the month the First Japanese Army had been brought up to its full strength, amounting probably to between 60,000 and 70,000 men of all arms. It was divided into three divisions, the 12th, the 2nd and the Guards. The 12th Division, it will be remembered, was the first section of the army to put foot on Korean soil, being landed at Chemulpo during the first days of the war, after the destruction of the _Varyag_ had left that part of the coast clear for the Japanese disembarkation. It may be well to record its composition exactly, as it is typical of all the Japanese divisions. It was made up as follows:--Infantry, 12,000 (four regiments of three battalions each); cavalry, 500 (one regiment); artillery, 900 (one regiment, 36 guns, two field batteries, two mountain batteries); engineers, 700; transport corps, 600; hospital corps, 700; ammunition column, 500; post office corps, veterinary corps, pontoon corps and balloon corps, 1,000; total, 16,900. Attached to these combatant troops were a force of 5,500 coolies for transport purposes, bringing the grand total of the division, combatant and non-combatant, up to 22,400. The whole was under the command of Lieutenant-General Inouye, whose chief subordinates were Major-Generals Kigoshi and Otani. [Illustration: RUSSIAN CONCENTRATION ON THE YALU.] [Sidenote: Kuroki's Line of Front] As his army arrived at the front, General Kuroki began gradually to occupy a wider front on the south bank of the Yalu, his left wing operating at the mouth of the river in conjunction with a naval force under the command of Admiral Hosoya, and his right extending to a distance of twenty or twenty-five miles up the river, past Sukuchin. [Sidenote: The Russian Position]