But before dealing with the momentous events which now occurred in rapid succession, both on land and sea, it will be necessary to return for a few moments to the earlier fortunes of the First Army, whose advance through Korea as far as Ping-Yang was described in Chapter III. It will be remembered that a small skirmish took place between Russian and Japanese patrols to the north of that town on February 28th. A month elapsed before the opposing forces came seriously into touch with one another again. During that period General Kuroki slowly but steadily continued his advance in the face of terrible difficulties arising from the weather and the state of the roads. The mud on these north Korean highways in the spring makes them almost impassable, but the Japanese had thought of everything, and brought large supplies of wood with which they practically relaid the road, and made it admit even of the passage of heavy artillery. The Cossack patrols retired before this persistent advance, and no real attempt to dispute it was made till the vanguard of the Japanese neared Chong-ju, a little town about thirty miles north of Anju and fifty south of Wiju. Here, on March 28th, they found six squadrons of Cossacks belonging to General Mishtchenko's Brigade, posted on an adjacent hill, prepared to dispute the forward movement. A brisk engagement ensued. The small force of Japanese which first appeared upon the scene, according to the testimony of General Mishtchenko himself, gallantly held their ground in spite of the commanding position occupied by the Russians and the raking cross fire which they maintained, and it was only after half an hour of fierce fighting that they gave way and fell back upon their supports which were hastening to the front. Reinforcements now rapidly arrived, and the Russians, finding their position untenable, retired along the road to the north, yielding up possession of the town to the Japanese. In this smart little affair the Russians, according to their account, lost three killed and twelve wounded, the Japanese casualties amounting to five killed, including one officer, and twelve wounded, including two officers. [Sidenote: The Advance to the North] After the capture of Chong-ju General Kuroki moved forward rapidly, finding no resistance. On April 2nd he occupied Syoush-kou, a place eighteen miles west of Chong-ju, and forty miles south of Wiju, and two days afterwards his scouts entered Wiju itself, an important town on the south bank of the Yalu. The Russians did not find themselves strong enough to oppose the Japanese advance in Korea, and determined instead to resist it on the north bank of the Yalu. General Kuroki therefore occupied Wiju without firing a shot, and set to work busily to consolidate his forces for the great enterprise of crossing the Yalu. [Sidenote: Concentration of Troops]