This was the Russian position on the North bank of the estuary of the Yalu. In physical aspect it bore a strong resemblance to the position that confronted General Buller on the Tugela. There was the plain of the delta with the unfordable river beyond, and behind that were the rugged heights in which the Russians were entrenched. Their left flank rested on mountains that appeared inaccessible to large bodies of troops and unsuited to any operations other than those of guerilla warfare; their right wing was covered by a broad deep river, while their front must be approached over a network of streams and flat country. According to the rules of war the position was impregnable. The only vulnerable point seemed to be on the right, where the Yalu is navigable by ships of shallow draft, and a cultivated plain stretches to the foot of receding hills that diminish in height as they draw nearer to the mouth of the estuary. On Friday, April 22nd, the Russians made their first effort to discover the strength of their adversaries and to ascertain at what point an attempt would be made to force the passage of the river. Four junks manned by infantry crossed over from the West of Antung. They were driven back by rifle fire and returned to the Manchurian side under cover of guns on a hill to the North-west of Antung. About the same time a thousand Cossacks were despatched to feel for the Japanese right flank. Fording the Yalu at Piek-tung, they disarmed some Korean soldiers and left three hundred troopers to occupy the place until the 28th, when they fell back across the river to Tcho-san before the advance of a Japanese battalion. The Japanese completed their preparations on April 24th; their pontoons were ready and in their appointed places; their troops were massed in Wiju and behind the hills to the South; their gun positions had been well chosen to cover pioneers and landing parties and were artfully masked. But before the streams could be bridged the enemy must be driven from the islands of Kulito and Chonchagtai as well as from Tiger Hill. On the evening of the 25th, two gunboats, two torpedo boats, and two armed launches entered Yongampo and made a demonstration in the direction of Antung with the object of deceiving the enemy as to the direction of the real attack.