On his ride up from Wiju Bob had been greatly puzzled by a series of huge screens of brushwood, matting, and stalks placed along or across the roadway. What object, he wondered, could they serve? It was not until he reached the high ground near the Yalu that their purpose became clear to him. He saw then that the heights on the Russian side of the river completely overlooked the lower hills on the Korean bank; in ordinary circumstances every movement could be observed from the Russian lines; the numbers and dispositions of troops, the construction of fortifications and batteries, could all be noted with the aid of strong field-glasses. From the Japanese point of view this was a serious weakness of the position. Secrecy is so essential a condition of the Japanese system of conducting warfare that General Kuroki was led to adopt a novel and somewhat extraordinary method of baffling the curiosity of the enemy. Looking back from a point of vantage near the river, Bob saw a force of blue-coated Japanese infantry marching to the front along the Mandarin road. Suddenly they disappeared behind a leafy screen, and though he watched carefully, expecting to see them emerge again farther along the highway, he was unable to detect any further sign of their presence. The incident recalled a conjuring trick of Mr. Maskelyne; and to the Russians beyond the river it must have been both puzzling and irritating. Thanks to this system of screens they could neither form an estimate of the strength of the Japanese opposed to them, nor make any likely guess as to the probable point of attack. Their position was one of extreme strength; but uncertainty regarding General Kuroki’s movements largely discounted the advantages they enjoyed as a defensive force entrenched among rugged hills. Here and there, indeed, General Kuroki allowed them to obtain a hint of his arrangements; they snapped at the bait—with what result is now written in history.