Gen. Yi ordered Gen. Sa Tă-su to go and guard the ferry at the Im-jin river which was now partly frozen but impassable for boats and ordered the Koreans to go to work building a bridge for the transport of the Chinese army. Here was a piece of work that might have daunted a better engineer than the average Korean general. But the way the Koreans went about it and the brilliant success they achieved show what the Korean was capable of when really in earnest. And it shows as well how thoroughly they were determined to see chastisement inflicted upon the Japanese. A swift broad river partly frozen, no possibility of driving piles nor of erecting any supports from the bed of the river itself. It must be a suspension bridge or none at all. On either side of the river heavy timbers were planted firmly in the ground some twenty feet apart. Behind these horizontally were laid heavy logs. Then between these supports on either bank were stretched fifteen heavy strands of the tough fibrous vine called _chik_ by the Koreans. It is the _pueraria thunbergiana_. Of course these sagged in mid-stream so that they swept the water. To remedy this, stout levers were inserted between the strands and twisted until the cables swung clear of the water by many feet. The foundation having thus been laid, willow branches were spread thickly upon the cables and finally a heavy layer of earth was added and the whole was packed down tight by the treading of many feet. And so was completed the first suspension bridge which history records. We see that during this war the Koreans had originated three important things, namely the iron-clad, the mortar and bomb, and now the suspension bridge. And on this bridge the whole Chinese army crossed in safety. But Gen. Yi was tired of the war and was extremely anxious to get back to China. So when he heard that Kato was crossing the peninsula he said, “He may come to P’yŭng-yang and in that case I must hasten back to that place and hold it against him.” So he started back toward that city, leaving Gen Wang P’il-jŭk in charge of the forces that were advancing on Seoul. At this point mention must be made of the victories of Gen. Chöng Mun-bu in Ham-gyŭng Province. In three successive fights he had defeated a large, though not the main, body of Japanese and seems to have entirely cut it off from forming a junction with Gen. Kato as he retreated toward Seoul with his dwindling though still formidable army. After the departure of the Japanese, Gen. Chöng went to the far north, even to the far Tu-man River and inflicted severe punishment on all those who had aided the Japanese or had sided with them in the betrayal of the two princes. This done, he pacified the disturbed province as much as he could and then disbanded the militia and sent them to their homes.