"The geographies of my country are quite numerous, but all maps are influenced to a certain extent by the limit of the paper employed in their construction, and so distances are very incorrectly given. Thus ten or more ri (Korean unit of distance--about 2/5-mile) are sometimes represented as two or three hundred ri; while sometimes two or three hundred ri are represented as two or three. The bearings given are also incorrect. Such a map offers great disadvantages to people who attempt to learn about their country. Therefore I have taken all care in constructing this one, both as to direction and distances of places, as well as to the situations of mountains and rivers. For distances I have made a scale in which one hundred ri are taken as one ja (Korean foot), and ten ri as one poun (Korean inch, ten to the foot). I have laid off distances in all directions from the capital, so that the general shape and position of the eight provinces are correctly represented. The islands, however, are only placed in direction with reference to the provinces to which they belong, without regard to actual distances. Where mountain ranges and rivers are represented as boundaries, they are necessarily repeated upon the sheets of adjoining provinces. In the measurement of distances one ja represents one hundred ri in level places, and from one hundred and twenty to one hundred and thirty ri where the mountains are high." The assumption that the unit of scale represents an increased distance in mountainous regions is a peculiarity of Chinese as well as of Korean maps. Travelers who employ either are obliged in estimating days' journeys to consider the character of the country ahead before applying the unit of measurement.