The Revising Process of ‘Kaisei Nihon Yochirotei Zenzu (Sekisui-zu)’
‘Kaisei Nihon Yochi Rotei Zenzu’ by Sekisui Nagakubo, measuring around 83 × 134 cm and traditionally referred to as ‘Sekisui-zu’, is the earliest woodblock-printed map of Japan employing lines of longitude and latitude. Sekisui-zu is much more detailed than traditional maps like those of Ryūsen Ishikawa, with 4200 place names in the first edition compared with Ryūsen’s 900. Most of the first editions are hand-coloured in nine hues (presumably Yamato-e pigments), seven of which distinguish different regions. Sekisui-zu is still not a survey map but nevertheless acts with great geographical accuracy as a route map. This map of Japan was published a full 30 years in advance of the first surveyed manuscript map, by Tadataka Ino.The first edition bears the printed date of ‘1779’ but, according to Sekisui`s documents, etc. its actual publication was in the next year. Sekisui scrutinised not only former maps and documents but also travellers’ communications so vigorously that he revised his map time and time again. The first edition alone was revised at least twelve times by replacing the parts of woodblock with implants of more accurate ones, by the time the second edition of complete replacement of wood block was released in 1791. Most notable replacement was at the north end of Honshu, east part of Kanto province and east part of the Seto Inland Sea. The woodblock used to print the area between the Hitachi and Musashi prefectures was also replaced more than three times, as it seems to have become impossible to re-carve.The second edition was fully revised and contains more complex information, for example with nearly 6000 place names, most of which had been corrected by the first publication. This was revised only (at least) three times, mainly around the Izu Islands in a later issue. This edition was hand-colored in five different hues for each region. This was Sekisui’s last edition and three other editions, mostly colour printed, were released posthumously in 1811, 1834, and 1841. For eighty years of the late Edo period, Sekisui`s ‘Kaisei Nihon Yochi Rotei Zenzu’ was accepted as the definitive map of Japan.