Global influence of the map of Japan produced by Japanese cartographer Sekisui Nagakubo
Both epoch-making high accuracy map of Japan named 日本分野図, Nihon bunya zu “Allocation Map of Japan” (Dr. Kazutaka Unno called it as “Astronomical Map of Japan”)compiled by Japanese Cartographer 森幸安 Kouan Mori in 1754,and following, 改正日本輿地路程全図”Kaisei Nihon Yochi Rotei Zenzu “Revised General Route Map of Japan” by 長久保赤水 Sekisui Nagakubo in1779 were created according to the latitude data observed in 14 provinces in Japan recorded in 天文瓊統 Tenmon Keitou (book of Astronomy and divination in Japan) written by Japanese astronomer 渋川春海 Harumi Shibukawa. And in 天文瓊統 Tenmon Keitou (book of Astronomy and divination in Japan) the latitude of 北京 Beijing, 南京 Nanjing and 高麗 Korea recorded in 四海験測 Si hăi yān tsē Nationwide survey conducted by 郭守敬 Guo Shoujin et al in1279 in 元 Yuan Dynasty were displayed for revision of calendar to new 授時暦 Shoushi-li calendar. 渋川春海 Harumi Shibukawa adopted 授時暦 Shoushi-li calendar formulated by 郭 守敬 Guo Shoujin et al to his 貞享改暦 Joukyou revision of calendar in Japan 1685. This proves that the technology of observation of the latitude in Japan was transmitted from China for revision of calendar and observed latitude datas recorded in Tenmon Keitou were exploited to the cartography of Map of Japan without land survey project.In 1754 森幸安 Kouan Mori compiled his 日本分野図, Nihon bunya zu “Allocation Map of Japan” by Chinese technology of 方格図 fānggētu grid map east and west equidistant from the distance of latitude 1° by Chinese Cartographer 羅洪先 Luo Hong xian’s 廣輿図 Guan YuTu, “Vast map of China” in Ming. Kouan Mori improved his map of Japan to realise the particularity in each allocation grid. Kouan Mori learned global atlas from duplicate the Matteo Ricchhi’s 坤輿万国全圖 Kunyu Wanguo Quatu:general map of Myriad countries on the earth 1602. In 1779, 長久保赤水 Sekisui Nagakubo made many modifications to the Kouan Mori’s maps and improve it to carry in pocket, named 改正日本輿地路程全図 Kaisei Nihon Yochi Rotei Zenzu “Revised General Route Map of Japan” and published it. Since 1809, this Nagakubo’s map has been repeatedly duplicated and translated into the language of each country in Europe and published, in Russia in 1809 and 1810, in France in 1827 by name of famous Surveyor Krusenstern. In 1855–1862 by United Kingdom Admiralty published the map “Japan Nipon (mean Honshuu Island) Kiusiu and Sikok and a part of coast of Korea” based on a replica map by Krusenstern in 1827. However, these were published without knowing the name of the Japanese original author Sekisui Nagakubo.