- Inō Tadataka
Inō was born in
Kujukuri, a coastal village in Kazusa Province, in what is now Chiba Prefecture, and was adopted (aged seventeen) by the prosperous Inō family of Sawara (now a district of Katori, Chiba), a town in Shimo-Usa Province. He ran the family business, expanding its sake brewingand rice-trading concerns, until he retired at the age of 49. At this time he moved to Edoand became a pupil of astronomer Takahashi Yoshitoki, from whom he learned Western astronomy, geography, and mathematics.
In 1800, after nearly five years of study, the
Shogunate permitted Inō to perform a survey of the country using his own money. This task, which consumed the remaining seventeen years of his life, covered the entire coastline and some of the interior of each of the Japanese home islands. During this period Inō reportedly spent 3,736 days making measurements (and travelled 34,913 kilometres), stopping regularly to present the Shogun with maps reflecting his survey's progress. He produced a number of detailed maps (some at a scale of 1:36,000, others at 1:216,000) of select parts of Japan, mostly in Kyūshūand Hokkaidō.
Inō's magnum opus, his 1:216,000 map of the entire coastline of Japan, remained unfinished at his death in 1818, but was completed by his surveying team in 1821. An atlas collecting all of his survey work, entitled "Dai Nihon Enkai Yochi Zenzu" (大日本沿海與地全図 maps of Japan's coastal area), was published that year. It showed the entire country on eight pages at 1:216,000, 214 pages of select coastal areas at 1:36,000, and three pages of fine detail at 1:432,000. The "Inō-zu" (Inō's maps), many of which are accurate to 1/1000 th of a degree, remained the definitive maps of Japan for nearly a century, and maps based on his work were in use as late as 1924.
In addition to his maps, Inō produced several scholarly works on surveying and
mathematics, including "Chikyu sokuenjutsu mondo" and "Kyukatsu en hassenho".
Inō is celebrated as one of the architects of modern Japan. A museum, dedicated to his memory, was opened in his former home in Sawara, and in 1996 was designated a National Historic Site. In November 1995 the Japanese government issued a commemorative 80
Yen postage stamp, showing Inō's portraitand a section of his map of Edo. Most of the complete copies of the atlas have been lost or destroyed (often by fire), although a mostly-complete copy of the large-scale map was discovered in the collection of the U.S. Library of Congressin 2001.
* F. Ogawa, 'Ino Tadataka, les premiers pas de la geographie moderne au Japon', Ebisu 16: 95-119 (1997)
* [http://www.rekihaku.ac.jp/e_zyoosetu/no3/pict53.html A photograph of the entire 1:216,000 coastal map]
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