was a Japanese surveyor and cartographer. He is known for completing the first map of Japan using modern surveying techniques. Early life Inō was born in the small village of Ozeki in the middle of Kujūkuri beach, in Kazusa Province (in what is now Chiba Prefecture). He was born to the Jimbō family and his childhood name was Sanjirō. His mother died when he was seven and after a somewhat tumultuous childhood (not uncommon at the time), he was adopted (age 17) by the prosperous Inō family of Sawara (now a district of Katori, Chiba), a town in Shimōsa Province. He ran the family business, expanding its sake brewing and rice-trading concerns, until he retired at the age of 49. After retirement, he moved to Edo and became a pupil of astronomer Takahashi Yoshitoki, from whom he learned Western astronomy, geography, and mathematics. Mission In 1800, after nearly five years of study, the Tokugawa shogunate authorized Inō to perform a survey of the country using his own money. This task, which consumed the remaining 17 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 traveled 34,913 kilometres), stopping regularly to present the Shōgun with maps reflecting his survey's progress. He produced detailed maps (some at a scale of 1:36,000, others at 1:216,000) of select parts of Japan, mostly in Kyūshū and 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, Dai Nihon Enkai Yochi Zenzu (:ja:大日本沿海輿地全図 Maps of Japan's Coastal Area), was published that year. It had three pages of large-scale maps at 1:432,000, showed the entire country on eight pages at 1:216,000, and had 214 pages of select coastal areas in fine detail at 1:36,000. The Inō-zu (Inō's maps), many of which are accurate to 1/1000 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. Expeditions Inō's surveys were done in ten expeditions. The first survey started on June 11, 1800 and included five members. This survey was mainly to begin charting the coast of Hokkaidō (where Russian ships had come to