Background
Yoshitoki Takahashi was commonly known by the name Sakuzaemon, he was born in Osaka in 1764. He was a son of a lower-grade samurai named Tokujiro in the service of the shogunate.
Yoshitoki Takahashi was commonly known by the name Sakuzaemon, he was born in Osaka in 1764. He was a son of a lower-grade samurai named Tokujiro in the service of the shogunate.
In 1778 Yoshitoki succeeded his father as head of the family and, though poor, devoted himself to learning, taking instruction in mathematics and matters pertaining to the calendar from Matsuoka Yoshikazu.
Around 1788 he began studying under Asada Gôryü, the leading astronomer of the time, making improvements in the various instruments used for astronomical observation at the same time that he devoted his energies to studies of the calendar.
In time his fame as an astronomer began to spread, and in 1795, on the recommendation of his teacher, Asada Goryu, he was selected to fill the post of temmonkata, official astronomer to the shogunate, and, along with his fellow student and friend Hazama Shigetomi, was ordered to devote himself to calendrical reform.
One of his principal disciples, Ino Tadataka, was ordered by the shogunate to carry out a land survey of all of Japan, and the fact that he was able to complete the task was due in large part to the efforts of his teacher. Unfortunately Yoshitoki died of illness at the relatively young age of forty.