2024 Volume 133 Issue 1 Pages 49-61
At the beginning of the 19th century, Ino observed the apparent altitudes of stars crossing the meridian to calculate latitude. Then, he revised the values using astronomical refractions provided in Rekisho Kosei Kohen, a Chinese version of a European astronomy book published in 1742. Before starting a field survey, he prepared an inventory of the most recently observed altitudes of stars at his home observatory, which was located at a latitude of 35 degrees 40.5 minutes. During a field survey, he also observed the altitudes of stars at a survey site. The difference in latitudes between the site and his observatory could be obtained from the difference in altitudes of the same star. Using this method, he fixed the latitudes of 1,220 sites on the Japanese Archipelago. It is worth noting that he did not use a catalog of stars, but an inventory of star altitudes he had prepared, although he obtained star declinations for the year, which were derived from declination and precession in the Gisho Kosei catalogue of stars, a Chinese version of a European astronomy book published in 1752.
