The author, Iwahashi Yoshitaka (Zenbei, 1756-1811), was a telescope manufacturer. Heitengi (a kind of astrolabe) is a quick-reference chart for the paths of the sun, moon, and stars, and is used by turning the disc. The European continent area in the northern hemisphere on the top layer shows the location of the Netherlands in red. The title slip design was probably influenced by the title slip of Shiba Kokan's Chikyu zenzu. Belonged to the astronomer Watanabe Toshio.