The Completed Inō Map Reaches the Shogunate

In 1821, three years after Inō Tadataka’s death, the shogunate’s astronomical office completed and submitted the Dai Nihon enkai yochi zenzu. Its measurements came from the survey sequence of 1800–1816, and its final compilation continued after the fieldwork and Inō’s own life had ended.

The set offered different views of the same accumulated information: 214 large-scale sheets, eight medium-scale sheets and three small-scale sheets. Large sheets preserved local coastal detail, while the smaller sets joined wider regions. The organization turned expedition records into maps usable at more than one geographical extent.

Later survey institutions drew on this work for national mapping. The original set stored at the palace was destroyed by fire in 1873, so surviving copies and related versions carry much of its present record. A surviving museum sheet is therefore evidence of copying and preservation as well as of the original survey. The 1821 submission completed one major compilation, without making later maps or modern reconstructions identical to that lost set.