Scholarly Contacts Accompanying the Survey Projects of Inoh Tadataka

Abstract

 The accomplishments of the survey projects of Inoh Tadataka in early 19th century Japan should not be evaluated merely from the visible results of his maps of the country. The latest surveying technologies and instruments, as well as his knowledge of the astronomical almanac, had a wide range of influences upon the surveying skills and astronomical knowledge of local surveyors and scholars. Inoh's Sokuryo-nikki (Survey diary) and records of local counterparts preserved in throughout Japan are reviewed and connections are evaluated. The records have been unearthed in recent years by historians editing regional histories and local history researchers. These investigations are important aspects of recent studies of Inoh's projects and supplement basic research of Otani (1917) and Hoyanagi (1974). During his journeys to survey Japan over seventeen years, Inoh kept a daily journal. It records some 12,000 people who attended or guided Inoh's team. However, his journal lacks details of connections among them. Local records contain extensive practical information concerning the project. Generally, officials of local lords or village officials accompanied the team of surveyors. They would learn on the job. According to their records and letters, some made and improved upon Inoh's surveying instruments. Others wanted to become students of Inoh and later attended private classes in Edo. Still others discussed calendrical calculations, trigonometric functions, and logarithm. Subsequently, some returned to their home regions and took charge of local surveys. As a result, we can recognize the wide range of influences the surveying project of Inoh Tadataka had.