沼尻墨せんの考案した地球儀の製作技術

Abstract

Numajiri Bokusen was born in 1775 and died in 1856 in Tsuchiura (the present Tsuchiura City, Ibaraki Prefecture). He was adopted into the family of doctor Numajiri Sekigyu in the same town. He studied drawing, penmanship, astronomy and geography. Later, he ran and taught at a private elementary school (terakoya). Among his products, his most important achievements were in the geographical field. He constructed an epochal terrestrial globe from wood, bamboo and Japanese paper in 1855. It is alleged that he actually investigated it in 1800, but had hidden it after a warning from his neighboring friend who was a samurai (warrior and servant) of the Tsuchiura-Han (feudal clan). In 1855 he finally decided to produce and distributed his globes to various parts of the country. Some of them have been found in the possession of old families in several places. They are made by using the technology to frame Japanese umbrellas, which does not require the use of nails. Each globe is folded up in a similar manner to a coarse oil-paper umbrella. This is significantly advantageous compared with others during that period. Later his globe was called the “Kasasiki-chikyugi” (umbrella-like globe). While his globe is famous in Japan, research data on it are insufficient. Therefore, the author examined it and measured the size of each part. This could not be done perfectly because the measurement could only be done when the globe was unfolded. However, much information was obtained. This paper describes the form of the globe with its size and some details of the history of its preservation. The shapes of the shorelines on the globe were evidently renewed. Therefore, it is confirmed that the map was scheduled to be engraved as a woodcut based on the latest information available at the time. Since similar portable globes were produced in other countries, the author will examine the relationships between them.