Between Meiji era and the end of World War II, map production in Japan was conducted by the Land Survey Department of the General Staff Headquarters, the former Japanese army. Not only did the Department produced maps of Japanese territory, it also created maps of the areas outside the Japanese territory, which were referred to as “Gaihozu
”. Presently, “Gaihozu
” include the maps of the former Japanese territories, and are predominantly in scales ranging from 1:25,000 to 1:500,000. Their geographical coverage stretches to Alaska northward, covering areas of U.S. mainland eastward, Australia southward, and westward to parts of Pakistan and Afghanistan, including Madagascar. The methods of the map production varied from surveys by the Japanese survey squads, reproducing maps produced abroad and secret surveys by sealed order.
As these maps were complied for military necessity, most of Gaihozu
were classified as secret; and after the war, many of them were either destroyed or confiscated. Thanks to the efforts of then researchers, some of Gaihozu
, however, were delivered to institutions such as Tohoku University. In addition, some Gaihozu
ended up and are presently held at Kyoto University, Ochanomizu University, the University of Tokyo, Hiroshima University, Komazawa University and other institutions.
Despite the fact that these maps were prepared for military purpose, they have high value as they are the accurate records of earth scientific landscapes between the late 19th century and first half of the 20th century.
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