<論説>初期外邦測量の展開と日清戦争

Abstract

日本が一九四五年八月までアジア太平洋地域について作製した地図を外邦図とよぶ。外邦図の作製は、明治初期に既存の地理情報の編集から始まるが、現場での測量をともなう本格的な地図作製は、日清戦争時に編成された臨時測底部以降とされてきた。他方筆者らは、アメリカ議会図書館で、一八八○年代に日本軍将校が作製した、中国大陸・朝鮮半島・台湾の手描き原図を大量に発見した。本稿ではこの概要を紹介し、将校らの偵察旅行、測量技術、さらにそれらにもとづく二〇万分の一図の編集を検討した。その結果将校らの旅行は、現地側が派遣する護衛が随伴するなど、基本的にその承認を得ていたこと、測量の精度は高くなく、密度も低くて、日清戦争にあわせて準備された二〇万分の一図は、主要交通路とその結節点を描く点と線の図にならざるを得なかったことが判明した。ただし、独自の測貴活動に基づいており、この時期を「初期実測時代」とするのが適切とした。

After the Meiji Restoration in i868, the Japanese military started the preparation of maps of East Asian countries, focusing on the Korean Peninsula and China. The Sokuryo chizu hyakunen-shi (A Hundred Years of Surveying and Map-making), an authoritative history of the modern cartography of Japan published in 1970, gives a brief account of the maps that were compiled after 1874 on the basis of traditional Korean and Chinese maps in combination with modern charts made by Western countries. However, this account is followed by a description of a wartime survey by the Rinji Sokuzu-bu (the Provisional Surveying Unit) during the Sino-Japanese War (1894-5), which implies it was the first survey conducted in foreign countries. A remarkable gap between the map compilation of early stage and wartime surveying in the middle of the 1890s is seen in this narrative. Examining the maps of the Geography and Map Division of the Library of Congress, Washington, D.C. in March 2008, the authors found numerous draft maps of the areas concerned, which had been prepared by Japanese army officers during the 1880s. Following this discovery, the authors made a thorough investigation of these maps along with a study of the records on the travel and surveying of the army officers. The purposes of this paper are to provide an outline of the army officers' activities and to ascertain the important features of the maps. After the establishment of the General Staff Office in December, 1878, several Japanese army officers launched a survey of the main routes in the coastal provinces of China. They took bearings with compasses and measured distances by pace, and the results were recorded on plotting paper. Most of the draft maps are middle scale (1:100, 000 or 1:200, 000) and describe roads and waterways that connect central places. We were able to confirm that some officers carried safe- conduct passes (護照) issued by the Chinese authorities. A high-ranking officer wrote in an article contributed to The Reports of the Tokyo Geographical Society that Chinese soldiers dispatched by a provincial office escorted him from Mukden (Shenyang) to Liaoyang. An additional clause to the Japan-Korea Amity Treaty (Kanghwa Treaty), concluded after the Soldiers' Riot in 1882, made it possible for Japanese army officers to travel throughout Korean territory, most of which had been closed to foreigners. Under the escort of Korean officials, they made field trips on the courses stated in the safe-conduct passes issued by the Korean authorities, and produced similar draft maps to those made of China. Just before the start of the Sino-Japanese War, these draft maps were compiled into a collection of 131 sheets on a 1:200, 000 scale, covering areas from Korea to the environs of Peking. However, the longitude and latitude and the coastline shown in them were derived from foreign sources, especially nautical charts made by Western countries. Blank space between the main routes prevails in most sheets. These maps that show little more than the routes between major places, accordingly, had limited use on the battlefields of the Sino-Japanese War and supplementary maps were prepared to compensate for their weaknesses.