Yabuuchi insisted that the study of the history of calendrical science yields a key
element in understanding the history of China from ancient to modern times.
In 1941, he analyzed calendrical history from the Yin Zhou (殷周) to Sui (隋)
Dynasties and found that North and South Dynasties (南北朝) in the fourth and fifth
centuries adopted different calendar systems that were unified into a single calendar
in the Sui Dynasty, reflecting the political conditions in the late fifth century
(Yabuuchi 1941). On this finding, Yabuuchi wrote in his recollections: “Through
technical studies I could obtain a keystone to understand the history of China”
(Yabuuchi 1982). Thereafter, the study of calendrical history in China became his
life’s work, along with the history of mathematics. In 1944, Yabuuchi published two
books, the Calendrical History of the Sui and Tang Dynasties (隋唐暦法の歴史)
and Introduction to the History of Chinese Mathematics (支那数学史概説). In these
books, he not only summarized the great achievements of mathematics and astronomy in ancient China but also pinpointed developmental features of the sciences in
China in these fields compared to the contemporary West.
2. Study of science and technology
From 1948, Yabuuchi led a research group on the study of Tian Gong Kai Wu (天
工開物), an encyclopedia of Chinese science and technology authored by Song
Yingxing (宋応星) in the later Ming (明) Dynasty (Yabuuchi 1954). This book
consists of 18 topics, including grains, ceramics, iron wares and others. It served as
the starting point for the systematic study of Chinese society. Yabuuchi and his
colleagues studied this book closely. A Japanese translation and critical essays were
published in 1954 (Yabuuchi et al. Studies on Tian Gong Kai Wu, 天工開物の研
究). This was Yabuuchi’s great contribution to the study of Chinese history from a
sociological point of view.
4.5.3 Watanabe Toshio and History of Astronomy in Japan
Watanabe Toshio (渡辺敏夫, 1905–1998) contributed to the history of astronomy in
the Tokugawa period.
He enrolled in Kyoto Imperial University and studied astronomy under Shinjo.
After graduation in 1928, he continued his study of the history of astronomy and in
1955 was appointed professor of astronomy at the Tokyo University of Mercantile
Marine (東京商船大学), where he remained until retirement in 1969. During his
term as professor, he concentrated his attention on the collection of classical
astronomical data of the Tokugawa period, including the discovery of many hidden
data in the form of letters, diaries, memoranda, and others. These data reached
around 5000 items, and they are now preserved at the National Diet Library as the
Watanabe Collection.
Based on these extensive data, Watanabe studied the history of astronomy in the
Tokugawa period, particularly the lives and works of Hazama Shigetomi and Asada
Goryu (Watanabe 1943, 1983). The comprehensive history of astronomy in the
112
4 Astronomy in Early Showa. II. Kyoto 1926–1945
element in understanding the history of China from ancient to modern times.
In 1941, he analyzed calendrical history from the Yin Zhou (殷周) to Sui (隋)
Dynasties and found that North and South Dynasties (南北朝) in the fourth and fifth
centuries adopted different calendar systems that were unified into a single calendar
in the Sui Dynasty, reflecting the political conditions in the late fifth century
(Yabuuchi 1941). On this finding, Yabuuchi wrote in his recollections: “Through
technical studies I could obtain a keystone to understand the history of China”
(Yabuuchi 1982). Thereafter, the study of calendrical history in China became his
life’s work, along with the history of mathematics. In 1944, Yabuuchi published two
books, the Calendrical History of the Sui and Tang Dynasties (隋唐暦法の歴史)
and Introduction to the History of Chinese Mathematics (支那数学史概説). In these
books, he not only summarized the great achievements of mathematics and astronomy in ancient China but also pinpointed developmental features of the sciences in
China in these fields compared to the contemporary West.
2. Study of science and technology
From 1948, Yabuuchi led a research group on the study of Tian Gong Kai Wu (天
工開物), an encyclopedia of Chinese science and technology authored by Song
Yingxing (宋応星) in the later Ming (明) Dynasty (Yabuuchi 1954). This book
consists of 18 topics, including grains, ceramics, iron wares and others. It served as
the starting point for the systematic study of Chinese society. Yabuuchi and his
colleagues studied this book closely. A Japanese translation and critical essays were
published in 1954 (Yabuuchi et al. Studies on Tian Gong Kai Wu, 天工開物の研
究). This was Yabuuchi’s great contribution to the study of Chinese history from a
sociological point of view.
4.5.3 Watanabe Toshio and History of Astronomy in Japan
Watanabe Toshio (渡辺敏夫, 1905–1998) contributed to the history of astronomy in
the Tokugawa period.
He enrolled in Kyoto Imperial University and studied astronomy under Shinjo.
After graduation in 1928, he continued his study of the history of astronomy and in
1955 was appointed professor of astronomy at the Tokyo University of Mercantile
Marine (東京商船大学), where he remained until retirement in 1969. During his
term as professor, he concentrated his attention on the collection of classical
astronomical data of the Tokugawa period, including the discovery of many hidden
data in the form of letters, diaries, memoranda, and others. These data reached
around 5000 items, and they are now preserved at the National Diet Library as the
Watanabe Collection.
Based on these extensive data, Watanabe studied the history of astronomy in the
Tokugawa period, particularly the lives and works of Hazama Shigetomi and Asada
Goryu (Watanabe 1943, 1983). The comprehensive history of astronomy in the
112
4 Astronomy in Early Showa. II. Kyoto 1926–1945