Description
This object poses several interesting characteristics. Inside the lid, the inscriptions in the middle read "compared difference of time in each prefectural city during the Imperial Japan", surrounded by a ring of Japanese cities and their difference of time, precisely in minutes and seconds. On the face of the sundial, the outer ring and the two small circles use the Chinese Sexagenarian Circle (天干地支), as well as incorporating the Bagua (八卦) terms. Lastly, there are nine Roman numerals in the following order, VIII, IX, X, XI, XII, I, II, III, IIII. The number four is not IV but instead of IIII since it is inscribed on a time measuring instrument.

Before Meiji era (1868-1912), different regions and cities in Japan all had different time zones. A series of industrialisation movements in the 19th Century, such as trains and factories, gradually required more precise and coherent time measurement. In Meiji 19, or 1886, under the imperial degree Ordinance No. 51, Japan united the national time differences and implementing two time zones according to the prime meridian that passes through Greenwich Observatory, UK. The "general standard time" in Japan is defined by the 135 degree east longitude. The united time zone (U+9) will be changed again (Ordinance No. 167) in 1896 into two time zones: the original "standard time" became "Central Time", which still based on 135 degree east, where as a new "Western Standard Time", based on 120 degree east, applies to Taiwan, Penghu Islands (澎湖群島), Yaeyama Islands (八重山列島), and Miyako Islands (宮古列島).

The fact that the cities inscribed on the inside of the lid do not include Taiwan and the Penghu Islands indicate that this sundial followed the Ordinance No. 51 instead of No. 167. Taiwan and Penghu Islands only became part of the Japanese territories as colonies in 1895, as part of the Treaty of Shimonoseki signed between China and Japan. This historical event helps narrow down the date range.

This is a common type of sundial during the Meiji and early Taisho era (大正時期, 1912-1926). Later models of Taisho and Showa era (昭和時期, 1926-1989) also had similar dial face designs, according to the Timekeeper website in Japan (since 1998), though they missed the paper inside the lid with the difference of time in major cities.
28/03/2023
Created by: Guey-Mei Hsu on 28/03/2023