A rare and early Japanese bell clock (Tsurigane Dokei) within a finely cast bronze bell with Japanese characters and double headed dragon form handle; having a posted, iron, double spring driven, striking movement with crown wheel escapement and time regulated by a large circular balance with moveable double weights, originally for adjusting the temporal hours every day before each sunrise and sunset with the change of each Japanese season. The brass dial with single, fixed hand has traditional Japanese numerals 9 through 4 with applied silvered butterflies to the original surrounding dial plate. The rotating dial with adjustable "hour" and "half hour" markers is a common 19th Century upgrade to many very early Japanese clocks that have a single foliot or balance, since changing the weights and hence the rate before sunrise and sunset each day was extremely unhandy. This is verified by J. Drummond Robertson in The Evolution of Clockwork , page 226 saying "we find some of the old clocks "converted" to the new style of motion work. The old fixed hour circle with its revolving centre was removed and the new revolving circle and its fixed hand with adjustable "hour" plates was substituted." This is the case in each of the only other examples of Japanese Bell Clocks of which we are aware: see Japanese Clocks by N.H.N. Mody, plate 113, fig.1 for an almost identical example to the clock being offered. This dial conversion is also apparent in the Bronze Bell Clock sold at Sotheby's Masterpieces From the Time Museum Sale, Part Two, 19 June 2002, lot 126. An inscription on the bell reads Fukushima ya Katsutaro 1689, who may be the maker of either the clock or the bell. Most Japanese spring driven clocks have a fusee to the time train and a going barrel to the strike train. This movement is anomalous, in that is has two going barrels. It may be that the Japanese had not developed a method of turning a fusee at this early date, C.1690

Japanese, double foliot lantern clock, large, "Nicho Tenpu Yagura-dokei", 30 hour, steel framed movement with tooled brass covers, now on a purpose made wall bracket and with later weights

Dokei Japanese Weight Driven Stick Clock