Swiss. An unusual silver double dial World Time keyless lever watch

Swiss. An unusual silver double dial World Time keyless lever watch
Unsigned, circa 1910
With keyless movement, the white enamel dial with Arabic numerals, blued steel spade hands, subsidiary seconds, the white enamel dial to the reverse with a extensive range of world cities and locations, centred by a revolving disc calibrated for 24 hours with diurnal and nocturnal indication, set by a small pink gilt crown in the band, in circular plain case with gilt crown, unsigned
55 mm. diam.