Explore Tanaka Hisashige’s 1851 Myriad Year Clock, where a single winding of a brass mainspring runs for about a year and drives the temporal-hour dial, the 24 solar terms, the weekday, the sexagenary cycle, the moon age, a Western clock, and a celestial globe all at once.
Edo masterpiece · 1/7
An Edo automaton maker packed a whole year into a single mainspring
The Myriad Year Clock is a machine completed in 1851 by Hisashige Tanaka, known as "Karakuri Giemon." Each face of the hexagon shows a different calendar, and on the celestial globe at the top the sun and moon travel across the sky of Kyoto. All of it keeps running in step for about a year on one winding of the mainspring inside the base.
Circle the model and confirm that the six faces and the celestial globe are all connected as one machine. The 30-second discovery buttons jump you straight to the highlights.
Solar term穀雨
Hour昼八つ（未の刻）
Calendar水・己酉・lunar 2
Mainspring~237 days left
PowerBeatCalendarBellSky
30-second discovery
Choose a highlight and it switches the layer, speed, and focus all at once.
Numbers that surprise
Mainsprings: four brass bands, each 1.9 mm thick, 65 mm wide, and about 3 m long (coiled to 120.5 mm across), made from scratch in an age with no steel spring stock.
Runtime: about a year on one winding, when wadokei of the time were normally rewound every few days.
Parts: over 1,000, almost all handmade.
Displays: six faces + celestial globe = 7 systems. Unequal hours, equal hours, solar terms, luminaries, sexagenary cycle, moon age, and the heavens in one machine.
Face 2 (solar terms and dates) is the only manual face — a logbook dial for noting the day you wound the spring, while the other five faces and the globe run in sync.
Dawn-six and dusk-six are shifted about 44 minutes (about 11 degrees on the dial) toward night from actual sunrise and sunset — Tanaka divided the day by the brightening of the sky.
Parts atlas — 97 kinds, 702 pieces — straight from the ledger
Guesses stay labelled as guesses: "reconstruction" marks working hypotheses absent from the primary sources. Pick a part to light it up in 3D and trace its path from the mainspring.
