As many of us know, the last “two minutes” of any sporting event can last far longer than that. And, as the joke goes, “I’ll just be a minute shopping for clothes” is similarly distorted.
The Edo Period Daimyo Clock of Unequal Hours
In the Japanese Edo Period (1603-1868), a variable hour system was used(dating back to the 9th century). The day was divided into 12 segments of unequal length. It seemed almost impossible to track unequal periods of time, but Japanese clock-makers devised a remarkable way to keep time in this way. The history of Japanese advances in mechanical timekeeping is indeed fascinating.
Wow. I had no idea.
They actually changed the frequency of the clock! I’d have assumed the gear ratio would be made to vary instead.