Japan 50hz VS 60 hz

[flipoclock]

This is the 2nd clock I bought in Japan. It dates back, probably to the early eighties more than the 70ies... It is new in box and even though it is quirky, I still like/love it!

With the clock in its box also was a paper card which explains to me the mystery of the 50hz vs 60hz in Japan. Appearantly, the country was divided! Apart from a few white spots which are odd, they appearantly had 50 AND 60hz.

I wonder what the story behind the division is..... Does anyone have a clue?

[RetroFlip]

Basically early in the process of wiring Japan, one power company bought equipment from Germany that used 50hz and the other bought power generating equipment from the United States using 60hz.
Here's a good article about the topic:
https://www.japantimes.co.jp/news/20.../#.WZtliyh94uU

[flipoclock]

very intriguing! thanks for the link!