583 Miseshime #5: Kampu Seisai[Exemplary Punishments in the Meiji #5: Punishment for an Adulteress]

There were a lot of adulterers and adulteresses (maotoko in dialect) or immoral lovers in pits though there was only a law (abolished in 1947) concerning the offence of women who committed adultery. This shown punishment was reportedly inflicted according to a law of Takashima Coal Pit in Hizen (Nagasaki Prefecture).
Each of the adulterers in this pit was burned, being hung upside down, and many of them died. Each of the adulteresses was stripped naked and tied to a double-bar cross erected beside the main highway. Every passerby had to whip the private parts of such a woman one time with a provided rod. If a passerby whipped the victim softly out of sympathy, the personnel foreman as a watchman rebuked him/her. He forced the passerby to whip her once more, saying, “Hey, your whipping was not hard enough. Use the rod like this,” and showing how to whip her himself. Sympathy for the victim only served to torment her more.

[Not sure if it's true.]