A take-on stone is a stone instructing a coachman to add an extra horse or horses to a conveyance in order to help pull the coach up a steep hill. A take-off stone, conversely, is an instruction to unhitch the horse(s). Such stones are few.
There are supposed to be three such stones surviving on Mortimer Road, on the moors above Bradfield, near Sheffield. This road leads from Penistone to Grindleford in the Derbyshire Peak District. Turnpiked from earlier packhorse routes, it was a financial failure, and its fascinating story is told in a book by Howard Smith (1993). Its route is also traced on the Stocksbridge and District History Society website.
The take-off stone illustrated here is at the top of the hill just north of the Strines Inn, near the end of the West Riding stretch of the road.