" Come old, decrepid, lame or blind,
Into my mill to take a grind."
An historical novel by Glenn Patterson, called "the Mill for Grinding Old People Young" is partly set in a Belfast hostelry of the same name. These premises actually existed in early 19th century Belfast, run by a Peggy Barclay. Indeed, there was an enterprise of a similar name - "The Old Grinding Young" - in Dublin's Upper Clanbrassil Street (Harold's Cross). It seems to have been there since the early 1800s and lasted until the 1960s. As an aside, there is an obvious double meaning from the name "The Old Grinding Young" - just to acknowledge a 200 year old play on words.
From where did this curious idiom come from ?
As it happens, there is very old crockery in circulation - an example of which is in the Victoria & Albert Museum in London - which bear graphic illustrations of old or infirm people being fed into a meat-grinder type devices but with young people emerging. The background to this is explained in a book ("The Wedgewoods)" on the history of Josiah Wedgwood, the famous Staffordshire commercial potter.
In it, the author Llewellynn writes of a Wedgewood teapot design (illustrated above);
The teapot bears on one side a remarkably well engraved and sharply printed representation of the quaint subject of the mill to grind people young again - the kind of curious machine which one recollects in one's boyish days were taken about from fair to fair by strolling mountebanks
So it started out as a fair-ground contrivance- somewhat akin to the mechanical turk - except that an old person would enter the device and a young person would leave, presumably wearing similar clothing to complete the illusion. Consider this was the time of the industrial revolution and all sorts of mechanical contraptions were appearing and they may have seemed somewhat magical or genuinely awesome at the time. Perhaps the emerging technology could turn back the clock... a dream which has persisted since old humans have envied younger ones.
Similar analogies arose of mills that were capable of grinding out curious things - such as "The Good Intent Mill" - a name which served as a vehicle for electoral fraud by some wit (Hansard 1805).
Saunders's News-Letter - 7th February 1829
"The Wedgwoods" by Llewellynn Jewitt - published in London, 1865.
Hansard Archives - Middlesex Election, volume 3, debated on Tuesday 29th January 1805.Middlesex