WHY 21 producers commissioned a “based on real events” film telling how Dr Mortimer Granville invented a DIY solution for women beset with unfulfilled libidinal needs, is not important, but the result is a delightful comedy that probably takes liberties with the truth.

Until the sexual revolution of the ‘60s and particularly during the 19th century, it was common belief that women could not have orgasms. Women who understood the physiology of their needs probably did for themselves in privacy.

Writers Stephen and Lisa Dyer have given director Tanya Wexler a happy, uncomplicated screenplay redolent with stylistic homages to Gilbert, Wilde and Dickens.

Dr Dalrymple (Jonathan Pryce) engages Granville (Hugh Dancy) to share the workload of manustuprating women complaining of “hysteria”. Granville’s flat-mate (Rupert Everett) has invented the forerunner of today’s vibrator. The film is about where the interaction of those two concepts led.

Dalrymple has two daughters. Emily (Felicity Jones) is meek and unassertive. Charlotte (Maggie Gyllenhaal) has a strong social conscience and suffragette principles.

Where the film is going is never in doubt. Getting there is much fun, sprinkled with occasional bloopers that don’t harm the plot. It pays scant attention to men’s role in women’s erotic pleasure in the 1870s. A collection of talented actresses play characters of various ages and social conditions who happily submit to Dalrymple and Granville’s treatments. The profound implications of its low-level bawdiness and the pleasure to us watching are delightful.

 Opens July 12 at Dendy and Greater Union

 AUTHOR’S NOTE: Masturbation is when one does it for one’s self, while “manustuprating” is when somebody else does it for you.