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Locks for privacy & security


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(Picture: Hugh Sainsbury/Crossness Engines Trust)


Ashwell’s lock provided a helpful indication of whether a toilet was free – and bolts of this kind continue to be widely installed in shared facilities today.

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(Picture: © Darren Martin/The Magic Circle/


A decade after Ashwell’s indicating lock was invented to spare blushes outside Britain’s toilets, in 1892 the first coin-operated lock was patented by John Nevil Maskelyne. Maskelyne was a man of many talents, being a theatrical producer and accomplished magician – in fact, he served as the second president of The Magic Circle in the early 20th century.


Being able to use the toilet in safety and privacy is something most of us take for granted today. But even centuries ago, people were keen to avoid being interrupted – or interrupting others – on the loo. An ancient text for Buddhist monks, translated into Chinese in the fifth century, instructs the reader that, when arriving at the toilet facilities, they should make their presence known to a current user by snapping their fingers or coughing.


Since then, people have sung and whistled while in the toilet to alert those approaching of their presence. And in Japan, you can buy a product designed to reduce embarrassment: Otohime (‘Sound Princess’) is a device that plays the sound of a flush to mask bodily noises but without wasting water.

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(Picture: Hugh Sainsbury/Crossness Engines Trust)


More than two billion people around the world, though, don’t have access to safe, hygienic and private toilet facilities. This is a particularly significant problem for women, who may face not just embarrassment or shame but also assault when defecating in the open. And it can have long-term consequences: a lack of adequate lockable toilets in schools may also deter children, particularly girls, from attending.

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