Lucinda Lambton, Britain's leading lavatory historian and author of Temples of Convenience & Chambers of Delight, says: "Victorian public conveniences were a great triumph. and things of great beauty. The highest art of the human mind was applied to those human pedestals. Britain led the way through technology. The highest order of taste was applied to public conveniences."
Though Britain didn't invent them, it was among the first countries to introduce them widely across the country. "The real hero was George Jennings," says Lambton. "He built lavatories across the world, and in the UK, from Dundee to Plymouth, built underground, of slate, with cast-iron arches. And he led the way at the Great Exhibition in Hyde Park in 1851."
Some 827,280 visitors paid to use the loos at the Great Exhibition - the first occasion to have public conveniences installed. Jennings (1810-82) was much mocked for being determined to provide lavatories for them all. "Visitors are not coming to the Exhibition merely to wash," scoffed the critics.
In fact, they were a huge success. Visitors paid a penny - hence the expression - and got a clean seat, a towel and a shoe shine in return.
It being the Victorian age, the first public loos were given all sorts of euphemisms. Jennings called them "monkey closets" and "halting stations". They were also known as "retiring rooms". But, for all the coyness, after the Great Exhibition there was an unabashed nationwide boom in building them (often underground with glass bricks above to illuminate them) - a marvel of philanthropic plumbing that opened up the public sphere. Though, notably, not for women, who could only go so far as their bladders would allow them, until The Ladies' Sanitary Association began, slowly but successfully, to campaign for more ladies' loos.
Jennings's genius was in designing lavatories with a powerful flush that effectively and hygienically removed all the waste that used to slop around British streets. Thus the ancient cry of "Gardy loo" (from the French, "Gardez l'eau" - "Watch out for the water") that survived in some British cities until the Forties, when people threw their unmentionables out into the street.
Prince Albert was so impressed with Jennings's system that he awarded him the Medal of
the Society of Arts for his "India rubber tube taps and tube" that supplied the water. Jennings even patented his lavatory, complete with ballcock, lever and water container - still recognised today as a feat of design.
Jennings's prototype was picked up around the world, as well as by 36 railway companies. During the Crimean War, he advised the British government on how to improve the sanitation at Scutari hospital, on the recommendation of Florence Nightingale.
His public lavatories were found across the country, with attendants who made a living out of charging for the closets and towels. By the time he died in 1882, thrown from his horse while crossing Albert Bridge, he had built up a fortune of £76,721 - £4.5 million in today's money. As the Emperor Vespasian, who made a fortune out of urine tax on public conveniences (the urine was used to tan leather and whiten togas), said in the first century AD: "Pecunia non olet" - "Money doesn't smell."
Public conveniences prospered throughout the late 19th century. "They reached a peak in 1900 after half a century of development," says Lambton. Her favourite example is at the Isle of Bute in Rothesay, Scotland, built in 1899 and lined with decorative ceramic tiles, with a ceramic mosaic floor.
"They are the very jewels in the British sanitarian's crown. You are surrounded by curvaceous black 'marble' forms, made out of an imitation stone, 'St Anne's Marble'," she says.
The urinals on Rothesay were manufactured by Thomas Twyford (1849-1921), inventor of the single-piece, ceramic flush lavatory.
"Twyford's 'Unitas' WC sold so many hundreds of thousands abroad, that its name became part of the Russian language, denoting excellence," says Lambton. Thomas Crapper (1836-1910) made upmarket loos, gaining several royal warrants, inventing the plumbing U-bend and setting up the first bath, lavatory and sink showroom on the King's Road in Chelsea.
The Rothesay lavatories were at risk of destruction until they were given a £300,000 restoration in 1994. Today, they're a popular attraction. But they are very much the exception, as other Victorian facilities have closed across the land.
Under 1992 Workplace Regulations, businesses are obliged to provide lavatories for their employees. Network Rail has committed to ending charges at all the large stations it owns by the end of 2019. But local authorities aren't legally obliged to supply public conveniences - and so councils have closed thousands of loos and cut back on caring for them.
Budgets on cleaning and maintenance staff are down 53 per cent on 2013. Things have got so bad that you can now even download apps such as "Lavatory Finder" and "Flush" to track down the last surviving public conveniences.
If only the Government could follow the philosophy of the late, great George Jennings, who declared that "the civilisation of a people can be measured by their domestic and sanitary appliances".