Thomas Crapper Day

What the day is

Thomas Crapper Day is observed on January 27, the date of his death in 1910. He was a real plumber and a successful sanitary engineer, and the two things everybody says about him are both false.

Origin and background

He did not invent the flush toilet. A workable flushing water closet was described by Sir John Harington in 1596, and the designs that actually made it practical came from Alexander Cumming, who patented the S-bend trap in 1775, and Joseph Bramah, who improved the valve in 1778. Crapper was born decades after all of that. By the time he set up in business the flush toilet already existed; what he did was manufacture and sell it well.

Nor does the word derive from him. Crap is a much older English word for refuse and waste, in use centuries before he was born. The coincidence is real but runs the other way: American servicemen in Britain during the First World War saw his company's name stamped on cisterns, and the existing word and the name reinforced each other.

What he genuinely contributed is less quotable and more useful. He held several patents, including improvements to the ballcock, promoted the floating ballcock valve, and ran showrooms that displayed sanitary ware openly at a time when discussing such fittings was considered indelicate. Normalizing the subject mattered: sanitation improved public health enormously in this period, and it improved faster where people would talk about it.

The S-bend he did not invent is the piece of engineering worth appreciating, since the water trapped in the bend is what keeps sewer gas out of the house.

How to take part

• Correct someone about the invention claim, politely.
• Look at the trap under a sink and understand what the standing water is doing.
• Check for a running toilet, which wastes a remarkable volume unnoticed.
• Thank a plumber, whose trade did more for life expectancy than most professions.
• Read about Victorian sanitary reform, which is the real story behind the joke.