Thomas Crapper took out nine plumbing patents between 1881 and 1896, but none of these patents was for the “valveless water-waste preventer” he is often credited with having invented.
The first patent for a siphonic flush was taken out by Joseph Adamson in 1853, eight years before Crapper started his plumbing business.
Many types of siphonic systems were patented in the 1880s, but none by a Crapper until George Crapper, Thomas’ nephew, was awarded an 1897 patent for “improvements in or relating to automatic syphon flushing tanks.”
Crapper may have sold or installed water closets, but he didn’t have much to do with their development.
