S-Trap Flush Toilet

Alexander Cumming, Britain, patent of 1775. The sliding valve and water seal that ended the chamber pot era.

Overview

London watchmaker Cumming patented the first flush toilet design with an S-shaped trap holding water against sewer gas. His sliding valve mechanism was fussy, but the trap became permanent plumbing standard. Joseph Bramah improved and patented the valve closet in 1778, building a lock and plumbing empire. Thomas Crapper later popularized and held plumbing patents, though he did not invent the flush. Cumming's seal made indoor sanitation survivable.