Modern toilet design began in 1596, when Sir John Harington invented a device for Queen Elizabeth (his Godmother) that released wastes into cesspools. Harrington invented two elements of the modern toilet: a valve at the bottom of the water tank, and a wash-down system.

In 1775, Alexander Cummings designed a toilet with a water trap under a bowl. In the late 1800s, the first recognizably modern toilets were developed by entrepeneurs like Thomas Crapper, a plumber who brought toilet design and modern manufacturing technology together. His name has became synonymous with toilets; our troops came home from World War I calling toilets “crappers.” Other names associated with the development of modern toilets are George Jennings, Thomas Twyford, Edward Johns and Henry Doulton.

The late 1800s was the heyday of toilet design, with models following the earth closet, pan closet, and water closet designs. Modern design was complemented by the invention of toilet paper by American Joseph Cayetti in 1857. The main toilet designs were:

1. Earth closet – Dry earth is used to cover waste material for later removal. Henry Moule patented one design in 1869, advertising it as a great improvement over the cesspit.

2. Pan closet – A simple but fairly unsanitary design featuring a basin with a pan at the bottom. This pan could be tipped to discharge its contents into a receptacle.

3. Valve closet – An opening at the bottom of a pan was sealed by a valve. When flushed, the valve opened and water was released into the pan by some mechanism. Modern airplane toilets are often a version of the valve closet.

4. Hopper closet – This inexpensive design featured an inverted cone as the receptacle, with a squirt of water released for (generally inadequate) flushing. Because of its low cost, it was used mainly by poor people.

5. Wash-out or flush-out water closet – Water was used to seal the drain tube, as in the modern trap. Combined with a flushing mechanism and siphoning action, this evolved into the modern toilet.

– Courtesy of SewerHistory.org.