The Internet? Television? The internal combustion engine? All of these things are important, but they pale in significance next to arguably the most important invention of all time—the toilet.
Archeological research indicates that toilets flushed by water have existed since about 2500 B.C.E. Inhabitants of the Indus Valley developed a sophisticated system of toilets and accompanying plumbing; each house had a toilet with a seat, the waste being borne away by water in a sewer system covered with dry-clay bricks. This system was used in India for most of the existence of the Indus Valley Civilization, which ran from about 3000 to 1700 B.C.E.
Ancient Egypt also developed a similar system that removed waste through the use of running water. The ancient Romans were so fastidious that .they constructed a toilet for use when they were traveling. Their sewerage systems were sophisticate and public toilets were common.
After some lamentably unsanitary times from 500 to 1500 C.E., the toilet saw some major innovations during the second half of the last millennium. John Harrington, godson of England's Queen Elizabeth I, had invented the water closet in 1596, but his invention was not widely adopted. The late 1700s saw development in toilet technology, with several inventors taking up Harrington's ideas and producing further refinements. One of these, developed in 1778 by Joseph Bramah, was installed in many ships.
The first all-ceramic toilet appeared in 1885, designed by china manufacturer Thomas Twyford. It incorporated in one piece the earlier innovation of the water trap, consisting of water held within a U-shaped bend in the outflow pipe that insulated the user from malodorous air in the sewage system below.
