Tang dynasty
The inventor Ding Huan (fl. 180 AD) of the Han dynasty invented a rotary fan for air conditioning, with seven wheels 3 m (10 ft) in diameter and manually powered. In 747, Emperor Xuanzong had a "Cool Hall" built in the imperial palace, which the "Tang Yulin" () describes as having water-powered fan wheels for air conditioning as well as rising jet streams of water from fountains. During the subsequent Song dynasty, written sources mentioned the air conditioning rotary fan as even more widely used.
Alexander Cumming
Alexhander Cumming (sometimes referred to as Alexander Cummings) FRSE (1733 –8 March 1814) was a Scottish watchmaker and instrument inventor, who was the first to patent a design of the flush toilet, which had been pioneered by Sir John Harrington, but without solving the problem of foul smells. The S-trap (or bend) was invented by Cumming in 1775 to retain water permanently within the bowl, thus preventing sewer gases from entering buildings. It survives in today's plumbing modified as a U- or J-shaped pipe trap located below or within a plumbing fixture.