Science and technology of the 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" (唐語林) 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.
Willis Bradley Haviland
Willis Hoag Haviland, a farmer, and his second wife, Hannah Wing Haviland, were first cousins once removed, which caused friction with the Quaker Meeting to which they belonged, ending in severance with the church. Hannah Wing Haviland's half-sister was Ann Elizabeth Button (27 Mar 1823 – 15 Mar 1849), wife of David Jay Haviland (29 Mar 1820 – 13 Aug 1868); they were the parents of Elizabeth R. Haviland (1845–1888) who would marry Duane Williams Carrier and have only child Willis Haviland Carrier in 1876, later the inventor of modern air conditioning technology. Willis Haviland Carrier was named after Willis Hoag Haviland, who after Elizabeth's father's death took care of her before she was married. (Willis Hoag Haviland was also Elizabeth's uncle-in-law.)