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.
The Icee Company
Knedlik partnered with the John E Mitchell Company in Dallas to develop the machine, for which Knedlik received a patent in 1960. The first machine was made from a car air conditioning unit. It worked by combining and freezing water, carbon dioxide, and a flavor mix. After 5 years Knedlik's idea had become the iconic Icee Machine after drawing the attention of 7-Eleven. The convenience store chain purchased several machines and later changed the name to Slurpee based on the slurping sound people make when drinking the beverage.