Ceiling fan be used to reduce the stratification of warm air in a room by forcing it down to affect both occupants' sensations and thermostat readings, thereby improving climate control energy efficiency. Punkah-type ceiling fans date back to 500 BC, and are native to India. Unlike modern rotary fans, these punkah fans move air by moving to and fro, and were operated manually by cord. The first rotary ceiling fans appeared in the early 1860s and 1870s in the United States. At that time, they were not powered by any form of electric motor. Instead, a stream of running water was used,
Portrait of a Man with a Blue Chaperon a fur lined brown jacket over a black undervest. His headdress, a chaperon, contains two wings which hang down over the man's shoulders and extend to his chest. The edges of the cloth are given a shredded look at the edges of their trains. The hood is brightly and dramatically coloured using pigment extracted from the expensive lapis lazuli gemstone to give it its bright, intense hue. The headdress is of a similar but less extravagant type to that seen in van Eyck's c. 1433 "Portrait of a Man", and worn by a figure in the distance in his c.