Air conditioning
Modern air conditioning emerged from advances in chemistry during the 19th century, and the first large-scale electrical air conditioning was invented and used in 1902 by US inventor Willis Carrier. The introduction of residential air conditioning in the 1920s helped enable the great migration to the Sun Belt in the United States.
Samuel Dalziel Heron
Samuel Dalziel Heron (18 May 1891 – 10 July 1963) was a British born aerospace engineer who made major contributions to the design of piston engines. While working in Britain he carried out the first systematic research into air-cooled cylinders. In the U.S.A he contributed to the design of the Curtiss R1454, invented the sodium cooled poppet valve and became technical director for aeronautical research for the Ethyl Corporation.