100 Fixing the Calendar 1582

   The Coolest Invention 1834

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53   The Coolest Invention 1834 
HUMANS HAVE BEEN KEEPING themselves and their food cool for eons. The Chinese placed ice in cellars as early as 1000 B.C. An 8th century Baghdad caliph packed imported snow between the walls of his summer home. But it wasn't until Jacob Perkins, a 68-year-old Massachusetts inventor living in London, received a patent for a compressor in 1834 that anyone figured out how to make ice artificially. Perkins's machine used the same principles found in household refrigerators today: A compressed fluid--ether in his case, later ammonia and Freon--was evaporated to produce a cooling effect, then condensed again. 

It was 17 years before the first commercial refrigerators were installed in an Australian brewery. By the end of the century they were being used to ship beef around the world, chill wine in Paris restaurants and build skating rinks. In 1902, Willis Carrier installed the first air conditioner in a Brooklyn printing plant--it not only cooled but also controlled humidity--and before long his machines were showing up in department stores and movie theaters. The first household refrigerators appeared in the early 1920s. Less than 1 percent of the homes in America are now without one, and most contain frozen foods--thanks to a process developed by Clarence Birdseye--another marvel of the Cool Age. 

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