How the Refrigerator Changed History

How the Refrigerator Changed History — page 5 — came from New York and New England where workers harvested it in the winter from frozen rivers and ponds In winter ice was expensive In summer it was often completely unavailable When Gorrie heard about other scientists experiments with mechanical ice systems he quit his job as a physician and threw himself into creating an ice making machine In an 1844 article in Apalachicola's Commercial Advertiser newspaper Gorrie described how his invention would work If the air were highly compressed it would heat up by the energy of compression If this compressed air were run through metal pipes cooled with water and if this air cooled to the water temperature was expanded down to atmospheric pressure again very low temperatures could be obtained even low enough to freeze water in pans in a refrigerator box Gorrie recognized that his invention would be far easier to sell if it appealed to an audience beyond patients suffering from malaria and their doctors He wrote about the benefits of artificial ice promoting its commercial and humanitarian benefits Gorrie found a wealthy investor to sponsor his project and enlisted the Cincinnati Iron Works to build a model of this first commercially available refrigeration machine A replica of John Gorrie's ice machine is on display in the Garrie Museum in Apalachicola Florida 10

How the Refrigerator Changed History — page 6

How the Refrigerator Changed History — page 7 — WILLIAM CULLEN In the 1740s William Cullen a scientist and professor at the University of Glasgow began experimenting with the evaporation of liquids to learn how they could serve as coolants Cullen used a pump to create a vacuum over a container of ether and then heated the ether As the ether began boiling it absorbed heat from the container's surroundings causing the container to cool But Cullen's work was purely scientific He was a theorist who wanted to learn about science for the sake of knowledge not for practical application Cullen's discovery served as a starting point for a number of other inventors who improved on one another's ideas ultimately leading to today's refrigerator A Century in the Making Gorrie's design was based on principles established by William Cullen of the University of Glasgow in Scotland almost a century earlier Cullen showed that when a liquid evaporates it extracts heat from its surroundings Compressing a gas on the other hand causes it to heat up Removing the pressure causes the gas to expand and absorb heat In 1755 Cullen demonstrated this principle to create a small amount of ice by heating ether a flammable liquid until it became a gas This principle of refrigeration cooling caused by the rapid expansion of gases remains basic to An estimated 500 million refrigerator freezers were refrigeration today in use in the world as of February 2015 In 1805 the American inventor Oliver Evans capitalized on Cullen's

How the Refrigerator Changed History — page 8 — basic principle to design a refrigeration machine that used vapor instead of liquid Evans one of the most prolific inventors of his time never built his refrigeration machine perhaps because he was too busy inventing the first high pressure steam engine and a predecessor to the automobile This task fell to fellow American inventor Jacob Perkins who began experimenting with refrigeration after moving to London England in the 1830s In 1834 Perkins built a closed loop system that moved heat from one place to another Rather than release the gas into the air the device pumped it away from the refrigeration area and compressed it again The system released the heat into the outside air and pumped the gas back to begin the cycle again Jacob Perkins's closed loop system advanced

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