struggling with Tudor's campaign and the death of his partner, John Gorrie also died, bankrupt and humiliated. His original icemaker plans and the prototype machine are held today at the National Museum of American History, Smithsonian Institution in Washington, D.C. In 1853, Alexander Twining was awarded U.S. Patent 10221 for an icemaker. Twining’s experiments led to the development of the first commercial refrigeration system, built in 1856. He also established the first artificial method of producing ice. Just like Perkins before him, James Harrison started experimenting with ether vapor compression. In 1854, James Harrison successfully built a refrigeration machine capable of producing 3,000 kilograms of ice per day and in 1855 he received an icemaker patent in Australia, similar to that of Alexander Twining. Harrison continued his experiments with refrigeration. Today he is credited for his major contributions to the development of modern cooling system designs and functionality strategies. These systems were later used to ship refrigerated meat across the globe. In 1867, Andrew Muhl built an ice-making machine in San Antonio, Texas, to help service the expanding beef industry before moving it to Waco in 1871. In 1873, the patent for this machine was contracted by the Columbus Iron Works, which produced the world's first commercial icemakers. William Riley Brown served as its president and George Jasper Golden served as its superintendent. In 1876, German engineer Carl von Linde patented the process of liquefying gas that would later become an important part of basic refrigeration technology (U.S. Patent 1027862). In 1879 and 1891, two African American inventors patented improved refrigerator designs in the United States (Thomas Elkins – U.S. patent #221222 and respectively John Standard – U.S. patent #455891). In 1902, the Teague family of Montgomery purchased control of the firm. Their last advertisement in Ice and Refrigeration appeared in March 1904. In 1925, controlling interest in the Columbus Iron Works passed from the Teague family to W.C. Bradely of W.C. Bradley, Co. Professor Jurgen Hans is credited with the invention of the first ice machine to produce edible ice in 1929. In 1932 he founded a company called Kulinda and started manufacturing edible ice, but by 1949 the business switched its central product from ice to central air conditioning. The ice machines from the late 1800s to the 1930s used toxic gases such as ammonia (NH3), methyl chloride (CH3Cl), and sulfur dioxide (SO2) as refrigerants. During the 1920s,