Charles Corydon Hall

Hall was the son of Theodore Hall and his wife Jennie Clemmons.[1] He was born on a farm at Norfolk, Connecticut July 3, 1860. The family soon after moved to Sandisfield, Massachusetts. He grew up and went to the local elementary public schools there while a young boy. His father died in 1870 when he was ten years old.[2] Later he went to an academy in Marlboro, Massachusetts. Hall then went to Westfield High School in Westfield, Massachusetts. After graduation he attended Worcester Polytechnic Institute and obtained a degree of Chemical Engineer in 1882.[3]

Original 1897 Alexandria rock wool plant, picture signed by inventor C. C. Hall (with the hat)

Hall soon after completing college took a position as a chemist at St. Louis Ore Steel Company in St. Louis, Missouri. He was employed there for five years. He then took on a steel plant management position at Belleville, Illinois.[4] In the early 1890s it was discovered that Alexandria, Indiana, had a large supply of natural gas. The steel plant wanted to take advantage of this cheap fuel, so sent Hall to that city to investigate the possibilities of operating a steel mill plant there. He started the disassembly of the Belleville plant in 1895 and reconstructed it in Alexandria. Hall moved with his family to Alexandria permanently at that time. The plans of operating this plant in this city fell through when it merged with Republic Iron and Steel Company and transferred the facilities to Youngstown, Ohio.[2][5][6]

Hall was on a business trip in Pittsburgh in 1897 and saw mineral wool being made from steel slag. Some of the drawbacks he noted were that it soon disintegrated into powder and was unstable when moist.[7] He thought that perhaps Alexandria's abundance of limestone to make a rock wool product similar to the steel mineral wool might be something to work on.[2] Hall then located a run-down sheet metal building he could use for research and development. Using his chemical engineering background he began exploration of the bedrock material characteristics.[8][9]

Hall observed that the Alexandria limestone had a melting point near that of glass, a peculiar feature not found in most limestone.[10][11] Testing this molten stone in steel cupola furnaces he blew blasts of air through it and drew out fiber strings.[12][13][14] The rock wool fibers resembled clumps of sheep wool.[15] These were similar to that of the steel slag mineral wool fibers.[16] His product however didn't have sulfur in it, which he considered caused the deterioration problems with steel mineral wool.[15] He ascertained that his rock fiber material was an excellent insulator against extreme temperatures. Hall then obtained some investors in 1897 and with $600 started a plant to produce this insulating material in Alexandria.[6][10]

Styles of mineral wool as mat and roll

Hall negotiated the purchase on several hundred acres of land that contained limestone that could be used in the future for making rock wool. At the time he was manufacturing this insulating material, the chief users of insulation were breweries, distilleries, and cold storage facilities. For their insulation they used cork that was imported from Spain and Portugal. These firms were skeptical of Hall's new insulating material because it didn't look like what they were used to. He then made board-like sheets of his fiber material under the brand name Rock Cork.[2] Hall in 1902 created the Chemical Crystal Company to produce this product as the first factory in the United States to do so.[17][18] Hall's product was cheaper than imported cork, fireproof, and vermin-proof.[2]

A few years after Crystal chemical Works started the natural gas supply of the area had been used up.[19] All the local industries moved out, including the original investors of Hall's company. It then ceased to exist.[6] Hall in 1906 organized another group of investors for the Banner Rock Products Company.[13] It operated the same plant in Alexandria.[20] The new company had the first factory to make commercial insulation profitably.[15] It used coke then as a substitute fuel to raise the temperature of the furnaces to 2800 degrees to melt the rock to produce the rock wool fiber material. One of the first uses of the rock wool was for industrial insulation of boilers and pipes.[21] Other uses were for coating industrial ovens, heat barriers in vehicles, for noise reduction in motors, and in home appliances like toasters and blenders.[15] One consumer that used much of what was produced was the Frigidaire Appliance Company for insulating their refrigerators that they built in Dayton, Ohio.[22]

The Banner Rock Company was first to commercially make stone wool insulation for the construction industry. The business was very productive by 1920 and the leader in the field.[23] Hall then acquired additional lots in Alexandria for building.[24] A second plant was built and his Purdue-educated son,[25] Cordy, became the sales manager.[2] He developed a talented sales team and sold the insulating products throughout the United States, Mexico, and South America.[26] Eventually two additional plants were constructed.[3][14] Alexandria became known as the home of rock wool.[15] Hall initiated the rock wool insulation industry in America and is considered its father and progenitor.[18][27][28]

Hall met his future wife, Julia Stith, while living in St. Louis.[2] They were married in 1885 and had five children. One died at four years of age and the others grew to adulthood.[29] Julia died in 1910. Hall then married again to Carrie Scott. They had no children.[30] She died in 1934. He was affiliated with the Alexandria churches and played roles in the town's musical comedies.[15] Hall served one term on the Alexandria city council. [31] He was known for smoking a meerschaum pipe.[2]

Hall sold Banner Rock Company in 1929 to Johns-Manville Corporation[32] and retired after being forty-seven years in the manufacturing business.[30] He ran C.C. Hall Sales Corporation, a roofing company in his retirement, which he did to the end of his life.[29] Hall died of heart disease at his home on North Canal Street in Alexandria August 19, 1935.[33] He is buried at the family plot in Odd Fellows cemetery.[30] At the time of his death he had four of his children still living. He also had thirteen grandchildren and one great granddaughter.[5]

• Phillips, Clifton J. (1968). Indiana in Transition, 1880-1920. Indiana Historical Society Press. ISBN 978-0-87195-092-5.
• Indiana Academy of Science (1937). Proceedings of the Indiana Academy.
• Indiana History Bulletin (1949). Indiana History Bulletin. Indiana Historical Bureau.
• Kane, Joseph Nathan (1997). Famous First Facts. H.W. Wilson Company. #2047 - The first rock wool insulation factory was the Crystal Chemical Works, Alexandria, Indiana, opened on June 1, 1897, by Charles Corydon Hall, who melted limestone rock in a specially designed water-jacketed cupola. The rock was blown by steam pressure into fine wool-like threads for use as insulating material. The Johns Manville Corporation acquired the works in 1929.
• Modern Productions (1974). Forest Industries Review. Modern Productions.
• Rom, William N. (2007). Environmental and Occupational Medicine. Lippincott Williams & Wilkins. ISBN 978-0-7817-6299-1.