a 1969 purchase by Kerr Glass Manufacturing Corporation until about 1976. One final run of Kerr DP-1s was manufactured in 1978. These particular units have flat domes, and are rather scarce among insulators found "in the wild". The former Whitall Tatum plant in Millville was purchased by a series of companies, including the American Can Company. Ball-Foster purchased the factory in 1995, and in 1999, after 193 years of nearly continuous glass production, the factory was shut down. The buildings where the WT glass furnaces sat have been demolished. References http://www.cr.nps.gov/history/online_books/nj2/chap5.htm https://web.archive.org/web/20070927130740/http://www.ettc.net/njarts/details.cfm?ID=911 News article in the "Bridgeton News", January 3, 2007 on the demolition of the Whitall-Tatum, Kerr, Ball-Foster glass works buildings. Richard Wentzel, chapter in "Insulators: A History and Guide to North American Glass Pintype Insulators" by John & Carol McDougald (1990). John M. Whitall: The Story of His Life, by his daughter Hannah W. Smith. Philadelphia, 1879. Glassmaking companies of the United States Defunct glassmaking companies Companies based in Cumberland County, New Jersey Manufacturing companies established in 1806 Manufacturing companies disestablished in 1938 1806 establishments in New Jersey 1938 disestablishments in New Jersey 1938 mergers and acquisitions Defunct manufacturing companies based in New Jersey