The W. M. Welch Scientific Company
1880 - 1968
William M. Welch founded his educational supply company in 1880, and it merged with the E.H. Sargent company in 1968.
"History of Sargent Welch," Sargent Welch, https://www.sargentwelch.com/store/content/externalContentPage.jsp?path=/www.sargentwelch.com/en_US/history_of_sargent_welch.jsp (accessed 05/05/2015)