Mathewson, Edward Payson.

Edward Payson Mathewson was a mining engineer. He began his career with the Pueblo Smelting and Refining Company in Colorado, rising to superintendent in 1889. He later worked for H. Guggenheim & Sons in Mexico, New Jersey, and Chile. In 1902 he joined the Anaconda Mining Company and worked in Montana until 1916. He became a private consultant in 1918 and began teaching at the University of Arizona in 1926.

From the description of Edward Payson Mathewson papers, 1890-1936. (University of Wyoming, American Heritage Center). WorldCat record id: 232606137