[51]: 90–96, 101–102 [52] He also helped increase copper production in Kyshtym, Russia, through the use of pyritic smelting. He also agreed to manage a separate mine in the Altai Mountains that, according to Hoover, "developed probably the greatest and richest single body of ore known in the world".[51]: 102–108 [53]
In his spare time, Hoover wrote. His lectures at Columbia and Stanford universities were published in 1909 as Principles of Mining, which became a standard textbook. The book reflects his move towards progressive ideals, as Hoover came to endorse eight-hour workdays and organized labor.[54] Hoover became deeply interested in the history of science, and he was especially drawn to the De re metallica, an influential 16th century work on mining and metallurgy by Georgius Agricola. In 1912, Hoover and his wife published the first English translation of De re metallica.[55] Hoover also joined the board of trustees at Stanford, and led a successful campaign to appoint John Branner as the university's president.