CHURCH, John Adams, American mining engineer: b. Rochester, N. Y., 5 April 1843; d. New York, 19 Feb. 1917. He was educated in New York city, completing his course in the School of Mines, Columbia University, in 1867. The two years immediately following his grad uation were passed in European travel. From 1872 to 1873 he was acting professor of metal lurgy and mineralogy at Columbia, at the same time editing Engineering and Mining Jour nal. Several years later he was appointed a member of the United States Geographical and Geological Survey. Much of his work for the government was done in Nevada. He was as signed to make a detailed study of the Com stock lode, and at the completion of the work startled the scientific world by evolving the theory that the presence of heat at the bottoms of deep mine shafts is due to a chemical action in the rock and not to the approach to the earth's fires. His report received recognition
by Columbia University and the degree of doctor of philosophy was 'conferred on him. From Nevada Mr. Church went to Ohio State University as professor of mining and metal lurgy. He entered the employ of the Chinese government in 1886, and for four years under Viceroy Li Hung Chang he supervised the re opening of several famous silver mines in Mon golia. Mr. Church served on the Assay Com mission under President Cleveland. He was the author of 'Mining Schools in the United (Notes on a Metallurgical Journey in Europe' (1875) ; Comstock Lode' (1880); on Artesian Wells in Arizona,' and other volumes of a technical character. He was a member of the American Institute of Mining Engineers and of the Century Club.