1. 1891. American Journal, December This was written some time ago. Seeand January 1892. A forthcoming Bulletin, No. 96, U.S. Geological Survey, contains the work in full
2. 1889. Bulletin U.S. Geolog. Survey, No. 54 95–95. These are cylindrical stems, 0.5 centim. thick, 25 centim. long, with two parallel canals running from end to end, through which the platinum wires are threaded.Cf.