H. L. Bridgman, a mining engineer, was born in 1854 in Keokuk, Iowa. He studied at the School of Mines of Clausthal, Germany. After his return to the United States, he was employed at the Iron Silver mine, in Leadville, Colorado. In 1883 he moved to Chicago, where he was one of the first engineers to introduce and perfect the electrolytic refining of copper. He was for several years superintendent of the Works of the Chicago Copper Refining Co. at Blue Island, Illinois, where he was instrumental in the organizing and implementation of this method. While superintendent, he invented a machine for the mechanical sampling of ores, which he described in a paper presented in 1891 to the American Institute of Mining Engineers, of which he was a member since 1879. In 1898 he moved to Mexico to conduct explorations and mining operations in the State of Nuevo Leon. He died at Blue Island on September 20, 1900.
The notebook is 167 pages. The first 75 pages are travels to various mines in Germany recorded by Bridgman in German (using Roman and not Gothic script). These notes and small text drawings detail the various smelting furnaces and processes at the mine head of different mines in Germany. One of the detail drawings at page 7 of the manuscript is an open hearth smelter similar to the one credited to Bridgman for first stage copper refining in the 1890s. These notes and sketches of German mines reveal a high level of knowledge on industrial and chemical processes as well as practical mining information. The second part of the manuscript is in English and is illustrated with color pen and ink drawings of mine sections and mining machinery and technology. It opens with an account of Bridgman’s arrival at the Iron Silver mine of Stevens & Leiter at Leadville in April 1879. This is within a year of the original 'strike' that started the rush. The mine was also the site visited by western photographer W. H. Jackson who recorded the diggings in a photograph. The text immediately moves to a description of the mine accompanied by a detailed sectional drawing of Iron Hill and the various claims associated with it plotted on the sketch. There is a detailed discussion of the geological formation along with a description of the silver vein. The text then records the basis of competing claims. All competing claims against Stevens & Leiter were similar and dismissed. Bridgman then begins to record details of the mining and smelter technology, e.g., the water jacket furnaces. Both were located at Leadville. After successful adjudication of the Stevens & Leiter suit he moved to Salmon City, Idaho (1883) and the Ranger Mine and Mill. Here he recorded the design and use of Michigan (so named) mine sled sand, a mine car. There is an elaborate analysis of the Ranger Mill with sections, floor plans and construction details. This is accompanied by a 20 page description of the free milling of gold ore and mercury amalgamation of gold at the mill.
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H. L. Bridgman mining technology and travel notebook, MG 5753. Special Collections and Archives, University of Idaho Library, Moscow, Idaho.
Special Collections and Archives of the University of Idaho Library purchased this manuscript from Palinurus Antiquarian Books, Jenkintown, Pennsylvania, in October 2012.
Processed in March 2013.
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