Base Bar
notes: label: Description
content: Alexander Dallas Bache was, in 1843, named Director of the U.S. Coast Survey, one of the leading scientific agencies of the country. William Wurdemann was a talented German craftsman who came to the United States in 1834, settled in Washington, D.C., and found work making and repairing instruments for several federal agencies. Working together, Bache and Wurdemann developed compensated base bars for measuring, with extreme accuracy, the base lines for the Survey’s primary triangulations. These were used on several base lines, from the late 1840s until 1873.
label: Description
content: This 6-meter base bar, Bache-Wurdeman No. 2, consists of two bars, one of brass and one of iron, encased in a metal tube. In use, it would be held several feet above the ground, and equipped with a complicated mechanism for meeting an adjoining set.
label: Description
content: Ref: Lt. E. B. Hunt, “Description of United States Coast Survey apparatus for measuring base lines,” Report of the Superintendent of the Coast Survey showing the Progress of the Survey During the Year 1854 (Washington, D.C.), pp. 103-108.
setName: label: See more items in
content: Medicine and Science: Physical Sciences
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: PH.285229
label: accession number
content: 57456
label: catalog number
content: 285229
objectType: label: Object Name
content: base bar (6 meter)