- This unusual instrument is probably best described as a precise level with a graduated horizontal circle. The telescope is provided with a long and graduated level vial, and an ingenious clamp and tangent screw moving against the silvered vertical arc controls its elevation. This arc extends 20 degrees either way, and is graduated to 10 minutes and read by vernier to 20 seconds. The horizontal circle is silvered, graduated to 15 minutes, and read by opposite verniers with reflecting glasses and magnifiers to 30 seconds. A trough compass and a circular level are mounted above the horizontal circle. The signature reads "Wm. Würdemann, Washington, D.C. 565."
- The U. S. War Department transferred this instrument to the Smithsonian in 1931, in a pine box marked "Capt. M. C. Meigs, Washington Aqueduct -Wurdemann--Grading Transit--1854." It was used by Montgomery C. Meigs, the captain in the U. S. Army Corps of Engineers who was tasked with surveying the course of a new Washington Aqueduct in 1853. Since William Würdemann was the leading mathematical instrument maker in Washington at that time, it is reasonable that he was asked to make instruments for this important task.
- Currently not on view
- Object Name
- date made
- Würdemann, William
- place made
- United States: District of Columbia, Washington
- overall: 8 1/2 in; 21.59 cm
- horizontal circle: 5 1/2 in; 13.97 cm
- needle: 4 1/4 in; 10.795 cm
- telescope: 11 1/4 in; 28.575 cm
- level: 5 1/2 in; 13.97 cm
- overall: 8 7/8 in x 12 1/2 in x 6 1/2 in; 22.5425 cm x 31.75 cm x 16.51 cm
- ID Number
- accession number
- catalog number
- Credit Line
- War Department
- Data Source
- National Museum of American History
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