Theodolite
date: label: date made
content: 1825-1850
name: label: maker
content: Troughton and Simms
notes: label: Description
content: This is a standard theodolite as made by Troughton & Simms in the second quarter of the 19th century. The horizontal circle is silvered, graduated to 20 minutes, and read by two verniers with magnifiers to 20 seconds. The vertical arc is graduated and read in a similar manner. The scale "Diff. of Hypo. & Base" that appears on the back of the vertical arc is used to correlate the angle of elevation or depression with horizontal distances when surveying sloping ground. The instrument is marked "Troughton & Simms LONDON" and "No. 1" (which was probably added by a former owner).
label: Location
content: Currently not on view
place: label: place made
content: United Kingdom: England, London
setName: label: See more items in
content: Medicine and Science: Physical Sciences
label: See more items in
content: Surveying and Geodesy
label: See more items in
content: Measuring & Mapping
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: PH.330222
label: catalog number
content: 330222
label: accession number
content: 288699
objectType: label: Object Name
content: theodolite
physicalDescription: label: Measurements
content: overall: 13 1/2 in; 34.29 cm
label: Measurements
content: horizontal circle: 8 1/2 in; 21.59 cm
label: Measurements
content: needle: 4 in; 10.16 cm
label: Measurements
content: telescope: 13 7/8 in; 35.2425 cm
label: Measurements
content: hanging level: 6 1/8 in; 15.5575 cm
label: Measurements
content: overall: 16 3/8 in x 14 5/8 in x 18 9/16 in; 41.5925 cm x 37.1475 cm x 47.14875 cm