Telescopic Alidade
name: label: maker
content: E.R. Watts and Son
notes: label: Description
content: This is an example of the distance alidade devised by Edward Ayearst Reeves (1862-1945), a well-known British geographer, astronomer, and cartographer. The vertical arc is graduated to 30 minutes and read by vernier and magnifier to 5 minutes. The two long edges of the base are beveled, and one is equipped with a parallel rule. Since the pedestal and telescope can fold down flat against the base, the instrument is easily portable. The "E. R. WATTS & SON 1914 No 34" inscription refers an instrument firm that was established in London in 1857. Casella offered a similar instrument, describing it as "Reeve's Pattern Folding Alidade."
label: Description
content: Ref: Ref: E. A. Reeves, Maps and Map-Making (London, 1910), p. 50.
label: Description
content: C. F. Casella & Co., Ltd., <i>Surveying and Drawing Instruments and Appliances</i> (London, about 1940), p. 30.
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
publisher: label: Related Publication
content: C. F. Casella & Co., Ltd.. Surveying and Drawing Instruments and Appliances
creditLine: label: Credit Line
content: Mrs. Llewellyn N. Edwards
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: PH.325675
label: catalog number
content: 325675
label: accession number
content: 257193
objectType: label: Object Name
content: alidade (telescopic)
physicalDescription: label: Measurements
content: base: 15 in; 38.1 cm
label: Measurements
content: telescope: 12 in; 30.48 cm
label: Measurements
content: overall in case: 3 3/4 in x 15 3/4 in x 4 3/4 in; 9.525 cm x 40.005 cm x 12.065 cm