Pocket Alt-Azimuth
name: label: maker
content: Casella, Louis Paschal
notes: label: Description
content: The Pocket Altazimuth combines a sighting telescope with a magnetic compass for determining bearings, and a pendulum (or wheel) clinometer for determining vertical inclinations. Small, compact, and accurate, it was said to be especially useful for travelers and military surveys.
label: Description
content: L. Casella introduced the form in 1864, noting that is was "improved and modified by the kind assistance of Francis Galton, F.R.S." The reference is to Francis Galton, (1822-1911), a Fellow of the Royal Society of London, whose work ranged over a number of fields.
label: Description
content: The U. S. Geological Survey transferred this example to the Smithsonian in 1907. The This inscription reads "L. Casella Maker to the Admiralty & Ordnance LONDON 166."
label: Description
content: Ref: L. P. Casella, <i>An Illustrated and Descriptive Catalogue of Surveying, Philosophical, Mathematical, Optical, Photographic, and Standard Meteorological Instruments</i> (London, [about 1871]), p. 71.
label: Description
content: Karl Pearson, <Life, Letters and Labours of Francis Galton</i> (Cambridge, 1914-1930), vol. 2, p. 50.
label: Location
content: Currently not on view
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: L. P. Casella. Illustrated and Descriptive Catalogue of Surveying, Philosophical, Mathematical, Optical, Photographic, and Standard Meteorological Instruments
creditLine: label: Credit Line
content: U.S. Geological Survey
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: PH.247920
label: catalog number
content: 247920
label: accession number
content: 47736
objectType: label: Object Name
content: Pocket Alt-Azimuth
physicalDescription: label: Measurements
content: overall: 3 in x 5 1/2 in x 1 1/4 in; 7.62 cm x 13.97 cm x 3.175 cm
label: Measurements
content: overall: 2 7/8 in x 1 1/4 in x 5 1/2 in; 7.3025 cm x 3.175 cm x 13.97 cm