Heliostat
date: label: date made
content: 1874
name: label: maker
content: Alvan Clark & Sons
notes: label: Description
content: In 1874 and again in 1882, the planet Venus passed between the Earth and the Sun, causing what was known as a Transit of Venus. In preparation for these important events, the U.S. government established a Transit of Venus Commission that would organize and equip eight teams of astronomers and send them to observation stations around the world. A key component of that equipment was a weight-driven heliostat designed to send an image of the sun into a horizontal telescope. This is the mirror of one of those heliostats. It is seven inches diameter, of unsilvered glass, and slightly thicker on one side than the other.
label: Description
content: Ref: Simon Newcomb, Observations of the Transit of Venus, December 8-9, 1874 (Washington, D.C., 1883), p. 15.
label: Location
content: Currently not on view
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: 2005.0172.11
label: accession number
content: 2005.0172
label: catalog number
content: 2005.0172.11
objectType: label: Object Name
content: heliostat
physicalDescription: label: Measurements
content: overall: 18 3/4 in x 21 1/2 in x 16 1/2 in; 47.625 cm x 54.61 cm x 41.91 cm
label: Measurements
content: overall; heliostat: 1 3/4 in x 8 in; 4.445 cm x 20.32 cm
label: Measurements
content: overall: container: 4 3/4 in x 14 1/2 in x 10 1/4 in; 12.065 cm x 36.83 cm x 26.035 cm
label: Measurements
content: overall: container: 18 3/4 in x 21 1/2 in x 16 1/2 in; 47.625 cm x 54.61 cm x 41.91 cm
label: Measurements
content: overall: p7147: 25 in x 72 in x 48 in; 63.5 cm x 182.88 cm x 121.92 cm