Sundicator, A Device for Predicting Solar Times and Positions
name: label: inventor
content: Spencer, Thomas
notes: label: Description
content: This square horizontal dial is contained in a clear and black hinged plastic case. There are two narrow pieces of black foam lining the case. The Sundicator is a device for predicting either the location of the sun at a given time or the time the sun will be in a certain location. The instrument consists of a clear plastic circle fastened with a screw to a white plastic base with black felt protecting the underside. The base is marked with a compass circle calibrated from 0 to 180 by 10 X 2 with hash marks for each single degree. The four compass points are lettered. The interior of the compass circle contains a polar dial which is calibrated from 7 P.M. to noon to 5 A.M. by hour with vertical lines at every half-hour point. The horizontal lines of the dial are marked with four columns of numbers: 2, 4, 6, 8; 1, 3, 5, 7, 9; 1, 3, 5, 7, 9; and 2, 4, 6, 8. A table between the inset compass and polar dial explains that each number represents a date range given in the table. There are also columns for "Time Corr[ection]" in the table with values ranging from -14 to +15. The clear plastic circle is marked in red with a scale calibrated from 10 to 80 by 10. The scale indicates the sun's altitude and is to be used as a pointer. There is an inset compass (diameter of 1.6 cm) lettered with eight compass points.
label: Description
content: Harold Dodd and Thomas Spencer (d. 1995) received U.S. patent number 2,715,273 for this instrument on 16 August 1955. Spencer was a 1934 Harvard graduate, naval commander, and insurance broker who donated three Sundicators to the museum during a visit in 1969. He sold these devices for some years through Thomas Spencer Enterprises of Santa Barbara, CA. Photographers use sun locators like the Sundicator with a map and parallel ruler to predict when and where the sun will rise.
label: Description
content: Patent 2,570,341 was granted to George H. Hake on 9 October 1951 for plastic hinges on cases.
label: Description
content: Reference:
label: Description
content: Deborah Smullyan, ed., "Obituaries". harvard-magazine.com, accessed 26 September 2002.
label: Location
content: Currently not on view
topic: label: Subject
content: Mathematics
label: Subject
content: Astronomy
setName: label: See more items in
content: Medicine and Science: Mathematics
creditLine: label: Credit Line
content: Gift of Thomas Dickinson Spencer
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: MA.333707
label: catalog number
content: 333707
label: accession number
content: 300657
objectType: label: Object Name
content: computing device
physicalDescription: label: Measurements
content: overall: 1.8 cm x 12 cm x 12.6 cm; 23/32 in x 4 23/32 in x 4 31/32 in