Equatorial Sundial by Schmidtbaur
name: label: maker
content: Schmidtbaur
notes: label: Description
content: This universal mechanical equinoctial dial rests on three brass levelling screw feet. The gold-colored metal base plate contains a 360-day calendar which is labeled with the starting dates (in Latin) and signs for the zodiac. An inset compass is calibrated from 0 to 90 x 4 with lines for every 2 degrees. The four cardinal points are inscribed in Latin (Septentrio, Occasus, Meridies, and Ortus); the compass rose is marked for variation at 20 degrees. An ornate hinged levelling bob with a tiny weight on a chain is attached to the base plate and partially obscures the markings for the months of May and June. A latitude arc (calibrated from 30 to 90 by 10 degrees with lines for each degree) is also attached to the base plate. It fits into a groove on the side of the hinged hour plate which lies on top of the base plate; the user would actually set the arc for the complement of his or her latitude. The metal and brass hour plate is calibrated from IIII to XII to VIII by I with an arrow marking each half-hour and a double leaf shape engraved at each hour line. A slit gnomon and glass-covered minute dial are affixed at the center of the hour dial. The minute dial is calibrated from 0 to 60 by second with "1" and "3" indicating 15 and 45 seconds, respectively, and a fleur de lis marking the other 5-second points. The user moves the index along the hour dial until sunlight passes through the gnomon and falls on the pointer, which indicates the hour. Gears move the minute hand to the appropriate number. The gear housing is covered on the underside of the hour dial with an engraved metal plate shaped like a four-leaf clover. This sundial does not work when the sun is south of the equator. It was probably made by Schmidtbaur in Germany in the 1700s.
label: Location
content: Currently not on view
topic: label: Subject
content: Mathematics
label: Subject
content: Timekeeping
setName: label: See more items in
content: Medicine and Science: Mathematics
label: See more items in
content: Science & Mathematics
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: MA.336091
label: accession number
content: 316529
label: catalog number
content: 336091
objectType: label: Object Name
content: Sundial, Equatorial
physicalDescription: label: Measurements
content: overall: 3 cm x 9 cm x 9 cm; 1 3/16 in x 3 17/32 in x 3 17/32 in