Gunter Quadrant
date: label: date made
content: 1790
notes: label: Description
content: This brass Gunter-type horary quadrant has one brass sight on the top of the quadrant along one radius. There is no pinhole in this sight; it is completely solid. It appears that there was never a second sight. The plumb-bob and string which belong at the vertex are missing. The quadrant contains a geometric square marked from 10 to 50 to 10 in units of one degree, an hour arc (U-shaped) from I to VI to XI to XII and an azimuth arc from 30 to 90 to 120 by ten degrees, an ecliptic arc calibrated by zodiac symbol, a declination scale to 24 degrees, a horizon arc marked from 10 to 30, a second hour arc marked from VIII to I, a calendar arch lettered by month, and a circumference marked from 0 to 90 in units of one-half degree. There are suns between most Roman numerals on the hour arcs, moons on each side of the calendar arch, and sets of three dots at each 5-degree mark on the circumference. Five stars are charted: VH, BE, LH, A, PW. This dial was made for a latitude of approximately 52 degrees. There is no instrument maker with initials T. D. who worked around 1790 in Clifton, or in the inventory of the National Maritime Museum, Greenwich.
label: Description
content: References:
label: Description
content: Gloria Clifton, <I>Directory of British Scientific Instrument Makers...</I>, Greenwich: National Maritime Museum, 1995.
label: Description
content: <i>An Inventory of the Navigation and Astronomy Collections in the National Maritime Musuem</I>, Greenwich, National Maritime Museum.
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: Trigonometry
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: MA.330843
label: catalog number
content: 330843
label: accession number
content: 305777
objectType: label: Object Name
content: sundial, quadrant
physicalDescription: label: Physical Description
content: brass (overall materials)
label: Measurements
content: overall: .6 cm x 12.5 cm x 12.5 cm; 1/4 in x 4 15/16 in x 4 15/16 in