Turkish Horary Quadrant
notes: label: Description
content: This undated Turkish quadrant is made of yellow paper lacquered to a wooden base. Lines, script, and numerals are marked in red and black pigment. All markings are in Arabic. The edges are painted red. One edge is indented, serving to sight the sun. A hole near the square corner would hold a plumb bob.
label: Description
content: One side of the quadrant contains scales for declination and right ascension, azimuth arcs, an ecliptic arc, and hour arcs. The circumference is calibrated from zero to ninety by single degree in groups of five.
label: Description
content: The reverse contains a grid for reading off sines and cosines. It also has two semicircles at right angles to each other, an arc connecting the twenty-fourth mark on each axis, and two red lines sloping up to the right. Numerous dots are at points of intersection on the grid. Both axes of the grid are marked in groups of five units. The circumference on this face is also calibrated from zero to ninety degrees by degree in groups of five.
label: Description
content: References:
label: Description
content: A similar horary quadrant is at the Museum of the History of Science of Oxford University. <www.mhs.ox.ac.uk/database/index.htm>, inventory number 35612 (accessed 29 February 2016).
label: Description
content: Glen van Brummelen, <I>The Mathematics of the Heavens and the Earth: The Early History of Trigonometry</I>, Princeton and Oxford: Princeton University Press, 2009, esp. pp. 209-211.
label: Description
content: A similar instrument in the collections of the Greenwich Maritime Museum is described in Hester Higton, <I>Sundials at Greenwich</I>, Oxford: Oxford university Press, 2002, esp. pp. 368-369.
label: Location
content: Currently not on view
place: label: place made
content: Turkey
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
label: See more items in
content: Science & Mathematics
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: MA.317639
label: catalog number
content: 317639
label: accession number
content: 231062
objectType: label: Object Name
content: sundial, quadrant
physicalDescription: label: Physical Description
content: wood (base material)
label: Physical Description
content: paper (scales material)
label: Measurements
content: overall: 1.6 cm x 14 cm x 14.1 cm; 5/8 in x 5 1/2 in x 5 9/16 in