.png)
Horary Quadrant & Nocturnal
[Text Description Below.]
.png)
- 40024
- A Rare Brass Horary Quadrant with A Constellation Engraved Nocturnal:
- English, ca. 1680. Signed: “Hen:Wynne fecit.”. This was Henry Wynne (b 1640-d 1709), who worked as a mathematical instrument maker under his own name on Chancery Lane in London in 1662 and died in 1709. He began his apprenticeship in 1654 with Ralph Greatorex, and was made a freeman in the Clockmakers Guild in London in 1662. Over his career he had 8 apprentices including Thomas Tuttell and Richard Glynne, and he was appointed a master in the Clockmakers Company of London in 1690. He is known to have produced a variety of instruments including barometers, compasses, drawing instruments, sundials, microscopes and quadrants (1). He is noted for his magnificent double horizontal dials, such as the one in the Buccleuch Collection at Drumlanrig Castle. In 1677 Wynne made the magnetic dip needles with which Henry Bond’s longitude solution was tested.
- Discussion:
- This beautifully engraved brass instrument has a radius of 5.75 in (14.5 cm) and is 2 mm thick. In the center, there is an engraving of a 7 mm Tudor rose emblem. It is laid out with a variant of the Gunter-type projection. It has degree and date scales on the limb, declination scale, line of ecliptic, horizon line and azimuth lines. Above the declination scale, and below the signature, the calendar is divided into four arcs. It starts at March II and runs alternately counterclockwise and clockwise. Each arc represents a season: Winter, Autumn, Summer, and Spring…from the top down.
- The left half of the projection indicates the hour lines, curving to the left for winter, and to the right for summer. The winter hours are labeled VI to XI at the top and V to I in reverse below. The arc below the winter hours (VI to XI) represents the celestial equator. The summer hours are labeled VII to I in reverse. The arc above the summer hours represents the Tropics of Cancer and Capricorn.
- The right half of the projection carries the azimuth lines, curving to the left for summer and to the right for winter. The azimuths are labeled 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, along the arc of the equator with the first three printed vertically, and are drawn every five degrees.
- The sky positions of five bright stars are plotted on the quadrant and defined as follows with the date when they cross the south meridian at midnight:
Nocturnal:
The reverse of the instrument is equipped with a 12.5 cm diameter nocturnal, illustrated with celestial cartography. The nocturnal has a fixed hour scale engraved on the quadrant in two sets of (I-XII), and is thus a complete horary circle calibrated to 24 hours. The rotatable brass volvelle is engraved with a date scale and celestial constellations shown by pictorial illustrations with main star indications. These are the traditional Ptolemaic circumpolar (Never setting.) constellations of Ursa Major, Ursa Minor, Draco, Cepheus, and Cassiopeia, shown in geocentric view (i.e. On Earth looking outward.) The date scale is 12 months of the year, dividing the disc into 12 equal sections; i.e. I (Jan), F (Feb), M (Mar), A (Apr), M (May) I (Jun), I (Jul), A (Aug), S (Sep), O (Oct), N (Nov), D (Dec). Each month is further subdivided by rulings into 1 day intervals.
In use one can perform many observations and calculations with the instrument. By aligning the sunbeam through the pinhole sight vanes (missing), one can determine the time of day by using a plumb line and bead. One can predict sunrise and set, length of daylight, etc. for any date. By sighting any of the five stars, one finds the time at night. The nocturnal is even simpler to use: face North, hold the instrument vertical, rotate the volvelle until the orientation of the constellations matches that seen in the sky, and read the time against the current date. This use is described in more detail in an elusive work by William Leybourn (3). Condition: The condition is very fine with brass patination consistent with its age.
Provenance: Bonham’s Knightsbridge Sale 16871; Lot 88, 2009.Ex private collection London.
Bibliography:
1. Clifton, Gloria (1995 ) Directory of British Scientific Instrument Makers 1550-1851, IBSN [0 302 00634 6] p. 307.
2. Webster, Roderick and Marjorie (1998) Western Astrolabes, ISBN [1-891220-01-2] p. 127-146. 3. Leybourn, William (1731) The description and Use of a Portable Instrument, Vulgarly known by the Name of Gunter’s Quadrant (3rd ed. 1731).
In use one can perform many observations and calculations with the instrument. By aligning the sunbeam through the pinhole sight vanes (missing), one can determine the time of day by using a plumb line and bead. One can predict sunrise and set, length of daylight, etc. for any date. By sighting any of the five stars, one finds the time at night. The nocturnal is even simpler to use: face North, hold the instrument vertical, rotate the volvelle until the orientation of the constellations matches that seen in the sky, and read the time against the current date. This use is described in more detail in an elusive work by William Leybourn (3). Condition: The condition is very fine with brass patination consistent with its age.
Provenance: Bonham’s Knightsbridge Sale 16871; Lot 88, 2009.Ex private collection London.
Bibliography:
1. Clifton, Gloria (1995 ) Directory of British Scientific Instrument Makers 1550-1851, IBSN [0 302 00634 6] p. 307.
2. Webster, Roderick and Marjorie (1998) Western Astrolabes, ISBN [1-891220-01-2] p. 127-146. 3. Leybourn, William (1731) The description and Use of a Portable Instrument, Vulgarly known by the Name of Gunter’s Quadrant (3rd ed. 1731).
.png)