Gunter Quadrant

This seventeenth century boxwood Gunter-type quadrant has two brass sights along the side of one radius. There is a hole drilled in the side of the quadrant between the sights. 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 2 degrees, an hour arc from 1 to 6 to 12 and an azimuth arc from 20 to 90 to 120, 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 4 to 12 and arc marked from 10 to 50 by 10 degrees, a calendar arch named by month, and a circumference marked from 0 to 90 in units of one-half degree. There are two small "beetles" on either side of the calendar arc which may possibly be a maker's mark. This dial was made for a latitude of approximately 52 degrees.

Reference:

Abraham Rees, "Quadrant," Cyclopaedia (London, 1819), vol. 29.

The Whipple Museum of the History of Science, Catalogue 6: "Sundials and Related Instruments," Part 4, Section 3, "Horary Quadrants."

Currently not on view