RARE HADLEY'S QUADRANT BY JOHN URINGS II
Britain, 18th Century
Signed on the inset ivory plaque on the cross-bar "{...] Urings Fecit London". Mahogany "T-frame" and radius arm with clamp. Index with a 90-degree arc; diagonal scale for dividing the increments on the index scale. Mounted brass peep hole sight, mirrors and filters. Lacking box.
Length 19.25". Width of arc 16".
Provenance:
Sotheby's, London, Frank Collection of Scientific Instruments, 1986.
The Kelton Collection of Marine Art & Artifacts.

Notes:
This very early quadrant, made shortly after Hadley's patent expired in 1747, exhibits features common to most early examples. First is its large size, which enabled the index arc to be engraved and read more accurately, before the use of ivory or metal arcs that allowed for finer calibration. Second is its two sighting locations, one on either arm. This instrument has only a 90-degree arc on the index. Third is the use of the diagonal scale for dividing the increments on the index scale. Though theoretically very accurate, the index was difficult to read in practice. Fourth is that it is mostly a wooden instrument. Finally, it uses peep holes, not telescopes, which were expensive at the time.

John Urings (1738-c.1773) is known to have made a variety of different kinds of instruments. Other known examples include a 1752 Davis backstaff and a 1763 octant, as well as both telescopes and microscopes.

Overall excellent condition. There are 2-3 areas of minor wear to the surface of the frame. There is a minor loss to the back edge of the radius. The 2 original filters are intact and in excellent condition. There is minor crazing to the front silvered mirrors as would be expected with an instrument of this age. The absence of a condition report does not imply an object is free of defects. All items may have normal signs of age and wear commensurate with their
age; these issues will likely not be mentioned in the condition report. Please contact Eldred's before the auction with any condition questions. Questions about condition will not be answered after purchase. Condition reports are provided as a courtesy, and we are not responsible for any errors or omissions. Important note on frames: Frames are not guaranteed to be in the same condition as they are in the item photograph. Due to handling and shipping, many frames, especially antique ones, are prone to losses. If you have questions about the condition of a frame, please contact us prior to the auction.