surveyor's Y level
Date: circa 1765
Inventory Number: 0068a
Classification: Surveyor's Level
Subject:
Maker: Benjamin Martin (1704 - 1782)
User: John Winthrop (1714 - 1779)
User: Samuel Williams (1743 - 1817)
Cultural Region:
Place of Origin:
City of Use:
Dimensions:
19 x 66 x 15 cm (7 1/2 x 26 x 5 7/8 in.)
Accessories: small wooden base made by Ebenezer Gay in 1976
Bibliography:
The Apparatus of Science at Harvard, 1765-1800
Description:
Made in brass, this instrument comprises a telescope, a spirit level and a compass. The telescope is supported by a Y-bracket, from which the name Y-level comes from. The telescope can be removed from its support and turned back to front to make measurements. In the field, this surveyor's level was mounted on a ball-and-socket joint, parallel plates and four leveling screws, which was then attached to a mahogany tripod. A small wooden circular base has been built in 1976 to display the instrument itself without the tripod and other field accessory.
Signedon compass card: B. Martin London
FunctionA surveyor's level is used to draw level surfaces and to determine the difference in altitude between several points.
Historical AttributesIn a shipment of apparatus sent from London in August 1765, Harvard acquired "A Siphon Spirit Level Compleat with: Mahogany Leggs & Parallel Plates in 2 Wainscott Boxes" made by Benjamin Martin and worth £8.18.6. This instrument was not only used to teach Harvard students surveying, but was most likely loaned to the Massachusetts militia during the American Revolution in order to survey the line between its encampment and the British position. If so, it was eventually returned to the College and there inventoried with other equipment after John Winthrop's death in 1779.
The instrument may have been taken by Professor Samuel Williams on the solar eclipse expedition in 1780 to Penobscot Bay, Maine, which was at the time behind British enemy lines.
The instrument may have been taken by Professor Samuel Williams on the solar eclipse expedition in 1780 to Penobscot Bay, Maine, which was at the time behind British enemy lines.
Published ReferencesDavid P. Wheatland, The Apparatus of Science at Harvard, 1765-1800 (Cambridge: Harvard University Press, 1968), 77-78.