1-foot Cassegrain reflecting telescope
Date: circa 1758
Inventory Number: 0053
Classification: Telescope
Subject:
Maker: James Short (1710 - 1768)
User: John Winthrop (1714 - 1779)
User: Samuel Williams (1743 - 1817)
Cultural Region:
Place of Origin:
Dimensions:
with tube horizontal: 43 x 26.8 x 35.6 cm (16 15/16 x 10 9/16 x 14 in.)
Material:
Accessories: dust cap; object glass micrometer (0059)
Bibliography:
The Apparatus of Science at Harvard, 1765-1800
Description:
This one-foot, Cassegrain reflector is altazimuthly mounted on a pedestal with three, folding scroll feet. The telescope is brass. Both primary and secondary mirrors are present.
The altitude and azimuth adjustment keys are made of brass with ivory handles. The altitude key can be removed. There are knurled screws for tightening the parts together and for adjusting the focus.
A brass pointer is affixed to the top of the telescope tube at the far end, and serves as a finder. There is a vernier scale along the side for adjusting the secondary mirror. The scale is divided [-.2]-0-2-[2.2], with subdivisions every .05, and the vernier giving readings to .01 along its scale of 0-25.
A dust cover is present.
The altitude and azimuth adjustment keys are made of brass with ivory handles. The altitude key can be removed. There are knurled screws for tightening the parts together and for adjusting the focus.
A brass pointer is affixed to the top of the telescope tube at the far end, and serves as a finder. There is a vernier scale along the side for adjusting the secondary mirror. The scale is divided [-.2]-0-2-[2.2], with subdivisions every .05, and the vernier giving readings to .01 along its scale of 0-25.
A dust cover is present.
In Collection(s)
Signedat end of barrel: JAMES SHORT LONDON 163 / 954 = 12.
Historical AttributesShort's formula of "163 / 954 = 12" indicates that this telescope was the 163rd telescope he made with a focal length of 12 inches out of a total production of 954 telescopes of differing focal lengths. These serial numbers suggest that that this telescope was made around 1758.
Harvard acquired it in 1765, however, after the fire that consumed most of the apparatus. It was described on the bill of lading as "one Reflecting Telescope of 12. Inches focal length by James Short." It cost £14.14.0. It came with "one Object Glass Micrometer of 21 1/2 feet focus" of the same cost.
John Winthrop used the pair to observe the Transit of Venus in 1769 from Cambridge, Massachusetts. The telescope appears in a portrait of Winthrop painted in 1773 by John Singleton Copley.
In October 1780, Winthrop's successor, Professor Samuel Williams, and several students took the telescope behind enemy lines during the American Revolution in order to observe a total solar eclipse on Long Island in Penobscot Bay, Maine. (He also took another Short reflector, 0002, the Ellicott clock, 0070, and most likely the Nairne azimuth compass, 0095, Martin octant, 0007, and Martin surveyor's level, 0068.) The expedition was endorsed by Harvard and the American Academy of Arts and Sciences, and sponsored by the General Court of Massachusetts.
Harvard acquired it in 1765, however, after the fire that consumed most of the apparatus. It was described on the bill of lading as "one Reflecting Telescope of 12. Inches focal length by James Short." It cost £14.14.0. It came with "one Object Glass Micrometer of 21 1/2 feet focus" of the same cost.
John Winthrop used the pair to observe the Transit of Venus in 1769 from Cambridge, Massachusetts. The telescope appears in a portrait of Winthrop painted in 1773 by John Singleton Copley.
In October 1780, Winthrop's successor, Professor Samuel Williams, and several students took the telescope behind enemy lines during the American Revolution in order to observe a total solar eclipse on Long Island in Penobscot Bay, Maine. (He also took another Short reflector, 0002, the Ellicott clock, 0070, and most likely the Nairne azimuth compass, 0095, Martin octant, 0007, and Martin surveyor's level, 0068.) The expedition was endorsed by Harvard and the American Academy of Arts and Sciences, and sponsored by the General Court of Massachusetts.
Primary SourcesJohn Singleton Copley, portrait of John Winthrop, circa 1773; Harvard University Art Museums.
Samuel Williams, "Observations of a solar eclipse, October 27, 1780, made on the east side of Long-Island, in Penobscot-Bay," Memoirs of the American Academy of Arts and Sciences 1 (1785): 86-102.
Samuel Williams, "Observations of a solar eclipse, October 27, 1780, made on the east side of Long-Island, in Penobscot-Bay," Memoirs of the American Academy of Arts and Sciences 1 (1785): 86-102.
Published ReferencesDavid P. Wheatland, The Apparatus of Science at Harvard, 1765-1800 (Cambridge: Harvard University Press, 1968), 12-13.
Rolf Willach, "List of Extant Reflecting Telescopes Made by James Short," i>Journal of the Antique Telescope Society, no. 29 (Fall 2007): 11-22, no. 102.
Brandon Brame Fortune with Deborah J. Warner, Franklin and His Friends (Washington, DC: Smithsonian National Portrait Gallery, 1999), 88.
New York Times, Science Section, Tuesday, 13 April 1999.
