1-foot Gregorian reflecting telescope
Date: 1761
Inventory Number: SM-1911-283a
Classification: Telescope
Subject:
Maker: Benjamin Martin (1704 - 1782)
Donor: Thomas Hancock (1724 - 1764)
User: John Winthrop (1714 - 1779)
Cultural Region:
Place of Origin:
City of Use:
Dimensions:
with tube horizontal: 43.5 x 32.2 x 54.6 cm (17 1/8 x 12 11/16 x 21 1/2 in.)
box: 12.8 x 60.2 x 20 cm (5 1/16 x 23 11/16 x 7 7/8 in.)
Material:
Accessories: spare eyepiece; eyepiece cover; dust cap; box
Description:
This small brass Gregorian reflector has a long focusing screw with a knurled head. Primary and secondary mirrors are present, as are two eyepieces, each with dark filters.
The telescope has an altazimuth mount. Two removable heart-shaped keys make the adjustments in the vertical and horizontal planes. There are crossed bubble levels on the mount. The mount is attached to a turned pedestal the sits on a folding tripod formed of scrolling legs, each foot having a knurled leveling screw.
There is also an eyepiece cover and dust cap. The storage box is rectangular and made of mahogany.
The telescope has an altazimuth mount. Two removable heart-shaped keys make the adjustments in the vertical and horizontal planes. There are crossed bubble levels on the mount. The mount is attached to a turned pedestal the sits on a folding tripod formed of scrolling legs, each foot having a knurled leveling screw.
There is also an eyepiece cover and dust cap. The storage box is rectangular and made of mahogany.
In Collection(s)
Signedby eyepiece: B * Martin LONDON Fecit.
Inscribedon tube: The Gift of the Honble, THO. HANCOCK Esqr,; / of Boston, to Harvard College Cambridge.
FunctionA Gregorian telescope is a type of reflecting telescope that uses two concave mirrors to magnify the objects in its view.
Historical AttributesThis Gregorian telescope was the gift of Thomas Hancock, the uncle of John Hancock, to Harvard College in 1761. Hancock hoped that John Winthrop, Professor of Mathematics and Natural Philosophy would use the telescope to observe the Transit of Venus in June 1761. The instrument arrived in time for Winthrop to take it with him to St. Johns, Newfoundland, where he was the only "professional" observer of the Transit in North America.
Curatorial RemarksOn long term loan from the Science Museum, London.
ProvenanceGift to Harvard College in 1761 by Thomas Hancock, Boston; whereabouts unknown in the 19th century;
currently on long term loan to Harvard from the Science Museum, London.
currently on long term loan to Harvard from the Science Museum, London.