Telescope

Object Details

Ramsden, Jesse

Description

A telescope on an equatorial mount allows an astronomer to follow a star as it moves across the sky (or, rather, as the earth rotates below it). Several British and European forms were introduced in the latter decades of the 18th century. This one was designed and made by Jesse Ramsden.

Ramsden’s Universal Equatorial instruments were expensive, and appreciated by people of means, We do not know who owned this example originally. But we do know that Thomas Jefferson had an instrument of this sort.

The telescope is 16.25 inches long. The achromatic objective has an aperture of 2.5 inches. The eyepiece is missing. There is a graduated circle for right ascension and another for declination, as well as a mechanism for adjusting the instrument for use at any latitude. The horizontal limb is marked “Ramsden London.”

Ref: Description of a New Universal Equatoreal, Made by Mr. J. Ramsden, with the Method of Adjusting in for Observation (London, 1773).

Description of the Universal Equatoreal, and of the New Refraction Apparatus, Much Improved by Mr. Ramsden (London, 1791).

Anita McConnell, Jesse Ramsden(1735-1800). London’s Leading Scientific Instrument Maker (Aldershot, 2007).

Allan Chapman, “Jesse Ramsden” in Oxford Dictionary of National Biography.

Location

Currently not on view

Credit Line

Perkin Elmer Corporation

ID Number

PH.330487

accession number

293727

catalog number

330487

Object Name

telescope, refracting

telescope

Physical Description

brass (overall material)

Measurements

overall: 29 in x 15 3/4 in x 15 1/2 in; 73.66 cm x 40.005 cm x 39.37 cm

overall: 28 1/2 in x 13 3/4 in x 15 1/2 in; 72.39 cm x 34.925 cm x 39.37 cm

place made

United Kingdom: England, London

See more items in

Medicine and Science: Physical Sciences

Astronomy

Science & Mathematics

National Museum of American History

Subject

Astronomy

Record ID

nmah_1183781

Metadata Usage (text)

CC0

GUID (Link to Original Record)

https://n2t.net/ark:/65665/ng49ca746b3-648c-704b-e053-15f76fa0b4fa