Gregorian reflecting telescope, 1852

Made:
1852 in London

Brass Gregorian reflecting telescope of 3-inch aperture by John Cuthbert, London on altazimuth mount with claw foot stand and adjustable feet, 1852.

Dated 1852, this reflecting telescope uses the Gregorian optical configuration. First proposed by James Gregory in 1663, it produces upright images. This is a convenience for a telescope that was as likely to be used for terrestrial viewing as for looking for objects in the sky. Made by the London instrument maker, Cuthbert the telescope has a brass dumpy tube. The tripod stand with levelling screws allows the telescope to be used on a table while focussing is achieved by moving the tiny mirror at the top of the tube. With a metal mirror and brass construction it differs little from telescopes made a hundred years earlier in the eighteenth century.

Details

Category:
Astronomy
Object Number:
1908-124
Materials:
brass (copper, zinc alloy), speculum (alloy of copper and tin), glass and complete
Measurements:
overall: 370 mm x 300 mm x 220 mm,
type:
telescope - gregorian and telescope - reflecting
credit:
Mr B.D. Bolas

Parts

Brass Gregorian reflecting telescope of 3-inch aperture by John Cuthbert

Brass Gregorian reflecting telescope of 3-inch aperture by John Cuthbert

Brass Gregorian reflecting telescope of 3-inch aperture by John Cuthbert, London with altazimuth mount a claw foot stand with adjustable feet.

Measurements:
depth: 220mm
height: 370mm
width: 300mm
Materials:
brass (copper, zinc alloy) , speculum (alloy of copper and tin) and glass
Object Number:
1908-124 Pt1
type:
instrument component , telescope - gregorian and telescope - reflecting
Image ©
The Board of Trustees of the Science Museum
Brass case for storage of secondary mirror

Brass case for storage of secondary mirror

Brass case for storage of secondary mirror with support and eyepiece blanking cap from Gregorian reflecting telescope of 3-inch aperture by John Cuthbert, London.

Materials:
brass (copper, zinc alloy)
Object Number:
1908-124 Pt2
type:
components , flat mirrors and metal mirrors