Small reflecting telescopes were popular in the 18th century. James Cook used one to observe the 1769 transit of Venus from Tahiti. This fine example is by a respected instrument maker who was from a well-known family of instrument makers. It is the first 18th century reflecting telescope in the collection.

The Dudley Adams telescope demonstrates many important aspects of the early history of the telescope, especially reflecting telescopes that have now grown into giants like the twin Keck telescopes with 10-metre diameter mirrors and the two Gemini telescopes with 8-metre mirrors. The first known reflecting telescope was made by the English scientist Isaac Newton whose second telescope was shown at a meeting of the Royal Society in London in 1672.

The telescope has primary and secondary speculum metal mirrors as the technique of depositing silver on glass was not perfected till the 1850s. It is of the compact Gregorian design with a concave ellipsoidal secondary mirror reflecting light to an eyepiece through a hole in the primary. This design was proposed by James Gregory in 1663, five years before Newton built his first telescope.

Small brass Gregorian telescopes were popularised by the famous maker James Short from about 1740 to his death in 1768. Short sold his telescopes to those who could afford his high prices. This telescope though by a different maker is of a similar design to a typical one by Short including the simple azimuth mounting. This mounting adapts well to terrestrial use, but not so well to any attempt to use the telescope for serious astronomical research.

The telescope was made by Dudley Adams who was born in 1762 and died in 1830. He was the son of George Adams who was also a well-known instrument maker and the brother of another George whose premises at 60 Fleet St he took over in 1796. Dudley Adams worked from 1788 until he became bankrupt in 1817.

The telescope was part of a large collection of clocks and watches assembled by the American collector Albert Odmark. Odmark worked for Boeing in Seattle and in the 1960s became one of the first Americans to join the Antiquarian Horological Society in London.

Telescope, reflecting, and case, brass / glass / mahogany / silk , made by Dudley Adams, London, England, 1788-1817

A brass barrel telescope with primary and secondary speculum mirrors with an engraved back plate. A focusing rod is attached to the side of the barrel. The barrel is attached with a narrow mounting plate to a tilting compass joint supported on a tapering brass column with three folding inswept legs with scroll feet. There are removable dust caps for each end of the telescope and two brass detachable eyepiece tubes.

The telescope is housed in a purpose built mahogany case. The case is lined with pale green silk that has an embroided flower decoration. Two wooden fittings covered in green felt keep the telescope stable inside the box.

Brass eyepiece tube screws into the back of the barrel of telescope.

Made: Dudley Adams; London, England; 1788 - 1817


Used: Odmark, Albert;

See parts

2005/134/1

1788 - 1817

147 mm

238 mm