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Other Dollond Instruments

 

Brass Library Telescope

Signature Dollond , London

Date circa 1790
Number of Draws 1
Dimensions English Metric
Main Tube Length 43.0in 1092mm
Main Tube Diameter 2.8in 71mm
Total Length 56.3in 1430mm
Closed Length 53.5in 1359mm
Objective Clear Aperture Diameter 2.7in 68mm

Description

This telescope has a long round parallel lacquered brass barrel. The objective lens is an achromatic doublet with a push-on cap. It has a single brass draw with rack and pinion focusing by a thumbwheel. It has several alternative eyepiece tubes that screw into the draw. 1. Terrestrial--This long tube contains four lenses, the front and rear parts fitting inside the tube at opposite ends. There is a separate pair of rear lenses, which can be exchanged to increase magnification. There are also two sun filters, of different densities, that screw onto the slightly tapered eyecup. 2. Astronomical--There are two very short two-lens eyepieces, of Huygens type. One is for higher magnification. They have slightly flared eyecups. There is a lens missing from one of the eyepieces. It is signed "Dollond * London" on the brass back plate of the barrel. The telescope mounts on a folding cabriole table top stand. It comes with a fitted mahogany case. Inside the case lid is a copper plate with this inscribed: "Alfred Lochee ESQ. M.D. With the grateful thanks of a patient and friend M.W."

 


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