Brass Library Telescope

Signature

Dollond , London

Date

circa 1790

Number of Draws

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."

College of Optical Sciences
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