Twin-Telescope Binoculars

Twin-Telescope Binoculars

Signature

T M J.B.L.

Date

Late 1800s

Dimensions

English

Metric

Main Tube Length

6.1in

156mm

Main Tube Diameter (obj)

4.4in

112mm

Main Tube Diameter (eye)

1.1in

28mm

Extended Length

9.3in

235mm

Closed Length

1.3in

32mm

Inter-Pupilary Distance (min)

2.2in

55mm

Inter-Pupilary Distance (max)

2.7in

68mm

Objective Clear Aperture Diameter

1.3in

32mm

Description

This pair of binoculars has tapered brass barrels, covered with brown leather. The objective lenses are achromatic doublets, contained in brass cells. It has long brass eyepiece tubes, four lens eyepieces, and flared hollow eyecups. The frame is hinged, so that the user can adjust for the distance between the eyes. On the middle cross piece of the frame there is a small scale, marked with gradations from 0 to 3, where this frame adjustment is indicated. Focusing is done with a central thumb wheel. All metal parts on the binoculars are brass, painted black.

"T M J.B.L." is stamped on the face of both eyecups. These initials are not listed in the Webster Signature Database of makers. Between the T and M is a small logo, possibly a face with emanating rays.

College of Optical Sciences
The University of Arizona, 1630 East University Boulevard, Tucson, Arizona U.S.A. 85721-0094