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MUSEUM OBJECT

Title:  
Telescope
Description:  
Dimension:H:7.000in L:45.000in Dimensions of instrument Tripod: 66 x 35 x 35
Creator:
Dollond
Dates:
1750-99
Abstract:  

The 43" tube is fabricated of cast brass sheet. The focal length is 45" and total length of the tube equals 46 1/2" and it is mounted on a mahogany tripod for use in a standing position. The finder is a 9 3/4" telescope with crossed hairs. The control handle for horizontal adjustment is missing, as is part of that for vertical adjustment. The wooden tripod can be used as altazimuth or parallactic mounting so that the telescope might be used for terrestrial or celestial viewing. The wooden, cylindrical, telescope base on top of the tripod is divided into two halves of an angle of 25 1/2° and pivoted at the center on a tapered axis, vertical to the plane of division. When the two halves form a cylinder, the top surface is horizontal and may be used for terrestrial viewing. By turning the top half 180°, the top surface makes an angle of 51° with the horizontal (the latitude of London). These two positions are indicated on the cylindrical bodies by two lines, 180° apart. The lines of marked by two thin ivory strips inlaid in the wood. Marked, "Dollond, London." (Robert P. Multhauf, "Catalogue of Instruments and Models," 1961).
Call #:  
58.25



MUSEUM OBJECT

Title:  
Telescope
Description:  
Dimension:H:36.000in W:25.000in L:34.000in
Creator:
Rittenhouse, David
Dates:
1768-69
Abstract:  

The telescope is made of brass and consists of a 33 1/2" tube on 25" axis with a 1 3/4" aperture and a focal length of 32". Mounted on a brass stand of two rigidly connected A-frames, for use on a table. There are crossed hairs in focal plane, semi-circular scale of 9" radius attached to the bottom of the tube, and a suspended spirit level. Its construction is generally in accordance with earlier European convention. Unmarked. (Robert P. Multhauf, "Catalogue of Instruments and Models," 1961).
Call #:  
58.24