|
Date: |
|
Description: | Canivet a La Sphere a Paris 1770
arms of City of Rouen(?)
noc Praemium Yrbs Rothom dedit, Addixit// que Academia Joanni Sebast.//Mabire de Beauficel 1770
Graduations-Semicircle graduated 0-180, 180-0. The alidade 9.7" (24.5cm) long has a vernier scale at each end, graduated 0-60, to 30'. There is a straight edge 11.25" (28.6cm) long at the lower part of instrument. A ball and socket head and a square plate 3.9" x 3.9" (10 x 10 cm) are attached to back of instrument.
Sights-Two sight vanes 2.3" (6cm) long mounted on straight edge, one sight with a vertical slit with a rectangular aperture above (complete with thread), the other with a rectangular aperture (complete with thread) with a vertical slit above. Two sight vanes 2.6" (6.5cm) long mounted on alidade, one sight with a vertical slit with a rectangular aperture above (complete with thread), the other with a rectangular aperture (complete with thread) with a vertical slit above.
Compass- Dia. 3.6" (9cm) mounted at centre of instrument. Fitted with a tapered flat bar needle 2.9" (7.5cm) long, with a brass pivot cap at centre. Graduated to 16 points and quadrantally in degrees. Fitted with a needle locking mechanism which is operated by a milled knob at back of instrument.
AUDIT - object needs to be marked with its NAV number. Ex T.9. | Publisher: | "http://collections.rmg.co.uk/" | Subjects: | graphometers | Source: | Royal Museums Greenwich | Identifier: | http://collections.rmg.co.uk/collections... | Go to resource |
|
More Like this...
-
-
-
-
graphometer
Graduations-Semicircle graduated 0-180, 180-0 by…
-
-
-
Graphometer
Choizy AParis 1667
Graduations-Semi-circle graduated…
-
-
-
|