拍品专文
One of the bubble levels is viewed from the top of the instrument as often seen, the other is a much rarer internal level that is viewed through the alidade
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GEORGE ADAMS JR., LATE 18TH CENTURY
细节
A BRASS THEODOLITE
GEORGE ADAMS JR., LATE 18TH CENTURY
the horizontal plate with graduated scale 0-360° with vernier, signed G.Adams London, 8-point silvered compass rose with outer degree scale, the graduated arc 90°-0-90° with vernier, the alidade with crosshair and two internal bubble levels and crosshair.
8in. (20cm.) high on stand
GEORGE ADAMS JR., LATE 18TH CENTURY
the horizontal plate with graduated scale 0-360° with vernier, signed G.Adams London, 8-point silvered compass rose with outer degree scale, the graduated arc 90°-0-90° with vernier, the alidade with crosshair and two internal bubble levels and crosshair.
8in. (20cm.) high on stand