• Exhibition Text

    • Brass, silverplate

      c. 1700, Netherlands

      With its adjustable sighting rule and scales of degrees, the theodolite measures horizontal angles, a basis for calculating ground distances. The surveyor mounted it on a tripod and took bearings of a point on the landscape from two base line positions. The compass at center provides for orientation.

      AMNH Hayden Planetarium Collection 2043

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