Description

Beautiful graphometer with double glasses signed Richer in Paris and dated 1808. It is equipped with its ball jointed foot with adjustments by microscmmetric screw. A double-spectrum graphometer is a measuring instrument used in surveying and geodesy to measure horizontal and vertical angles with high precision. It is also sometimes called a double-scope theodolite. Here is a description and an explanation of its use: The double glasses graphometer is an optical instrument composed of two glasses mounted on the same horizontal axis. Each of these scopes is equipped with a reticle (a type of aiming grid) through which the operator can observe aiming points, such as stakes, milestones or other targets. The graphometer is mounted on a stable tripod and can be leveled to ensure it is perfectly horizontal. It is also equipped with horizontal and vertical graduated circles for measuring angles. The primary use of a double-scope graphometer is to measure horizontal and vertical angles between aiming points.