Graphometer Signed "santi" In Marseille, France—early 19th Century

An elegant French graphometer made by the scientific instrument manufacturer Santi in Marseille in the early 19th century. The instrument is signed “Santi à Marseille” on the movable alidade.

This graphometer consists of a finely engraved, graduated brass semicircle featuring a double angular scale. At the center is a magnetic needle compass, protected by its original glass cover, which allows the instrument to be oriented in the field. The pivoting alidade is equipped with sighting pins at both ends, while the fixed brackets located at the ends of the dial facilitate precise measurements of horizontal angles.

On the reverse side, the instrument is equipped with a ball joint that allows it to be mounted on a tripod, thus enabling precise adjustment during topographic surveying operations.

The graphometer was one of the primary geodetic instruments used between the 17th century and the mid-19th century by surveyors, military engineers, and cartographers for land surveying, the construction of roads, canals, and fortifications, before being gradually replaced by the theodolite.

The Santi company, active in Marseille in the early 19th century, was among the French manufacturers of scientific and navigational instruments, producing precision instruments for topographic, nautical, and scientific applications.

The instrument is preserved in fine original condition, displaying a pleasant antique patina on the brass. The engravings remain sharp, and the central compass is intact, making this specimen a remarkable testament to the quality of French craftsmanship in scientific instruments of that era.