An Ebony and Brass Quadrant with Ivory scales made by William Clarke of London and dated 1807

Ivory mounted scales and name plate. Slight chip on the ivory vernier scale. Two screws missing: one to secure the index arm, the other (one of three) on the back to rest on a flat surface. The name plate is inscribed "Made by W. Clarke, London for John Young, 1807." William Clarke worked at 13 Wapping Wall, London from 1797 - 1820. Length of index arm: 15 1/4". Provenance: The William Guthman collection.