Details
An ivory sector,
with brass hinge, signed Dollond London; another signed Halse & Son London; another ivory sector; and an ivory-edged ebony parallel rule signed Baker 244 High Holborn London -- 12.1/2in. (31.8cm.) wide (4)
with brass hinge, signed Dollond London; another signed Halse & Son London; another ivory sector; and an ivory-edged ebony parallel rule signed Baker 244 High Holborn London -- 12.1/2in. (31.8cm.) wide (4)