Scientific, Instrument, Compass, Military Directional, Charles Delagrave, Paris, Antique c. 1900 (Sold)

Description

This instrument has a wooden two-part case comprised of an upper leaf (sometimes called the top leaf) and a lower or horizontal leaf (sometimes called the bottom leaf) that are hinged to close to protect the interior compass and sighting vane when not in use. On the outside of each leaf, respectively, are applied, varnished printed paper tables and instructions. The upper leaf has planimetry and leveling instructions; the lower leaf has an inclination table for making computations. The sides have rulers that when opened have graduated markings from 0 to 16 centimeters. The two leaves are hinged at one end. On the other end are two hooks to fasten both leaves closed shut when not in use, as well as a metal loop for carrying.

The interior horizontal leaf has an inset glazed compass with printed circular North-South-East-West directional card, the magnetized arrow colored blue on one half, and silver on the other. It has a hinged rectangular brass sighting vane which can be set at different angles to 90 degrees or lowered flat when not in use, and also has a brass thumb screw to freeze or release the magnetized needle. The interior upper leaf has a round mirror opposing the compass with an inset rectangular transparent pane revealing two parallel stretched strings as sighting lines that coordinate with the opposing sighting vane.

Compass dial legend: Systeme du Colonel Peigné/ Ch. Delagrave et cie/ Paris

Condition: Generally very good to fine overall, the outer paper well intact and readable (thus rare), with light toning and wear and very minor bubbling from shrinkage, the interior compass and metal components quite clean with just light metal oxidation.