Degree circle painted 90-0-90-0-90° every 1°. Bracket crosses the diameter of the circle and rotating within a Y-bearing so that circle can be positioned vertically or horizontally. Locking screws on arms of Y. Center of bracket has compass needle axis with locking screws. Blue-silver needle type 7. Y-bearing supported on small plate calibrated for azimuth 0-90-0-90-0 degrees every five degrees. Plate rotates on a tribrach base with leveling-screw feet. Metal index attached to one leg. Bubble level in plate. Copper has textured grey finish.
Materiale
"W. M. WELCH SCIENTIFIC COMPANY/WELCH/ESTABLISHED 1880/1515 Sedgwick St., Chicago, U.S.A."
