A very good antique surveying compass by William & Lewis E Gurley, Troy, USA c1880

Antique surveyors compass having 4″ hand engraved and decorated silvered dial showing cardinals reading clockwise N-W-S-E with the maker “W. & L.E. Gurley, Troy, NY” to the upper section and the Gurley trademark star to north. Outer stepped ring displaying quadrant scale 0°-90°-0°-90°-0°, divided to ½° increments. Polished steel needle on jewelled pivot, blued to north half, balancing weight, silvered transit lock. Two bubble spirit levels set at right angles to each other at E and S. Original flat glass contained within brass bezel.

All within a heavy lacquered brass case with twin folding sighting vanes, one with fine wire or horsehair. Finely engraved magnetic declination adjustment scale to righthand side, the upper scale reading 20°-0°-20°, the middle 30°-0°-30‚ and the lowest 60°, together with adjusting screw. The verso with transit lock screw and socket for tripod attachment.

All contained within a precisely fitted mahogany case, mounting staff to right hand side. Original Gurley label to lid, with handwritten annotations for C. Hals.all, Baslow and R. Bakewell.

Condition: In exceptional original condition, the dial and glass clear, the needle swinging freely and finding north easily, the transit lock working well. The spirit bubble levels crisp and retaining their luminous green colour. The lacquered brass retaining almost all its original rich finish. The mahogany case with patina and a few marks commensurate with age and use, the inner lid and label with portion missing, either because of or to allow for the north sight hinge. The ball joint section missing.

Comments: William Gurley and his younger brother Lewis E. Gurley founded the W. and L.E. Gurley Company in Troy, N.Y., in 1852. At that time the company specialised in manufacturing and supplying precision instruments for civil engineers and surveyors. The company continues today as Gurley Precision Instruments, and still operates in the building it constructed in 1862 in Troy.

No serial number dates this surveyor’s compass to pre-1908, and the positioning of the maker’s address to the top part of the dial indicates earlier production.

To Use the Compass: In using the compass, the surveyor should keep the south end towards his person and read the bearing from the north end of the needle. He will observe that the E and W letters on the face of the compass are reversed from their natural position, in order that the direction of the line of sight may be correctly read. (From the 1878 Gurley Manual of Surveying Instruments)

The side mounted magnetic declination adjustment allows old surveys to be retraced accurately by adjusting for the change in magnetic north since the original survey.

Gurley surveying compasses are not common, and those with the twin spirit levels inset into the dial even less so. Coupled with its exceptionally fine condition, this very handsome American compass is one for the serious collector or connoisseur alike, or a special gift for a surveyor or civil engineer.