Description

A rare and unusual miner’s compass in the style of Joseph Schablas(f)s(z) of Vienna, early 19th century. Although unsigned, it is of the highest quality and shows many features attributed to the famous Austrian scientific instrument maker. The 4 inch square compass has a silvered dial of unique demarcations. Firstly, the cardinal points are latinized (North: SE-septentriones, East: OR-oriens, South: ME-meridiens and West: OC-occidens). Secondly, the outer dial is divided into a 24 hour clock ( 4 minute divisions). Thirdly, the 360 degree engine divided compass ring is in 15 degree increments with a further 24 (0-15 degrees in 5 degree increments and thence divided into one degree block accuracy). The bar style steel needle has a jewelled pivot point and locks via a brass sliding bar with octagonal pin, with a square nut on the reverse of the wooden case. Original glass is held in place by a double machined brass ring. The pine? case has a sliding lid with finger groove (like a pencil case). The compass was intended for plane table surveying as there is no ferrule on the reverse for a tripod. Faults?? slight oxidation of the dial at 15 hours (225 degrees) and some ink stains to the sliding cover. Operation of the compass is smooth and accurate (still points North: SE) and the needle locks securely. Robust construction for the pocket and the mine. Case measures 5 x 4 1/2 x 1 inch (12.5 x 11.75 x 2.5 cm.).