A very good five glass gilt and lacquered brass recording drum aneroid barograph by Richard Frères, Paris, no. 138082 c1930

Conventional barograph movement driven from an eight cell pressure sensor acting on levers and links actuating a grained aluminium recording arm with angled protector. Steel grained cross beams, finely set pivots, the whole raised on four turned pillars over a full length chassis struck with “RF” logogram, serial no. “138082” and “Richard Frères, Constructeurs Brevetes, Paris.” Ink station with almost certainly the original bottle.

The standard drum, 3¾” diameter x 3½” high, with top plate mounted winding and regulation ports, the base struck “8 Jours Echap. Cylindre” (8 day cylinder escapement), “RF” logogram, hand drawn no. “138082,” matching chassis number, additionally struck “8082,” paper clip retainer.

The base with finished in an ogee pattern and raised on slab squares. Calibration square below. The lift off lid with five heavy bevelled glasses and locating lugs.

Condition: The subject of a full service, conservation, and calibration under laboratory conditions. The movement working well across almost all the pressure range, registration is not found above 30.8″ or below 28.2″ – this is normal and a function of ageing of materials and slight losses of low pressure over its near 100 year life. The clockwork professionally serviced. The recording arm and nib replaced, otherwise remaining in completely original condition. The external finish worn and in places weak, retaining enough to remain attractive. The glasses chip free. The ink bottle dipper broken, though this could be repaired with a brass sleeve.

Comments: By far the finest barograph makers of the 19th century and well into the 20th century, these instruments are properly engineered with a great deal of thought put into making a scientifically constructed instrument. For example, the cross beams are made in steel because of the setting up of end float or ‘shake’ in the pivots – steel has a much lower coefficient of expansion than brass and so the set tolerances remain closer over wider temperature variations. The pivots are finely set with locking nuts, another feature that ensures good function. The execution of the engineered parts precise and properly formed.

Most certainly a very desirable collector’s item of which very few are seen.