Bourdon & Richard barometer constructed principally in lacquered brass, open centre 7½” printed card dial calibrated in centimeteres of mercury with a range from 73 – 79 and annotated with French meterological terms, the lower part marked “Barometre Metallique.” Japanned steel pointer, gilt brass telltale, original hand-blown convex glass, formed brass bezel. Fine movement constructed in steel and lacquered brass, with crescent-shaped ovoid section vacuum chamber, bearing via twin levers upon a fan-shaped rack engaged with a slipping pinion to the arbour. The upper back plate stamped with the cartouche “EB,” marking the production of Felix Richard for Eugene Bourdon, and the lower backplate the serial no. “1783” as well as “Richard a Paris.” The rack with the earlier ‘pointed end’ design. The whole set within its original turned and japanned timber wall hanging case, the verso with hanger, large centrally positioned  removable access cover secured on three swinging  keepers, separate compartment housing containing original adjustment key with swinging keeper.

These instruments were the great competitor to Vidi’s aneroid barometers, and the rivalry was, of course, intense. The Bourdon & Richard’s design, requiring far higher standards of craftsmanship, had an immediate disadvantage in higher production costs. It is probably for this reason, and the fact that the design per se was less rugged than that of the Vidi capsule aneroid, that the numbers produced were relatively few and therefore the reason these instruments are seldom seen – the even rarer 7½” and 8″ versions represent a small proportion of production.

As mentioned, these instruments are very finely crafted, the true magnificence and apparent simplicity of the movement revealed by the open dial. The instrument, if moved, will deflect, and the measured response of the pointer will be noted – a characteristic unique to this design. Response, sensitivity and progression are legendary and these attributes perfectly explain why they are so highly regarded.

This antique Bourdon & Richard barometer is very early production, pre-dating the detail on the lower section of the chapter ring of the medals awarded at the Exhibitions in 1849 and 1851 seen on later instruments from this maker. Of the very few 7½” or 8″ Bourdon barometers seen, most are contained within spun brass cases – this instrument, no. 1783, is only the second such early example observed mounted within its original timber case designed specifically for wall hanging (the other is featured in Collins, Philip R., Aneroid Barometers and Their Restoration).

These instruments have a unique means of calibration – a special key is required which, when fitted into the centrally positioned port to the rear of the instrument, engages on a square at the base of the arbour. In so doing, a lever placed in the same plane and close to the arbour is caused to engage with the slipping drive pinion, thus the arbour may be turned whilst the movement is “braked.” Most notably this instrument still possesses its original adjustment key, provision being made for this with a stowage compartment in the rear of the case, and maintained in this position by a swinging keeper. These setting keys are invariably missing so the presence of this is truly exceptional.

It is always a pleasure to see one of these instruments for they never fail to surprise and impress. The elegance in design and consummate skill in craftsmanship are unsurpassed as a barometer, and this one is no exception.

Surviving in entirely original condition, the timber case with some marks and minor impressions, minor wear to finish, the dial with some distortion, minor losses and marks. Conserved, serviced and checked, accurate with very good progression and sensitivity. Crisp overall.

A wonderful early instrument of extreme rarity, particularly so with its original setting key. Probably the finest of all aneroid barometers, and certainly the most desirable, this is absolutely a collector’s piece.

Dimensions: 12″ diameter x 3½” deep

Stock No: BA0427

Price: SOLD