Bourdon & Richard barometer having open centre 5” engraved and silvered dial annotated in standard metrological terms in Spanish, “Tempestad,” “Gde Lluvia,” “Lluvia oVto,” “Variable,” “Bn Tiempo,” BnTpo Fijo,” “Muy Seco,” the barometric scale calibrated in centimetres of mercury with a range from 73.0 – 79.0, further divided to mmHg. the lower part marked “Barometro Metalico” with twin medallions, to the left “Medaille d’Or Exposition 1849 – E. Bourdon et Richard Brevetes, Paris,” to the right “Exposition Universelle, Londres 1851 – Grande Medaille de 1 Classe.” Blued-steel pointer, gilt brass telltale, deep bevelled glass. Fine movement 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 standard Bourdon design but with the unusual addition of a hair spring mounted to the base of the rack shaft. The upper back plate stamped with the cartouche “FB,” marking the production of Felix Richard for Eugene Bourdon, and “Compense,” the lower backplate carrying the serial no. “15169,” and “Richard a Paris,” further marked “6.” The rack with the earlier ‘pointed end’ design. The mount for the Bourdon tube marked “2 Serie,” “Bourdon & Richard,” “15169” and “Brevetes a Paris,” and the two ends of the tube marked “Compense.”
Inset mercurial thermometer set on a silvered and engraved curved register with twin scales marked in degrees Fahrenheit and Centigrade having ranges of 10 – 150 and -15 – 70 respectively, supported from and screwed to the barometric dial on three finely executed brackets. Removable glass and bezel on a bayonet. Drum form case with detachable verso on a bayonet having sliding cover to adjustment key port to centre. Key adjustment mechanism working well. Case extension with suspension loop.
These instruments may be considered scarce by any standard – those with original fitted thermometers are extremely rare. This instrument is a development or more finely tuned version of the original pattern – the rack shaft has a tensioning hair spring added to its base designed to reduce backlash and therefore provide more accurate registration, an addition not present on most of these instruments, including other Series 2 models.
Original condition, the dial generally oxidised with some silvering lacking, the case with some heavy oxidation and losses to lacquered finish. The instrument responds well to pressure change with good sensitivity and progression. Serviced and conserved.
**Update** Comes with replica adjustment key. Adjustment mechanism working correctly.
Though showing obvious signs of age, this Spanish Bourdon & Richard barometer has survived in good original working order. As an example it easily qualifies as collectable, being very difficult to find another.
Dimensions: 5½” diameter x 2¼” deep
Stock No: BA0462