Barometers Realm

This mantel clock with barometer and thermometer, circa 1880, manufactured by the renowned French horological firm Japy Frères, feature a massive, heavy case, cast in decorative art-foundry iron. The surface is finished with a traditional bitumen-oil varnish — the same “stove-black” Japanese/asphalt coating used in the second half of the 19th century to protect and simultaneously decorate cast iron. The colour of the base is a deep black with a soft matte sheen. The front of the case has a decorative bronzing: a thin layer of bronze powder over varnish, creating the appearance of aged patinated bronze. This finishing technique was widely used by French masters aiming to visually approximate cast iron to bronze while preserving the plastic expressiveness of the casting.

The ornament of the case is a vivid example of late French historicism: a central cartouche with scrolls, leaves of acacia or grapevine, acanthus volutes to either side, and small pierced openings enhancing depth. The top is crowned with a symmetrical pediment, the lower section formed as a broad architectural stand with volutes and an arched profile. The case accommodates three instruments: left — barometer; right — clock; centre — thermometer.

The clock — Japy Frères, 8-day pendule movement, spring-driven, classic pendule de Paris. Single-spring winding, eight-day run, typical barrel construction. The movement uses an anchor escapement with pendulum and rate adjustment. The enamel dial is white, with Roman hour numerals and an outer minute track. The hands are steel, in Breguet pomme style, with crescent tips and no counter-poise. The brass bezel with inset mineral glass, thinly facetted at the edge, opens forward to provide access to the winding square and time-setting — a solution typical for French mantel clocks of 1870–1890.

The barometer — aneroid, with a white card dial protected by mineral glass set into a brass bezel. The concentric barometric scale is graduated in millimetres of mercury, 690–800 range. Weather terms are printed outside the scale in Dutch. The trend-indicator hand with a knurled central adjuster is made of brass.

The barometric movement is a simple type based on a copper aneroid capsule with an internal spring. The upper membrane of the capsule responds to atmospheric pressure and transmits motion to a brass lever with counterweight; the lever acts on the main arbor from which a fusee-style chain drives the pointer shaft.

The central instrument on the case is a mercury thermometer on an elegant enamelled plate, calibrated in two scales: Celsius and Réaumur. The fine enamel emphasises the visual purity of the ground — a point of pride for Japy Frères, who during these years developed in-house enamel production and even manufactured enamelled kitchenware (from saucepans to dairying cans), fully utilising the capacities of their factories.

Overall — an exquisite Japy Frères ensemble: clock, barometer, and thermometer united within a single cast case, combining functionality with the decorative mastery of the historicist era. A rare, expressive and collection-worthy object — a perfect example of how the industrial houses of Franche-Comté blended engineering, aesthetics, and applied science in one creation.