Barometers: Scientific Instruments as Decorative Art
Barometers -- instruments for measuring atmospheric pressure to predict weather -- have been produced since Evangelista Torricelli invented the mercury barometer in 1643. By the 18th century, barometers had evolved from purely scientific tools into finely crafted decorative objects combining precision instrument-making with cabinetwork of the highest order. English, French, Dutch, and American examples from the 18th and 19th centuries are the most actively collected, with fine examples serving as both functional instruments and striking wall or table furnishings.
Types and Styles
- Stick (cistern) barometers: The earliest and most accurate form; a straight vertical tube of mercury mounted in a wooden or brass case; English examples by Daniel Quare, John Patrick, and George Adams are most prized
- Wheel (banjo) barometers: Round dial face with decorative wooden surround, thermometer, hygrometer, and spirit level; the most common form collected; popular 1780-1870
- Admiral Fitzroy barometers: Large Gothic-style barometers with printed weather prediction charts; produced from the 1860s after Vice-Admiral Robert Fitzroy published instructions
- Aneroid barometers: Use a metal bellows rather than mercury; smaller, portable, and produced from the 1840s; both wall-mounted and desk models
- Marine barometers: Gimballed instruments designed for shipboard use; by Negretti & Zambra, Short & Mason, and other nautical instrument makers
- Sympiesometer barometers: Rare early 19th-century instruments using oil and gas; by Alexander Adie of Edinburgh
Identification and Marks
- Maker signatures: Quality barometers are signed on the dial plate or register; Italian immigrant makers dominated the English trade (Negretti, Zambra, Tagliabue, Pastorelli)
- Register plates: Engraved or printed silvered brass plates showing pressure readings and weather predictions
- Case style dating: Mahogany cases with stringing and shell inlay suggest 1790-1830; rosewood with mother-of-pearl suggests 1830-1860; oak suggests later Victorian
- Mercury condition: A bright, clean mercury column indicates a working instrument; dark, oxidized mercury needs professional service
- Aneroid maker marks: Negretti & Zambra, Dollond, Short & Mason, and Tycos are premium makers
Auction Price Ranges
| Category | Typical Range | Exceptional Examples |
|---|---|---|
| English wheel/banjo barometers | $300 - $2,000 | $5,000 - $15,000 for fine Georgian examples |
| English stick barometers | $500 - $3,000 | $10,000 - $50,000 for important early makers |
| Admiral Fitzroy barometers | $300 - $1,500 | $3,000+ for original Gothic oak models |
| French gilt bronze barometers | $500 - $5,000 | $15,000+ for Louis XV/XVI examples |
| Marine gimballed barometers | $200 - $1,500 | $5,000+ for early signed examples |
| Aneroid desk barometers | $100 - $600 | $2,000+ for complex multi-function types |
| Sympiesometer / rare types | $2,000 - $10,000 | $25,000+ for Adie originals |
Condition Factors
- Mercury presence: Many mercury barometers have been emptied for shipping or safety; refilling requires professional skill and affects value
- Case condition: Original finish, intact veneers, and complete inlay are essential; replaced components reduce value significantly
- Dial/register plate: Original silvered plates with clear engraving are preferred; re-silvered or replaced plates diminish value
- Glass: Original blown glass tubes are desirable; replaced modern glass tubes are acceptable but noted
- Functionality: Working instruments command 30-50% premium over non-functional examples
Collecting Tips
- Buy working instruments when possible: A functional mercury barometer is both a collector's piece and a remarkably accurate weather instrument
- English wheel barometers are the most accessible: Abundant supply, attractive designs, and moderate prices make them ideal starting pieces
- Early stick barometers are the pinnacle: Pre-1800 signed stick barometers by major London makers represent the highest achievement in the field
- Shipping mercury instruments requires care: Mercury is a regulated substance; professional packing and shipping is essential
- Restoration is accepted within limits: Professional re-silvering of register plates and careful case restoration are acceptable; major rebuilds are not
- French barometers are decorative standouts: Louis XV and Louis XVI gilt bronze barometers are as much about the case as the instrument and appeal to decorative arts collectors