Antique Barometers Identification Guide: Types, Makers & Values

The History of Barometers

The barometer was invented in 1643 by Italian physicist Evangelista Torricelli, a student of Galileo. Torricelli discovered that atmospheric pressure could support a column of mercury in a glass tube, and that changes in the mercury level corresponded to weather changes. This revolutionary discovery led to the development of the first practical weather-predicting instruments.

Early Development (1643-1700)

The earliest barometers were simple scientific instruments used primarily by natural philosophers and wealthy patrons of science. These primitive devices consisted of a glass tube filled with mercury, inverted in a cistern. Italian and French craftsmen produced the first decorative barometers, often incorporating elaborate Baroque ornamentation.

The Golden Age (1700-1850)

The 18th century saw the barometer evolve from a scientific curiosity into an essential household item. English makers, particularly Italian immigrants working in London, dominated production. The wheel or banjo barometer was developed during this period, making the instrument more decorative and easier to read. Renowned makers like Daniel Quare, John Patrick, and later the Negretti and Zambra firm established standards of excellence that collectors still prize today.

Victorian Era and Beyond (1850-1920)

The Victorian era brought mass production and new technologies. The aneroid barometer, invented by Lucien Vidie in 1844, offered a mercury-free alternative that was more portable and less fragile. Admiral Robert FitzRoy popularized weather prediction and developed standardized weather glass designs. By the early 20th century, barometers had become common household items, though fine craftsmanship continued in specialty pieces.

Types of Antique Barometers

Antique barometers can be broadly classified into several distinct categories based on their operating mechanism and design. Understanding these types is fundamental to identification and valuation.

Mercury Barometers

Mercury barometers use a column of liquid mercury in a glass tube to measure atmospheric pressure. The main subtypes include:

• Stick or Cistern Barometers: The simplest form, featuring a straight glass tube mounted on a wooden backboard
• Wheel or Banjo Barometers: Use a float and pulley system to move a dial hand, housed in a distinctive round case
• Angle or Diagonal Barometers: Feature an angled tube for amplified readings
• Marine or Gimbal Barometers: Designed for use on ships with compensation for vessel movement

Aneroid Barometers

Aneroid barometers use a sealed metal chamber that expands and contracts with pressure changes. They became popular after 1850 and include:

• Wall Aneroid Barometers: Round instruments for household display
• Pocket Barometers: Portable instruments for travelers and mountaineers
• Desk Barometers: Decorative pieces for office or study
• Combination Instruments: Barometers combined with thermometers, hygrometers, or clocks

Specialty Types

Collectors also seek specialty barometers including:

• Sympiesometers: Oil-based instruments invented by Alexander Adie
• Storm Glasses: Chemical weather predictors popularized by FitzRoy
• Fortin Barometers: Precision scientific instruments with adjustable cisterns

Mercury Barometers: Stick and Cistern Types

The stick barometer, also called a cistern barometer, is the most direct descendant of Torricelli's original invention. These elegant instruments feature a glass tube approximately 36 inches long, mounted on a wooden backboard, with a reservoir of mercury at the base.

Identifying Features of Stick Barometers

Authentic antique stick barometers share several key characteristics:

• Glass Tube: Hand-blown glass with slight irregularities; machine-made uniform tubes suggest later manufacture
• Cistern Cover: The mercury reservoir is typically covered with a turned wooden or boxwood cover, often with decorative rings
• Register Plates: Brass or silvered brass plates with engraved scales, typically reading from 27 to 31 inches
• Vernier Scale: A sliding scale for precise readings, found on quality instruments
• Trunk: The wooden case housing the tube, often with decorative moldings

Styles by Period

Stick barometer designs evolved significantly over time:

• Queen Anne (1700-1720): Simple, elegant cases in walnut with arched pediments
• Georgian (1720-1800): Mahogany cases with architectural details, broken pediments, and urn finials
• Regency (1800-1830): More restrained classical designs with string inlay and ebony details
• Victorian (1837-1901): Oak and rosewood cases with carved ornamentation

Reading a Mercury Barometer

Understanding the scale markings helps with authentication. Traditional markings include weather predictions such as "Stormy," "Rain," "Change," "Fair," and "Very Dry" alongside numerical scales measuring inches of mercury. Quality instruments feature hand-engraved scales with elegant script.

Wheel Barometers: The Banjo Design

The wheel barometer, commonly called a banjo barometer due to its distinctive shape, was developed in the early 18th century to make mercury barometers easier to read. A float resting on the mercury surface connects via a thread to a pulley wheel that moves a pointer on a circular dial.

Anatomy of a Wheel Barometer

A typical wheel barometer consists of several components:

• Dial: A circular face, typically 8-10 inches in diameter, with silvered or painted scales
• Pointer: A brass hand indicating current pressure
• Set Hand: A second pointer manually positioned to track changes
• Thermometer: Most wheel barometers incorporate a spirit thermometer in the trunk
• Hygrometer: Many feature a humidity indicator, often with a piece of catgut or whale bone
• Spirit Level: A small bubble level ensuring proper mounting
• Convex Mirror: Common on Georgian and Regency examples for decorative purposes

Italian Influence on English Production

Many of the finest English wheel barometers were made by Italian immigrants, particularly from the Como region. Names like Negretti, Zambra, Tagliabue, Ronchetti, and Fontana appear frequently on quality instruments. These makers brought sophisticated glass-working skills and established workshops in London, Edinburgh, and other British cities.

Regional Variations

Wheel barometer styles varied by region:

• London: Elegant mahogany cases with restrained classical ornament
• Provincial English: Often more elaborate with shell and flower inlays
• Scottish: Distinctive features including thistle motifs
• French: More ornate with ormolu mounts and elaborate carving

Aneroid Barometers

The aneroid barometer represented a revolutionary advancement in weather instrument technology. Invented by Lucien Vidie in France in 1844 and refined by other makers, these instruments use a sealed, flexible metal chamber that responds to pressure changes, eliminating the need for toxic mercury.

How Aneroid Barometers Work

The heart of an aneroid barometer is a partially evacuated metal capsule, typically made of beryllium copper or phosphor bronze. As atmospheric pressure changes, the capsule expands or contracts. This movement is amplified through a system of levers and transmitted to a pointer on a dial face.

Types of Aneroid Barometers

Aneroid technology enabled many new forms:

• Wall Aneroids: Round instruments in wooden, brass, or carved cases for home display
• Pocket Aneroids: Compact instruments in protective cases for travel; prized by mountaineers and surveyors
• Marine Aneroids: Precision instruments in brass gimbal mounts for shipboard use
• Desk Sets: Aneroid barometers combined with inkwells, pen holders, or clock movements
• Altimeters: Aneroids calibrated to show altitude rather than pressure

Notable Aneroid Makers

Several firms became renowned for aneroid barometer production:

• Negretti & Zambra: The premier English maker, suppliers to the Royal Navy
• Short & Mason: Known for precision meteorological instruments
• PHBN (Pertuis, Hulot, Bourgeois, Naudet): French manufacturer of high-quality movements
• Holosteric: A trademark for high-precision aneroid capsules

Famous Barometer Makers

Knowledge of notable makers is essential for identification and valuation. The most collectible barometers bear the names of renowned craftsmen and firms.

English and Italian-English Makers

• Daniel Quare (1649-1724): Royal clockmaker who developed the portable barometer; extremely rare and valuable
• John Patrick (fl. 1695-1745): London maker known for scientific instruments
• Negretti & Zambra (1850-1999): The most famous Victorian maker, founded by Italian immigrants
• Dollond (1750-1927): Optical instrument makers who also produced fine barometers
• Joseph Somalvico (fl. 1790-1820): London-based Italian known for elegant wheel barometers
• P. & G. Fontana: Respected provincial makers with workshops in several cities

French Makers

• Nicolas Fortin (1750-1831): Developed the precision Fortin barometer
• Antoine Lerebours: Scientific instrument maker to the French Academy
• Henri Lepaute: Clockmaker who produced combination barometer-clocks

American Makers

• Benjamin Pike Jr.: New York scientific instrument dealer
• Taylor Instrument Company: Rochester firm producing quality aneroid barometers
• Fee & Stemwedel: Chicago makers of precision instruments

Identifying Maker's Marks

Look for signatures in these locations:

• Engraved on the register plate or dial face
• Printed on paper dial inserts
• Stamped on brass components
• Labeled on the case back or inside

Dating Antique Barometers

Accurately dating a barometer requires examining multiple elements including style, construction methods, materials, and maker's marks.

Style Indicators

• 1700-1750: Walnut cases, plain glass tubes, simple arched tops
• 1750-1790: Mahogany cases, architectural details, broken pediments
• 1790-1830: Satinwood and inlaid decoration, classical motifs, slender proportions
• 1830-1870: Rosewood and oak, heavier proportions, carved details
• 1870-1920: Oak predominates, often with carved barley-twist columns

Construction Details

Examine these features for dating clues:

• Screws: Hand-cut screws with off-center slots indicate pre-1850 manufacture
• Glass: Hand-blown glass has irregularities; uniform tubes suggest machine production after 1850
• Wood Preparation: Hand-planed surfaces differ from machine-sawn timber
• Inlay Techniques: Marquetry methods evolved over time

Dial and Scale Features

Dial characteristics help establish age:

• Silvered Brass: Most common on 18th and early 19th century instruments
• Painted Enamel: More common after 1850
• Printed Paper: Typically found on later Victorian pieces
• Weather Terminology: "Stormy" vs "Storm," "Fair" vs "Set Fair" varies by period

Materials and Construction

Understanding the materials used in barometer construction aids both identification and assessment of authenticity.

Case Woods

Different woods were fashionable in different eras:

• Walnut: Dominant wood for early 18th-century barometers
• Mahogany: The preferred wood from 1750-1850, especially Cuban mahogany with rich figuring
• Rosewood: Popular in the Regency and early Victorian periods
• Satinwood: Used for inlays and occasionally full cases in the late 18th century
• Oak: Dominant in later Victorian barometers

Decorative Materials

• Ebony and Boxwood: Used for stringing and small turned elements
• Mother of Pearl: Popular for shell-inlaid wheel barometers
• Brass: Used for mounts, bezels, finials, and register plates
• Silver: Occasionally used for scale plates on fine instruments
• Ivory: Used for buttons and small decorative elements (note: subject to trade restrictions)

Mercury and Glass

The mercury tube is the heart of traditional barometers:

• Period tubes were hand-blown with slight irregularities
• The bore diameter affects sensitivity; narrower bores are more responsive
• Original mercury should appear bright silver; oxidized mercury is grey and dull
• Many antique barometers have had their mercury removed for safety

Dial Types and Inscriptions

The dial is often the most examined part of a barometer and provides crucial information about origin, age, and quality.

Scale Markings

Traditional barometer scales include:

• Numerical Scale: Typically 27-31 inches of mercury, or metric equivalents
• Weather Predictions: "Stormy," "Much Rain," "Rain," "Change," "Fair," "Set Fair," "Very Dry"
• Vernier Scale: A sliding scale for precise readings to 1/100th inch

Dial Types by Period

• Silvered Brass (1700-1850): Engraved scales on silvered metal, often with decorative flourishes
• Painted Enamel (1850-1920): Porcelain enamel dials with printed or painted scales
• Paper Dials: Printed paper glued to metal backing, common on later Victorian pieces

Inscriptions and Signatures

Valuable information found on dials includes:

• Maker's name and location
• Royal warrants or patents
• Serial numbers (especially on Negretti & Zambra instruments)
• Dedication inscriptions on presentation pieces

Case Styles and Woods

The case style is one of the primary factors in dating and valuing antique barometers. Case designs evolved with changing furniture styles and tastes.

Stick Barometer Cases

• Pediment Top: Broken arch, swan-neck, or architectural pediments typical of Georgian examples
• Trunk Forms: Rectangular, bowfront, or chamfered shapes
• Cistern Covers: Turned wood, often with decorative rings
• Finials: Brass or wooden urn shapes, flame finials, or acorn forms

Wheel Barometer Cases

• Banjo Form: The classic shape with round dial head and elongated trunk
• Shell Inlay: Patera or fan shapes in contrasting woods
• Architectural Details: Columns, scrolls, and pediments
• Convex Mirror: Many Georgian examples include a small mirror in the trunk

Aneroid Cases

• Round Wooden: Simple oak or mahogany cases with brass bezels
• Carved Oak: Elaborate Victorian cases with barley-twist or foliate carving
• Brass: Marine and scientific instruments often had all-brass cases
• Combination: Barometers integrated with clocks or desk sets

Assessing Condition

Condition significantly affects value. A systematic examination reveals the true state of an antique barometer.

Case Condition

• Original Finish: Undisturbed original finish is highly desirable
• Repairs: Look for replaced veneers, filled cracks, or refinished areas
• Inlay: Missing or replaced inlay elements reduce value
• Structural Integrity: Check for warping, splitting, or loose joints

Mechanism Condition

• Mercury Presence: Many instruments have had mercury removed; original mercury is ideal but increasingly rare
• Glass Tube: Cracks, chips, or replacements affect value
• Movement Function: The wheel mechanism or aneroid capsule should respond to pressure changes
• Dial Condition: Original dials in good condition are essential for top values

Thermometer and Accessories

• Spirit Level: Often missing or replaced
• Thermometer: Original thermometers with intact bulbs are desirable
• Hygrometer: The catgut or whalebone element often needs replacement
• Set Hand: The brass reference pointer should be present

Authentication and Reproductions

The popularity of antique barometers has led to numerous reproductions and outright fakes. Knowing how to spot these is essential for collectors.

Common Red Flags

• Too Perfect: Genuine antiques show appropriate wear; unmarked perfection suggests reproduction
• Inconsistent Components: Mixed periods or styles in one instrument indicate assembly from parts
• Modern Materials: Plywood, particleboard, or plastic components reveal recent manufacture
• Anachronistic Features: Elements from different periods combined in one piece

Reproduction Indicators

• Machine-Made Details: Uniform turnings, perfect inlay cuts, identical carved elements
• Modern Finishes: Spray lacquer or polyurethane instead of period French polish or wax
• Artificial Aging: Distressing, staining, or faked wear patterns
• Generic Signatures: Famous maker names added to plain instruments

Verification Methods

• Compare with documented examples in reference books and museum collections
• Examine under UV light for finish anomalies
• Check screws, nails, and hardware for period-appropriate manufacture
• Research the purported maker's typical products and locations

Value Factors and Market Trends

Antique barometer values vary widely based on numerous factors. Understanding the market helps collectors make informed decisions.

Primary Value Factors

• Maker: Renowned makers like Daniel Quare or Negretti & Zambra command premium prices
• Age: Pre-1800 examples are generally more valuable than Victorian pieces
• Type: Stick barometers typically fetch higher prices than common wheel barometers
• Condition: Original, complete, working instruments are worth several times more than incomplete or non-functioning examples
• Provenance: Documented history of ownership adds value

Current Market Ranges

• Georgian Stick Barometers: $2,000-$20,000+ depending on maker and condition
• Georgian Wheel Barometers: $800-$8,000 for quality examples
• Victorian Oak Aneroids: $200-$800 for typical examples
• Quality Victorian Wheel Barometers: $500-$3,000
• Pocket Aneroids: $100-$500 for common types; more for fine makers

Market Trends

Current collecting trends show:

• Strong demand for Georgian and Regency pieces with original mercury
• Increasing interest in scientific and marine barometers
• Steady market for decorative Victorian examples as accent pieces
• Growing appreciation for unusual types like sympiesometers and precision instruments

Care and Maintenance

Proper care ensures your antique barometer remains functional and retains its value.

Handling Mercury Barometers

• Transport: Always keep mercury barometers vertical; tilting can cause tube breakage or mercury spillage
• Mercury Safety: If mercury is present, handle with extreme care; mercury is toxic
• Professional Service: Have mercury barometers serviced only by qualified specialists

Case Care

• Cleaning: Dust gently with a soft brush; avoid polish on original finishes
• Environment: Avoid direct sunlight, extreme temperatures, and humidity fluctuations
• Waxing: A light application of quality furniture wax protects the finish

Dial and Mechanism

• Cleaning Dials: Never use water or solvents on silvered or painted dials
• Movement: Aneroid movements occasionally need lubrication by a specialist
• Calibration: Comparison with a known accurate barometer allows adjustment

Building a Collection

Whether you're a beginning collector or an experienced enthusiast, building a meaningful barometer collection requires strategy and knowledge.

Starting a Collection

• Begin Modestly: Start with affordable Victorian examples to develop your eye
• Focus: Specialize in a particular type, period, or maker
• Study: Invest in reference books and visit museum collections
• Network: Join collector groups and attend specialist auctions

Where to Find Antique Barometers

• Specialist Dealers: Offer expertise and often guarantee authenticity
• Auctions: Major houses like Christie's and Bonhams hold scientific instrument sales
• Antique Shows: Allow hands-on examination before purchase
• Estate Sales: Can yield undiscovered treasures at fair prices

Collection Development

• Document each piece with photographs and provenance information
• Consider insurance for valuable items
• Display barometers away from direct heat and sunlight
• The Antique Identifier app can help research and authenticate potential acquisitions