A barograph is a mechanical weather instrument that records continuous changes in atmospheric pressure onto a revolving paper chart. It combines a barometer mechanism with a clockwork drum. These devices sit inside protective wooden enclosures with glass panels so the inked arm remains visible while recording weekly weather patterns.

How do aneroid and mercury barometers differ?

Aneroid barometers utilise a sealed metal vacuum capsule that flexes with air pressure changes to move a dial pointer. They contain no liquid. Mercury barometers rely on a column of liquid metal balancing against atmospheric pressure within a vertical glass tube mounted on the timber backboard.

Where were these instruments placed?

Victorian and Edwardian households placed these instruments in hallways, libraries, or studies where family members could check daily weather trends before travelling. Large examples also stood in marine offices and shop displays. Wall-hanging versions required secure mounting near eye level to allow easy reading of the circular dials and thermometer scales.

How do I date an oak barometer?

Dating relies on stylistic clues in the timber case, such as heavy Victorian carvings, Edwardian geometric inlays, or later Art Nouveau motifs. Maker signatures and patent dates marked on the metal dials or paper charts provide further chronological evidence. Changes in glass bevelling and the complexity of the internal barometer movement also help narrow down the decade of manufacture.