Antique Barometer from the firm Callaghan & Co

Beautiful antique barometer that works according to the principle of the almost vacuum box of Vidi. This type of barometer works as follows: in the round box, the lid is wavy and can expand under low pressure, low air pressure, and is pushed in under high air pressure. This movement of pressing in and expanding is transmitted via a spring, levers, and a small chain to the pointer, which moves to the right under high pressure indicating nice weather and to the left under low pressure. Beautiful antique instrument in very good and original condition.