Top Quality Regency brass cased travelling barometer.c.1830. Made by highly regarded maker,Adie & Son of Edinburgh(w.1822-35). Silvered engraved dial with altimeter to the surround. Polished brass case. Wall mounted if desired. Fully overhauled. Measures 3"diameter x 1.25"deep. Adie & Son patented the sympiesometer. Makers of fine scientific instruments.