Precision Recording Barometer / Barograph Negretti & Zambra, London c.1950

An exceptionally rare barograph by Negretti & Zambra. This instrument has four capsule stacks arranged as two balanced pairs and their deflections are transmitted to the main lever through flexing strips therefore avoiding hysteresis (friction errors) & loss of motion. A large open scale, the pen travels 5” for 3” of mercury. Set into a light oak case with beveled glass & chart These instruments were manufactured in very limited numbers for professional use & very rarely come on the market.