Mahogany framed barograph by Negretti & Zambra. The mechanical eight-day movement is housed in the drum, fitted with a seven-day chart which covers one full rotation of the drum. The ink trace, or barogram, on the recording paper is a visual record of changes in pressure.
The aneroid barometer mechanism has ten stacked vacuum capsules and utilises a gate suspension, a refinement developed to improve sensitivity. The barograph has its original glass ink bottle recessed into the case. With hinged lid with brass carry handle.
Height 8 Inches
Width 13 Inches
Depth 6.5 Inches