Brass and wood barograph, 20th century

Measuring instrument with mahogany wood case and brass hardware. The top lid has a glass front and lift up, attached by a hinge on the left side. It has a plaque stating "MET 20780 / SMALL BAROGRAPH / SERIAL No. MO/29/81 PHOENIX INSTRUMENTS". 

Measures: 19 x 16 x 31.7 cm.