Barograph

A pen traced a record of air pressure on paper while the barometer rose or fell, showing a flight's altitude.

Maker: Douglass Products Corp.
Place: United States of America
Materials: Steel, Aluminum Alloy, Copper Alloy, Paper, Coated Leather, Synthetic Fabric, Plastic, Paint, Grease Pencil, Adhesive, Ink, Unknown Sealant
Dimensions: 3-D: 12.4 × 8.6 × 4.1cm (4 7/8 × 3 3/8 × 1 5/8 in.)
Museum: National Air and Space Museum
Credit line: Transferred from the Department of Commerce

Range 10,000ft.; circa 1918; pocket model; duration use: 3 hrs.