Up in the Air

Professor J.G. Hutton used the American Paulin Altimeter Model SA-1. The altimeter is a squat metal cylinder with a large white face housed in a leather case. It was used to measure altitude. Inside, a small flexible metal box is under a partial vacuum, and is highly sensitive to pressure change. These changes are detected and amplified by clockwork, which displays on the face of the dial. This particular model must be first leveled, often on a tripod, before an accurate reading can be made. When not in use, the mechanism can be locked to prevent damage to the delicate mechanics. The altimeter measures 5.75” in diameter and is only 4” tall. Hutton used this while he was studying soils in the field. It is currently on display in the Groundbreakers: Early Agricultural Scientists and Engineers of SDSU. #AgMuseum #Altimetry