Altimeter
Collier's New Encyclopedia (1921)
a form of barometer graduated to indicate altitude directly in feet or meters. It is used in meteorology and aeronautics. AMERICAN LEGION. (See UNITED STATES, 1921-1922.) ANGLO-JAPANESE TREATY. Termination of. (See WASHINGTON CONFER- ENCE: Four-Power Treaty.) ANTIOCH COLLEGE. Reorganization of. A new plan looking to the practical education and self-support of college students by means of remunerative industrial employments, arranged in connection with their college courses, was put into operation in September, 1921, under the presidency of Arthur E. Morgan. The plan includes the establishment of industries in a college factory under the direction of experienced managers and with the college students as employees, the students' time to be divided between college study and remunerative work. Other students will be placed for part of their time (two students working in alternate shifts) in various industries in neighboring towns and cities, these industries being such as will give experience of direct application to college courses. Under the plan, credit is to be given for the actual accomplishments of students and not for hours spent on any given subject, and the aim of the courses arranged for is to eliminate the tradiarra tional cleavage between cultural and practical standards. The new board of trustees under which the plan is being carried out is composed of a number of prominent American business men, engineers, administrators, and educators from all parts of the country. ARMAMENT CONFERENCE. (See WASHINGTON CONFERENCE.) ARMENIA. Under Soviet Russia since 1920. Soviet republic, which (October, r, 1921) 1921) became part of a Transcaucasian Federation under Russian domi-
What Has Changed in the Last Century
When Collier's wrote this in 1921, the altimeter was simply "a form of barometer graduated to indicate altitude directly in feet or meters" — and that pressure-sensing instrument is still on the panel of nearly every aircraft flying today. What has changed is everything around it: Paul Kollsman's sensitive altimeter of 1928 added an adjustable pressure sub-scale, so pilots could correct for the day's weather, and the modern system of standardised altimeter settings and flight levels grew out of that fix. Aircraft now also carry radio and radar altimeters, developed from the 1920s and 1930s onward, which bounce a signal off the ground to give true height above terrain rather than air pressure, and GPS supplies a further independent altitude reading. The 1921 definition is not wrong, then — it simply describes one instrument where a cockpit now has three.
Written for this edition, 2026.