Edward Hitchcock built this ingenious apparatus to demonstrate the principles of astronomy to Deerfield Academy students and to make astronomical observations. It allowed Hitchcock to predict eclipses in the local area. He published this information in almanacs that he authored between 1814 and 1818. Although astronomy did not become Hitchcock's career, the mental skills he perfected were of service later in his profession as an earth scientist and in his tenure as president of Amherst College.
A torquetum enables the user to convert between three different coordinate systems: ecliptic coordinates (celestial latitude and longitude), equatorial coordinates (declination, right ascension), and altazimuth coordinates (declination, the horizon and compass direction).