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Modeling the Earth's, Moon's & Planets' Rotations
TRIPPENSEE PLANETARIUM CO./ RAND MCNALLY CO. [Detroit, c. 1908-1920]
Large brass globe representing the sun, 3-inch diameter globe of earth, representations of the moon & Venus, mounted on maple arm, all interconnected by a sprocketed chain, in turn mounted on a maple pedestal atop a brass base on which are engraved the seasons, names of the zodiac constellations & the months of the year.14 inches high; 21 inches long; excellent condition.
Called a Tellurian, here in superb condition, this precisely crafted model, by virtue of an intricate chain mechanism and interlocking wheels, demonstrates when rotated the positions of the earth, moon, Venus and the Sun to each other and at specific times of the year. As the maple arm with the heavenly bodies rotates, it sits above a plate in the base on which the time of year can be seen. In all this model offers a very ingenious means to understand a number of complex, interrelated astronomical phenomena.
The Trippensee Planetarium Company began in Detroit, Michigan in 1897 as the Laing Company. Frank Trippensee, an employee, acquired the company with his brothers in 1905. In 1908, they patented the chain drive used for the present model. The three-inch terrestrial globe was manufactured by Rand McNally and copyrighted 1891.
Hovey, Edward. Elements of Mathematical Geography - A Hand Book for School and Home Use in Connection with the Trippensee Planetarium. Detroit: 1911.