Orreries, from our Current Exhibit, “On the Sunny Side”

September 5th, 2013
Copernican model orrery, shown in exhibit case with 18th-century books on orreries

In our current exhibit entitled “On the Sunny Side,” we’re pleased to be able to display a “Copernican model orrery” kindly lent to us by Jim Lattis, co-founder and director of UW Space Place. This model orrery was produced by the Trippensee Planetarium Company of Saginaw, Michigan, and appears to be made of something like Bakelite. At its center is a bright yellow sun, with planets on movable arms surrounding it. For much of the 20th century, the Trippensee Planetarium Company manufactured astronomy models.
Accompanying the orrery in the exhibit are several 18th-century publications in English about orreries and other astronomical instruments used for observation and demonstration. We call your attention here to one of them, a relatively rare edition of an elementary textbook, An easy introduction to mechanics, geometry, plane trigonometry, measuring heights and distances, optics, astronomy [etc.] by James Ferguson (1710-1776), published in 1768 in London. It contains an advertisement for devices and aids to learning astronomy – notably, what were called “Cards of astronomy, and a living orrery, made with sixteen school-boys.”

As the text explains, the cards would carry “the names and periods” of planets and moons in the solar system,” and each of the boys would hold a card corresponding to a planet or moon. “Now begin your play, fix your boys in their circles, each with his card in his hand, and then put your orrery in motion.” With sufficient repetition, this game, the author claimed, would fix “clear and sure ideas of the solar system.” A “seventeenth boy of a large size must be used for the sun in the  center” (pp. xx-xxi). We’re just sorry that the volume contained no illustration of such a living orrery!

Others at the time were less enthusiastic about its pedagogical value. An anonymous reviewer in The monthly review. Or, literary journal by “Several Hands” (July 1768) could not “altogether approve” of the living orrery, thinking it “a crude and trivial performance.” Not only that, but if the boys were to “act the diurnal as well as the annual motions (in which case it would resemble a dervises [dervish’s] dance), the whole solar system would be liable to a vertigo, and all the planets would drop from their respective orbits” (p. 64).

A sidenote: Although James Ferguson is well-represented in ECCO, that is, the extensive compilation Eighteenth-century collections online, this Easy introduction (London, 1768) does not currently appear there.