Brass construction. The instrument consists of a plate supported by an L-shaped arm and foot. A thumbscrew on the plate causes a pencil below to describe the figure, through a train of four gears, the last of which carries the pencil at the end of an arm. (Robert P. Multhauf, "Catalogue of Instruments and Models," 1961).
The elliptograph or ellipsograph, was a tool for drawing ellipses. In the early 19th century, several inventors devised tools to "describe" small ellipses, useful shapes for engineers and architects who needed to show circles in perspective. APS records confirm that an unsuccessful contender for the Magellanic Premium (2009.29) submitted this elliptograph and another in 1819. According to the rules of the Premium, unsuccessful entries were to be burned. However, some entries have survived in the APS collections. The anonymous applicant sent a letter along with his submissions, including detailed descriptions. He noted that this elliptograph was actually defective, the result of poor work by a constructor he employed to produce his invention.
|Dimensions||W-2 L-4 inches|
|Credit line||American Philosophical Society|