Description and Notes:
The mechanism of this type of ellipsograph is known as "Trammel of Archimedes," which is a four-bar linkage with two perpendicularly intersected prismatic pairs. This device was referred to as "elliptic trammel" by W. F. Stanley, who also indicated that the ordinary ones used for drawing purposes has a 3.5 inch cross. This one is only about half of the ordinary size, therefore, according to Stanley, "it does not work very perfectly, from the necessary shortness of the sliding pieces." Indeed, but nontheless a quality made piece.
This ellipsograph comes with the original card board box, which contains also the instructions and catalog, as well as the original purchase receipt, and, accordingly, it can be dated to no later than 1951.
There are two scales engraved on two opposite sides of the wooden rod, the one shown on the above photo is in centimeters and the other one is in inches. The steel handle which inserted to the drawing lead holder is a later addition.