Description

SOLD – The Trammel of Archimedes, also known as an ellipsograph, is a mechanical drawing instrument designed for the accurate construction of ellipses. The device operates by constraining two sliding points to move within perpendicular grooves, while a rigid connecting rod pivots between them. As the sliders are guided along their respective tracks, any point fixed to the rod describes a precise elliptical curve.

The proportions of the ellipse are determined by the distances between the tracing point and the two sliding pivots, which define the semi-major and semi-minor axes. This elegant and mathematically exact method allowed draughtsmen to produce consistent and repeatable ellipses without calculation.

Trammels of this type were widely used in engineering, architectural drafting, instrument making, and technical illustration, and are today valued both as functional drawing tools and as demonstrations of classical mechanical geometry.

The case is warped – see last picture.