Wittgenstein's rod

The answer depends on three parameters: the radius of the circle, the distance from the center to S, and the length of the segment AB.

The shape described by B can be seen as a 'figure-eight' which in some cases degenerates to a single lobe looking like an inverted cardioid.

If B remains on the same side of S with respect to the center of the circle, instead of a ray one can consider just a segment or the rod AB.

When I work the mechanism its movement proves the proposition to me; as would a construction on paper.

Or – what it persuades me of.This text has been included among the notes selected for publication in Remarks on the Foundations of Mathematics and the editors have dated in the as spring of 1944.