First, matters arising.

In “The return of the Ratchet Spiral” I suggested that the length of the spiral path was 2,880’. I was wrong and, in mitigation, I did say “by rough calculation”. I hope nobody was seriously misled and I hope that you can forgive me.

Now, in a substantially calmer frame of mind, I have recalculated and the path length is about 2,298’. This is extrapolated from an accurate measurement of the centre circle diameter which was 43’. I would have liked to have walked it but did not. The ratchet-steps are 10’9” from centre-to-centre of paths. The spiral path, throughout its length, is 3’4” wide and the internal diameters of the ellipsis circles are 34’8”, 26’8” and 16’8”. I hope this information is useful ...   more »