These designs were prompted by the “pursuit curves” of Mr. I. J. Good The first one consists of his six ‘hyperboloids’ and the second an equal number of ‘spearheads’ The former possesses what may be termed cyclical symmetry and the latter triple axial symmetry

There seems to be a technical improvement in these designs over those of Mr. Good’s insofar as the black areas at the centre of his triangular doodles are conspicuous by their absence over here.