D.r W. H. Owens has made the following written contribution: In his recent paper Flinn (1988) mounted a spirited defence of the deformation plot introduced by him and now widely known as the ‘Flinn plot’. In comparing this plot with other graphical presentations, however, his cause is, perhaps, somewhat overstated.
Finn points out that, by producing the axes of his logarithmic plot in the negative sense, the plot may be used to present the full range of shapes and orientations of ellipsoids having a common set of orthogonal axes, a task for which other authors, including myself, have used a three-axis logarithmic plot involving non-orthogonal axes, introduced by Nadai (1963). That the two plots are closely related (by a linear transformation) is clear; that Flinn's plot is ‘more convenient to use’ is open to debate. Although it is slightly more difficult to plot against isometric that against orthogonal axes I, for one, did not adopt this conventions solely through a spirit of masochism, as Flinn suggests, but because the gains it offered were thought to be worthwhile. The principal gain, of course, is in the degree of symmetry that is achieved in the plot—compare Flinn's fig. 1c and Hsu's (1966) fig. 5. On Flinn's plot similarly shaped ellipsoids, differing only in orientation, plot with different relationships to the axes and at different distances from the origin. This might be construed a disadvantage. Further, Flinn's parameter, k, widely used to describe ellipsoid shape, now becomes a function of shape and orientation