Books : reviews

A. W. F. Edwards.
Cogwheels of the Mind: the story of Venn diagrams.
Johns Hopkins University Press. 2004

rating : 3.5 : worth reading
review : 27 December 2010

[Venn diagram for six sets]

This delightful little book (less than 100pp of widely spaced text and many figures) discusses Venn diagrams. Now, for those who think a Venn diagram is two or three overlapping circles, it might not be clear how that can fill a whole book. But here we have the history, the author's generalisation to any number of intersecting sets via stereographic projection, their relationships to Gray and binary codes, rotationally symmetric solutions, and maximal planar subgraphs of the hypercube. A fun quick read, and nicely written. And who can resist an author who says:

pp45-6. The reason why my diagrams were published in a popular weekly journal (the New Scientist) and not in a mathematical journal is that the British government had recently imposed a "Research Assessment Exercise" on the universities, an element of which was the scoring of papers in refereed journals, the scores being credited to departments. As a protest at such an absurd scheme I deliberately sent my paper to the New Scientist so that it would not "count." Unanticipated benefits were quick publication, a huge circulation, color printing---and a fee!