About the biographies. The whole book reads as if Harker made a set of notes for each collector set out in the order that he covers their live and work and then went through writing about each against the background of his conclusions.

The overlong paragraphs are at their worst when he covers a group of collectors. We get the parents and place of birth for each all in one long paragraph. Then another long paragraph with a later part of all their biographies, and so on.

Such individual biographical notes would be really useful (and would be easier for an expert to check for ‘fairness’. If the work was for a science PhD a supervisor might have advised him to put the bios in a table so that the reader could concentrate on his overall ‘thesis’.