Secord gives a dazzlingly detailed account of this scientific trench warfare and its social consequences. One ends up with a marvellous feeling for the major taxonomic enterprises in Darwin's younger day: mapping, ordering, conquering 'taming the chaos" of the strata. All of these of course had social and imperial ramifications; and Secord mentions geology's moral appeal (in supporting a divinely-stratified Creation) to a beleaguered elite intent...