British artists have excelled in the medium of watercolour painting to such an extent that they have almost made the medium their own. Certainly the art was perfected in Britain and in turn influenced many artistic movements both in Europe and North America. These monumenal volumes cover the work of some six thousand artists. Space is given to the more obscure artists, both professional and amateur, as well as to the great artists, such as Turner and Cotman. Whilst much of the information is purely biographical and factual, Mallalieu includes his own personal judgements of the artists" works and styles. By its nature watercolour painting provides a wider and more fertile collecting field than oil painting, with reasonable prices for all but the very finest works of the great masters. These volumes therefore appeal to theamateur collector as well as being a means of identifying possible acquisitions to the dealer and auctioneer, for whom it is an essential tool of the trade.