Dry-Fly Fishing in Theory and Practice (1889) is British author and angler Frederic M. Halford's second and most influential book on dry fly fishing. It followed Floating Flies and How to Dress Them (1886) and this pair of books initiated some 40 years of a rigid, and sometimes dogmatic school, the Halfordian school, of dry fly fishing, especially on English chalk streams. The work also played a significant role in the development of dry-fly fishing in America. Source: Wikipedia (en)