The current literature concerning 17th century clay pipes is listed. Methods of dating clay pipes from the 17th century Netherlands and distinguishing them from British pipes are compared and evaluated. A typological method, based on D. Duco, is shown to give the most accurate results while F. H. W. Friederich's methods produced too early datings. Typology and manufacturing methods are the best ways of distinguishing between British and Dutch pipes, clay color and clay hardness being of no use. -- AATA