Jeremy, Have you looked at the article by Tom Wells "Nail Chronology: The Use of Technologically Derived Features" that was published in Historical Archaeology 1998, 32(2):78-99? His article was also reprinted in the SHA reader Approaches to Material Culture Research for Historical Archaeologists that was compiled by David R. Brauner and his students. This volume is available from the SHA and can be found on their web site. The bib in the Wells article is particularly useful. Peace, George L. Miller URS Corporation 561 Cedar Lane Florence, New Jersey 08518