More on nails,

I seem to have forgotten that ferrous metal technology changed between 1840
and 1900, which might be reflected in nail metal recovered on sites. Analysis
of the metal might reveal these technological changes from wrought iron
through Bessemer steel. It is my understanding the Canadians have been
examining these changes in blacksmith shops through the late 19th century.
This is just another reason not to destroy nails recovered at archaeology
sites.

Ron May
Legacy 106, Inc.