A word of caution on the use of nail dating. There are several formulae for
calculating the age of a building based on the presence or absence of cut nails
versus wire nails. However, reuse of machine-cut nails and stubborn
resistance to wire nails by old carpenters kept the Tremont Nail Company and others in
cut nails well into the 20th century. Moreover, during the Great Depression,
people salvaged forged and machine-cut square nails in new construction during
the 1930s and again during World War II (when most metal was diverted for the
war effort). I read in U.S. Army Quartermaster Corps reports that they turned
to using wooden fasteners due to the shortage of metals by 1944.

Ron May
Legacy 106, Inc.