|Cut nails after 1800, Eric Sloan.
An examination, not only of the records above mentioned but also
of dated nails, shows that about the year 1825, the cut-nail machine,
still working by water-power rather than by hand, and not yet
by steam, had been so perfected as to make cut nails no longer
by two operations but by a single operation in one machine, in
which the apparatus cut the nail, instantly clamped it and, at
a single blow, stamped the head.
These stamped heads, at first (c. 1825 to 1830) comparatively
thin, lopsided and imperfect, became more thick, square and typically
regular after 1830 and are always easily recognizable after about
But regardless of their variations, in any case, stamp-headed
cut nails, if used in constructing a house, reasonably date it
as after about 1825.
Dating of Old Houses,
Henry C. Mercer, SC.D., Doylestown, Pennsylvania, 1923.