|Screws, 1700s to c. 1840, Eric Sloan
|Screws, c. 1840, Eric Sloan
The unmistakable pointed wood screw, now universally used, was
patented by United States patent No. 4704, August 20, 1846, before
which time, all wood screws in general use, unless pointed by
hand-filing, were blunt.
Because these pointless screws would not start by driving into
the wood, penetrate, except by a previous gimlet or brad-aw hole,
the pointed wood-screw suddenly and universally superseded them.
Therefore, the wood-screw if pointless and original, will date
a house before 1846; if pointed, after that date. These facts,
marking the end of the old house-building period, though only
applicable to the very latest buildings, are nevertheless important,
since they may help to detect wholesale restorations or additions
and show when kitchen fire-place doors stopped open-fire cooking,
or where old latches, hinges, or doors have been shifted out of
time or place.
Dating of Old Houses,
Henry C. Mercer, SC.D., Doylestown, Pennsylvania, 1923.