Dating antique chairs
Screws are relative newcomers to the production of furniture, primarily because they are so hard to make by hand.
But as the complexity and sophistication of furniture increased in the late 17th century and the use of brass hardware, locks and concealed hinges became more popular, there was an obvious need for a fastener that could hold two surfaces together without having to penetrate the back surface of the second piece.
In many cases the same smith who made the nails occasionally turned his craft to the making of screws and thereby left us with personal traces of the maker.
When a suitable degree of “roundness” was achieved, the hot shaft was jammed into a form on the anvil, similar to the swage block used in making the hammered head of the rose head nail.
The screw on the right is a modern gimlet screw, post 1848, with tapered shaft, even threads, pointed tip and centered slot. The handmade nails of the period derived much of their holding power from the ability to drive the nail through two surfaces and bend it over on the back side, i.e. But that solution would not work for securing the top on a chest of drawers or table top without either driving a nail through the top from above or clinching it on the top to hold it fast.
The same problem arose while trying to affix a lock to the back side of a drawer.
Easy to see the early stool in antique chairs later isn't it?
Today, if you run into these somewhat tall antique chairs you will probably notice that they're not very consistent in the height of the seat.