Someone just asked me about dating a 19th century guitar based on the fret wire type, and I couldn't find any information in my library or on line that would tell me when that style of fret wire was developed and/or popularized.
Fret wire with a "mushroom" cross section was used by American manufacturers before 1900. All Gibson instruments had tang frets from the outset in 1902. Some makers (e.g. Washburn) used both tang and bar frets concurrently for at least a couple of decades.
Clinton Smith patented patented the rolled tang fret wire that has built-in barbs in 1927, and it was made by Horton-Angell shortly thereafter. Previously, fret tangs were smooth, or had dents in the bottom that would fatten it a bit, either rolled in after the wire was made, or done individually by the luthier.
Horton-Angell became Cook-Horton sometime in the 1970s, if I remember correctly.
Tang was created in the 60's so the assternots could drink OJ in outerspace.
And what have you been drinking (or smoking :-) ) ?
Tim's responses always crack me up. (-:
Good one Tim!
There were lots of people in very different "schools" building guitars in the 19th C. Dating them by fretwire type would be complicated.
My friend Joël Dugot, at the Cite de la Musique in Paris, says they have an 1828 Lacote guitar with T-frets. Lacote was a prolific and influential maker. Joël says metal frets (they call 'em flat frets) have been in use since the 16th century, particularly on wire-strung instruments. He further says T-frets have been in use in France since 1810-1820 or so. Americans got into them rather late, it seems.