Thanks for that. I don't have any of the earlier ones, but I have all four sizes of the #18, and use them. I consider them the best production bevel gauge I have encountered.
Fascinating. I've always called this tool an angle finder. Never heard it called a bevel. Is it called that so carpenters could find the correct rounding pattern to bevel an edge before routers were invented?
One of the dictionary definitions of "bevel" is simply "the angle when one line meets another when not at a right angle." So it follows that the term got applied to the tool that let's you set those angles. Early catalogs refer to them as "Sliding T-Bevels" or simply "Bevels."