Coordinating sectionalizing devices with translucent load curves on log graph paper? Probably hasn't been done in decades. History? What I know of it is so specialized that very few have an interest. That hasn't even gotten to a degree I never used, or sundry obsolete things that, like using DEBUG for .com programs, I've mostly forgotten, or various "just one" things that I learned to do without being an expert in a given area. Could probably still hew a log and might could split a rail, but couldn't build a log house and likely would have trouble making a rail fence. But everyone's like that.