This picture is taken from the above mentioned book, which describes some of the early lines, the builders and the hardware used. Of course to the interest of us collectors, he describes the insulators used! There have been a couple of Bureau Knob insulator types that were used. This was before the formal production of insulators began. I think Reid's picture was accurate in comparison to the next picture I have submitted. A knob from a drawer or cabinet would have had a hole all the way through.