Threadless peg that was found inside the insulator. Most of the peg has rotted away except the portion that was covered with a piece of burlap that had been soaked in creosote. The cloth served two purposes: (1) to provide a tight fit between the insulator and the peg, and (2) to act as a sponge to hold the creosote. When the creosote dried it 'glued' the insulator to the peg making it more secure. Even after 140 years, you can still smell the unmistakeable odor!!