A correction to the title. These old gents aren't quarrying mill stones; they're braking and forming sharpening stones for local use and for heavy industry. I saw the entire series and from what I can gather, the town was a major producer of grinding stones at one time in its history. At the time the film was made in 1971 the quarry was the last one to operate in that area, and the industrial historical society documented the process for posterity. Modern industrial cutting and abrasive technology put these guys out of work decades ago.