Countertop contractor Michael Parodi creates final edge detail for soapstone countertops. Tile contractor Mark Ferrante cuts down 12-inch marble tiles to make a crisp-looking wainscoting. Norm visits the oldest continuously operated mill site in America where David Graf makes an oval mirror frame for the Arlington house using 150-year-old power tools. Tom scribes new oak stair treads to the old fieldstone foundation wall. Soapstone countertops are darkened using carnauba wax and walnut oil. In the second half of the hour, on ASK THIS OLD HOUSE, the guys celebrate 300 episodes of ASK THIS OLD HOUSE by looking back at some of their best moments and revealing some behind-the-scenes secrets.