VALVE-STEMS AND STUFFING-BOXES.
Each valve has its own rod, and separate connection with the lever. In most instances the stem of the back valve is made hollow, and the stem of the forward valve is passed through it, so as to avoid the use of more than one stuffing-box upon the steam-chest; but in several instances they have been fitted up with two stuffing-boxes, the separate valve-stems working side by side.