4. Start on line A-A at point X, circle 1, and draw a line connecting it with line B-B on circle 1’. Then connect B-B on circle 1’ with C-C on circle 2 and so on until a spiral has been drawn the entire length of the cylinder. This line will form the ridge of the spiral as shown in the middle diagram.
5. Next begin on line C-C at circle 1, and draw a line connecting it with D-D on circle 1’ then to line A-A on circle 2, and so on as before. This spiral represents the center of the groove or the portion which is to be cut away. This is not shown in the diagram because more or less confusion would be caused with the line representing the ridge of the spiral.
6. Begin on line C-C at circle 1, and saw to a depth of ¾". Saw the entire length of the cylinder leaving about 1½" at the ends. Do not follow the line here, but switch off gradually and follow circles 1 and 15, so as to allow the spiral to begin and end gradually and not abruptly.
7. Rough out with a knife or chisel by cutting on both sides of the saw cut. Then use a wood rasp to finish shaping out the spiral. When properly shaped out allow the lathe to turn slowly and smooth with sandpaper by following the spiral as the lathe turns.
8. Cut the design on both ends of the cylinder and polish.