Figure 30.
Figure 31.
Cut a piece of copper the length required, having the width about three times the diameter of the tube that is to be made. The edges must first be made parallel by filing. In a block of maple or some hard wood, with a wood file, make a groove as shown at [Figure 30]. Place the strip of metal over the groove and, with a somewhat pointed hammer, drive the metal into it until it takes the shape of a V. [Figure 31 A]. Then place it on the flat part of the block and strike on the edges with the hammer, turning them in until they meet, as at B and C.
Figure 32.