Directly in the middle of the hole through the field iron bore a quarter-inch hole for the armature shaft to pass through; then make an [L] piece, of brass, two inches high, three-quarters of an inch wide, and with the foot an inch long, as shown at Fig. 42. Two holes are made in the foot through which screws will pass into the base, and near the top a quarter-inch hole is to be bored, the centre of which is to line with that through the back, at the middle of the field core. The shaft is made from steel three-eighths of an inch in diameter and six inches and a half long. One inch from one end the shaft should be turned down to a quarter of an inch in diameter, and one inch and a quarter from the other end it must be reduced to a similar size. The short end mounts in the back and the long one receives the pulley, after the latter passes through the [L] bearing. A piece of three-eighth-inch brass tubing an inch long is slipped over the shaft two inches from the pulley end and secured with a flush set-screw. This tubing is then threaded and provided with two nuts, one at either end, so that when the armature [U] is slipped on the collar the nuts can be tightened and made to hold the magnet securely on the shaft. This shaft is clearly shown in the sectional drawings Fig. 43. At the left side the shaft (S) passes into the wood back through the quarter-inch hole. At the outside a brass plate with a quarter-inch hole is screwed fast and acts as a bearing. The shaft does not touch the field-magnet (F M), because the hole is large enough for the quarter-inch shaft to clear it. A fibre washer (F W) is placed on the shaft before it is slipped through the back. This prevents the shaft from playing too much, and deadens any sound of “jumping” while rotating. At the middle the shaft (S) passes through the brass collar on which the threads are cut. A M represents the armature magnet, and W W the washers and nuts employed to bind it in place. At the right, S again represents the shaft, B the bearing, C the commutator hub, and P the pulley, while R is the small block under the hub to which the brushes and binding-posts are attached. From the descriptions already given of dynamos, and with these figure drawings as a guide, it should be an easy matter to assemble this motor.