The coarse wire, or primary winding, on the armature is connected with the lever and with the screw of the circuit breaker; when the lever is touching the screw, any current produced in the primary winding has a complete path, or _circuit_, in which to flow. The fine wire, or secondary winding, is wound on top of the primary, and its inmost end is connected to the outmost end of the primary so that one forms a continuation of the other. The outmost end of the secondary leads to the spark plug; any current produced in the secondary winding flows to the spark plug, and, if intense enough, will jump across the small gap in the plug, and return to the secondary by way of the primary. Referring to Figure 43, a weak current is produced in the primary while the armature revolves from D to B; at that time the circuit breaker is closed, so the current can flow in the path thus provided for it. A current also tries to flow in the secondary, but is too weak to jump across the gap in the spark plug. As the armature comes closer to the point C, Figure 43, the primary current becomes more intense, and the electricity in the secondary increases its endeavor to jump the gap in the spark plug, but is still unable to do so. As the armature passes over the point C, the circuit breaker opens. The primary current, which is then most intense, finds its path taken away from it, and it seeks another, which it finds by flowing into the secondary winding. This flow of primary current, added to the pressure already existing in the secondary, forms a current sufficiently intense to jump across the gap in the spark plug, and in so jumping it produces the ignition spark. As the armature passes to position D, Figure 43, the circuit breaker closes, and the action is repeated. [Illustration: FIG. 46.—“K-W” INDUCTOR] A magneto of this type is thus seen to give two sparks to every revolution of the armature. K-W and Dixie magnetos operate on the same general principle as the Bosch, with the difference that the wire windings are separate from the armature, and do not revolve. The revolving part, which is called an _inductor_, consists of blocks of iron, so shaped that, as they revolve, they alternately lead the magnetism to the core of the winding and then away from it. The result is that the core gains magnetism and then loses it, and these continual changes in strength produce sparking currents in the winding. The inductor of a K-W magneto is shown in Figure 46. It consists of a shaft on which are mounted two blocks of iron at right angles. The section of shaft that joins them is the core of the winding; the wire is wound on it just as thread is wound on a spool, but with a space between, so that the shaft may revolve inside of the coil.