PRACTICAL CONTINUOUS-CURRENT DYNAMOS.
The electrical output of our simple dynamo would be increased if, instead of a single turn of wire, we used a coil of many turns. A further improvement would result from mounting on the shaft, inside the coil, a core or drum of iron, to entice the lines of force within reach of the revolving coil. It is evident that any lines which pass through the air outside the circle described by the coil cannot be cut, and are wasted.
