FIG. 32–FARADAY'S FIRST DYNAMO
A current flows in the copper disk as it whirls between the poles of the magnet.
By permission of Joseph G. Branch.]
All this work occupied but ten days in the autumn of 1831, though years of preparation had gone before. In these ten days the foundation was laid for the induction-coil, modern dynamo-electric machinery, and electric lighting. Fig. 33 shows the laboratory in which Faraday did this work.
FIG. 33–FARADAY'S LABORATORY, WHERE THE FIRST DYNAMO WAS MADE
From the water-color drawing by Miss Harriet Moore.
Faraday continued to explore the field opened up before him. In one experiment two small pencils of charcoal lightly touching were connected to the ends of a secondary coil. A spark passed between the charcoal points when the primary circuit was closed. This was the first transformer producing a tiny electric light (Fig. 34).