Skip to main content

callan.jpg

Nicholas Joseph Callan made many discoveries during his lifetime; he was the first to establish the link between rate-of-change of current and electromagnetic induction, and discovered the principle of the self-exciting dynamo.

We hope you enjoyed this essay.

Please support this 70-year tradition of trusted historical writing and the volunteers that sustain it with a donation to American Heritage.

Donate

Stay informed - subscribe to our newsletter.
The subscriber's email address.