African-American Contributions to Science
Granville T. Woods: Railway Telegraph
In 1887 he produced the “Synchronous Multiplex Railway Telegraph,” which enabled messages to be sent from moving trains and railways stations. In addition to these contributions, Woods was also very green. He invented a light dimmer in 1890 that resulted in 40 percent energy savings. (Photo: Hulton Archive/Getty Images)
The opinions expressed are solely those of the author and do not necessarily reflect the views of Comcast.













