As part of the History Revival: Coastal Chronicles lecture series join us for a presentation by Fred Dylla on the Cape Henlopen Lighthouse.

Lighthouses are the sentinels that warn sailors of dangerous shorelines. Lighthouses in the US before the 1850’s were so poorly lit these beacons often lured sailors to dangers rather than offering fair warning. The original lighthouses constructed on US shores in the 18th and early 19th century were lit with whale oil lamps with simple parabolic mirror reflectors. On a clear night the visibility could be measured in miles. The situation changed dramatically in Europe when a young French engineer, Augustin Fresnel, designed and manufactured a remarkable new type of lens that could project lighthouse beams more than 20 miles. These new “Fresnel” lenses were not adopted by the US Lighthouse Service until after a key measurement was made in the Delaware Bay comparing the brightness of the Brandywine Light with a newly installed Fresnel lens to the Cape Henlopen light with its simple parabolic reflector. When the young Naval engineer who performed the experiment showed the US Congress that the new lens also saved considerable whale oil, Fresnel lenses were rapidly deployed on the US coasts with considerable savings in lives and lost cargoes.

Presenter Fred Dylla is a physicist with a long interest in the history of science and technology. Before retiring to Lewes in 2015, he was the Executive Director of the American Institute of Physics. Dylla co-moderates the “Science and Society” series at the Lewes Public Library.

The History Revival: Coastal Chronicles lecture series is a collaborative effort of the Zwaanendael Museum and Lewes Public Library. The Atlantic Ocean and Delaware Bay have been an integral part of Delaware’s history, and have connected the small state to global events and issues. Maritime communities and industries have taken advantage of Delaware's coast for centuries. Delawareans past and present have benefited and struggled against the water's constant change. Through lectures, music, and historical theater, the goal of History Revival: Coastal Chronicles is to widen the understanding of maritime history within Delaware.

This lecture series is partially funded by the Delaware Humanities, a state program of the National Endowment for the Humanities.