In fact, these illustrations are depicting the variety of lighthouse lanterns in use at the turn of the century. They were published in Scientific American Supplement, No. 1032 published on October 12, 1895.
If you were sailing out on a dark sea, the shining light from a lighthouse might have seemed like a portal to another dimension. Warning lights from shore are recorded long throughout history. It’s believed that the Colossus of Rhodes held a brazier in his hand which maintained a fire for use as a guide to vessels into harbor. New York City’s Statue of Liberty carries an electric torch to the same effect.
The design of lighthouses that is familiar to most of us was in use in the 18th century as engineering developments provided the ability to build on high risk sites. The light source itself has changed dramatically over the centuries. Early sources of illumination were candles or oil lamps, but the power of the light source was relatively weak until the invention of the gas lamps which gave off 4 times the luminescence.
In conjunction with improvements in fuel for the light, the application of optical lenses increased and focused the light intensity. The invention of the Fresnel lens by French physicist August-Jean Fresnel in the early 19th century allowed for lighter, thinner lenses that captured and focused light so that it was able to viewed at much greater distances. The first Fresnel lens was installed in a lighthouse in 1823.
The images shown provide examples of several types of lights for lighthouses. These images show a Section of a Tower & Lantern of a 1st Order Lens, a fixed Large Range Light and a Second Order Lens & Lamp.
KATE WELLS is the Rhode Island Collection Librarian at PPL. When she was 8 years old, she dreamed of a pizza robot. That dream became a reality with the invention of the iPhone and food delivery apps.