Every lighthouse has a unique light. The lights may be different colors, flash for different periods of time, or remain solid. The light pattern is called the characteristic. The Cape May Lighthouse characteristic is a flash once every 15 seconds.

The lights don’t flash; they only look like they do. Lights are placed on something like a spinning table. As a light spins to the back of the lighthouse, it looks like it shut off. When it spins to the front, ships can see the light again. The amount of time a light is on or off can be changed by changing the speed of the table.

One of the most powerful lenses is the Fresnel lens (pronounced Frey-nel). It was invented in 1822. It looks like a large glass beehive. The Fresnel lens reflects light from a source (like a candle), focuses it to one spot, and sends out a beam.

There are seven levels (called orders) of Fresnel lenses. The closer the source, the further the light shines. An order 1 lens is the closest. A light shines more than 20 miles using an order 1 lens.

Next: Lighthouse Histor