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.
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.
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
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