Well naturally the word lantern caught my eye plus the fact that fireflies are prevalent in the Philippines where I am living right now.
Interesting story, and very interesting how scientists adapted it to modern day Light Emitting Diode (LED) technology which is used in your el-cheapo flashlights up to modern high-intensity LEDs for beacons and marker lamps of all sorts used in lighthouses and light beacons. Continue reading →
Every lighthouse light has its own characteristics – 1. the number of flashes per minute, 2. it’s range, which is dependent on intensity, lenses, and height, and 3. the number of beams from the light, plus other identifying features.
Flashes per Minute
Hand-cranked gear mechanism - Pachena Point
The number of flashes per minute is regulated by the speed of rotation which is governed by the motor turning gears to drive the light around. The old heavy Fresnel lens lights sat on a bath of mercury and rotated in the early days from a hand-wound clockwork mechanism, later to be replaced by an electric motor, and later to be replaced altogether.
Enclosed lights such as the DCB-10 and DCB-36 (originally used as airport beacons) were only driven by electricity and gearing regulated the speed of rotation.