Overview of the Lighthouse
The Egyptians were the first nation to use tower-type lighthouses. The UK and the US were also involved in lighthouse construction, often carried out in wild conditions being constantly lashed by seas and winds. There are many fine early examples of early lighthouses built by brave men, many still existing and operating today.
The warning light was the most important component of the lighthouse. The first sources of lights were beacons in which fires were burned. These were open at the top to provide ventilation and were tended by the lighthouse keeper.
Next were the candles and various oil burners using a wick; the Argand Wick Lamp consisted of two glass cylinders covering the wick to promote a steadier flame that was visible for several miles.
The French Scientist Augustine Fresnel invented the modern Fresnel lens in 1822, being first used in a lighthouse in 1841 and the forerunner of the modern lenses in use today.
An early and modern Fresnel lens is shown below:
Modern day lighthouses have their own characteristic light patterns. These are made up of the number of flashes, their exposure time, and the time between flashes. These characteristics are noted on navigation charts alongside the name of the lighthouse, assisting in the confirmation of a ships position from the pattern of the flashes and location of the lighthouse.
The lighthouse keepers’ job was a lonely one. They were required to stay on the lighthouses for long periods before being relieved. This spell of duty was often extended if bad weather prevented his replacement from making it onto the often inaccessible lighthouse locations.
The lighthouse keepers duties included tending to the light source and operating audible alarms such as foghorns or even firing cannons during fog or bad visibility. Today, most lighthouses are unmanned and automatically controlled by various Government boards and departments who are responsible for their monitoring, upkeep and maintenance.