Inspiring paintings, poems, songs, and numerous stories, lighthouses have become historical landmarks
over time because of their legendary history and their maritime importance.
Ever since man attempted travel by sea, navigational tools & guides were used. In the very early days,
mariners tended to sail by day for visibility and near coasts. Natural landmarks, winds, ocean currents,
and the use of stars were the main aids available. Since electricity and the light bulb were hundreds of
years away, fires lit on shore were the earliest indications of nighttime seaside navigational. However,
they were not very bright and needed to be tended frequently.
In 290 B.C., Colossus was erected at the entrance of
Rhodes which was built by Chares of Lindos. The sun-god of Helios was made of bronze, measured 132 ft.
high, and held a fire in his hand. 80 years later, it was destroyed due to an earthquake. Later,
Egypt constructed a lighthouse on the island of Pharos. Measuring 425 ft. tall and built by Sostratos
of Knidos in 299-288 B.C., it marked the entrance of Alexandria. It too was destroyed because of an earthquake.
Also, the Romans were known to build at least 30 lighthouses on the Mediterranean Sea.
beacons to be recorded in writing, were built by the Greeks in the 6th & 5th century
B.C. to mark the entrances of harbors, such as Piraeus. A tower called the Torre de Hercules
in Coruna, Spain has stood since the 1st century A.D. and is actually still used today!
not always used. Where water levels are too deep or where a lighthouse would be too expensive or impractical,
lightships were used. Not nearly used as much, they were still an effective landmark & navigational
option for seafarers.
Initially, unlit towers on land were used. It was raised in order to be visible at a distance.
These towers and their different styles were partly influenced by other uses such as a lookout, defense tower, or for
residence. Soon after, small candles grouped together forming a larger “lamp”, were put on
tall posts, in nearby trees, or up onto a pole called “the swape”. In Scandinavia,
during the 1500’s, a fire was kept in an iron basket which was raised & lowered to light and tend.
Before the 19th
century, lighthouse towers were built using wood or stone because the materials were readily available. Soon,
masonry towers were built because of their durability and were less vulnerable to fire. Masonry towers
were the most popular during the 1800’s. Around the turning point of the 20th century,
concrete towers reinforced with steel began to replace the brick masonry towers. The 1st was
constructed in 1908 at Point Arena, California. Most major reinforced lighthouse towers are currently found
on the west coast where they are best adapted for the threat of earthquakes.
The illumination source of the lighthouse changed through
time also. Early ancient light towers were made of stone and used wood, charcoal, or tar. Wood
burned quickly and it needed to be tended to frequently. Charcoal or tar emitted fumes & smoke which
were hazardous. Whatever the source, it wasn’t very practical and efficient. By
the 1600’s, oil (whether animal or vegetable) lamps became the primary choice. In 1765, Antonie Lavoisier
developed a large spherical parabolic beacon reflector. This allowed the rays of light from the tower to
be focused. In 1782, Swiss physicist Aime Argand made a hollow wick increasing the air supply which led
to a virtually smokeless flame which was constant and 10x brighter. It was called the Argand Lamp and it
revolutionized tower lighting at that time. By 1855, Kerosene became prevalent and was used almost universally
by 1889. In 1892, acetylene (a pure chemical compound of Hydrogen & Carbon) was discovered.
Using acetylene was much cheaper and burned 20x brighter than kerosene.
In 1784, the catoptric optic was developed. It is a rotating reflector-lamp system driven by a clockwork
weight mechanism in which it turned the reflectors back & forth giving the impression of a light controlled by a light
switch. In 1822, Augustin Fresnel revolutionized the lighthouse light. He began his
optic experiments in 1816 and by 1819, the French Academy of Sciences awarded him a prize for research on light diffraction.
He manufactured, cut, & shaped individual pieces of glass together which acted as several prisms which would refract
& intensify the light to even greater power. These lenses were used extensively throughout the world
and known as Fresnel Lenses. Many of these lenses are being replaced today by other illuminating
sources such as airport beacons or plastic.
Today, all lighthouses either use electricity or solar power for their source of light. 3 inventions or
developments resulted in the automation of today’s lighthouse:
1. Electricity – Used in
most lighthouses by 1940.
2. 1916 – Device that automatically changed burned-out incandescent bulbs was developed.
3. Automated timing mechanisms to turn lights on & off, and the development
of electric fog signals.
As a result, most lighthouses do not need to be manned. In the
U.S. today, lighthouses exist in 31 out of 50 states.