“Lighthouses are marks and signs…being a matter of a high and precious nature, in respect of salvation of ships and lives, and a kind of starlight in that element.” ~ Francis Bacon
Initially, bonfires were built to guide seafaring navigators. The fires were eventually elevated to extend their range. As innovative structures were developed, coal fires replaced open bonfires. Later, candles and oil lamps, magnified by reflectors were used for illumination. Modern inventions such as incandescent lamps, radar beacons, foghorns, and diaphones (a device which uses compressed air that can be heard for eight miles) have resulted in lighthouses that require very little tending.
Colossus of Rhodes Image from https://anotherbagmoretravel.wordpress.com/2012/11/10/greece-the-colossus-of-rhodes/
292 to 280 BC - The Colossus of Rhodes (Greek) – 120 foot tall bronze statue of Helios, the Greeks sun god; stood at the entrance to the harbor; felled by and earthquake in 224 BC
332 BC - Pharos of Alexandria (Egypt) – First lighthouse built of stone and masonry; 400 - 500 feet tall; bonfire atop the structure could be seen for 100 miles; destroyed by an earthquake
40 AD - Tour d’Order at Boulonge (France) – a fire tower used to guide sailors into the harbor
Tower of Hercules image © Tomás Fano
100 AD - Tower of Hercules at Corunna (Spain) – still standing today; the oldest existing structure of this kind
12th century- France and Italy are leaders in lighthouse construction and innovation; over 1500 structures built
1716- Beacon Hill, in Boston, was named for the first lighthouse in the U.S.
Image from http://www.hbaonline.com/project/hog-island-lighthouses-fresnel-lens/
1822 - The Fresnel lens was invented by Augustin Jean Fresnel; a large glass lens which uses reflection, refraction, and polarization to illuminate
Fresnel lens in the Point Bonita Lighthouse, San Francisco Bay
1852- The first lighthouse on the west coast of the U.S. was built on Alcatraz Island
1858- Electricity was first used at South Foreland Light in England
1921- Radio controlled beacons to direct ships were introduced (New York)