History of lighthouses

The History of Lighthouses refers to the development of the use of towers, buildings, or other types of structures as an aid to navigation for maritime pilots at sea or on inland waterways.

However, Themistocles had earlier established a lighthouse at the harbour of Piraeus connected to Athens in the 5th century BC, essentially a small stone column with a fire beacon.

Presumably locally available fuels will have included wood and probably coal to keep a fire going continuously during the night, and there is a large chimney leading to the top room at the Tower of Hercules.

Lighthouse keepers may have added combustible liquids to reduce the expenditure on fuel and keep the light steady during gales, but little information exists in the literature from the time.

Depictions of lighthouses on Roman coins, inscriptions, carvings, and mosaics present an inconsistent view of the actual appearance of the structures.

A century later, in the Late Middle Ages, a 40-foot (12 m) tower was built by Edward the Black Prince at Cordouan near the Gironde estuary.

Its upper level was rebuilt between 1780 and 1790, increasing the height from 49m to 60m and incorporating an Argand lamp and one of the first parabolic mirrors which was turned by clockwork developed by a clockmaker in Dieppe.

[10] With the increasing number of ships lost along the Newcastle to London coal route, Trinity House established the Lowestoft Lighthouse in 1609, a pair of wooden towers with candle illuminants.

Advances in structural engineering and new and efficient lighting equipment allowed for the creation of larger and more powerful lighthouses, including ones exposed to the sea.

The Eddystone Rocks, an extensive reef near Plymouth Sound, England, and one of the major shipwreck hazards for mariners sailing through the English Channel,[12] were the site of many technical and conceptual advances in lighthouse construction.

The difficulty of gaining a foothold on the dangerous rocks, particularly in the predominant swell, meant that it was a long time before anyone attempted to place any warning on them.

The first attempt was an octagonal wooden structure, anchored by 12 iron stanchions secured in the rock, and built by Henry Winstanley from 1696 to 1698.

[13][14] Following the destruction of the first lighthouse, Captain Lovett[15][note 1] acquired the lease of the rock and, by Act of Parliament, was allowed to charge passing ships a toll of one penny per ton.

He commissioned John Rudyard (or Rudyerd) to design the new lighthouse, built as a conical wooden structure around a core of brick and concrete.

He pioneered the use of "hydraulic lime," a form of concrete that will set under water, and developed a technique of securing the granite blocks together using dovetail joints and marble dowels.

Construction started at a site in Millbay where Smeaton built a jetty and workyard in the south-west corner of the harbour for unloading and working the stone.

[21] Scottish engineer Robert Stevenson was a seminal figure in the development of lighthouse design and construction in the first half of the 19th century.

This structure was based upon the design of the earlier Eddystone Lighthouse by John Smeaton, but with several improved features, such as the incorporation of rotating lights alternating between red and white.

He innovated in the choice of light sources, mountings, reflector design, the use of Fresnel lenses, and in rotation and shuttering systems, providing lighthouses with individual signatures, allowing them to be identified by seafarers.

Around 100 of these complex structures were built on the Atlantic coast line from the Delaware and Chesapeake Bays down to the Florida Keys and Gulf of Mexico.

He was given a grant by the Dublin Ballast Board in 1865, and he fitted his new gas 'crocus' burner at the Baily Lighthouse in Howth Head,[note 2] giving an output 4 times more powerful than the equivalent oil lights.

[34] In 1870, the light at Wicklow Head was fitted with Wigham's patent intermittent flashing mechanism, which timed the gas supply by means of clockwork.

The fuel was vaporized at high pressure and burned to heat the mantle, giving an output of over six times the luminosity of traditional oil lights.

Acetylene produced an ultra-bright white light and immediately superseded the duller-flamed LPG as the fuel of choice in lighthouse illuminations.

In a rugged coastal area like Scandinavia, his mass-produced, robust, minimal maintenance lights were a significant boon to safety and livelihood.

[36] With the development of the steady illumination of the Argand lamp, the application of optical lenses to increase and focus the light intensity became a practical possibility.

The idea of creating a thinner, lighter lens by making it with separate sections mounted in a frame is often attributed to Georges-Louis Leclerc, Comte de Buffon.

[40] Scottish physicist Sir David Brewster is credited with convincing the British authorities to adopt these lenses in their lighthouses.