Update: 01-01-2025| Illumination sources through Ages | ||
| Type | Fuel | Dates |
| Open fire | Wood | ???? - 1700 |
| Braziers | Wood / Coal | ???? - 1850 |
| Candles | Tallow / Wax | 1540 - 1790 |
| Oil lamps | Animal / Vegetable Oil | 1500 - 1910 |
| - Spider lamps | Animal / Vegetable Oil | 1760 - 1855 |
| - Argand's lamp | Animal / Vegetable Oil | 1782 - 1880 |
| - Fresnel - Arago lamp | Animal / Vegetable Oil | 1819 - 1880 |
| - Doty's lamp | Kerosene | 1870 - 1910 |
| Acetylene / Carbid lamps | Acetylene | 1896 - still |
| Incandescent Oil Vapor lamp | Kerosene | 1898 - still |
| Electric Arc lamp | Electricity | 1857 - 1920 |
| Electric Incandescent Bulb | Electricity | 1899 - still |
The first warning lights for sailors were built long before the Christian era. The earliest known reference to a lighthouse dates back to 1200 BC. This reference appeared in the Iliad, Homer's Greek epic poem.
The first onshore beacons were open fires. Later these open fires were replaced by iron baskets filled with burning wood or coal that were hung on a hill, building or on long poles. It was not until the 18th century that these baskets were replaced by candles (Eddystone - England), oil and gas lanterns with reflectors and later supported by Fresnel lenses
In the early 20th century, these lights were replaced by electric lamps. These first lamps have been further developed from arc lamps to incandescent lamps. Now more and more LED lamps are being used, which together with solar panels are much more sustainable.As indicated, there are records from way back before Christ that open fires were used to guide navigators on their travels along the coasts. These open fires were often unreliable due to the variability between burning well, with a lot of flames and therefore light, or burning poorly with few flames or with a lot of smoke obscuring the light. Wood was mainly used for these fires.
These open fires were maintained by both public and private companies. Patents were issued to certain individuals for the maintenance of beacons in England and Scotland. While in other countries the government took full responsibility for building and maintaining the warning lights.
However, it also happened that, by not too reliable persons, fires were lit to deceive the sailors in the hope that they would be shipwrecked and that they could rob the ship's cargo.Warning lights for the early mariners consisted mainly of open fires and later fire beacons held on a grate or in an iron basket known as a brazier. These braziers were usually placed on an elevated location or platform near the shore. The first British lighthouse to use coal was Dungeness Lighthouse (Kent, England) in 1616. This lighthouse consumed a whopping 400 tons of coal per year.
The quality of visible light from coal fire pits varied considerably with weather conditions. When there was a strong wind blowing from the land to the sea, the light on the coast became quite bright, but when the wind came from the sea, the sea side of the fire was quite dark, while the fire on the land side was bright but useless . This was a big problem. Precisely when the wind was blowing towards the coast, the chance of shipwreck was greater and the brightest light was needed on the coastal side.
Initially these fires were lit in the open air, but to limit the influence of the wind they were enclosed in a glass enclosure and a flue to dissipate the smoke that forms around the fire and often obscures the light. The lanterns were not always a success because the glazing turned black and in a number of cases were removed again.
One of the earliest known coal lighthouses with a lantern can be found on the Isle of St Agnes in the Isles of Scilly (Cornwall, England). This light was first lit on October 30, 1680; it was supplied by coal that was burned in a brazier on top of the tower. In 1756 the brazier was placed in a lantern construction consisting of 16 sash windows, covered, with several chimneys.
The lighthouse was coal-fired until 1790, when it was converted to oil: twenty-one Argand lamps (see later) with reflectors, mounted on a three-sided revolving arrangement. This 'very new and ingenious operation' represented an innovation in optical design which was subsequently adopted in other lighthouses.
In 1806, the lantern structure at the top of the tower was rebuilt (as seen today) to accommodate an enlarged three-sided revolving array of 30 lamps, each with a 21-inch reflector.The Isle of May, Scotland is the site of a lighthouse built in 1636. The original lighthouse consisted of a stone tower with a large brazier at the top for burning coal. A primitive hoist was used to carry the coal to the brazier at the top of the tower.
Three men were responsible for keeping the fire burning. The coals were lit every night. It burned an average of just over a ton of coal per night. This coal fire remained in use until February 4, 1816, when it was replaced by a new type of lighting, such as oil lamps.
The first use of candles consisted of a simple lantern displayed at a window by a hermit or monk. It was not until the closed lantern room was developed that the use of candles became possible for use in lighthouses. The light from individual candles was rather dim, however, when a number of candles were placed in a candlestick and protected from the wind by the lantern windows, the light was a considerable improvement over that of the coal fires.
In the Middle Ages, the candle was the main source of lighting. Candlemakers were united in the Candlemakers Guild. Cheap candles were made from fat (tallow), more expensive ones from beeswax. The tallow candles did not burn as nicely as the wax candles. A tallow candle was soft, smoked, gave soot, always dripped and gave an unpleasant smell (as a result of the formation of acrolein). The wick was made of twisted cotton threads, the charred end of which had to be cut (blown) from time to time. Lighthouse keepers usually made the candles themselves, on site, because commercially produced candles were virtually non-existent.
The first original "Winstanley" Eddystone Lighthouse (Cornwall, England) used candles when it was first lit in 1698. At "Smeaton's" Eddystone Lighthouse in 1759, the first light seen was from 24 candles, which produced a rather dim light, although it is said that the light could be seen through a telescope from Plymouth Hoe, 12 nautical miles away. The candles Smeaton used at Eddystone weighed 2/5 pounds each and the 24 candles had to be changed about once every three hours. (see right-hand column)
The Cresset was one of the earliest forms of oil lamp used in a lighthouse. It consisted of a hollowed-out stone bowl, which was filled with fish oil, with one or more small wicks of string. As the years passed, various other types and shapes of oil lamps came into use.
The lamps were mostly made by local artisans. There were no standard types of lamps in use at the time; however, most lamps had solid rope wicks made of loosely braided cotton and a fairly small communal oil reservoir that fed one or more wicks.
These lamps initially burned fish oil, seal oil, and later whale oil.
They were simply assembled and used no chimneys or reflectors. These lamps produced very poor light with a lot of smoke and acrid fumes. Small tin lamps were tried but failed due to their lack of sufficient oil supply and poor flame qualities. The massive fuses had very poor burning of the oil on the wick, creating large amounts of smoke.
Later improvements were made by flattening the fuses so that the ambient air can better reach both sides. While this produced a better flame, smoke and soot were still produced and not all of the oil was burned.By the 1760s the early oil lamps in the lighthouses were replaced by so-called Spider or Pan lamps. The name Spider refers to the many wick's that were used per lamp and that were supplied with oil by a pan (reservoir). Pan Lamps were made in different shapes. There were round and rectangular pans and a donut shaped pan lamp was used in the early lightvessels. Pan lamps with a round shape were also called compass lamps.
The Pan Lamp solved the problem of limited oil supply and could run for twelve hours or more on a single fill of oil. The Pan Lamp had multiple rope wicks. The number of fuses varied from two to as many as twenty-four, with eight to ten fuses being common. The pan lamp produced more light than the other early oil lamps because large diameter individual wicks were placed almost side by side across the surface of the metal pan and the flames could all be seen at the same time.
The main drawbacks, however, was the enormous oil consumption and the smoke and fumes produced in the lantern room which were sometimes unbearable. Pan lamps were used for a very long time until the mid-1850s.
François-Pierre-Amédée Argand, better known as Ami Argand (1750-1803) was a Genevan physicist and chemist. He developed an improved version of the oil lamp known until then, which was fitted with a simple flat wick. Later his lamp would get his name and is now commonly known as the Argand lamp.
Francois-Pierre-Amédée Argand was born in Geneva, Republic of Geneva, the ninth of ten children. His father was a watchmaker, who believed that Ami should become a clergyman.
However, Ami had a greater aptitude for science and became a student of the noted botanist and meteorologist Horace-Bénédict de Saussure.
He published several scientific papers on meteorological topics while living in Paris in his late twenties. He took a job as a chemistry teacher and developed some ideas to improve the distillation of wine into brandy, and successfully built a large distillery with his brother.
Around 1780 he started thinking about improvements to the previously mentioned conventional oil lamp. The basic idea was to use a cylindrical wick for air to flow through and around (see image at right). Argand's design allowed for much more oxygen in the flame, more efficient fuel burn and a much brighter light. A cylindrical chimney improved the airflow around the flame.
A mechanism to raise and lower the wick was also modified, allowing for optimizations. The light was much brighter than a previously used candle (a factor of five to ten), burned cleaner and the use of oil was cheaper than the use of candles.
In 1783, Argand met brothers Jacques-Étienne and Joseph-Michel Montgolfier in France and became deeply involved in their experiments to design a hot air balloon. There he also met Antoine-Aroult Quinquet, to whom he had shown an early prototype of his modified oil lamp.
Without permission but with minor adjustments, Quinquet started making and selling these oil lamps and added the constricted chimney. This narrowed chimney gave a brighter flame of up to seven candle power. This led to a lengthy legal battle over patent infringement. During the development of this oil lamp into a successful product, quite a few problems had to be overcome. Argand experimented with many materials to arrive at practical solutions.
For example, the design and manufacture of the round wick was solved by a lacemaker who found the right way to make this wick. The right type of glass also had to be found for the glass chimney. This glass had to be able to withstand the high temperature of the flame, even for a longer period of time.
All available types of oil that could potentially be used were examined. Part of this was the research into purifying these oils. Ultimately, whale oil was chosen as the best oil for these lamps and a major new industry was eventually created.
The mechanism for holding the wick and moving it up and down had many variations. Even the solder used to fabricate the oil reservoir posed a problem when the soft solder joints were discovered to be leaking. But that problem was also eventually solved by Argand. So the invention of the lamp was not just one invention, but rather the improvement and development of a complete system of parts that all work together.
In October of 1783 Argand decided to produce his lamp in England. He formed a partnership with William Parker and Matthew Boulton to manufacture the lamp. In 1784 he received a patent for his design. Argand also had a close relationship with James Watt, who conducted some experiments on the efficiency of the lamp and advised Argand on his patent infringement legal matters.
Demand for the lamps was high and he and his partners initially struggled to manufacture them, but they eventually became the standard source of lighting in homes and shops.
All available types of oil that could potentially be used have been investigated. Part of this was the research into purifying these oils. Eventually, whale oil was chosen as the best oil for these lamps and a large new industry eventually emerged. The whale oil was used until about 1846 in Scottish lighthouses. Because of the costs, rapeseed oil was then often used. Olive oil, lard oil and coconut oil were also used for lighthouse purposes in different parts of the world.
Many imitators and improvers developed new variations of this design, and thousands of factories sprung up to produce them over the following decades. Around 1850 they were finally supplanted by the kerosene lamp.After many trials, Augustin Fresnel and François Arago discovered that the Argand lamp improved by Monsieur Bertrand Guillaume Carcel in 1800 could be used with multiple concentric wicks in one housing. The Carcel lamp had a mechanical twin-piston pump driven by a clockwork that forced excess oil through a tube to the wick, flooding the wick and cooling the entire burner.
By December 1819, Fresnel and Arago had made a multi-concentric-wick lamp using the Carcel cooling principle and the first three-wick burner was operational in their laboratory. These oil lamp had improved on early oil lamps to produce a smokeless constant flame that was seven times brighter than a candle.
Within a few months they also developed a four-wick burner and proposed using it in the first 1st Order Fresnel lens to be manufactured. The four-burner burner was first used in 1823 and the three-burner burner was first used in 1824. Fresnel produced burners with two, three and four concentric wicks.An American ship's captain, Henry Harrison Doty, thought he could solve the problems surrounding the use of kerosene in lighthouse burners. He described his efforts as follows:
“In 1866 the idea occurred to me that if paraffin (Ed: kerosene) as now produced, of high specific gravity and safety standard, could be used in Lighthouse Illumination, it would be a great reform in the economics and intensity of coastal lighting. reaches. I therefore resolutely committed myself to the solution of the problem, how this could be affected not only for the single wick burner, but also for lamps with concentric wicks. After more than two years of incessant study and experimentation, I managed to discover the means of doing this for all the different types of burners, and that too, without causing any structural rearrangement of the device or lamp currently in use.
Doty mentioned the specific gravity of the kerosene because the heavier the kerosene, the less volatile it was, and therefore the safer it was to use.
The French Lighthouse Service has long been regarded as the leader in technical innovation and quality. Captain Doty took samples of his newest burners and in November 1868 went to Emperor Napoleon III to convince him of their advantage and request that France bring them to justice.
Doty's request was granted and a trial within the French Lighthouse Service began in December 1868 and was successfully completed in January 1869. A number of French lighthouses were subsequently converted to kerosene fuel, with the Doty burner modifications. The French did not use the Doty burner directly. Instead, they bought the rights to use Doty's design principles in their own burner designs.The above lamps are only a limited selection of basic oil lamps. Lighthouse services in the different countries all have a derivative form of the above original lamps. This is partly determined by specific regional circumstances. More examples are mentioned on the US Lighthouse society website.
The acetylene process was invented by a Canadian, Thomas Leopold "Carbide" Willson. In 1892, he discovered an economically efficient process for making calcium carbide, which is used in the production of acetylene gas. In 1895 he sold his patent to Union Carbide. Willson also invented the idea of making and storing acetylene in a buoy in 1904. Acetylene is also sometimes called Dalen gas. When Acetylene is employed in lighthouse work, the gas is either supplied in cylinders, or is generated on the spot. For example, the Eile Ness lighthouse at the eastcoast of Scotland (see: Warning system), had his own acetylene plant on the lighthouse site.
The high lighting power and the intrinsic brightness of the acetylene flame make it a very suitable light source for lighthouses and beacons. Trials were made in Grangemouth, Scotland in the early 1900s with an unattended beacon supplied with gas once every three weeks, lit with considerable success for several years by an acetylene flame.
Many buoys and beacons on the German and Dutch coast are supplied with oil gas mixed with 20% acetylene, which has increased the lighting intensity by more than 100%. In France, a lamp using acetylene gas mixed with air was installed at the Chassiron lighthouse (1902).
The French Lighthouse Service has perfected a glowing acetylene burner with a diameter of 55 mm. mantle with an intensity of more than 2000 candle power, with an intrinsic luminosity of 60 candles per square cm.
In 1896, two Frenchmen, George Claude and Albert Hess, developed a method of storing compressed acetylene by dissolving it in acetone in steel cylinders. In this system, the gas is compressed into cylinders filled with a porous substance and with acetone, a liquid that has the remarkable ability to absorb twenty-four times its own volume of acetylene gas at atmospheric pressure.
Around 1900 an acetylene gas lamp was installed at Cloch Lighthouse, Scotland, and the acetylene gas was used for all the lighthouse's installations such as the lighting of the houses, lighthouse lamp, fog signals and the 'engine room'.
In 1904, the development of dissolved acetylene was enhanced when John Höjer approached the Gas Accumulator Company (later known as the AGA Company) with a request to redesign the current device.
Mr. Gustaf Dalen from Stockholm, Sweden solved the problem with his development of the AGA compound to store the gas in cylinders. An experimental buoy of the Swedish Pilotage Service was installed in Kalmarsund, showing a fixed acetylene light in 1905. In the following year, the buoy was equipped with the Dalen flashing light for the first time.
This Dalen strobe reduced the amount of gas consumed and proved to require little maintenance. A sun valve (Swedish: solventil, "solar valve") is a flow control valve that automatically shuts off gas flow during daylight. It earned its inventor Gustaf Dalén the 1912 Nobel Prize in Physics.
The sun valve was the key component of the Dalén light used in lighthouses from the 1900s through the 1960s, by which time electric lighting was dominant. Prominent engineers, such as Thomas Edison, doubted that the device could work. The German patent office required a demonstration before approving the patent application.
The valve is controlled by four metal rods enclosed in a glass tube. The central rod that is blackened is surrounded by the three polished rods. As sunlight falls onto all of the rods, the absorbed heat of the sun expands the dark rod, switching a valve to cut the gas supply. After sunset, the central rod cools down, contracting to become the same length as the polished rods and opening the gas supply. The gas is lit by the small, always-burning pilot light.
Dalen's system of acetylene lighting for marine navigation proved very reliable, as exemplified by the lighthouse at Chumbe Island off Zanzibar. This lighthouse was constructed in 1904 and converted to unstaffed automatic acetylene gas operation in 1926. The acetylene lighting installation, controlled by a sun valve, remained in use until the lighthouse was converted to a solar-powered (photovoltaic) system in 2013.
In 1921 Francis Everard Lamplough (an engineer with AGA's rival firm in lighthouse parts provision: Chance Brothers ) patented an alternative 'light valve' in the hope of breaking Dalén's effective monopoly. In subsequent years it was installed on several lighthouses and beacons, but because of its dependence on liquid it could only be used in static locations (unlike Dalén's valves, very many of which were installed on floating buoys).
Lamplough's 'valve' was a form of rocker switch, on which were mounted two glass bulbs, one black, the other clear, part-filled with liquid ether and linked by a tube. During the day, heat from the sunlight would cause the air in the black bulb to expand, forcing the liquid into the clear bulb, the additional weight tipping the switch and cutting off the current to the lamp; at night, or at other times of insufficient daylight, the process was reversed, reconnecting the current.One of the first lamps to burn gasified oil was developed by Nyberg and Lyth in Sweden in 1881. It worked by evaporating rapeseed oil and burning it without a jacket, as a Bunsen burner does. However, this type of lamp was not efficient in producing extra light output.
The next step was the addition of the incandescent gas jacket, invented by Carl Auer von Welsbach, in Vienna, in 1885. This led to the first raw kerosene Incandescent Oil Vapor (IOV) lamp, which was installed at L'lle Penfret lighthouse , by the French, in 1898. It used air pressure and a fuel vaporizer tube where the kerosene was preheated to a fine vapor before being ignited like a flame. This dramatically increased the oxygen at the flame and provided a brighter flame using less fuel.
In 1901, Arthur Kitson, an American, invented an improved burner in which the oil was converted to vapor under pressure in a retort and then mixed with air in a mixing chamber to form a gas for heating a platinum gauze jacket. The platinum mesh quickly charred and within a short time Kitson abandoned it in favor of a Welsbach-style light bulb made of silk impregnated with zirconia.
This lamp produced at least three times the light output of the previously used Argand style lamps. Another similar incandescent lamp was developed by CW Scott, the engineer of the Commissioners of Irish Lights in 1902, and still other versions were developed by Sir Thomas Matthews, engineer of Trinity House in England.The History of Electricity (NL) describes the impression that the electric and magnetic phenomena have left on man throughout history. Since ancient times, many people and agencies have pondered the electrical phenomena such as lightning, which they observed but could not explain. Scientific understanding of the nature of electricity grew throughout the eighteenth and nineteenth centuries through the work of researchers such as Coulomb, Ampere, Faraday, and Maxwell.
By the 19th century, it had become clear that electricity and magnetism were linked, and their theories were unified: wherever charges are in motion, electric current arises, and magnetism results from electric current. The source for electric field is electric charge, while that for magnetic field is electric current (moving charges).
In 1800, Alessandro Volta invented the electric battery, which allowed electricity to be stored for a longer period of time. In 1802, Sir Humphry Davy invents the arc lamp that allowed light to be produced by means of an electric current, and he first demonstrated it publicly in 1809.
Thanks to the invention of the dynamo, electrical energy could be generated on a large scale and many times cheaper than with chemical elements, like Volta did with its battery. Following Faraday's discovery of electromagnetic induction, Pixii developed the first dynamo in 1832. After Pixii, the dynamo was significantly improved by various scientists in the following years. This paved the way for electric lighting in lighthouses.
Right-hand picture: Pixii's magnetoelectric machine. In 1831, Faraday showed that the principle of magnetic induction could be used to generate electricity mechanically. In 1832, Pixii was one of the first to construct a usable device. It consisted of fixed coils and a rotatable permanent magnet. The principle can be compared to that of the bicycle dynamo.In 1883 the lighthouse authorities of Great Britain determined that an exhaustive series of experiments should be carried out at the South Foreland with a view to ascertaining the relative suitability of electricity, gas and oil as lighthouse light sources. The experiments extended over a period of more than twelve months, and were attended by representatives of the chief lighthouse authorities of the world.
The results of the trials tended to show that the rays of oil and gas lights suffered to about equal extent by atmospheric absorption, but that oil had the advantage over gas by reason of its greater economy in cost of maintenance and in initial outlay on installation.
The electric light was found to suffer to a much larger extent than either oil or gas light per unit of power by atmospheric absorption, but the infinitely greater total intensity of the beam obtainable by its use, both by reason of the high luminous intensity of the electric arc and its focal compactness, more than outweighed the higher percentage of loss in fog.
The final conclusion of the committee on the relative merits of electricity, gas or oil as lighthouse illuminants is given in the following words: “That for ordinary necessities of lighthouse illumination, mineral oil is the most suitable and economical illuminant, and that for salient headlands, important landfalls, and places where a very powerful light is required electricity offers the greater advantages.”
The British scientist Sir Humphry Davy, who a few years later would also develop the mining lamp named after him, came up with the idea for the arc lamp as early as 1810. He developed that idea into a working result in his laboratory. He invented the first lamp that worked on electricity.
That was relatively soon after electrical generators became available around the turn of the century. Remarkable, because this was well before the light bulb was discovered. Many other electrical appliances would take a good century to come. However, Sir Davy understood early on that electricity offered excellent opportunities for creating well-functioning and inexpensive lighting. And so he became responsible for the first generation of arc lamps. Later others would improve on it, but the basic principle remained the same.
All this did not mean that the arc lamp was immediately usable on a large scale. That was not yet possible because there was no sufficient electricity available anywhere. It was not until the middle of the 19th century that enough generators and pipes were available to actually enable the use of the arc lamp.
The first generation Davy's arc lamps worked using two carbon rods (electrodes) placed point-to-point. That is why it is also called carbon rod lamp. When voltage was applied, the current flowed between the two carbon rods. Where they touched, it would then become so hot that it glowed red. If the distance between the bars was then slightly increased with a screw, an arc of bright white light was created, the so-called arc. The heat evaporated the carbon rods, which gave extra light. This meant that the rods burned up slowly and had to be replaced regularly. Fresh carbon rods gave light for about six hours.
To protect the carbon rods, the lamp itself consisted of a large glass bulb. This also helped to prevent glare from the particularly bright light.
The light from the arc lamp was not stable and always flickered a bit. Since oil and gas lamps also flickered a lot, this was not a major problem for a long time. Problematic were the malodorous fumes emanating from the lamp. These were largely caused by released ozone. The lamp was also quite a fire hazard, but no more than other lamps.
In the early 20th century, alternating current was introduced to improve the operation of the incandescent lamp. This caused problems with the existing arc lamp, because it worked best at 50 volts direct current; the type of electricity for which all electricity facilities were equipped during the 19th century. The arc lamp did work on alternating current, but certainly not optimally. The light became even more unstable and the lamps also produced an annoying humming noise.
Nikola Tesla then developed a new arc lamp that was suitable for alternating current. By using electromagnets, he managed to silence the lamp again and, moreover, to stop the flickering.
Despite the imperfections, the arc lamp still got the necessary applications. That was because for a long time it was by far the strongest bulb available. Because of the fumes it was mostly outdoor lighting. In optical systems such as lighthouses, the arc lamp was particularly suitable because that light was amplified with mirrors or lenses, as it provides a high light output from a small area.
Right-hand picture: Arc lamp by Victor Serrin One of the problems in the construction of arc lamps was the vaporization of the carbon rods due to the enormous heat. Because the rods were arranged in line with each other, their mutual distance quickly became too great and the arc disappeared. To solve this, all kinds of regulators were developed. Victor Serrin developed an arc lamp with a regulator that also made it possible for the first time to distribute electric light.
Frenchman Victor Serrin designed the first self-starting and self-regulating arc lamp in the 1850s. The only known example of that device, built in 1857 by the great French instrument maker Louis Clement François Bréguet, is housed at SPARK Museum.
Sir Joseph Wilson Swan FRS (31 October 1828 – 27 May 1914) was an English physicist, chemist, and inventor. He is known as an independent early developer of a successful incandescent light bulb, and responsible for developing and supplying the first incandescent lights used to illuminate homes and public buildings, including the Savoy Theatre, London, in 1881.
Advances in filament design, vacuum technique and glass-blowing led to the rapid refinement of the lamps and ultimately to the ubiquity of electric lighting. In 1850, Swan began work on an incandescent light bulb using charred paper filaments in an evacuated glass bulb. By 1860 he was able to demonstrate a working device, but the lack of a good vacuum and adequate electrical source resulted in an inefficient, short-lived light bulb.
In 1875, Swan returned to investigate the incandescent lamp problem using a better vacuum and a charred wire as a filament.
Swan first publicly demonstrated his carbon filament lamp at a lecture to the Newcastle upon Tyne Chemical Society on December 18, 1878. However, after burning with bright light for several minutes in his laboratory, the lamp failed due to excessive current. On January 17, 1879, this lecture was successfully repeated with the lamp shown in actual operation; Swan had solved the problem of electric incandescent lighting by means of a vacuum lamp.
On February 3, 1879, he publicly demonstrated a working lamp to an audience of over seven hundred in the lecture hall of the Literary and Philosophical Society of Newcastle upon Tyne.
Swan turned his attention to producing a better carbon filament and the way to attach its ends. He devised a method of treating cotton to produce "parchment thread", and obtained British Patent 4933 on 27 November 1880. From then on he began installing light bulbs in homes and monuments in England.
Swan's house itself in Underhill, Low Fell, Gateshead, was the world's first house with working light bulbs. The Lit & Phil Library in Westgate Road, Newcastle, was the first public space illuminated by electric light during a lecture by Swan on 20 October 1880. In 1881 he formed his own company, The Swan Electric Light Company, and began commercial production.
The Savoy, a state-of-the-art theatre in the City of Westminster, London, was the first public building in the world to be lit entirely by electricity. Swan provided about 1,200 light bulbs powered by an 88.3 kilowatt (118.4 hp) generator on open land near the theatre.
The builder of the Savoy, Richard D'Oyly Carte, explained why he had introduced Swan's electric light: "The greatest drawbacks to the enjoyment of the theatrical performances are undoubtedly the foul air and heat which all theatres As everyone knows, every gas burner consumes the same amount of oxygen like many people, and also causes great heat. The light bulbs do not consume oxygen and do not create any perceptible heat." On December 29, 1881, The Times described electric lighting as visually superior to gaslight.
The first private home, other than the inventor's, lit by the new incandescent light bulb was that of his friend, Sir William Armstrong at Cragside, near Rothbury, Northumberland. Swan personally oversaw installation there in December 1880. Swan had established "The Swan Electric Light Company Ltd" with a factory at Benwell, Newcastle, and by early 1881 had set up the first commercial production of incandescent lamps.
Modern lighthouse beacons vary in power from about 10,000 candelas to about 1 million candelas, depending on the prevailing weather conditions and the visibility requirements of vesselping traffic in the particular area. Every lighthouse emits a distinctive series of flashes known as its Light characters. These flash sequences allow seafarers to time intervals between flashes so that they can identify lighthouses with marks on sea maps or using a publication called the Light List. This publication, assigns a number to each lighted beacon and describes its identifying characteristics.
The early incandescent light bulbs were very unreliable and while they were experimented with at many locations they were not put into use. It was after Thomas Edison invented the tungsten filament light bulb that similar (but much larger) bulbs were used in lighthouses. Bulbs of 1000-3000 watts replaced arc lights in many lighthouses in the early 1900s.
When commercial power became available the first station to be connected in England was South Foreland, and in 1922 it became the first British lighthouse to be lit by an incandescent lamp. These early lamps had very large globes and optical difficulties were encountered as the filaments presented a complex patterned light source, later bulbs became smaller and the filaments were made smaller as well.
The Xenon discharge lamp, first introduced in 1947, gave a highly concentrated light source. It has one drawback in that its beam is very vertically narrow and the beam provides little, if any, of the ‘loom’ in the sky that mariners prefer to see. Later, in the Terschelling, Brandaris and other Dutch lighthouses, old incandescent bulbs were replaced by a super-high pressure mercury-iodine lamp, and in the United States, and elsewhere, various forms of Halogen lamp bulbs are now the norm.
The light sources used in lighthouses changed significantly over the years. Many styles of light sources were tried, some were a great success and some proved of little value. Yet all forms, ‘From Braziers and Bougies to Xenon and Solar panels,’ helped to make the lives of the mariners safer.
