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67-709: The Kugelbake stands at a busy shipping lane in the Cuxhaven borough of Döse and was once a vital nautical landmark. At this point, the estuary is about 18 km wide. Geographically speaking, the Elbe ends here and the North Sea begins. From a nautical point of view, the Kugelbake can be said to separate the Outer and Lower portions of the Elbe. It is also regarded as the symbolic separation between

134-449: A beacon for navigational aid for maritime pilots at sea or on inland waterways. Lighthouses mark dangerous coastlines, hazardous shoals , reefs , rocks, and safe entries to harbors; they also assist in aerial navigation . Once widely used, the number of operational lighthouses has declined due to the expense of maintenance and the advent of much cheaper, more sophisticated, and more effective electronic navigational systems. Before

201-402: A rescue service , if necessary. Improvements in maritime navigation and safety, such Global Positioning System (GPS), led to the phasing out of non-automated lighthouses across the world. Although several closed due to safety concerns, Canada still maintains 49 staffed lighthouses, split roughly evenly across east and west coasts. The remaining modern lighthouses are usually illuminated by

268-462: A substrate , to absorb the gas, allowing the gas to be stored, and hence used, safely. Dalén also invented the ' sun valve ', which automatically regulated the light and turned it off during the daytime. The technology was the predominant light source in lighthouses from the 1900s to the 1960s, when electric lighting had become dominant. With the development of the steady illumination of the Argand lamp,

335-640: A Diesel generator for backup. Many Fresnel lens installations have been replaced by rotating aerobeacons , which require less maintenance. In modern automated lighthouses, the system of rotating lenses is often replaced by a high intensity light that emits brief omnidirectional flashes, concentrating the light in time rather than direction. These lights are similar to obstruction lights used to warn aircraft of tall structures. Later innovations were "Vega Lights", and experiments with light-emitting diode (LED) panels. LED lights, which use less energy and are easier to maintain, had come into widespread use by 2020. In

402-436: A filament source. Experimental installations of laser lights, either at high power to provide a "line of light" in the sky or, utilising low power, aimed towards mariners have identified problems of increased complexity in installation and maintenance, and high power requirements. The first practical installation, in 1971 at Point Danger lighthouse , Queensland , was replaced by a conventional light after four years, because

469-414: A horizontal plane, and horizontally the light is focused into one or a few directions at a time, with the light beam swept around. As a result, in addition to seeing the side of the light beam, the light is directly visible from greater distances, and with an identifying light characteristic . This concentration of light is accomplished with a rotating lens assembly. In early lighthouses, the light source

536-461: A lens of conventional design. A Fresnel lens can be made much thinner than a comparable conventional lens, in some cases taking the form of a flat sheet. A Fresnel lens can also capture more oblique light from a light source, thus allowing the light from a lighthouse equipped with one to be visible over greater distances. The first Fresnel lens was used in 1823 in the Cordouan lighthouse at the mouth of

603-427: A more powerful hyperradiant Fresnel lens manufactured by the firm of Chance Brothers . While lighthouse buildings differ depending on the location and purpose, they tend to have common components. A light station comprises the lighthouse tower and all outbuildings, such as the keeper's living quarters, fuel house, boathouse, and fog-signaling building. The Lighthouse itself consists of a tower structure supporting

670-585: A museum and cruise ship terminal. On 15 March 1907 Cuxhaven gained city status within the state of Hamburg. In 1937 Cuxhaven became an urban district of the Stade Region within the Prussian Province of Hanover by the Greater Hamburg Act . In 1972 some municipalities of the neighboured rural district of Land of Hadeln were incorporated into the urban district of Cuxhaven. In 1977 Cuxhaven lost

737-583: A navigator with a line of position called a range in North America and a transit in Britain. Ranges can be used to precisely align a vessel within a narrow channel such as a river. With landmarks of a range illuminated with a set of fixed lighthouses, nighttime navigation is possible. Such paired lighthouses are called range lights in North America and leading lights in the United Kingdom. The closer light

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804-512: A number of screw-pile lighthouses. Englishman James Douglass was knighted for his work on the fourth Eddystone Lighthouse. United States Army Corps of Engineers Lieutenant George Meade built numerous lighthouses along the Atlantic and Gulf coasts before gaining wider fame as the winning general at the Battle of Gettysburg . Colonel Orlando M. Poe , engineer to General William Tecumseh Sherman in

871-402: A particular color (usually formed by colored panes in the lantern) to distinguish safe water areas from dangerous shoals. Modern lighthouses often have unique reflectors or racon transponders so the radar signature of the light is also unique. Before modern strobe lights , lenses were used to concentrate the light from a continuous source. Vertical light rays of the lamp are redirected into

938-415: A single stationary flashing light powered by solar-charged batteries and mounted on a steel skeleton tower. Where the power requirement is too great for solar power alone, cycle charging of the battery by a Diesel generator is provided. The generator only comes into use when the battery needs charging, saving fuel and increasing periods between maintenance. John Smeaton is noteworthy for having designed

1005-484: A strategically important city as German authorities and civilians feared it would be the site of an Allied invasion. During the Second World War , the town hosted a base of a Wehrmacht radio network, codenamed BROWN, which transmitted data regarding experimental weapon developments, including rocketry. From this location the last ENIGMA -code encrypted message of the war was transmitted on 7 May 1945. It reported

1072-498: Is twinned with: Cuxhaven has an oceanic climate ( Köppen : Cfb ; Trewartha : Dobk ), located on the coast of the Baltic Sea, the weather is noticeably warmer in winter and cooler in summer. The Cuxhaven weather station has recorded the following extreme values: Lighthouse A lighthouse is a tower, building, or other type of physical structure designed to emit light from a system of lamps and lenses and to serve as

1139-634: Is not accessible to the public. It is not really a landmark, for many cities in Germany have a similar tower. The high-test peroxide (HTP) submarine U1407 was raised from where she had been scuttled in Cuxhaven after WWII and rebuilt by the British, being commissioned as HMS Meteorite . It was the catalyst for a series of German-made air-independent propulsion submarines such as the Type 212 and Type 214 . Cuxhaven

1206-419: Is one example. Race Rocks Light in western Canada is painted in horizontal black and white bands to stand out against the horizon. For effectiveness, the lamp must be high enough to be seen before the danger is reached by a mariner. The minimum height is calculated by trigonometry (see Distance to the horizon ) as D = 1.22 H {\displaystyle D=1.22{\sqrt {H}}} , where H

1273-485: Is situated on the shore of the North Sea at the mouth of the Elbe River. Cuxhaven has a footprint of 14 kilometres (9 miles) (east–west) by 7 km (4 mi) (north–south). Its town quarters Duhnen , Döse and Sahlenburg are especially popular vacation spots on the North Sea and home to about 52,000 residents. Cuxhaven is home to an important fisherman's wharf and ship registration point for Hamburg as well as

1340-510: Is the height above water in feet, and D is the distance from the lighthouse to the horizon in nautical miles, the lighthouse range . Where dangerous shoals are located far off a flat sandy beach, the prototypical tall masonry coastal lighthouse is constructed to assist the navigator making a landfall after an ocean crossing. Often these are cylindrical to reduce the effect of wind on a tall structure, such as Cape May Light . Smaller versions of this design are often used as harbor lights to mark

1407-601: The Florida Reef along the Florida Keys, beginning with the Carysfort Reef Light in 1852. In waters too deep for a conventional structure, a lightship might be used instead of a lighthouse, such as the former lightship Columbia . Most of these have now been replaced by fixed light platforms (such as Ambrose Light ) similar to those used for offshore oil exploration . Aligning two fixed points on land provides

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1474-565: The Franco-Prussian War in 1870, the light was reduced to confuse potential enemies and in World War I it was completely removed for the same reason. In 1924 it was rebuilt, but instead of the eponymous ball, two round perpendicular composite discs were attached at the top. The current construction was built after 1945. The Kugelbake was also the spot where amateur radio pioneer Jonathan Zenneck experimented with radio communications between

1541-476: The Gironde estuary ; its light could be seen from more than 20 miles (32 km) out. Fresnel's invention increased the luminosity of the lighthouse lamp by a factor of four and his system is still in common use. The introduction of electrification and automatic lamp changers began to make lighthouse keepers obsolete. For many years, lighthouses still had keepers, partly because lighthouse keepers could serve as

1608-555: The Kiel Canal until 2008. Tourism is also of great importance. The city and its precursor Ritzebüttel belonged to Hamburg from the 13th century until 1937. The island of Neuwerk , a Hamburg dependency, is located just northwest of Cuxhaven in the North Sea. The city's symbol, known as the Kugelbake , is a beacon once used as a lighthouse ; the wooden landmark on the mouth of the Elbe marks

1675-510: The 20th century. These often have a narrow cylindrical core surrounded by an open lattice work bracing, such as Finns Point Range Light . Sometimes a lighthouse needs to be constructed in the water itself. Wave-washed lighthouses are masonry structures constructed to withstand water impact, such as Eddystone Lighthouse in Britain and the St. George Reef Light of California. In shallower bays, Screw-pile lighthouse ironwork structures are screwed into

1742-495: The Elbe and Weser estuaries. Its distinctive design, well known to skippers, is now a popular tourist destination. The first navigational aid was built on this spot around 1703 at the instigation of the Pilot Inspector Paul Allers after an existing bearing , a group of trees, was swept away by a fierce storm surge. It was constructed of wood and had a short service life due to the harsh weather and floods common on

1809-471: The Elbe, registered at Cuxhaven . It has crew of 6, a displacement of 3900 metric tons, is 79.3 m long and 18.6 m wide, and is equipped with a 1900 kW power plant. Cuxhaven Cuxhaven ( German: [kʊksˈhaːfn̩] ; Low German : Cuxhoben ) is a town and seat of the Cuxhaven district , in Lower Saxony , Germany . The town includes the northernmost point of Lower Saxony. It

1876-610: The Mainland and ships at sea during the winter of 1899–1900. A wooden hut was built within the structure, equipped with the necessary antennas and technical equipment for the very first coastal radio station in Germany . The first transmissions were sent between the Kugelbake and the steamship Silvana to a distance of 32 km. In the autumn of 1900, transmissions were sent as far as the Elbe Islands and Heligoland , 63 km away. In 2001

1943-452: The Romans, and developed a technique of securing the granite blocks together using dovetail joints and marble dowels . The dovetailing feature served to improve the structural stability , although Smeaton also had to taper the thickness of the tower towards the top, for which he curved the tower inwards on a gentle gradient. This profile had the added advantage of allowing some of the energy of

2010-405: The United Kingdom and Ireland about a third of lighthouses had been converted from filament light sources to use LEDs, and conversion continued with about three per year. The light sources are designed to replicate the colour and character of the traditional light as closely as possible. The change is often not noticed by people in the region, but sometimes a proposed change leads to calls to preserve

2077-470: The Wasser- und Schifffahrtsverwaltung (English: Water and Shipping Administration ) transferred the Kugelbake to the federal historic properties agency, since the beacon had lost its nautical importance. A foundation was established for the preservation of this historic landmark, which since 2002 has belonged to the city of Cuxhaven. A Ro-Ro vessel MV  Kugelbake was built in 2009 for container traffic on

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2144-499: The age. This structure was based upon Smeaton's design, but with several improved features, such as the incorporation of rotating lights, alternating between red and white. Stevenson worked for the Northern Lighthouse Board for nearly fifty years during which time he designed and oversaw the construction and later improvement of numerous lighthouses. He innovated in the choice of light sources, mountings, reflector design,

2211-439: The application of optical lenses to increase and focus the light intensity became a practical possibility. William Hutchinson developed the first practical optical system in 1777, known as a catoptric system. This rudimentary system effectively collimated the emitted light into a concentrated beam, thereby greatly increasing the light's visibility. The ability to focus the light led to the first revolving lighthouse beams, where

2278-484: The arrival of British troops and ends: "Closing down for ever – all the best – goodbye." Between 1945 and 1964 the Hermann-Oberth-Gesellschaft performed various civilian experiments in rocketry near Cuxhaven. The origins of tourism go back to the year 1816 when a seaside resort was founded in Cuxhaven. Since 1964 Cuxhaven has been a state-recognized climate seaside resort ( Seeheilbad ) and centre of

2345-481: The beam was too narrow to be seen easily. In any of these designs an observer, rather than seeing a continuous weak light, sees a brighter light during short time intervals. These instants of bright light are arranged to create a light characteristic or pattern specific to a lighthouse. For example, the Scheveningen Lighthouse flashes are alternately 2.5 and 7.5 seconds. Some lights have sectors of

2412-530: The boundary between the river and the North Sea and also adorns the city's coat of arms. Ritzebüttel, today a part of Cuxhaven, belonged to the Land of Hadeln , first an exclave of the younger Duchy of Saxony and after its de facto dynastic partition in 1296 of the Duchy of Saxe-Lauenburg , established de jure in 1260. In 1394 the city of Hamburg conquered the fortress of Ritzebüttel and made it its stronghold to protect

2479-525: The collapse of the Soviet government in 1990s, most of the official records on the locations, and condition, of these lighthouses were reportedly lost. Over time, the condition of RTGs in Russia degraded; many of them fell victim to vandalism and scrap metal thieves, who may not have been aware of the dangerous radioactive contents. Energy-efficient LED lights can be powered by solar panels , with batteries instead of

2546-457: The development of clearly defined ports , mariners were guided by fires built on hilltops. Since elevating the fire would improve visibility, placing the fire on a platform became a practice that led to the development of the lighthouse. In antiquity, the lighthouse functioned more as an entrance marker to ports than as a warning signal for reefs and promontories , unlike many modern lighthouses. The most famous lighthouse structure from antiquity

2613-468: The entrance into a harbor, such as New London Harbor Light . Where a tall cliff exists, a smaller structure may be placed on top such as at Horton Point Light . Sometimes, such a location can be too high, for example along the west coast of the United States, where frequent low clouds can obscure the light. In these cases, lighthouses are placed below the clifftop to ensure that they can still be seen at

2680-490: The estuary of the river Elbe , which connects that city with the open sea. The Hamburg America Line built a large ocean liner terminal at Cuxhaven in 1900. Connected directly to Hamburg by a dedicated railway line and station, it served as the major departure point for German and European emigrants until 1969 when ocean liner travel ceased. The ornate assembly hall and associated buildings survived wartime damage and peacetime urban renewal to be restored in 1998 for use as

2747-455: The lantern room where the light operates. The lantern room is the glassed-in housing at the top of a lighthouse tower containing the lamp and lens. Its glass storm panes are supported by metal muntins (glazing bars) running vertically or diagonally. At the top of the lantern room is a stormproof ventilator designed to remove the smoke of the lamps and the heat that builds in the glass enclosure. A lightning rod and grounding system connected to

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2814-531: The light is concentrated, if needed, by the "lens" or "optic". Power sources for lighthouses in the 20th–21st centuries vary. Originally lit by open fires and later candles, the Argand hollow wick lamp and parabolic reflector were introduced in the late 18th century. Whale oil was also used with wicks as the source of light. Kerosene became popular in the 1870s and electricity and acetylene gas derived on-site from calcium carbide began replacing kerosene around

2881-434: The light would appear to the mariners as a series of intermittent flashes. It also became possible to transmit complex signals using the light flashes. French physicist and engineer Augustin-Jean Fresnel developed the multi-part Fresnel lens for use in lighthouses. His design allowed for the construction of lenses of large aperture and short focal length , without the mass and volume of material that would be required by

2948-469: The lighthouse keepers. Efficiently concentrating the light from a large omnidirectional light source requires a very large diameter lens. This would require a very thick and heavy lens if a conventional lens were used. The Fresnel lens (pronounced / f r eɪ ˈ n ɛ l / ) focused 85% of a lamp's light versus the 20% focused with the parabolic reflectors of the time. Its design enabled construction of lenses of large size and short focal length without

3015-421: The metal cupola roof provides a safe conduit for any lightning strikes. Immediately beneath the lantern room is usually a Watch Room or Service Room where fuel and other supplies were kept and where the keeper prepared the lanterns for the night and often stood watch. The clockworks (for rotating the lenses) were also located there. On a lighthouse tower, an open platform called the gallery is often located outside

3082-505: The most brilliant light then known. The vaporized oil burner was invented in 1901 by Arthur Kitson , and improved by David Hood at Trinity House . 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. The use of gas as illuminant became widely available with the invention of the Dalén light by Swedish engineer Gustaf Dalén . He used Agamassan (Aga),

3149-738: The mouth of the Thames and was known as the Maplin Sands lighthouse, and first lit in 1841. Although its construction began later, the Wyre Light in Fleetwood, Lancashire, was the first to be lit (in 1840). Until 1782 the source of illumination had generally been wood pyres or burning coal. The Argand lamp , invented in 1782 by the Swiss scientist Aimé Argand revolutionized lighthouse illumination with its steady smokeless flame. Early models used ground glass which

3216-413: The point. It was rebuilt approximately every 30 years, the first reconstruction taking place around 1737. In 1853, the Kugelbake was lit nightly to guide ships in the difficult curvature of the estuary. The light consisted of a fire in a small hut located inside the structure. By 1878 the light served only as a reserve because a lightvessel was placed in the channel throughout the year. At the outbreak of

3283-463: The providing of a visible warning against shipping hazards, such as rocks or reefs. The Eddystone Rocks were a major shipwreck hazard for mariners sailing through the English Channel . The first lighthouse built there was an octagonal wooden structure, anchored by 12 iron stanchions secured in the rock, and was built by Henry Winstanley from 1696 to 1698. His lighthouse was the first tower in

3350-451: The seabed and a low wooden structure is placed above the open framework, such as Thomas Point Shoal Lighthouse . As screw piles can be disrupted by ice, steel caisson lighthouses such as Orient Point Light are used in cold climates. Orient Long Beach Bar Light (Bug Light) is a blend of a screw pile light that was converted to a caisson light because of the threat of ice damage. Skeletal iron towers with screw-pile foundations were built on

3417-541: The siege of Atlanta, designed and built some of the most exotic lighthouses in the most difficult locations on the U.S. Great Lakes . French merchant navy officer Marius Michel Pasha built almost a hundred lighthouses along the coasts of the Ottoman Empire in a period of twenty years after the Crimean War (1853–1856). In a lighthouse, the source of light is called the "lamp" (whether electric or fuelled by oil) and

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3484-508: The so-called holiday region of Cuxland . The town is served by Cuxhaven station . The island of Neuwerk is situated 8 kilometres (5 mi) off the coast from Cuxhaven. At low tide the water recedes so far from the coast that the island can be reached either by mudflat hiking or by horse carriage . A modern landmark of Cuxhaven is the Friedrich-Clemens-Gerke Tower , a telecommunication tower built of concrete, which

3551-484: The standard for lighthouses for over a century. South Foreland Lighthouse was the first tower to successfully use an electric light in 1875. The lighthouse's carbon arc lamps were powered by a steam-driven magneto . John Richardson Wigham was the first to develop a system for gas illumination of lighthouses. His improved gas 'crocus' burner at the Baily Lighthouse near Dublin was 13 times more powerful than

3618-533: The status as urban district and was integrated into the new rural District of Cuxhaven , being its capital. During the First World War Nordholz Airbase with its airship hangars , near Nordholz to the south of Cuxhaven, was one of the major Imperial German Navy airship stations. On Christmas Day 1914 it was attacked by Royal Navy seaplanes in the Cuxhaven Raid . It subsequently became

3685-516: The surface during periods of fog or low clouds, as at Point Reyes Lighthouse . Another example is in San Diego , California : the Old Point Loma lighthouse was too high up and often obscured by fog, so it was replaced in 1891 with a lower lighthouse, New Point Loma lighthouse . As technology advanced, prefabricated skeletal iron or steel structures tended to be used for lighthouses constructed in

3752-587: The third and most famous Eddystone Lighthouse , but some builders are well known for their work in building multiple lighthouses. The Stevenson family ( Robert , Alan , David , Thomas , David Alan , and Charles ) made lighthouse building a three-generation profession in Scotland. Richard Henry Brunton designed and built 26 Japanese lighthouses in Meiji Era Japan, which became known as Brunton's "children". Blind Irishman Alexander Mitchell invented and built

3819-483: The traditional light, including in some cases a rotating beam. A typical LED system designed to fit into the traditional 19th century Fresnel lens enclosure was developed by Trinity House and two other lighthouse authorities and costs about € 20,000, depending on configuration, according to a supplier; it has large fins to dissipate heat. Lifetime of the LED light source is 50,000 to 100,000 hours, compared to about 1,000 hours for

3886-407: The turn of the 18th century, as the number of lighthouses being constructed increased significantly due to much higher levels of transatlantic commerce. 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 function of lighthouses was gradually changed from indicating ports to

3953-476: The turn of the 20th century. Carbide was promoted by the Dalén light , which automatically lit the lamp at nightfall and extinguished it at dawn. In the second half of the 20th century, many remote lighthouses in Russia (then Soviet Union ) were powered by radioisotope thermoelectric generators (RTGs). These had the advantage of providing power day or night and did not need refuelling or maintenance. However, after

4020-463: The use of Fresnel lenses , and in rotation and shuttering systems providing lighthouses with individual signatures allowing them to be identified by seafarers. He also invented the movable jib and the balance-crane as a necessary part for lighthouse construction. Alexander Mitchell designed the first screw-pile lighthouse – his lighthouse was built on piles that were screwed into the sandy or muddy seabed. Construction of his design began in 1838 at

4087-523: The watch room (called the Main Gallery) or Lantern Room (Lantern Gallery). This was mainly used for cleaning the outside of the windows of the Lantern Room. Lighthouses near to each other that are similar in shape are often painted in a unique pattern so they can easily be recognized during daylight, a marking known as a daymark . The black and white barber pole spiral pattern of Cape Hatteras Lighthouse

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4154-476: The waves to dissipate on impact with the walls. His lighthouse was the prototype for the modern lighthouse and influenced all subsequent engineers. One such influence was Robert Stevenson , himself a seminal figure in the development of lighthouse design and construction. His greatest achievement was the construction of the Bell Rock Lighthouse in 1810, one of the most impressive feats of engineering of

4221-643: The weight and volume of material in conventional lens designs. Fresnel lighthouse lenses are ranked by order , a measure of refracting power, with a first order lens being the largest, most powerful and expensive; and a sixth order lens being the smallest. The order is based on the focal length of the lens. A first order lens has the longest focal length, with the sixth being the shortest. Coastal lighthouses generally use first, second, or third order lenses, while harbor lights and beacons use fourth, fifth, or sixth order lenses. Some lighthouses, such as those at Cape Race , Newfoundland, and Makapuu Point , Hawaii, used

4288-425: The world to have been fully exposed to the open sea. The civil engineer John Smeaton rebuilt the lighthouse from 1756 to 1759; his tower marked a major step forward in the design of lighthouses and remained in use until 1877. He modeled the shape of his lighthouse on that of an oak tree , using granite blocks. He rediscovered and used " hydraulic lime ", a form of concrete that will set under water used by

4355-437: Was a kerosene lamp or, earlier, an animal or vegetable oil Argand lamp, and the lenses rotated by a weight driven clockwork assembly wound by lighthouse keepers, sometimes as often as every two hours. The lens assembly sometimes floated in liquid mercury to reduce friction. In more modern lighthouses, electric lights and motor drives were used, generally powered by diesel electric generators. These also supplied electricity for

4422-407: Was sometimes tinted around the wick. Later models used a mantle of thorium dioxide suspended over the flame, creating a bright, steady light. The Argand lamp used whale oil , colza , olive oil or other vegetable oil as fuel, supplied by a gravity feed from a reservoir mounted above the burner. The lamp was first produced by Matthew Boulton , in partnership with Argand, in 1784, and became

4489-550: Was the Pharos of Alexandria , Egypt , which collapsed following a series of earthquakes between 956 and 1323. The intact Tower of Hercules at A Coruña , Spain gives insight into ancient lighthouse construction; other evidence about lighthouses exists in depictions on coins and mosaics, of which many represent the lighthouse at Ostia . Coins from Alexandria, Ostia, and Laodicea in Syria also exist. The modern era of lighthouses began at

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