Misplaced Pages

#667332

79-654: The Stonington Harbor Light is a historic lighthouse built in 1840 and located on the east side of Stonington Harbor in the Borough of Stonington , Connecticut . It is a well-preserved example of a mid-19th century stone lighthouse. The light was taken out of service in 1889 and the building has served as a museum for the Stonington Historical Society since 1925. It was listed on the National Register of Historic Places in 1976. The Stonington Harbor Light

158-510: A civil engineering degree can be obtained after four years of study in the various branches of mathematics, physics, mechanics, etc. The earned degree is called Grado en Ingeniería Civil . Further studies at a graduate school include master's and doctoral degrees. Before the current situation, that is, before the implementation of Bologna Process in 2010, a degree in civil engineering in Spain could be obtained after three to six years of study and

237-402: 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

316-640: 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 Many Fresnel lens installations have been replaced by rotating aerobeacons , which require less maintenance.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

395-463: A category of their own, typically each with their own degrees, either in separate university faculties or at polytechnic schools. In the United States, civil engineers are typically employed by municipalities, construction firms, consulting engineering firms, architect/engineer firms, the military, state governments, and the federal government. Each state requires engineers who offer their services to

474-457: A civil engineer may perform land surveying ; in others, surveying is limited to construction surveying , unless an additional qualification is obtained. Civil engineers usually practice in a particular specialty, such as construction engineering , geotechnical engineering , structural engineering , land development , transportation engineering , hydraulic engineering , sanitary engineering , and environmental engineering . A civil engineer

553-436: 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

632-677: A five-year program at a polytechnic . Traditionally, students were required to pass an entrance exam on mathematics to start civil engineering studies. This exam was abolished in 2004 for the Flemish Community , but is still organised in the French Community . In Scandinavian countries, "civil engineer" ( civilingenjör in Swedish; sivilingeniør in Norwegian; civilingeniør in Danish)

711-453: A form of concrete that will set under water used by 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

790-414: 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

869-555: A license may not call themselves "civil engineers". In Belgium, Civil Engineer (abbreviated Ir. ) ( French : Ingénieur Civil , Dutch : Burgerlijk Ingenieur ) is a legally protected title applicable to graduates of the five-year engineering course of one of the six universities and the Royal Military Academy. Their speciality can be all fields of engineering: civil , structural , electrical , mechanical , chemical , physics and even computer science . This use of

SECTION 10

#1733084472668

948-427: 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

1027-583: 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

1106-512: 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

1185-402: 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

1264-440: A person to obtain a degree in construction engineering . Mechanical engineering , automotive engineering , hydraulics and even sometimes metallurgy are fields in a degree in "Machinery Engineering". Computer sciences , control engineering and electrical engineering are fields in a degree in electrical engineering, while security , safety , environmental engineering , transportation , hydrology and meteorology are in

1343-518: A regular university from their military counterparts. Today the degree spans over all fields within engineering, including civil engineering, mechanical engineering, computer science, and electronics engineering, among others. There is generally a slight difference between a Master of Science in Engineering degree and the Scandinavian civil engineer degree, the latter's programme having closer ties with

1422-411: A reservoir mounted above the burner. The lamp was first produced by Matthew Boulton , in partnership with Argand, in 1784, and became 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

1501-415: 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

1580-469: A system for gas illumination of lighthouses. His improved gas 'crocus' burner at the Baily Lighthouse near Dublin was 13 times more powerful than 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

1659-407: A variety of locations and conditions. Much of a civil engineer's work is dealing with non-engineers or others from different technical disciplines, so training should give skills preparing future civil engineers in organizational relationships between parties to projects, cost and time. Many spend time outdoors at construction sites so that they can monitor operations or solve problems onsite. The job

SECTION 20

#1733084472668

1738-501: A warning signal for reefs and promontories , unlike many modern lighthouses. The most famous lighthouse structure from antiquity 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

1817-497: Is 1½ stories and about 30 feet (9.1 m) square. The federal government built a lighthouse on Windmill Point in Stonington Harbor in 1823; it was housed in a small granite lighthouse and was known by the same name. However, erosion led to its being torn down and its materials reused in the construction of this lighthouse. The light was originally lit by an oil lamp and broadcast by eight parabolic reflectors. This technology

1896-480: Is a first professional degree , approximately equivalent to Master of Science in Engineering , and a protected title granted to students by selected institutes of technology . As in English, the word has its origin in the distinction between civilian and military engineers; before the start of the 19th century only military engineers existed, and the prefix "civil" was a way to separate those who had studied engineering in

1975-680: Is a person who practices civil engineering – the application of planning, designing, constructing, maintaining, and operating infrastructure while protecting the public and environmental health , as well as improving existing infrastructure that may have been neglected. Civil engineering is one of the oldest engineering disciplines because it deals with constructed environment including planning, designing, and overseeing construction and maintenance of building structures, and facilities, such as roads, railroads, airports, bridges, harbors, channels, dams, irrigation projects, pipelines, power plants, and water and sewage systems. The term "civil engineer "

2054-507: Is concerned with determining the right design for these structures and looking after the construction process so that the longevity of these structures is guaranteed after completion. These structures should also be satisfactory for the public in terms of comfort. Some civil engineers, particularly those working for government agencies, may practice across multiple specializations, particularly when involved in critical infrastructure development or maintenance. Civil engineers generally work in

2133-424: Is located at the southern end of Stonington Point, marking the eastern side of Stonington Harbor. The light station consists of the tower and keeper's house; both are built out of large granite blocks, and the keeper's house has a wood-framed ell attached. The tower is an octagonal stone structure 35 feet (11 m) in height and 10 feet (3.0 m) in diameter, with a circular glass lantern house on top. The house

2212-419: 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

2291-493: Is referred to as the beacon or front range; the further light is called the rear range. The rear range light is almost always taller than the front. When a vessel is on the correct course, the two lights align vertically, but when the observer is out of position, the difference in alignment indicates the direction of travel to correct the course. There are two types of lighthouses: ones that are located on land, and ones that are offshore. Civil engineer A civil engineer

2370-475: Is roughly equivalent to a Bachelor of Science in Scandinavia, to become a "civil engineer" one often has had to do up to one extra year of overlapping studies compared to attaining a B.Sc./M.Sc. combination. This is because the higher educational system is not fully adapted to the international standard graduation system, since it is treated as a professional degree . Today (2009) this is starting to change due to

2449-510: 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

Stonington Harbor Light - Misplaced Pages Continue

2528-630: Is typically a blend of in-office and on-location work depending on the focus of each engineer. Most engineers work full-time. In most countries, a civil engineer will have graduated from a post-secondary school with a degree in civil engineering, which requires a strong background in mathematics and the physical sciences ; this degree is typically a bachelor's degree , though many civil engineers study further to obtain master's , engineer , doctoral and post doctoral degrees. In many countries, civil engineers are subject to licensure . In some jurisdictions with mandatory licensing, people who do not obtain

2607-631: The Bologna process . A Scandinavian civilingenjör will in international contexts commonly use the title of "Master of Science in Engineering" and will occasionally wear an engineering class ring . At the Norwegian Institute of Technology (now the Norwegian University of Science and Technology ), the tradition with an NTH Ring goes back to 1914, before the Canadian iron ring . In Spain ,

2686-702: The Escuela Especial de Ayudantes de Obras Públicas (now called Escuela Universitaria de Ingeniería Técnica de Obras Públicas de la Universidad Politécnica de Madrid ), founded in 1854 in Madrid. Both schools now belong to the Technical University of Madrid . In Spain, a civil engineer has the technical and legal ability to design projects of any branch, so any Spanish civil engineer can oversee projects about structures, buildings (except residential structures which are reserved for architects), foundations, hydraulics,

2765-601: 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

2844-510: 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

2923-750: The Institution of Civil Engineering Surveyors. The description "civil engineer" is not restricted to members of any particular professional organisation although "chartered civil engineer" is. In many Eastern European countries, civil engineering does not exist as a distinct degree or profession but its various sub-professions are often studied in separate university faculties and performed as separate professions, whether they are taught in civilian universities or military engineering academies. Even many polytechnic tertiary schools give out separate degrees for each field of study. Typically study in geology , geodesy , structural engineering and urban engineering allows

3002-462: The Swiss scientist Aimé Argand revolutionized lighthouse illumination with its steady smokeless flame. Early models used ground glass which 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

3081-405: 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

3160-486: The added advantage of allowing some of the energy of 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

3239-433: The advent of much cheaper, more sophisticated, and more effective electronic navigational systems. Before 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

Stonington Harbor Light - Misplaced Pages Continue

3318-481: 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

3397-406: 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. 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

3476-696: The civil engineering profession worldwide. Official members of the ASCE must hold a bachelor's degree from an accredited civil engineering program and be a licensed professional engineer or have five years responsible charge of engineering experience. Most civil engineers join this organization to be updated of current news, projects, and methods (such as sustainability) related to civil engineering as well as contribute their expertise and knowledge to other civil engineers and students obtaining their civil engineering degree. The ICE (Institution of Civil Engineers) founded in 1818, represents, as of 2008, more than 80,000 members of

3555-525: 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

3634-488: The construction of lenses of large aperture and short focal length , without the mass and volume of material that would be required by 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

3713-473: 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 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

3792-412: 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

3871-538: The environment, transportation, urbanism, etc. Mechanical and Electrical engineering tasks are included under the Industrial engineering degree. A chartered civil engineer (known as certified or professional engineer in other countries) is a member of the Institution of Civil Engineers , and has also passed membership exams. However, a non-chartered civil engineer may be a member of the Institution of Civil Engineers or

3950-464: The industry's demands. A civil engineer is the better-known of the two; still, the area of expertise remains obfuscated for most of the public. A noteworthy difference is the mandatory courses in mathematics and physics, regardless of the equivalent master's degree, e.g. computer science. Although a "college engineer" ( högskoleingenjör, diplomingenjör, or mellaningenjör in Swedish; høgskoleingeniør in Norwegian; diplomingeniør in Danish)

4029-455: 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

SECTION 50

#1733084472668

4108-531: 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

4187-505: The lighthouse at Ostia . Coins from Alexandria, Ostia, and Laodicea in Syria also exist. The modern era of lighthouses began at 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

4266-469: 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

4345-466: 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), 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

4424-421: 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

4503-485: The most impressive feats of engineering of 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

4582-405: The museum document the area's long and distinguished cultural and nautical history, and exhibits include the 1856 Fresnel lens . Lighthouse 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

4661-487: The public to be licensed by the state. Licensure is obtained by meeting specified education, examination, and work experience requirements. Specific requirements vary by state. Typically, licensed engineers must graduate from an ABET -accredited university or college engineering program with a minimum of bachelor's degree, pass the Fundamentals of Engineering exam (FE), obtain several years of engineering experience under

4740-435: The same fields as civil engineers do elsewhere. This degree is equivalent to a Master of Civil Engineering and is obtained after five or six years of study depending on the school granting the title. The first Spanish Civil Engineering School was the Escuela Especial de Ingenieros de Caminos y Canales (now called Escuela Técnica Superior de Ingenieros de Caminos, Canales y Puertos ), established in 1802 in Madrid, followed by

4819-458: The sea. The function of lighthouses was gradually changed from indicating ports to 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

SECTION 60

#1733084472668

4898-451: 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

4977-541: 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

5056-503: The supervision of a licensed engineer, then pass the Principles and Practice of Engineering Exam . After completing these steps and the granting of licensure by a state board, engineers may use the title "Professional Engineer" or PE in advertising and documents. Most states have implemented mandatory continuing education requirements to maintain a license. The ASCE (American Society of Civil Engineers) represents more than 150,000 members of

5135-516: 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

5214-587: 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

5293-487: The title may cause confusion to the English speaker as the Belgian "civil" engineer can have a speciality other than civil engineering. In fact, Belgians use the adjective "civil" in the sense of "civilian", as opposed to military engineers. The formation of the civil engineer has a strong mathematical and scientific base and is more theoretical in approach than the practical oriented industrial engineer ( Ing. ) educated in

5372-483: 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

5451-476: 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

5530-523: 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

5609-643: 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

5688-437: 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

5767-615: Was already obsolete at the time of the lighthouse's construction, and it was replaced by a sixth-order Fresnel lens in 1856. In the 1880s, the Stonington Breakwater Light was constructed farther out in the harbor, and the Stonington Harbor Light was decommissioned in 1889. The site is now the home of the Stonington Historical Society which uses the building as The Old Lighthouse Museum . Holdings in

5846-459: Was built by Henry Winstanley from 1696 to 1698. His lighthouse was the first tower in 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 ",

5925-662: Was built on piles that were screwed into the sandy or muddy seabed. Construction of his design began in 1838 at 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

6004-521: Was divided into two main degrees. In the first case, the earned degree was called Ingeniero Técnico de Obras Públicas ( ITOP ), literally translated as "Public Works Engineer" obtained after three years of study and equivalent to a Bachelor of Civil Engineering. In the second case, the academic degree was called Ingeniero de Caminos, Canales y Puertos (often shortened to Ingeniero de Caminos or ICCP ), that literally means "Highways, Canals and Harbors Engineer", though civil engineers in Spain practice in

6083-513: Was established by John Smeaton in 1750 to contrast engineers working on civil projects with the military engineers , who worked on armaments and defenses. Over time, various sub-disciplines of civil engineering have become recognized and much of military engineering has been absorbed by civil engineering. Other engineering practices became recognized as independent engineering disciplines, including chemical engineering , mechanical engineering , and electrical engineering . In some places,

6162-502: 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, 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

6241-588: Was used in 1823 in the Cordouan lighthouse at the mouth of 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

#667332