The Cape Canaveral Light is a historic lighthouse on the east coast of the U.S. state of Florida . The light was established in 1848 to warn ships of the dangerous shoals that lie off its coast. It is located inside the Cape Canaveral Space Force Station and managed by the Space Launch Delta 45 of the U.S. Space Force with the assistance of the Cape Canaveral Lighthouse Foundation. It is the only fully operational lighthouse owned by the United States Space Force.
139-474: The current 151-foot (46 m) lighthouse tower was first erected and lit in 1868 then relocated further inland between 1893 and 1894. It was originally equipped with a first-order Fresnel lens that was automated in 1967 and then retired from the tower in 1993. The Cape Canaveral lighthouse was erected to warn mariners of the outlying shoals off its coast. Broken ground and shoals extend 13 nautical miles (24 km; 15 mi) northward and northeastward of
278-698: A DCB-224 , a high-power searchlight that increased its range to 24 nautical miles (44 km; 28 mi). Ownership of the lighthouse was transferred by the Coast Guard to the United States Air Force on December 14, 2000. In 2002, the Cape Canaveral Lighthouse Foundation was formed and a memorandum of agreement was signed with the USAF. The following is the list of head lighthouse keepers that served
417-478: A federal structure with two overlapping power centers so that each citizen as an individual is subject to the powers of state government and national government. To protect against abuse of power, each branch of government – executive, legislative, and judicial – had a separate sphere of authority and could check other branches according to the principle of the separation of powers . Furthermore, there were checks and balances within
556-462: A podium made from bricks of the 1848 lighthouse, was built to commemorate its dedication in October 1997. In 2003, the oil house located in front of the ground floor door was restored to its original (1890s) state. Strong winds had damaged the roof in the 1970s. A window that was added to the brick structure in the early 1900s was also covered up during restoration. During the 2006-2007 project,
695-490: A "remarkably resilient institution". Congress is the "heart and soul of our democracy", according to this view, even though legislators rarely achieve the prestige or name recognition of presidents or Supreme Court justices ; one wrote that "legislators remain ghosts in America's historical imagination." One analyst argues that it is not a solely reactive institution but has played an active role in shaping government policy and
834-706: A 21-inch (530 mm) reflector. The lamps were set on a chandelier rotated via clockwork . During the Seminole War scare, Scobie abandoned the lighthouse, and refused to return to his post. Captain Mills Olcott Burnham (b. September 8, 1817) was appointed as the next lighthouse keeper in July 1853. Along with his position, Burnham was given 160 acres (65 ha) of land as part of the Florida Armed Occupation Act of 1842,
973-432: A constant light (from a fixed lens), one flash per minute (from a rotating lens with eight panels), and two per minute (16 panels). In late 1825, to reduce the loss of light in the reflecting elements, Fresnel proposed to replace each mirror with a catadioptric prism, through which the light would travel by refraction through the first surface, then total internal reflection off the second surface, then refraction through
1112-414: A conventional lens by dividing the lens into a set of concentric annular sections. An ideal Fresnel lens would have an infinite number of sections. In each section, the overall thickness is decreased compared to an equivalent simple lens. This effectively divides the continuous surface of a standard lens into a set of surfaces of the same curvature, with stepwise discontinuities between them. In some lenses,
1251-455: A cylindrical form while retaining the property of reflecting light from a single point back to that point. Reflectors of this form, paradoxically called "dioptric mirrors", proved particularly useful for returning light from the landward side of the lamp to the seaward side. As lighthouses proliferated, they became harder to distinguish from each other, leading to the use of colored filters, which wasted light. In 1884, John Hopkinson eliminated
1390-425: A focal height of 57 feet (17 m) and a visibility of 13 nautical miles (24 km; 15 mi). The old tower (1848), which stood next to the new tower for about two decades, was blown up and the rubble was used to prepare a foundation for the lighthouse at the new location. The cast iron tower was dismantled, moved by a tram pulled by mules, and reassembled at the new location about a mile westward together with
1529-401: A focal length of 920 mm ( 36 + 1 ⁄ 4 in) and stands about 2.59 m (8 ft 6 in) high, and 1.8 m (6 ft) wide. The smallest (sixth) order has a focal length of 150 mm (6 in) and a height of 433 mm ( 17 + 1 ⁄ 16 in). The largest Fresnel lenses are called hyperradiant (or hyper-radial). One such lens was on hand when it
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#17327979493931668-497: A legislation passed to populate the state. Sailors heavily criticized the white brick lighthouse with complaints that the light was too weak and too low to be seen before ships were on the reefs near the cape. In 1860, the government approved the construction of a new lighthouse. However, the start of the American Civil War stopped the work on the new tower. The lamps and mechanism of the lighthouse were removed from
1807-548: 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. Because of its use in lighthouses, it has been called "the invention that saved a million ships". The first person to focus a lighthouse beam using a lens was apparently the London glass-cutter Thomas Rogers, who proposed the idea to Trinity House in 1788. The first Rogers lenses, 53 cm in diameter and 14 cm thick at
1946-414: A metal housing, a reflector, a lamp assembly, and a Fresnel lens. Many Fresnel instruments allow the lamp to be moved relative to the lens' focal point , to increase or decrease the size of the light beam. As a result, they are very flexible, and can often produce a beam as narrow as 7° or as wide as 70°. The Fresnel lens produces a very soft-edged beam, so is often used as a wash light. A holder in front of
2085-589: A political party does not mean that such members are unable to caucus with members of the political parties. Members can also switch parties at any time, although this is quite uncommon. Article One of the United States Constitution states, "All legislative Powers herein granted shall be vested in a Congress of the United States, which shall consist of a Senate and House of Representatives." The House and Senate are equal partners in
2224-859: A position. Perhaps the most widespread use of Fresnel lenses, for a time, occurred in automobile headlamps , where they can shape the roughly parallel beam from the parabolic reflector to meet requirements for dipped and main-beam patterns, often both in the same headlamp unit (such as the European H4 design). For reasons of economy, weight, and impact resistance, newer cars have dispensed with glass Fresnel lenses, using multifaceted reflectors with plain polycarbonate lenses. However, Fresnel lenses continue in wide use in automobile tail, marker, and reversing lights. Glass Fresnel lenses also are used in lighting instruments for theatre and motion pictures (see Fresnel lantern ); such instruments are often called simply Fresnels . The entire instrument consists of
2363-444: A powerful effect of waking up a somewhat dormant Congress which investigated presidential wrongdoing and coverups; the scandal "substantially reshaped" relations between the branches of government, suggested political scientist Bruce J. Schulman . Partisanship returned, particularly after 1994; one analyst attributes partisan infighting to slim congressional majorities which discouraged friendly social gatherings in meeting rooms such as
2502-524: A revised constitution with a two-chamber or bicameral Congress. Smaller states argued for equal representation for each state. The two-chamber structure had functioned well in state governments. A compromise plan, the Connecticut Compromise , was adopted with representatives chosen by population (benefiting larger states) and exactly two senators chosen by state governments (benefiting smaller states). The ratified constitution created
2641-486: A rotating array outside the fixed array. Each panel of the rotating array was to refract part of the fixed light from a horizontal fan into a narrow beam. Also in 1825, Fresnel unveiled the Carte des Phares ('lighthouse map'), calling for a system of 51 lighthouses plus smaller harbor lights, in a hierarchy of lens sizes called "orders" (the first being the largest), with different characteristics to facilitate recognition:
2780-634: A state's at-large representation to the federal government by senators. Most incumbents seek re-election, and their historical likelihood of winning subsequent elections exceeds 90 percent. The historical records of the House of Representatives and the Senate are maintained by the Center for Legislative Archives, which is a part of the National Archives and Records Administration . Congress
2919-557: A substantial reduction in thickness (and thus mass and volume of material) at the expense of reducing the imaging quality of the lens, which is why precise imaging applications such as photography usually still use larger conventional lenses. Fresnel lenses are usually made of glass or plastic; their size varies from large (old historical lighthouses, meter size) to medium (book-reading aids, OHP viewgraph projectors) to small ( TLR / SLR camera screens, micro-optics). In many cases they are very thin and flat, almost flexible, with thicknesses in
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#17327979493933058-608: A system similar to Condorcet's in 1811, and by 1820 was advocating its use in British lighthouses. The French Commission des Phares [ FR ] (Commission of Lighthouses) was established by Napoleon in 1811, and placed under the authority of French physicist Augustin-Jean Fresnel 's employer, the Corps of Bridges and Roads. As the members of the commission were otherwise occupied, it achieved little in its early years. However, on 21 June 1819—three months after winning
3197-513: A way to remove defects by reheating and remolding the glass. Arago assisted Fresnel with the design of a modified Argand lamp with concentric wicks (a concept that Fresnel attributed to Count Rumford ), and accidentally discovered that fish glue was heat-resistant, making it suitable for use in the lens. The prototype, finished in March 1820, had a square lens panel 55 cm on a side, containing 97 polygonal (not annular) prisms—and so impressed
3336-543: Is a type of composite compact lens which reduces the amount of material required compared to a conventional lens by dividing the lens into a set of concentric annular sections. The simpler dioptric (purely refractive ) form of the lens was first proposed by Georges-Louis Leclerc, Comte de Buffon , and independently reinvented by the French physicist Augustin-Jean Fresnel (1788–1827) for use in lighthouses . The catadioptric (combining refraction and reflection) form of
3475-766: Is an accepted version of this page Minority (49) Minority (212) Vacant (3) [REDACTED] [REDACTED] The United States Congress is the legislature of the federal government of the United States . It is bicameral , composed of a lower body, the United States House of Representatives , and an upper body, the United States Senate . It meets in the United States Capitol in Washington, D.C. Members are chosen through direct election , though vacancies in
3614-693: Is directly responsible for the governing of the District of Columbia , the current seat of the federal government. The First Continental Congress was a gathering of representatives from twelve of the Thirteen Colonies . On July 4, 1776, the Second Continental Congress adopted the Declaration of Independence , referring to the new nation as the "United States of America". The Articles of Confederation in 1781 created
3753-440: Is elected and gives each House the power to create its own structure. Section Seven lays out the process for creating laws, and Section Eight enumerates numerous powers. Section Nine is a list of powers Congress does not have, and Section Ten enumerates powers of the state, some of which may only be granted by Congress. Constitutional amendments have granted Congress additional powers. Congress also has implied powers derived from
3892-493: Is essentially charged with reconciling our many points of view on the great public policy issues of the day. Congress is constantly changing and is constantly in flux. In recent times, the American South and West have gained House seats according to demographic changes recorded by the census and includes more women and minorities . While power balances among the different parts of government continue to change,
4031-433: Is extraordinarily sensitive to public pressure. Several academics described Congress: Congress reflects us in all our strengths and all our weaknesses. It reflects our regional idiosyncrasies, our ethnic, religious, and racial diversity, our multitude of professions, and our shadings of opinion on everything from the value of war to the war over values. Congress is the government's most representative body ... Congress
4170-466: Is nothing to indicate their locality. The land is usually not visible from off these outer shoals. Located closer to the land are the Chester, Bull and Southeast shoals, which are about 4.5 to 7.5 nautical miles (8.3 to 13.9 km; 5.2 to 8.6 mi) off the coast of the cape. The current Cape Canaveral Light is not the first lighthouse constructed on Cape Canaveral . On May 21, 1838, the building of
4309-459: Is on. They attach to the passenger-side window. Another automobile application of a Fresnel lens is a rear view enhancer, as the wide view angle of a lens attached to the rear window permits examining the scene behind a vehicle, particularly a tall or bluff-tailed one, more effectively than a rear-view mirror alone. Fresnel lenses have been used on rangefinding equipment and projected map display screens. Fresnel lenses have also been used in
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4448-532: Is required before an impeached person can be removed from office. The term Congress can also refer to a particular meeting of the legislature. A Congress covers two years; the current one, the 118th Congress , began on January 3, 2023, and will end on January 3, 2025. Since the adoption of the Twentieth Amendment to the United States Constitution , the Congress has started and ended at noon on
4587-475: Is the double-flashing lens of the Point Arena Light , which was in service from 1908 to 1977. The development of hyper-radial lenses was driven in part by the need for larger light sources, such as gas lights with multiple jets, which required a longer focal length for a given beam-width, hence a larger lens to collect a given fraction of the generated light. The first hyper-radial lens was built for
4726-529: The tabloidization of media coverage. Others saw pressure to squeeze a political position into a thirty-second soundbite. A report characterized Congress in 2013 as unproductive, gridlocked, and "setting records for futility". In October 2013, with Congress unable to compromise, the government was shut down for several weeks and risked a serious default on debt payments, causing 60% of the public to say they would "fire every member of Congress" including their own representative. One report suggested Congress posed
4865-414: The École Polytechnique , in order to save his remaining time and energy for his lighthouse work. In the same year he designed the first fixed lens—for spreading light evenly around the horizon while minimizing waste above or below. Ideally the curved refracting surfaces would be segments of toroids about a common vertical axis, so that the dioptric panel would look like a cylindrical drum. If this
5004-478: The 1 to 5 mm ( 1 ⁄ 32 to 3 ⁄ 16 in) range. Most modern Fresnel lenses consist only of refractive elements. Lighthouse lenses, however, tend to include both refracting and reflecting elements, the latter being outside the metal rings seen in the photographs. While the inner elements are sections of refractive lenses, the outer elements are reflecting prisms, each of which performs two refractions and one total internal reflection , avoiding
5143-544: The Board of Education . Congress began reasserting its authority. Lobbying became a big factor despite the 1971 Federal Election Campaign Act . Political action committees or PACs could make substantive donations to congressional candidates via such means as soft money contributions. While soft money funds were not given to specific campaigns for candidates, the money often benefited candidates substantially in an indirect way and helped reelect candidates. Reforms such as
5282-541: The Commerce Clause , the enumerated power to regulate commerce, in rulings such as McCulloch v. Maryland , have effectively widened the scope of Congress's legislative authority far beyond that prescribed in Section Eight. Constitutional responsibility for the oversight of Washington, D.C. , the federal district and national capital, and the U.S. territories of Guam , American Samoa , Puerto Rico ,
5421-650: The Congress of the Confederation in its legislative function. Although not legally mandated, in practice since the 19th century, members of Congress are typically affiliated with one of the two major parties , the Democratic Party or the Republican Party , and only rarely with a third party or independents affiliated with no party. In the case of the latter, the lack of affiliation with
5560-469: The Congress of the Confederation , a unicameral body with equal representation among the states in which each state had a veto over most decisions. Congress had executive but not legislative authority, and the federal judiciary was confined to admiralty and lacked authority to collect taxes, regulate commerce, or enforce laws. Government powerlessness led to the Convention of 1787 which proposed
5699-609: The Conservative Coalition . Democrats maintained control of Congress during World War II . Congress struggled with efficiency in the postwar era partly by reducing the number of standing congressional committees. Southern Democrats became a powerful force in many influential committees although political power alternated between Republicans and Democrats during these years. More complex issues required greater specialization and expertise, such as space flight and atomic energy policy. Senator Joseph McCarthy exploited
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5838-513: The Isle of May , Scotland, on 22 September 1836. The first large catadioptric lenses were made in 1842 for the lighthouses at Gravelines and Île Vierge , France; these were fixed third-order lenses whose catadioptric rings (made in segments) were one metre in diameter. Stevenson's first-order Skerryvore lens, lit in 1844, was only partly catadioptric; it was similar to the Cordouan lens except that
5977-560: The Meta Quest Pro , have switched to a pancake lens design due to its smaller form factor and less chromatic aberration than Fresnel lenses. Multi-focal Fresnel lenses are also used as a part of retina identification cameras, where they provide multiple in- and out-of-focus images of a fixation target inside the camera. For virtually all users, at least one of the images will be in focus, thus allowing correct eye alignment. Canon and Nikon have used Fresnel lenses to reduce
6116-523: The Northern Mariana Islands . These six members of Congress enjoy floor privileges to introduce bills and resolutions, and in recent Congresses they vote in permanent and select committees, in party caucuses and in joint conferences with the Senate. They have Capitol Hill offices, staff and two annual appointments to each of the four military academies. While their votes are constitutional when Congress authorizes their House Committee of
6255-514: The Sinclair TV80 . They are also used in traffic lights . Fresnel lenses are used in left-hand-drive European lorries entering the UK and Republic of Ireland (and vice versa, right-hand-drive Irish and British trucks entering mainland Europe) to overcome the blind spots caused by the driver operating the lorry while sitting on the wrong side of the cab relative to the side of the road the car
6394-408: The U.S. census results, provided that each state has at least one congressional representative. Each senator is elected at-large in their state for a six-year term, with terms staggered , so every two years approximately one-third of the Senate is up for election. Each state, regardless of population or size, has two senators, so currently, there are 100 senators for the 50 states. Article One of
6533-449: The second-wave feminism movement , when activists moved into electoral politics. Beginning in the 1970s, donors and political action committees like EMILY's List began recruiting, training and funding women candidates. Watershed political moments like the confirmation of Clarence Thomas and the 2016 presidential election created momentum for women candidates, resulting in the Year of
6672-488: The transverse wave hypothesis. Shortly after the Cordouan lens was lit, Fresnel started coughing up blood. In May 1824, Fresnel was promoted to Secretary of the Commission des Phares , becoming the first member of that body to draw a salary, albeit in the concurrent role of Engineer-in-Chief. Late that year, being increasingly ill, he curtailed his fundamental research and resigned his seasonal job as an examiner at
6811-429: The "biggest risk to the U.S. economy" because of its brinksmanship , "down-to-the-wire budget and debt crises" and "indiscriminate spending cuts", resulting in slowed economic activity and keeping up to two million people unemployed. There has been increasing public dissatisfaction with Congress, with extremely low approval ratings which dropped to 5% in October 2013. In 2009, Congress authorized another delegate for
6950-439: The 1960s opened the possibility for Black, Asian American, Latina and other non-white women candidates to run for Congress. Racially polarized voting, racial stereotypes and lack of institutional support still prevent women of color from reaching Congress as easily as white people . Senate elections, which require victories in statewide electorates, have been particularly difficult for women of color. Carol Moseley Braun became
7089-790: The 2002 Bipartisan Campaign Reform Act limited campaign donations but did not limit soft money contributions. One source suggests post-Watergate laws amended in 1974 meant to reduce the "influence of wealthy contributors and end payoffs" instead "legitimized PACs" since they "enabled individuals to band together in support of candidates". From 1974 to 1984, PACs grew from 608 to 3,803 and donations leaped from $ 12.5 million to $ 120 million along with concern over PAC influence in Congress. In 2009, there were 4,600 business, labor and special-interest PACs including ones for lawyers , electricians , and real estate brokers . From 2007 to 2008, 175 members of Congress received "half or more of their campaign cash" from PACs. From 1970 to 2009,
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#17327979493937228-574: The American response as a "police action". According to Time magazine in 1970, "U.S. presidents [had] ordered troops into position or action without a formal congressional declaration a total of 149 times." In 1993, Michael Kinsley wrote that "Congress's war power has become the most flagrantly disregarded provision in the Constitution," and that the "real erosion [of Congress's war power] began after World War II." Disagreement about
7367-576: The Commission that Fresnel was asked for a full eight-panel version. This model, completed a year later in spite of insufficient funding, had panels 76 cm square. In a public spectacle on the evening of 13 April 1821, it was demonstrated by comparison with the most recent reflectors, which it suddenly rendered obsolete. Soon after this demonstration, Fresnel published the idea that light, including apparently unpolarized light, consists exclusively of transverse waves , and went on to consider
7506-462: The Constitution's Necessary and Proper Clause . Congress has authority over financial and budgetary policy through the enumerated power to "lay and collect Taxes, Duties, Imposts and Excises, to pay the Debts and provide for the common Defence and general Welfare of the United States". There is vast authority over budgets, although analyst Eric Patashnik suggested that much of Congress's power to manage
7645-604: The Government of the United States, or in any Department or Officer thereof". Article Four gives Congress the power to admit new states into the Union. One of Congress's foremost non-legislative functions is the power to investigate and oversee the executive branch. Congressional oversight is usually delegated to committees and is facilitated by Congress's subpoena power. Some critics have charged that Congress has in some instances failed to do an adequate job of overseeing
7784-546: The House expanded delegates, along with their powers and privileges representing U.S. citizens in non-state areas, beginning with representation on committees for Puerto Rico's resident commissioner in 1970. In 1971, a delegate for the District of Columbia was authorized, and in 1972 new delegate positions were established for U.S. Virgin Islands and Guam . In 1978, an additional delegate for American Samoa were added. In
7923-510: The House of Representatives are elected for the two-year term of a Congress. The Reapportionment Act of 1929 established that there be 435 representatives, and the Uniform Congressional Redistricting Act requires that they be elected from single-member constituencies or districts . It is also required that the congressional districts be apportioned among states by population every ten years using
8062-477: The House of Representatives have equal legislative authority, although only the House may originate revenue and appropriation bills . Congress has an important role in national defense , including the exclusive power to declare war, to raise and maintain the armed forces , and to make rules for the military. Some critics charge that the executive branch has usurped Congress's constitutionally defined task of declaring war. While historically presidents initiated
8201-625: The Jeffersonian Republican Party and began the era of the First Party System . In 1800, Thomas Jefferson 's election to the presidency marked a peaceful transition of power between the parties. John Marshall , 4th chief justice of the Supreme Court , empowered the courts by establishing the principle of judicial review in law in the landmark case Marbury v. Madison in 1803, effectively giving
8340-464: The Rogers mirror of 60 years earlier, except that it subtended a whole hemisphere). Light radiated into the forward hemisphere but missing the bull's-eye lens was deflected by the paraboloid into a parallel beam surrounding the bull's-eye lens, while light radiated into the backward hemisphere was reflected back through the lamp by the spherical reflector (as in Rogers' arrangement), to be collected by
8479-464: The Senate may be filled by a governor 's appointment. Congress has 535 voting members: 100 senators and 435 representatives. The vice president of the United States , as President of the Senate, has a vote in the Senate only when there is a tie. The House of Representatives has six non-voting members . Congress convenes for a two-year term , commencing every other January. Elections are held every even-numbered year on Election Day . The members of
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#17327979493938618-467: The Stevensons in 1885 by F. Barbier & Cie of France, and tested at South Foreland Lighthouse with various light sources. Chance Brothers (Hopkinson's employers) then began constructing hyper-radials, installing their first at Bishop Rock Lighthouse in 1887. In the same year, Barbier installed a hyper-radial at Tory Island . But only about 30 hyper-radials went into service before
8757-635: The Supreme Court a power to nullify congressional legislation. The Civil War , which lasted from 1861 to 1865, which resolved the slavery issue and unified the nation under federal authority but weakened the power of states' rights . The Gilded Age (1877–1901) was marked by Republican dominance of Congress. During this time, lobbying activity became more intense, particularly during the administration of President Ulysses S. Grant in which influential lobbies advocated for railroad subsidies and tariffs on wool. Immigration and high birth rates swelled
8896-449: The U.S. Constitution requires that members of Congress be at least 25 years old for the House and at least 30 years old for the U.S. Senate, be a U.S. citizen for seven years for the House and nine years for the Senate, and be an inhabitant of the state which they represent. Members in both chambers may stand for re-election an unlimited number of times. The Congress was created by the U.S. Constitution and first met in 1789, replacing
9035-409: The United States by the 1870s. In 1858 the company produced "a very small number of pressed flint-glass sixth-order lenses" for use in lighthouses—the first Fresnel lighthouse lenses made in America. By the 1950s, the substitution of plastic for glass made it economic to use Fresnel lenses as condensers in overhead projectors. The Fresnel lens reduces the amount of material required compared to
9174-554: The White House a little more in favor of the executive branch", according to one account. Past presidents, including Ronald Reagan , George H. W. Bush , Bill Clinton , and George W. Bush , have made public statements when signing congressional legislation about how they understand a bill or plan to execute it, and commentators, including the American Bar Association , have described this practice as against
9313-504: The Whole votes, recent Congresses have not allowed for that, and they cannot vote when the House is meeting as the House of Representatives. On January 6, 2021, the Congress gathered to confirm the election of Joe Biden, when supporters of the outgoing president Donald Trump attacked the building . The session of Congress ended prematurely, and Congress representatives evacuated. Trump supporters occupied Congress until D.C police evacuated
9452-552: The Woman and the election of members of The Squad , respectively. Women of color faced additional challenges that made their ascension to Congress even more difficult. Jim Crow laws , voter suppression and other forms of structural racism made it virtually impossible for women of color to reach Congress prior to 1965. The passage of the Voting Rights Act that year , and the elimination of race-based immigration laws in
9591-557: The actors and the camera, distorting the scale and composition of the scene to humorous effect. The Pixar movie Wall-E features a Fresnel lens in the scenes where the protagonist watches the musical Hello, Dolly! magnified on an iPod . Virtual reality headsets, such as the Meta Quest 2 and the HTC Vive Pro use Fresnel lenses, as they allow a thinner and lighter form factor than regular lenses. Newer devices, such as
9730-607: The area. The event was the first time since the Burning of Washington by the British during the War of 1812 that the United States Congress was forcefully occupied. Various social and structural barriers have prevented women from gaining seats in Congress. In the early 20th century, women's domestic roles and the inability to vote forestalled opportunities to run for and hold public office. The two party system and
9869-417: The budget has been lost when the welfare state expanded since "entitlements were institutionally detached from Congress's ordinary legislative routine and rhythm." Another factor leading to less control over the budget was a Keynesian belief that balanced budgets were unnecessary. The Sixteenth Amendment in 1913 extended congressional power of taxation to include income taxes without apportionment among
10008-510: The center, were installed at the Old Lower Lighthouse at Portland Bill in 1789. Behind each lamp was a back-coated spherical glass mirror, which reflected rear radiation back through the lamp and into the lens. Further samples were installed at Howth Baily , North Foreland , and at least four other locations by 1804. But much of the light was wasted by absorption in the glass. In 1748, Georges-Louis Leclerc, Comte de Buffon
10147-405: The center. The result was an all-glass holophote, with no losses from metallic reflections. James Timmins Chance modified Thomas Stevenson's all-glass holophotal design by arranging the double-reflecting prisms about a vertical axis. The prototype was shown at the 1862 International Exhibition in London. Later, to ease manufacturing, Chance divided the prisms into segments, and arranged them in
10286-512: The completion of Augustin Fresnel's original Carte des Phares . Thomas Stevenson (younger brother of Alan) went a step beyond Fresnel with his "holophotal" lens, which focused the light radiated by the lamp in nearly all directions, forward or backward, into a single beam. The first version, described in 1849, consisted of a standard Fresnel bull's-eye lens, a paraboloidal reflector, and a rear hemispherical reflector (functionally equivalent to
10425-631: The curved surfaces are replaced with flat surfaces, with a different angle in each section. Such a lens can be regarded as an array of prisms arranged in a circular fashion with steeper prisms on the edges and a flat or slightly convex center. In the first (and largest) Fresnel lenses, each section was actually a separate prism. 'Single-piece' Fresnel lenses were later produced, being used for automobile headlamps, brake, parking, and turn signal lenses, and so on. In modern times, computer-controlled milling equipment (CNC) or 3-D printers might be used to manufacture more complex lenses. Fresnel lens design allows
10564-549: The development of more compact bright lamps rendered such large optics unnecessary (see Hyperradiant Fresnel lens ). Production of one-piece stepped dioptric lenses—roughly as envisaged by Buffon—became feasible in 1852, when John L. Gilliland of the Brooklyn Flint-Glass Company patented a method of making lenses from pressed and molded glass. The company made small bull's-eye lenses for use on railroads, steamboats, and docks; such lenses were common in
10703-612: The early years as political parties became pronounced. With the passage of the Constitution and the Bill of Rights , the anti-federalist movement was exhausted. Some activists joined the Anti-Administration Party that James Madison and Thomas Jefferson were forming about 1790–1791 to oppose policies of Treasury Secretary Alexander Hamilton ; it soon became the Democratic-Republican Party or
10842-487: The electorate. Lame duck reforms according to the Twentieth Amendment reduced the power of defeated and retiring members of Congress to wield influence despite their lack of accountability. The Great Depression ushered in President Franklin Roosevelt and strong control by Democrats and historic New Deal policies. Roosevelt 's election in 1932 marked a shift in government power towards
10981-475: The exact date on which Fresnel formally recommended lentilles à échelons is unknown. Much to Fresnel's embarrassment, one of the assembled commissioners, Jacques Charles , recalled Buffon's suggestion. However, whereas Buffon's version was biconvex and in one piece, Fresnel's was plano-convex and made of multiple prisms for easier construction. With an official budget of 500 francs, Fresnel approached three manufacturers. The third, François Soleil, found
11120-425: The exclusive power of removal , allowing impeachment and removal of the president, federal judges and other federal officers. There have been charges that presidents acting under the doctrine of the unitary executive have assumed important legislative and budgetary powers that should belong to Congress. So-called signing statements are one way in which a president can "tip the balance of power between Congress and
11259-595: The executive branch. Numerous New Deal initiatives came from the White House rather initiated by Congress. President Roosevelt pushed his agenda in Congress by detailing Executive Branch staff to friendly Senate committees (a practice that ended with the Legislative Reorganization Act of 1946). The Democratic Party controlled both houses of Congress for many years. During this time, Republicans and conservative southern Democrats formed
11398-463: The extent of congressional versus presidential power regarding war has been present periodically throughout the nation's history. Congress can establish post offices and post roads, issue patents and copyrights , fix standards of weights and measures, establish Courts inferior to the Supreme Court , and "make all Laws which shall be necessary and proper for carrying into Execution the foregoing Powers, and all other Powers vested by this Constitution in
11537-564: The fear of communism during the Second Red Scare and conducted televised hearings. In 1960, Democratic candidate John F. Kennedy narrowly won the presidency and power shifted again to the Democrats who dominated both chambers of Congress from 1961 to 1980, and retained a consistent majority in the House from 1955 to 1994. Congress enacted Johnson's Great Society program to fight poverty and hunger. The Watergate Scandal had
11676-572: The field of popular entertainment. The British rock artist Peter Gabriel made use of them in his early solo live performances to magnify the size of his head, in contrast to the rest of his body, for dramatic and comic effect. In the Terry Gilliam film Brazil , plastic Fresnel screens appear ostensibly as magnifiers for the small CRT monitors used throughout the offices of the Ministry of Information. However, they occasionally appear between
11815-704: The fifth floor of the lighthouse as the remaining floors have been deemed as a safety liability by the Space Force and require special access to ascend. The Cape Canaveral Lighthouse Foundation and volunteers are instrumental in the restoration projects and in interpreting the lighthouse history. Future plans of the foundation includes the restoration of the three keeper's cottages for multipurpose use. Fresnel lens A Fresnel lens ( / ˈ f r eɪ n ɛ l , - n əl / FRAY -nel, -nəl ; / ˈ f r ɛ n ɛ l , - əl / FREN -el, -əl ; or / f r eɪ ˈ n ɛ l / fray- NEL )
11954-472: The first lighthouse at the cape was requested by Florida territorial delegate Charles Downing . Nathaniel Scobie was appointed as the first lighthouse keeper and oversaw the construction of the lighthouse. The 65-foot (20 m) tall white conical brick tower and keeper's dwelling were completed in January 1848 at the cost of $ 13,300. Its light consisted of 15 Lewis lamps powered by whale oil , each with
12093-412: The first woman of color to reach the Senate in 1993. The second, Mazie Hirono , won in 2013. In 2021, Kamala Harris became the first female President of the Senate , which came with her role as the first female Vice President of the United States . Article One of the Constitution creates and sets forth the structure and most of the powers of Congress. Sections One through Six describe how Congress
12232-525: The flood. The white lighthouse tower was changed to its signature three black bands and three white bands in 1873, with the lantern room remaining white. Soon after, the iron tower became unbearable to the keepers under the Florida sun and humidity. They built and stayed in makeshift dwellings on the grounds of the lighthouse rather than stay in the oven-like tower. In 1876, funds in the amount of $ 12,000 were appropriated to construct permanent dwellings for
12371-478: The forward components. The first unit was installed at North Harbour, Peterhead , in August 1849. Stevenson called this version a "catadioptric holophote", although each of its elements was either purely reflective or purely refractive. In the second version of the holophote concept, the bull's-eye lens and paraboloidal reflector were replaced by a catadioptric Fresnel lens—as conceived by Fresnel, but expanded to cover
12510-462: The image projected by a lens onto the ground glass, thus aiding in adjusting focus and composition. The use of Fresnel lenses for image projection reduces image quality, so they tend to occur only where quality is not critical or where the bulk of a solid lens would be prohibitive. Cheap Fresnel lenses can be stamped or molded of transparent plastic and are used in overhead projectors and projection televisions . United States Congress This
12649-433: The implications for double refraction and partial reflection. Fresnel acknowledged the British lenses and Buffon's invention in a memoir read on 29 July 1822 and printed in the same year. The date of that memoir may be the source of the claim that Fresnel's lighthouse advocacy began two years later than Brewster's; but the text makes it clear that Fresnel's involvement began no later than 1819. Fresnel's next lens
12788-402: The internal structure of Congress is important to understand along with its interactions with so-called intermediary institutions such as political parties , civic associations , interest groups , and the mass media . The Congress of the United States serves two distinct purposes that overlap: local representation to the federal government of a congressional district by representatives and
12927-482: The keepers' houses. The move took nine months, and the lighthouse was relit at its new location on July 25, 1894. The 1900 Atlantic List of Lights indicated the color of the lantern room, which was probably painted during the move, as black. William H. Peck wrote about his meeting with lighthouse keeper Mills Burnham of Cape Canaveral in the Florida Star newspaper in 1887. In 1931, the mechanical clockwork of
13066-488: The keepers. By the 1880s, shoreline erosion was feared to be threatening the lighthouse, and the United States Congress appropriated funds to move the lighthouse inland. Initial work to move the tower was started in October 1893. A temporary 55-foot (17 m) square black skeletal pyramidal lighthouse was erected to keep that section of the sea lit during the move. The tower had a 4th-order lamp with
13205-486: The lack of term limits favored incumbent white men, making the widow's succession – in which a woman temporarily took over a seat vacated by the death of her husband – the most common path to Congress for white women. Women candidates began making substantial inroads in the later 20th century, due in part to new political support mechanisms and public awareness of their underrepresentation in Congress. Recruitment and financial support for women candidates were rare until
13344-430: The late 20th century, the media became more important in Congress's work. Analyst Michael Schudson suggested that greater publicity undermined the power of political parties and caused "more roads to open up in Congress for individual representatives to influence decisions". Norman Ornstein suggested that media prominence led to a greater emphasis on the negative and sensational side of Congress, and referred to this as
13483-488: The law. Generally militia forces are controlled by state governments, not Congress. Congress also has implied powers deriving from the Constitution's Necessary and Proper Clause which permit Congress to "make all laws which shall be necessary and proper for carrying into Execution the foregoing Powers, and all other Powers vested by this Constitution in the Government of the United States, or in any Department or Officer thereof". Broad interpretations of this clause and of
13622-408: The legislative process – legislation cannot be enacted without the consent of both chambers. The Constitution grants each chamber some unique powers. The Senate ratifies treaties and approves presidential appointments while the House initiates revenue -raising bills. The House initiates impeachment cases, while the Senate decides impeachment cases. A two-thirds vote of the Senate
13761-441: The legislature since there were two separate chambers. The new government became active in 1789. Political scientist Julian E. Zelizer suggested there were four main congressional eras, with considerable overlap, and included the formative era (1780s–1820s), the partisan era (1830s–1900s), the committee era (1910s–1960s), and the contemporary era (1970–present). Federalists and anti-federalists jostled for power in
13900-502: The lens can hold a colored plastic film ( gel ) to tint the light or wire screens or frosted plastic to diffuse it. The Fresnel lens is useful in the making of motion pictures not only because of its ability to focus the beam brighter than a typical lens, but also because the light is a relatively consistent intensity across the entire width of the beam of light. Aircraft carriers and naval air stations typically use Fresnel lenses in their optical landing systems . The "meatball" light aids
14039-403: The lens, entirely invented by Fresnel, has outer prismatic elements that use total internal reflection as well as refraction to capture more oblique light from the light source and add it to the beam, making it visible at greater distances. The design allows the construction of lenses of large aperture and short focal length without the mass and volume of material that would be required by
14178-468: The light loss that occurs in reflection from a silvered mirror. Fresnel designed six sizes of lighthouse lenses, divided into four orders based on their size and focal length. The 3rd and 4th orders were sub-divided into "large" and "small". In modern use, the orders are classified as first through sixth order. An intermediate size between third and fourth order was added later, as well as sizes above first order and below sixth. A first-order lens has
14317-460: The light source. The light path through these elements can include an internal reflection , rather than the simple refraction in the planar Fresnel element. These lenses conferred many practical benefits upon the designers, builders, and users of lighthouses and their illumination. Among other things, smaller lenses could fit into more compact spaces. Greater light transmission over longer distances, and varied patterns, made it possible to triangulate
14456-461: The light. The keeper's homes were later demolished leaving only the brick oil house in the vicinity of the lighthouse. After it was discovered that strong vibrations that accompany launches were loosening the prisms of the first-order Fresnel lens, it was finally removed in 1993 and sent to the lighthouse museum of the Ponce de Leon Inlet Light for restoration and display. The light was replaced by
14595-556: The lighthouse for some time. The lighthouse is open to public visitors and previously was a part of the Air Force Space and Missile Museum public tour. However, as of 2013 due to sequestration the Space Launch Delta 45 no longer offers a tour of the area. Currently, those seeking to visit the lighthouse, and nearby museum should book touring by the Cape Canaveral Lighthouse Foundation. Visitors may only ascend to
14734-467: The lighthouse terminating in the Hetzel and Ohio shoals, which have a depth of 11 ft (3.4 m) and 19 ft (5.8 m) respectively. Hetzel Shoal is located about 13.5 nautical miles (25.0 km; 15.5 mi) NE of the lighthouse and Ohio Shoals about 2.3 nautical miles (4.3 km; 2.6 mi) southward of Hetzel. In a heavy sea these shoals are marked by breakers, but with smooth sea there
14873-452: The lighthouse: De Soto Beach to its north, which was located in the vicinity of Launch Complex 36 and Stinkmore to the south, located near Launch Complexes 17 and 5 . When rockets began launching from the Cape in the early 1950s, all its residents, except the lighthouse keepers, were relocated to other areas. In 1960, the need for a keeper to live nearby was eliminated with the automation of
15012-555: The lower slats were replaced by French-made catadioptric prisms, while mirrors were retained at the top. The first fully catadioptric first-order lens, installed at Pointe d'Ailly in 1852, also gave eight rotating beams plus a fixed light at the bottom; but its top section had eight catadioptric panels focusing the light about 4 degrees ahead of the main beams, in order to lengthen the flashes. The first fully catadioptric lens with purely revolving beams—also of first order—was installed at Saint-Clément-des-Baleines in 1854, and marked
15151-402: The main beam, increasing the duration of the flash. Below the main panels were 128 small mirrors arranged in four rings, stacked like the slats of a louver or Venetian blind . Each ring, shaped like a frustum of a cone , reflected the light to the horizon, giving a fainter steady light between the flashes. The official test, conducted on the unfinished Arc de Triomphe on 20 August 1822,
15290-428: The middle of the 20th centuries; most lighthouses have now retired glass Fresnel lenses from service and replaced them with much less expensive and more durable aerobeacons , which themselves often contain plastic Fresnel lenses. Lighthouse Fresnel lens systems typically include extra annular prismatic elements, arrayed in faceted domes above and below the central planar Fresnel, in order to catch all light emitted from
15429-476: The need for filters by inventing the "group-flashing" lens, in which the dioptric and/or the catadioptric panels were split so as to give multiple flashes—allowing lighthouses to be identified not only by frequency of flashes, but also by multiplicity of flashes. Double-flashing lenses were installed at Tampico (Mexico) and Little Basses (Sri Lanka) in 1875, and a triple-flashing lens at Casquets Lighthouse ( Channel Islands ) in 1876. The example shown (right)
15568-423: The number of segments increases, the two types of lens become more similar to each other. In the abstract case of an infinite number of segments, the difference between curved and flat segments disappears. Imaging lenses can be classified as: Non-imaging lenses can be classified as: High-quality glass Fresnel lenses were used in lighthouses, where they were considered state of the art in the late 19th and through
15707-584: The other branches of government. In the Plame affair , critics including Representative Henry A. Waxman charged that Congress was not doing an adequate job of oversight in this case. There have been concerns about congressional oversight of executive actions such as warrantless wiretapping , although others respond that Congress did investigate the legality of presidential decisions. Political scientists Ornstein and Mann suggested that oversight functions do not help members of Congress win reelection. Congress also has
15846-634: The physics Grand Prix of the Academy of Sciences for his celebrated memoir on diffraction —Fresnel was "temporarily" seconded to the commission on the recommendation of François Arago (a member since 1813), to review possible improvements in lighthouse illumination. By the end of August 1819, unaware of the Buffon-Condorcet-Brewster proposal, Fresnel made his first presentation to the commission, recommending what he called lentilles à échelons ('lenses by steps') to replace
15985-412: The pilot in maintaining proper glide slope for the landing. In the center are amber and red lights composed of Fresnel lenses. Although the lights are always on, the angle of the lens from the pilot's point of view determines the color and position of the visible light. If the lights appear above the green horizontal bar, the pilot is too high. If it is below, the pilot is too low, and if the lights are red,
16124-399: The pilot is very low. Fresnel lenses are also commonly used in searchlights , spotlights , and flashlights . Fresnel lenses are used as simple hand-held magnifiers . They are also used to correct several visual disorders, including ocular-motility disorders such as strabismus . Fresnel lenses have been used to increase the visual size of CRT displays in pocket televisions , notably
16263-597: The process for going to war, they asked for and received formal war declarations from Congress for the War of 1812 , the Mexican–American War , the Spanish–American War , World War I , and World War II , although President Theodore Roosevelt 's military move into Panama in 1903 did not get congressional approval. In the early days after the North Korean invasion of 1950 , President Truman described
16402-703: The ranks of citizens and the nation grew at a rapid pace. The Progressive Era was characterized by strong party leadership in both houses of Congress and calls for reform; sometimes reformers said lobbyists corrupted politics. The position of Speaker of the House became extremely powerful under leaders such as Thomas Reed in 1890 and Joseph Gurney Cannon . By the beginning of the 20th century, party structures and leadership emerged as key organizers of Senate proceedings. A system of seniority, in which long-time members of Congress gained more and more power, encouraged politicians of both parties to seek long terms. Committee chairmen remained influential in both houses until
16541-431: The reflectors then in use, which reflected only about half of the incident light. Another report by Fresnel, dated 29 August 1819 (Fresnel, 1866–70, vol. 3, pp. 15–21), concerns tests on reflectors, and does not mention stepped lenses except in an unrelated sketch on the last page of the manuscript. The minutes of the meetings of the Commission go back only to 1824, when Fresnel himself took over as Secretary. Thus
16680-504: The reforms of the 1970s. Important structural changes included the direct popular election of senators according to the Seventeenth Amendment , ratified on April 8, 1913. Supreme Court decisions based on the Constitution's commerce clause expanded congressional power to regulate the economy. One effect of popular election of senators was to reduce the difference between the House and Senate in terms of their link to
16819-413: The several States, and without regard to any census or enumeration. The Constitution also grants Congress the exclusive power to appropriate funds, and this power of the purse is one of Congress's primary checks on the executive branch. Congress can borrow money on the credit of the United States, regulate commerce with foreign nations and among the states, and coin money. Generally, the Senate and
16958-415: The size of telephoto lenses. Photographic lenses that include Fresnel elements can be much shorter than corresponding conventional lens design. Nikon calls the technology Phase Fresnel . The Polaroid SX-70 camera used a Fresnel reflector as part of its viewing system. View and large format cameras can utilize a Fresnel lens in conjunction with the ground glass , to increase the perceived brightness of
17097-736: The spirit of the Constitution. There have been concerns that presidential authority to cope with financial crises is eclipsing the power of Congress. In 2008, George F. Will called the Capitol building a "tomb for the antiquated idea that the legislative branch matters". The Constitution enumerates the powers of Congress in detail. In addition, other congressional powers have been granted, or confirmed, by constitutional amendments. The Thirteenth (1865), Fourteenth (1868), and Fifteenth Amendments (1870) gave Congress authority to enact legislation to enforce rights of African Americans, including voting rights , due process , and equal protection under
17236-578: The station: Since toxic lead paint was used to paint the lighthouse, a restoration project from 1995 to 1996 sandblasted the harmful paint off. The original copper lantern was also replaced with a galvanized steel lantern and was made into a lighthouse gazebo at the grounds of the Air Force Space and Missile Museum at Launch Complex 26 inside the Cape Canaveral Space Force Station . A plaque mounted on
17375-413: The structure was repainted using modern materials. The original copper lantern was repaired and restored to the lighthouse. The displaced galvanized steel lantern took its place at the lighthouse gazebo leaving just the original copper vent ball on its top. Ground sample tests taken in 2008 showed a very high level of lead in the soil around the tower, and visitors were kept 50 yards (46 m) away from
17514-696: The test of the Cordouan lens in Paris, a committee of the Academy of Sciences reported on Fresnel's memoir and supplements on double refraction—which, although less well known to modern readers than his earlier work on diffraction, struck a more decisive blow for the wave theory of light. Between the test and the reassembly at Cordouan, Fresnel submitted his papers on photoelasticity (16 September 1822), elliptical and circular polarization and optical rotation (9 December), and partial reflection and total internal reflection (7 January 1823), essentially completing his reconstruction of physical optics on
17653-401: The third day of January of every odd-numbered year. Members of the Senate are referred to as senators; members of the House of Representatives are referred to as representatives, congressmen, or congresswomen. Scholar and representative Lee H. Hamilton asserted that the "historic mission of Congress has been to maintain freedom" and insisted it was a "driving force in American government" and
17792-534: The third surface. The result was the lighthouse lens as we now know it. In 1826 he assembled a small model for use on the Canal Saint-Martin , but he did not live to see a full-sized version: he died on 14 July 1827, at the age of 39. The first stage of the development of lighthouse lenses after the death of Augustin Fresnel consisted in the implementation of his designs. This was driven in part by his younger brother Léonor—who, like Augustin,
17931-443: The tower by Burnham and buried in his orange grove to protect them from Federal raids. At the end of the war, construction resumed on the lighthouse. The chosen replacement tower was made with cast iron plate designed so that it can be disassembled and moved to a new location at a minimal cost, in case the encroaching sea started threatening the lighthouse. The conical tower was lined inside by bricks for stability and insulation. It
18070-592: The tower that was turned by descending weights and needed winding every hour or two was modernized and replaced by an electric motor. President Harry S. Truman signed the legislation titled Public Law 60 on May 11, 1949, that established Cape Canaveral as the Joint Long Range Proving Ground, a site for missile testing by the military. By this time, several small communities had developed in Cape Canaveral , two of which lies near
18209-410: The whole forward hemisphere. The third version, which Stevenson confusingly called a "dioptric holophote", was more innovative: it retained the catadioptric Fresnel lens for the front hemisphere, but replaced the rear hemispherical reflector with a hemispherical array of annular prisms, each of which used two total internal reflections to turn light diverging from the center of the hemisphere back toward
18348-407: Was a rotating apparatus with eight "bull's-eye" panels, made in annular arcs by Saint-Gobain , giving eight rotating beams—to be seen by mariners as a periodic flash. Above and behind each main panel was a smaller, sloping bull's-eye panel of trapezoidal outline with trapezoidal elements. This refracted the light to a sloping plane mirror, which then reflected it horizontally, 7 degrees ahead of
18487-593: Was decided to build and outfit the Makapuu Point Light in Hawaii. Rather than order a new lens, the huge optic construction, 3.7 metres (12 ft) tall and with over a thousand prisms, was used there. There are two main types of Fresnel lens: imaging and non-imaging . Imaging Fresnel lenses use segments with curved cross-sections and produce sharp images, while non-imaging lenses have segments with flat cross-sections, and do not produce sharp images. As
18626-400: Was designed to withstand flooding from storm surges that accompany strong hurricanes by making the entrance to the tower on the third floor, accessible by an outdoor stairway (the ground level door was later added in the 1930s). This was tested in 1871 when a strong storm submerged the station. The lighthouse and its keepers survived but the lamp oil and their drinking water were spoiled by
18765-440: Was situated about 80 to 90 feet (24 to 27 m) from the location of the first tower. The new all-white lighthouse tower was completed in 1868, receiving a first-order Fresnel lens made by Henry-Lepaute and Company of Paris , France that was first lit on May 10, 1868. The lower three levels of the tower served as the living quarters for the keepers and his assistants complete with kitchen, living room and bedrooms. The tower
18904-447: Was supplemented by reflecting ( catoptric ) rings above and below the refracting (dioptric) parts, the entire apparatus would look like a beehive. The second Fresnel lens to enter service was indeed a fixed lens, of third order, installed at Dunkirk by 1 February 1825. However, due to the difficulty of fabricating large toroidal prisms, this apparatus had a 16-sided polygonal plan. In 1825 Fresnel extended his fixed-lens design by adding
19043-578: Was the first to replace a convex lens with a series of concentric annular prisms, ground as steps in a single piece of glass, to reduce weight and absorption. In 1790 (although secondary sources give the date as 1773 or 1788 ), the Marquis de Condorcet suggested that it would be easier to make the annular sections separately and assemble them on a frame; but even that was impractical at the time. These designs were intended not for lighthouses, but for burning glasses . David Brewster , however, proposed
19182-595: Was trained as a civil engineer but, unlike Augustin, had a strong aptitude for management. Léonor entered the service of the Lighthouse Commission in 1825, and went on to succeed Augustin as Secretary. The first fixed lens to be constructed with toroidal prisms was a first-order apparatus designed by the Scottish engineer Alan Stevenson under the guidance of Léonor Fresnel, and fabricated by Isaac Cookson & Co. using French glass; it entered service at
19321-511: Was witnessed by the Commission—and by Louis XVIII and his entourage—from 32 kilometres (20 mi) away. The apparatus was stored at Bordeaux for the winter, and then reassembled at Cordouan Lighthouse under Fresnel's supervision—in part by Fresnel's own hands. On 25 July 1823, the world's first lighthouse Fresnel lens was lit. As expected, the light was visible to the horizon, more than 32 kilometres (20 mi) out. The day before
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