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Hoover Dam

Hoover Dam is a concrete arch-gravity dam in the Black Canyon of the Colorado River, on the border between the U.S. states of Nevada and Arizona. Constructed between 1931 and 1936, during the Great Depression, it was dedicated on September 30, 1935, by President Franklin D. Roosevelt. Its construction was the result of a massive effort involving thousands of workers, and cost over 100 lives. In bills passed by Congress during its construction, it was referred to as the Hoover Dam, after President Herbert Hoover, but was named the Boulder Dam by the Roosevelt administration. In 1947, the name Hoover Dam was restored by Congress.

Since about 1900, the Black Canyon and nearby Boulder Canyon had been investigated for their potential to support a dam that would control floods, provide irrigation water, and produce hydroelectric power. In 1928, Congress authorized the project. The winning bid to build the dam was submitted by a consortium named Six Companies, Inc., which began construction in early 1931. Such a large concrete structure had never been built before, and some of the techniques used were unproven. The torrid summer weather and lack of facilities near the site also presented difficulties. Nevertheless, Six Companies turned the dam over to the federal government on March 1, 1936, more than two years ahead of schedule.

Hoover Dam impounds Lake Mead and is located near Boulder City, Nevada, a municipality originally constructed for workers on the construction project, about 30 mi southeast of Las Vegas, Nevada. The dam's generators provide power for public and private utilities in Nevada, Arizona, and California. Hoover Dam is a major tourist attraction, with 7 million tourists a year. The heavily traveled U.S. Route 93 (US 93) ran along the dam's crest until October 2010, when the Hoover Dam Bypass opened.

Search for resources
As the United States developed the Southwest, the Colorado River was seen as a potential source of irrigation water. An initial attempt at diverting the river for irrigation purposes occurred in the late 1890s, when land speculator William Beatty built the Alamo Canal just north of the Mexican border; the canal dipped into Mexico before running to a desolate area Beatty named the Imperial Valley. Though water from the Alamo Canal allowed for the widespread settlement of the valley, the canal proved expensive to operate. After a catastrophic breach that caused the Colorado River to fill the Salton Sea, the Southern Pacific Railroad spent $3 million in 1906–07 to stabilize the waterway, an amount it hoped in vain that it would be reimbursed for by the federal government. Even after the waterway was stabilized, it proved unsatisfactory because of constant disputes with landowners on the Mexican side of the border.

As the technology of electric power transmission improved, the Lower Colorado was considered for its hydroelectric-power potential. In 1902, the Edison Electric Company of Los Angeles surveyed the river in the hope of building a 40 ft rock dam which could generate 10,000 hp. However, at the time, the limit of transmission of electric power was 80 mi, and there were few customers (mostly mines) within that limit. Edison allowed land options it held on the river to lapse—including an option for what became the site of Hoover Dam.

In the following years, the Bureau of Reclamation (BOR), known as the Reclamation Service at the time, also considered the Lower Colorado as the site for a dam. Service chief Arthur Powell Davis proposed using dynamite to collapse the walls of Boulder Canyon, 20 mi north of the eventual dam site, into the river. The river would carry off the smaller pieces of debris, and a dam would be built incorporating the remaining rubble. In 1922, after considering it for several years, the Reclamation Service finally rejected the proposal, citing doubts about the unproven technique and questions as to whether it would, in fact, save money.

Planning and agreements
In 1922, the Reclamation Service presented a report calling for the development of a dam on the Colorado River for flood control and electric power generation. The report was principally authored by Davis and was called the Fall-Davis report after Interior Secretary Albert Fall. The Fall-Davis report cited use of the Colorado River as a federal concern because the river's basin covered several states, and the river eventually entered Mexico. Though the Fall-Davis report called for a dam "at or near Boulder Canyon", the Reclamation Service (which was renamed the Bureau of Reclamation the following year) found that canyon unsuitable. One potential site at Boulder Canyon was bisected by a geologic fault; two others were so narrow there was no space for a construction camp at the bottom of the canyon or for a spillway. The Service investigated Black Canyon and found it ideal; a railway could be laid from the railhead in Las Vegas to the top of the dam site. Despite the site change, the dam project was referred to as the "Boulder Canyon Project". With little guidance on water allocation from the Supreme Court, proponents of the dam feared endless litigation. Delph Carpenter, a Colorado attorney, proposed that the seven states which fell within the river's basin (California, Nevada, Arizona, Utah, New Mexico, Colorado and Wyoming) form an interstate compact, with the approval of Congress. Such compacts were authorized by Article I of the United States Constitution but had never been concluded among more than two states. In 1922, representatives of seven states met with then-Secretary of Commerce Herbert Hoover. Initial talks produced no result, but when the Supreme Court handed down the Wyoming v. Colorado decision undermining the claims of the upstream states, they became anxious to reach an agreement. The resulting Colorado River Compact was signed on November 24, 1922.

Legislation to authorize the dam was introduced repeatedly by two California Republicans, Representative Phil Swing and Senator Hiram Johnson, but representatives from other parts of the country considered the project as hugely expensive and one that would mostly benefit California. The 1927 Mississippi flood made Midwestern and Southern congressmen and senators more sympathetic toward the dam project. On March 12, 1928, the failure of the St. Francis Dam, constructed by the city of Los Angeles, caused a disastrous flood that killed up to 600 people. As that dam was a curved-gravity type, similar in design to the arch-gravity as was proposed for the Black Canyon dam, opponents claimed that the Black Canyon dam's safety could not be guaranteed. Congress authorized a board of engineers to review plans for the proposed dam. The Colorado River Board found the project feasible, but warned that should the dam fail, every downstream Colorado River community would be destroyed, and that the river might change course and empty into the Salton Sea. The Board cautioned: "To avoid such possibilities, the proposed dam should be constructed on conservative if not ultra-conservative lines."

On December 21, 1928, President Coolidge signed the bill authorizing the dam. The Boulder Canyon Project Act appropriated $165 million for the project along with the downstream Imperial Dam and All-American Canal, a replacement for Beatty's canal entirely on the U.S. side of the border. It also permitted the compact to go into effect when at least six of the seven states approved it. This occurred on March 6, 1929, with Utah's ratification; Arizona did not approve it until 1944.

Design, preparation and contracting
Even before Congress approved the Boulder Canyon Project, the Bureau of Reclamation was considering what kind of dam should be used. Officials eventually decided on a massive concrete arch-gravity dam, the design of which was overseen by the Bureau's chief design engineer John L. Savage. The monolithic dam would be thick at the bottom and thin near the top and would present a convex face towards the water above the dam. The curving arch of the dam would transmit the water's force into the abutments, in this case the rock walls of the canyon. The wedge-shaped dam would be 660 ft thick at the bottom, narrowing to 45 ft at the top, leaving room for a highway connecting Nevada and Arizona.

On January 10, 1931, the Bureau made the bid documents available to interested parties, at five dollars a copy. The government was to provide the materials, and the contractor was to prepare the site and build the dam. The dam was described in minute detail, covering 100 pages of text and 76 drawings. A $2 million bid bond was to accompany each bid; the winner would have to post a $5 million performance bond. The contractor had seven years to build the dam, or penalties would ensue.

The Wattis Brothers, heads of the Utah Construction Company, were interested in bidding on the project, but lacked the money for the performance bond. They lacked sufficient resources even in combination with their longtime partners, Morrison-Knudsen, which employed the nation's leading dam builder, Frank Crowe. They formed a joint venture to bid for the project with Pacific Bridge Company of Portland, Oregon; Henry J. Kaiser & W. A. Bechtel Company of San Francisco; MacDonald & Kahn Ltd. of Los Angeles; and the J.F. Shea Company of Portland, Oregon. The joint venture was called Six Companies, Inc. as Bechtel and Kaiser were considered one company for purposes of Six in the name. The name was descriptive and was an inside joke among the San Franciscans in the bid, where "Six Companies" was also a Chinese benevolent association in the city. There were three valid bids, and Six Companies' bid of $48,890,955 was the lowest, within $24,000 of the confidential government estimate of what the dam would cost to build, and five million dollars less than the next-lowest bid.

The city of Las Vegas had lobbied hard to be the headquarters for the dam construction, closing its many speakeasies when the decision maker, Secretary of the Interior Ray Wilbur, came to town. Instead, Wilbur announced in early 1930 that a model city was to be built in the desert near the dam site. This town became known as Boulder City, Nevada. Construction of a rail line joining Las Vegas and the dam site began in September 1930.

Labor force

Soon after the dam was authorized, increasing numbers of unemployed people converged on southern Nevada. Las Vegas, then a small city of some 5,000, saw between 10,000 and 20,000 unemployed descend on it. A government camp was established for surveyors and other personnel near the dam site; this soon became surrounded by a squatters' camp. Known as McKeeversville, the camp was home to men hoping for work on the project, together with their families. Another camp, on the flats along the Colorado River, was officially called Williamsville, but was known to its inhabitants as "Ragtown". When construction began, Six Companies hired large numbers of workers, with more than 3,000 on the payroll by 1932 and with employment peaking at 5,251 in July 1934. "Mongolian" (Chinese) labor was prevented by the construction contract, while the number of black people employed by Six Companies never exceeded thirty, mostly lowest-pay-scale laborers in a segregated crew, who were issued separate water buckets.

As part of the contract, Six Companies, Inc. was to build Boulder City to house the workers. The original timetable called for Boulder City to be built before the dam project began, but President Hoover ordered work on the dam to begin in March 1931 rather than in October. The company built bunkhouses, attached to the canyon wall, to house 480 single men at what became known as River Camp. Workers with families were left to provide their own accommodations until Boulder City could be completed, and many lived in Ragtown. The site of Hoover Dam endures extremely hot weather, and the summer of 1931 was especially torrid, with the daytime high averaging 119.9 °F. Sixteen workers and other riverbank residents died of heat prostration between June 25 and July 26, 1931.

The Industrial Workers of the World (IWW or "Wobblies"), though much-reduced from their heyday as militant labor organizers in the early years of the century, hoped to unionize the Six Companies workers by capitalizing on their discontent. They sent eleven organizers, several of whom were arrested by Las Vegas police. On August 7, 1931, the company cut wages for all tunnel workers. Although the workers sent the organizers away, not wanting to be associated with the "Wobblies", they formed a committee to represent them with the company. The committee drew up a list of demands that evening and presented them to Crowe the following morning. He was noncommittal. The workers hoped that Crowe, the general superintendent of the job, would be sympathetic; instead, he gave a scathing interview to a newspaper, describing the workers as "malcontents".

On the morning of the 9th, Crowe met with the committee and told them that management refused their demands, was stopping all work, and was laying off the entire work force, except for a few office workers and carpenters. The workers were given until 5 p.m. to vacate the premises. Concerned that a violent confrontation was imminent, most workers took their paychecks and left for Las Vegas to await developments. Two days later, the remainder were talked into leaving by law enforcement. On August 13, the company began hiring workers again, and two days later, the strike was called off. While the workers received none of their demands, the company guaranteed there would be no further reductions in wages. Living conditions began to improve as the first residents moved into Boulder City in late 1931.

A second labor action took place in July 1935, as construction on the dam wound down. When a Six Companies manager altered working times to force workers to take lunch on their own time, workers responded with a strike. Emboldened by Crowe's reversal of the lunch decree, workers raised their demands to include a $1-per-day raise. The company agreed to ask the Federal government to supplement the pay, but no money was forthcoming from Washington. The strike ended.

River diversion
Before the dam could be built, the Colorado River needed to be diverted away from the construction site. To accomplish this, four diversion tunnels were driven through the canyon walls, two on the Nevada side and two on the Arizona side. These tunnels were 56 ft in diameter. Their combined length was nearly 16,000 ft, or more than 3 mi. The contract required these tunnels to be completed by October 1, 1933, with a $3,000-per-day fine to be assessed for any delay. To meet the deadline, Six Companies had to complete work by early 1933, since only in late fall and winter was the water level in the river low enough to safely divert.

Tunneling began at the lower portals of the Nevada tunnels in May 1931. Shortly afterward, work began on two similar tunnels in the Arizona canyon wall. In March 1932, work began on lining the tunnels with concrete. First the base, or invert, was poured. Gantry cranes, running on rails through the entire length of each tunnel were used to place the concrete. The sidewalls were poured next. Movable sections of steel forms were used for the sidewalls. Finally, using pneumatic guns, the overheads were filled in. The concrete lining is 3 ft thick, reducing the finished tunnel diameter to 50 ft. The river was diverted into the two Arizona tunnels on November 13, 1932; the Nevada tunnels were kept in reserve for high water. This was done by exploding a temporary cofferdam protecting the Arizona tunnels while at the same time dumping rubble into the river until its natural course was blocked.

Following the completion of the dam, the entrances to the two outer diversion tunnels were sealed at the opening and halfway through the tunnels with large concrete plugs. The downstream halves of the tunnels following the inner plugs are now the main bodies of the spillway tunnels. The inner diversion tunnels were plugged at approximately one-third of their length, beyond which they now carry steel pipes connecting the intake towers to the power plant and outlet works. The inner tunnels' outlets are equipped with gates that can be closed to drain the tunnels for maintenance.

Groundworks, rock clearance and grout curtain
To protect the construction site from the Colorado River and to facilitate the river's diversion, two cofferdams were constructed. Work on the upper cofferdam began in September 1932, even though the river had not yet been diverted. The cofferdams were designed to protect against the possibility of the river's flooding a site at which two thousand men might be at work, and their specifications were covered in the bid documents in nearly as much detail as the dam itself. The upper cofferdam was 96 ft high, and 750 ft thick at its base, thicker than the dam itself. It contained 650,000 cuyd of material.

When the cofferdams were in place and the construction site was drained of water, excavation for the dam foundation began. For the dam to rest on solid rock, it was necessary to remove accumulated erosion soils and other loose materials in the riverbed until sound bedrock was reached. Work on the foundation excavations was completed in June 1933. During this excavation, approximately 1,500,000 cuyd of material was removed. Since the dam was an arch-gravity type, the side-walls of the canyon would bear the force of the impounded lake. Therefore, the side-walls were also excavated to reach virgin rock, as weathered rock might provide pathways for water seepage. Shovels for the excavation came from the Marion Power Shovel Company.

The men who removed this rock were called "high scalers". While suspended from the top of the canyon with ropes, the high-scalers climbed down the canyon walls and removed the loose rock with jackhammers and dynamite. Falling objects were the most common cause of death on the dam site; the high scalers' work thus helped ensure worker safety. One high scaler was able to save a life in a more direct manner: when a government inspector lost his grip on a safety line and began tumbling down a slope towards almost certain death, a high scaler was able to intercept him and pull him into the air. The construction site had become a magnet for tourists. The high scalers were prime attractions and showed off for the watchers. The high scalers received considerable media attention, with one worker dubbed the "Human Pendulum" for swinging co-workers (and, at other times, cases of dynamite) across the canyon. To protect themselves against falling objects, some high scalers dipped cloth hats in tar and allowed them to harden. When workers wearing such headgear were struck hard enough to inflict broken jaws, they sustained no skull damage. Six Companies ordered thousands of what initially were called "hard boiled hats" (later "hard hats") and strongly encouraged their use.

The cleared, underlying rock foundation of the dam site was reinforced with grout, forming a grout curtain. Holes were driven into the walls and base of the canyon, as deep as 150 ft into the rock, and any cavities encountered were to be filled with grout. This was done to stabilize the rock, to prevent water from seeping past the dam through the canyon rock, and to limit "uplift"—upward pressure from water seeping under the dam. The workers were under severe time constraints due to the beginning of the concrete pour. When they encountered hot springs or cavities too large to readily fill, they moved on without resolving the problem. A total of 58 of the 393 holes were incompletely filled. After the dam was completed and the lake began to fill, large numbers of significant leaks caused the Bureau of Reclamation to examine the situation. It found that the work had been incompletely done, and was based on less than a full understanding of the canyon's geology. New holes were drilled from inspection galleries inside the dam into the surrounding bedrock. It took nine years (1938–47) under relative secrecy to complete the supplemental grout curtain.

Concrete

The first concrete was poured into the dam on June 6, 1933, 18 months ahead of schedule. Since concrete heats and contracts as it cures, the potential for uneven cooling and contraction of the concrete posed a serious problem. Bureau of Reclamation engineers calculated that if the dam were to be built in a single continuous pour, the concrete would take 125 years to cool, and the resulting stresses would cause the dam to crack and crumble. Instead, the ground where the dam would rise was marked with rectangles, and concrete blocks in columns were poured, some as large as 50 ft and 5 ft high. Each five-foot form contained a set of 1 in steel pipes; cool river water would be poured through the pipes, followed by ice-cold water from a refrigeration plant. When an individual block had cured and had stopped contracting, the pipes were filled with grout. Grout was also used to fill the hairline spaces between columns, which were grooved to increase the strength of the joints.

The concrete was delivered in huge steel buckets 7 ft and almost 7 feet in diameter; Crowe was awarded two patents for their design. These buckets, which weighed 20 ST when full, were filled at two massive concrete plants on the Nevada side, and were delivered to the site in special railcars. The buckets were then suspended from aerial cableways which were used to deliver the bucket to a specific column. As the required grade of aggregate in the concrete differed depending on placement in the dam (from pea-sized gravel to 9 in stones), it was vital that the bucket be maneuvered to the proper column. When the bottom of the bucket opened up, disgorging 8 cuyd of concrete, a team of men worked it throughout the form. Although there are myths that men were caught in the pour and are entombed in the dam to this day, each bucket deepened the concrete in a form by only 1 in, and Six Companies engineers would not have permitted a flaw caused by the presence of a human body.

A total of 3250000 cuyd of concrete was used in the dam before concrete pouring ceased on May 29, 1935. In addition, 1,110,000 cuyd were used in the power plant and other works. More than 582 mi of cooling pipes were placed within the concrete. Overall, there is enough concrete in the dam to pave a two-lane highway from San Francisco to New York. Concrete cores were removed from the dam for testing in 1995; they showed that "Hoover Dam's concrete has continued to slowly gain strength" and the dam is composed of a "durable concrete having a compressive strength exceeding the range typically found in normal mass concrete". Hoover Dam concrete is not subject to alkali–silica reaction (ASR), as the Hoover Dam builders happened to use nonreactive aggregate, unlike that at downstream Parker Dam, where ASR has caused measurable deterioration.

Dedication and completion

With most work finished on the dam itself (the powerhouse remained uncompleted), a formal dedication ceremony was arranged for September 30, 1935, to coincide with a western tour being made by President Franklin D. Roosevelt. The morning of the dedication, it was moved forward three hours from 2 p.m. Pacific time to 11 a.m.; this was done because Secretary of the Interior Harold L. Ickes had reserved a radio slot for the President for 2 p.m. but officials did not realize until the day of the ceremony that the slot was for 2 p.m. Eastern Time. Despite the change in the ceremony time, and temperatures of 102 °F, 10,000 people were present for the President's speech, in which he avoided mentioning the name of former President Hoover, who was not invited to the ceremony. To mark the occasion, a three-cent stamp was issued by the United States Post Office Department—bearing the name "Boulder Dam", the official name of the dam between 1933 and 1947. After the ceremony, Roosevelt made the first visit by any American president to Las Vegas.

Most work had been completed by the dedication, and Six Companies negotiated with the government through late 1935 and early 1936 to settle all claims and arrange for the formal transfer of the dam to the Federal Government. The parties came to an agreement and on March 1, 1936, Secretary Ickes formally accepted the dam on behalf of the government. Six Companies was not required to complete work on one item, a concrete plug for one of the bypass tunnels, as the tunnel had to be used to take in irrigation water until the powerhouse went into operation.

Construction deaths

There were 112 deaths reported as associated with the construction of the dam. The first was Bureau of Reclamation employee Harold Connelly who died on May 15, 1921, after falling from a barge while surveying the Colorado River for an ideal spot for the dam. Surveyor John Gregory ("J.G.") Tierney, who drowned on December 20, 1922, in a flash flood while looking for an ideal spot for the dam was the second person. The official list's final death occurred on December 20, 1935, when Patrick Tierney, electrician's helper and the son of J.G. Tierney, fell from one of the two Arizona-side intake towers. Included in the fatality list are three workers who took their own lives on site, one in 1932 and two in 1933. Of the 112 fatalities, 91 were Six Companies employees, three were Bureau of Reclamation employees, and one was a visitor to the site; the remainder were employees of various contractors not part of Six Companies.

Ninety-six of the deaths occurred during construction at the site. Not included in the official number of fatalities were deaths that were recorded as pneumonia. Workers alleged that this diagnosis was a cover for death from carbon monoxide poisoning (brought on by the use of gasoline-fueled vehicles in the diversion tunnels), and a classification used by Six Companies to avoid paying compensation claims. The site's diversion tunnels frequently reached 140 F, enveloped in thick plumes of vehicle exhaust gases. A total of 42 workers were recorded as having died from pneumonia and were not included in the above total; none were listed as having died from carbon monoxide poisoning. No deaths of non-workers from pneumonia were recorded in Boulder City during the construction period.

Architectural style
The initial plans for the facade of the dam, the power plant, the outlet tunnels and ornaments clashed with the modern look of an arch dam. The Bureau of Reclamation, more concerned with the dam's functionality, adorned it with a Gothic-inspired balustrade and eagle statues. This initial design was criticized by many as being too plain and unremarkable for a project of such immense scale, so Los Angeles-based architect Gordon B. Kaufmann, then the supervising architect to the Bureau of Reclamation, was brought in to redesign the exteriors. Kaufmann greatly streamlined the design and applied an elegant Art Deco style to the entire project. He designed sculpted turrets rising seamlessly from the dam face and clock faces on the intake towers set for the time in Nevada and Arizona—both states are in different time zones, but since Arizona does not observe daylight saving time, the clocks display the same time for more than half the year.

At Kaufmann's request, Denver artist Allen Tupper True was hired to handle the design and decoration of the walls and floors of the new dam. True's design scheme incorporated motifs of the Navajo and Pueblo tribes of the region. Although some were initially opposed to these designs, True was given the go-ahead and was officially appointed consulting artist. With the assistance of the National Laboratory of Anthropology, True researched authentic decorative motifs from Indian sand paintings, textiles, baskets and ceramics. The images and colors are based on Native American visions of rain, lightning, water, clouds, and local animals—lizards, serpents, birds—and on the Southwestern landscape of stepped mesas. In these works, which are integrated into the walkways and interior halls of the dam, True also reflected on the machinery of the operation, making the symbolic patterns appear both ancient and modern.

With the agreement of Kaufmann and the engineers, True also devised for the pipes and machinery an innovative color-coding which was implemented throughout all BOR projects. True's consulting artist job lasted through 1942; it was extended so he could complete design work for the Parker, Shasta and Grand Coulee dams and power plants. True's work on the Hoover Dam was humorously referred to in a poem published in The New Yorker, part of which read, "lose the spark, and justify the dream; but also worthy of remark will be the color scheme".

Complementing Kaufmann and True's work, sculptor Oskar J. W. Hansen designed many of the sculptures on and around the dam. His works include the monument of dedication plaza, a plaque to memorialize the workers killed and the bas-reliefs on the elevator towers. In his words, Hansen wanted his work to express "the immutable calm of intellectual resolution, and the enormous power of trained physical strength, equally enthroned in placid triumph of scientific accomplishment", because "[t]he building of Hoover Dam belongs to the sagas of the daring." Hansen's dedication plaza, on the Nevada abutment, contains a sculpture of two winged figures flanking a flagpole.

Surrounding the base of the monument is a terrazzo floor embedded with a "star map". The map depicts the Northern Hemisphere sky at the moment of President Roosevelt's dedication of the dam. This is intended to help future astronomers, if necessary, calculate the exact date of dedication. The 30 ft bronze figures, dubbed "Winged Figures of the Republic", were both formed in a continuous pour. To put such large bronzes into place without marring the highly polished bronze surface, they were placed on ice and guided into position as the ice melted. Hansen's bas-relief on the Nevada elevator tower depicts the benefits of the dam: flood control, navigation, irrigation, water storage, and power. The bas-relief on the Arizona elevator depicts, in his words, "the visages of those Indian tribes who have inhabited mountains and plains from ages distant."

Power plant and water demands
Excavation for the powerhouse was carried out simultaneously with the excavation for the dam foundation and abutments. The excavation of this U-shaped structure located at the downstream toe of the dam was completed in late 1933 with the first concrete placed in November 1933. Filling of Lake Mead began February 1, 1935, even before the last of the concrete was poured that May. The powerhouse was one of the projects uncompleted at the time of the formal dedication on September 30, 1935; a crew of 500 men remained to finish it and other structures. To make the powerhouse roof bombproof, it was constructed of layers of concrete, rock, and steel with a total thickness of about 3.5 ft, topped with layers of sand and tar.

In the latter half of 1936, water levels in Lake Mead were high enough to permit power generation, and the first three Allis Chalmers built Francis turbine-generators, all on the Nevada side, began operating. In March 1937, one more Nevada generator went online and the first Arizona generator by August. By September 1939, four more generators were operating, and the dam's power plant became the largest hydroelectricity facility in the world. The final generator was not placed in service until 1961, bringing the maximum generating capacity to 1,345 megawatts at the time. Original plans called for 16 large generators, eight on each side of the river, but two smaller generators were installed instead of one large one on the Arizona side for a total of 17. The smaller generators were used to serve smaller communities at a time when the output of each generator was dedicated to a single municipality, before the dam's total power output was placed on the grid and made arbitrarily distributable.

Before water from Lake Mead reaches the turbines, it enters the intake towers and then four gradually narrowing penstocks which funnel the water down towards the powerhouse. The intakes provide a maximum hydraulic head (water pressure) of 590 ft as the water reaches a speed of about 85 mph. The entire flow of the Colorado River usually passes through the turbines. The spillways and outlet works (jet-flow gates) are rarely used. The jet-flow gates, located in concrete structures 180 ft above the river and also at the outlets of the inner diversion tunnels at river level, may be used to divert water around the dam in emergency or flood conditions, but have never done so, and in practice are used only to drain water from the penstocks for maintenance. Following an uprating project from 1986 to 1993, the total gross power rating for the plant, including two 2.4 megawatt Pelton turbine-generators that power Hoover Dam's own operations is a maximum capacity of 2080 megawatts. The annual generation of Hoover Dam varies. The maximum net generation was 10.348 TWh in 1984, and the minimum since 1940 was 2.648 TWh in 1956. The average power generated was 4.2 TWh/year for 1947–2008. In 2015, the dam generated 3.6 TWh.

The amount of electricity generated by Hoover Dam has been decreasing along with the falling water level in Lake Mead due to the prolonged drought since year 2000 and high demand for the Colorado River's water. By 2014 its generating capacity was downrated by 23% to 1592 MW and was providing power only during periods of peak demand. Lake Mead fell to a new record low elevation of 1,071.61 ft on July 1, 2016, before beginning to rebound slowly. Under its original design, the dam would no longer be able to generate power once the water level fell below 1,050 ft, which might have occurred in 2017 had water restrictions not been enforced. To lower the minimum power pool elevation from 1,050 to 950 ft, five wide-head turbines, designed to work efficiently with less flow, were installed. Water levels were maintained at over 1075 feet in 2018 and 2019, but fell to a new record low of 1,071.55 ft on June 10, 2021 and were projected to fall below 1066 feet by the end of 2021.

Control of water was the primary concern in the building of the dam. Power generation has allowed the dam project to be self-sustaining: proceeds from the sale of power repaid the 50-year construction loan, and those revenues also finance the multimillion-dollar yearly maintenance budget. Power is generated in step with and only with the release of water in response to downstream water demands.

Lake Mead and downstream releases from the dam also provide water for both municipal and irrigation uses. Water released from the Hoover Dam eventually reaches several canals. The Colorado River Aqueduct and Central Arizona Project branch off Lake Havasu while the All-American Canal is supplied by the Imperial Dam. In total, water from Lake Mead serves 18 million people in Arizona, Nevada, and California and supplies the irrigation of over 1,000,000 acre of land.

In 2018, the Los Angeles Department of Water and Power (LADWP) proposed a $3 billion pumped-storage hydroelectricity project—a "battery" of sorts—that would use wind and solar power to recirculate water back up to Lake Mead from a pumping station 20 mile downriver.

Power distribution
Electricity from the dam's powerhouse was originally sold pursuant to a fifty-year contract, authorized by Congress in 1934, which ran from 1937 to 1987. In 1984, Congress passed a new statute which set power allocations to southern California, Arizona, and Nevada from the dam from 1987 to 2017. The powerhouse was run under the original authorization by the Los Angeles Department of Water and Power and Southern California Edison; in 1987, the Bureau of Reclamation assumed control. In 2011, Congress enacted legislation extending the current contracts until 2067, after setting aside 5% of Hoover Dam's power for sale to Native American tribes, electric cooperatives, and other entities. The new arrangement began on October 1, 2017.

The Bureau of Reclamation reports that the energy generated under the contracts ending in 2017 was allocated as follows:

Spillways

The dam is protected against over-topping by two spillways. The spillway entrances are located behind each dam abutment, running roughly parallel to the canyon walls. The spillway entrance arrangement forms a classic side-flow weir with each spillway containing four 100 ft and 16 ft steel-drum gates. Each gate weighs 5,000,000 lb and can be operated manually or automatically. Gates are raised and lowered depending on water levels in the reservoir and flood conditions. The gates cannot entirely prevent water from entering the spillways but can maintain an extra 16 ft of lake level.

Water flowing over the spillways falls dramatically into 600 ft, 50 ft spillway tunnels before connecting to the outer diversion tunnels and reentering the main river channel below the dam. This complex spillway entrance arrangement combined with the approximate 700 ft elevation drop from the top of the reservoir to the river below was a difficult engineering problem and posed numerous design challenges. Each spillway's capacity of 200,000 ft3/s was empirically verified in post-construction tests in 1941.

The large spillway tunnels have only been used twice, for testing in 1941 and because of flooding in 1983. Both times, when inspecting the tunnels after the spillways were used, engineers found major damage to the concrete linings and underlying rock. The 1941 damage was attributed to a slight misalignment of the tunnel invert (or base), which caused cavitation, a phenomenon in fast-flowing liquids in which vapor bubbles collapse with explosive force. In response to this finding, the tunnels were patched with special heavy-duty concrete and the surface of the concrete was polished mirror-smooth. The spillways were modified in 1947 by adding flip buckets, which both slow the water and decrease the spillway's effective capacity, in an attempt to eliminate conditions thought to have contributed to the 1941 damage. The 1983 damage, also due to cavitation, led to the installation of aerators in the spillways. Tests at Grand Coulee Dam showed that the technique worked, in principle.

Roadway and tourism
There are two lanes for automobile traffic across the top of the dam, which formerly served as the Colorado River crossing for U.S. Route 93. In the wake of the September 11 terrorist attacks, authorities expressed security concerns and the Hoover Dam Bypass project was expedited. Pending the completion of the bypass, restricted traffic was permitted over Hoover Dam. Some types of vehicles were inspected prior to crossing the dam while semi-trailer trucks, buses carrying luggage, and enclosed-box trucks over 40 ft long were not allowed on the dam at all, and were diverted to U.S. Route 95 or Nevada State Routes 163/68. The four-lane Hoover Dam Bypass opened on October 19, 2010. It includes a composite steel and concrete arch bridge, the Mike O'Callaghan–Pat Tillman Memorial Bridge, 1,500 ft downstream from the dam. With the opening of the bypass, through traffic is no longer allowed across Hoover Dam; dam visitors are allowed to use the existing roadway to approach from the Nevada side and cross to parking lots and other facilities on the Arizona side.

Hoover Dam opened for tours in 1937 after its completion but following Japan's attack on Pearl Harbor on December 7, 1941, it was closed to the public when the United States entered World War II, during which only authorized traffic, in convoys, was permitted. After the war, it reopened September 2, 1945, and by 1953, annual attendance had risen to 448,081. The dam closed on November 25, 1963, and March 31, 1969, days of mourning in remembrance of Presidents Kennedy and Eisenhower. In 1995, a new visitors' center was built, and the following year, visits exceeded one million for the first time. The dam closed again to the public on September 11, 2001; modified tours were resumed in December and a new "Discovery Tour" was added the following year. Today, nearly a million people per year take the tours of the dam offered by the Bureau of Reclamation. Increased security concerns by the government have led to most of the interior structure's being inaccessible to tourists. As a result, few of True's decorations can now be seen by visitors. Visitors can only purchase tickets on-site and have the options of a guided tour of the whole facility or only the power plant area. The only self-guided tour option is for the visitor center itself, where visitors can view various exhibits and enjoy a 360-degree view of the dam.

Environmental impact

The changes in water flow and use caused by Hoover Dam's construction and operation have had a large impact on the Colorado River Delta. The construction of the dam has been implicated in causing the decline of this estuarine ecosystem. For six years after the construction of the dam, while Lake Mead filled, virtually no water reached the mouth of the river. The delta's estuary, which once had a freshwater-saltwater mixing zone stretching 40 mi south of the river's mouth, was turned into an inverse estuary where the level of salinity was higher close to the river's mouth.

The Colorado River had experienced natural flooding before the construction of the Hoover Dam. The dam eliminated the natural flooding, threatening many species adapted to the flooding, including both plants and animals. The construction of the dam devastated the populations of native fish in the river downstream from the dam. Four species of fish native to the Colorado River, the Bonytail chub, Colorado pikeminnow, Humpback chub, and Razorback sucker, are listed as endangered.

Naming controversy
During the years of lobbying leading up to the passage of legislation authorizing the dam in 1928, the press generally referred to the dam as "Boulder Dam" or as "Boulder Canyon Dam", even though the proposed site had shifted to Black Canyon. The Boulder Canyon Project Act of 1928 (BCPA) never mentioned a proposed name or title for the dam. The BCPA merely allows the government to "construct, operate, and maintain a dam and incidental works in the main stream of the Colorado River at Black Canyon or Boulder Canyon".

When Secretary of the Interior Ray Wilbur spoke at the ceremony starting the building of the railway between Las Vegas and the dam site on September 17, 1930, he named the dam "Hoover Dam", citing a tradition of naming dams after Presidents, though none had been so honored during their terms of office. Wilbur justified his choice on the ground that Hoover was "the great engineer whose vision and persistence ... has done so much to make [the dam] possible". One writer complained in response that "the Great Engineer had quickly drained, ditched, and dammed the country."

After Hoover's election defeat in 1932 and the accession of the Roosevelt administration, Secretary Ickes ordered on May 13, 1933, that the dam be referred to as Boulder Dam. Ickes stated that Wilbur had been imprudent in naming the dam after a sitting president, that Congress had never ratified his choice, and that it had long been referred to as Boulder Dam. Unknown to the general public, Attorney General Homer Cummings informed Ickes that Congress had indeed used the name "Hoover Dam" in five different bills appropriating money for construction of the dam. The official status this conferred to the name "Hoover Dam" had been noted on the floor of the House of Representatives by Congressman Edward T. Taylor of Colorado on December 12, 1930, but was likewise ignored by Ickes.

When Ickes spoke at the dedication ceremony on September 30, 1935, he was determined, as he recorded in his diary, "to try to nail down for good and all the name Boulder Dam." At one point in the speech, he spoke the words "Boulder Dam" five times within thirty seconds. Further, he suggested that if the dam were to be named after any one person, it should be for California Senator Hiram Johnson, a lead sponsor of the authorizing legislation. Roosevelt also referred to the dam as Boulder Dam, and the Republican-leaning Los Angeles Times, which at the time of Ickes' name change had run an editorial cartoon showing Ickes ineffectively chipping away at an enormous sign "HOOVER DAM", reran it showing Roosevelt reinforcing Ickes, but having no greater success.

In the following years, the name "Boulder Dam" failed to fully take hold, with many Americans using both names interchangeably and mapmakers divided as to which name should be printed. Memories of the Great Depression faded, and Hoover to some extent rehabilitated himself through good works during and after World War II. In 1947, a bill passed both Houses of Congress unanimously restoring the name "Hoover Dam." Ickes, who was by then a private citizen, opposed the change, stating, "I didn't know Hoover was that small a man to take credit for something he had nothing to do with."

Recognition
Hoover Dam was recognized as a National Historic Civil Engineering Landmark in 1984. It was listed on the National Register of Historic Places in 1981 and was designated a National Historic Landmark in 1985, cited for its engineering innovations.

Other sources

 * Arrigo, Anthony F. (2014). Imaging Hoover Dam: The Making of a Cultural Icon. Reno, NV: University of Nevada Press.

title: Hoover Dam


text:
Holger Pedersen

Holger Pedersen may refer to:

 * Holger Pedersen (linguist) (1867–1953), Danish linguist
 * Holger Pedersen (astronomer) (born 1946), Danish astronomer, at the European Southern Observatory

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Holger Pedersen


text:
Adventures of Huckleberry Finn

Adventures of Huckleberry Finn is a novel by American author Mark Twain, which was first published in the United Kingdom in December 1884 and in the United States in February 1885.

Commonly named among the Great American Novels, the work is among the first in major American literature to be written throughout in vernacular English, characterized by local color regionalism. It is told in the first person by Huckleberry "Huck" Finn, the narrator of two other Twain novels (Tom Sawyer Abroad and Tom Sawyer, Detective) and a friend of Tom Sawyer. It is a direct sequel to The Adventures of Tom Sawyer.

The book is noted for "changing the course of children's literature" in the United States for the "deeply felt portrayal of boyhood". It is also known for its colorful description of people and places along the Mississippi River. Set in a Southern antebellum society that had ceased to exist over 20 years before the work was published, Adventures of Huckleberry Finn is an often scathing satire on entrenched attitudes, particularly racism and freedom.

Perennially popular with readers, Adventures of Huckleberry Finn has also been the continued object of study by literary critics since its publication. The book was widely criticized upon release because of its extensive use of coarse language and racial epithets. Throughout the 20th century, and despite arguments that the protagonist and the tenor of the book are anti-racist, criticism of the book continued due to both its perceived use of racial stereotypes and its frequent use of the racial slur "nigger".

Plot
In St. Petersburg, Missouri, during the 1830s–1840s, Huckleberry Finn has received a considerable sum of money following The Adventures of Tom Sawyer  and the Widow Douglas and her sister Miss Watson become his guardians. Despite preferring life as an errant boy, Huck stays so he can be part of Tom Sawyer's gang. Huck’s father, "Pap", an abusive alcoholic, tries to appropriate Huck's fortune. When this fails, Pap imprisons him in a remote cabin.

After a delirium tremens crisis, in which Pap tries to kill Huck, Huck fakes his own murder and settles on Jackson's Island, where he reunites with Miss Watson's slave Jim, who ran away after overhearing she was planning to sell him. Huck and Jim decide to go down the Mississippi River to Cairo, in the free state of Illinois. After a flood, they find a timber raft and a house floating downstream. Inside the house, Jim finds a man who was shot to death but prevents Huck from seeing. Huck sneaks into town and discovers there is a reward for Jim's capture and he is suspected of killing Huck; they flee on their raft.

Huck and Jim come across a grounded steamboat on which two thieves discuss murdering a third. Finding their raft has drifted away, they flee in the thieves' boat. They find their raft and sink the thieves' boat, then Huck tricks a night watchman into a rescue attempt, which fails when the steamboat sinks. Huck and Jim are separated in a fog. When they reunite, Huck tricks Jim into thinking he dreamed the event. Jim is disappointed in Huck when Huck admits the truth. Huck is surprised by Jim's strong feelings and apologizes.

Huck is conflicted about supporting a runaway slave, but when two white men seeking runaways come upon the raft, his lies convince them to leave. Jim and Huck realize they have passed Cairo. With no way to go upriver, they decide to continue downriver. The raft is struck by a passing steamship, again separating them. On the riverbank, Huck meets the Grangerfords, who are engaged in a 30-year feud with the Shepherdsons. After a Grangerford daughter elopes with a Shepherdson boy, all the Grangerford men are killed in a Shepherdson ambush. Huck escapes and is reunited with Jim, who has recovered and repaired the raft.

Jim and Huck are joined by two confidence men claiming to be a King and a Duke, and they rope Huck and Jim into aiding in several scams. In one town, the King and the Duke cheat the townsfolk over two nights with a short, overpriced stage performance. On the third, the grifters collect the admission fee from previous audience members bent on revenge, then flee the town. In the next town, the swindlers impersonate the brothers of the recently-deceased Peter Wilks and attempt to steal his estate. Huck tries to retrieve the money for Wilks's orphaned nieces. Two other men claiming to be Wilks' brothers arrive, causing an uproar. Huck flees but is caught by the King and the Duke. He escapes but finds that they sold Jim to the Phelpses. Huck vows to free Jim, despite believing he will go to hell for it.

The Phelpses mistake Huck for their nephew Tom, who is expected for a visit, and Huck plays along. It turns out their nephew is Tom Sawyer. When Tom arrives, he pretends to be his brother Sid, and develops a theatrical plan to free Jim. Huck attempts to warn the King and the Duke that Jim alerted the local residents to their scam but sees them tarred and feathered and being run out of town on a rail.

Tom is wounded during Jim’s escape. Instead of fleeing, Jim stays to tend to him and is arrested and returned to the Phelpses. Tom's Aunt Polly arrives and reveals Huck’s and Tom’s true identities. She explains that Miss Watson has died, and that she freed Jim in her will. Tom admits he knew but wanted to "rescue" Jim in style. Jim tells Huck that Pap was the dead man in the floating house. Huck declares he will flee to Indian Territory to escape being adopted by the Phelpses.

Characters

In order of appearance:
 * Tom Sawyer is Huck's best friend and peer, the main character of other Twain novels and the leader of the town boys in adventures. He is mischievous, good-hearted, and "the best fighter and the smartest kid in town".
 * Huckleberry Finn, "Huck" to his friends, is a boy about "thirteen or fourteen or along there" years old (Chapter 17). He has been brought up by his father, the town drunk, and has a difficult time fitting into society. In the novel, Huck's good nature offers a contrast to the inadequacies and inequalities in society.
 * Widow Douglas is the kind woman who takes Huck in after he helps save her from a violent home invasion. She tries her best to "sivilize" (civilize) Huck, believing it is her Christian duty to do so.
 * Miss Watson is the widow's sister, a tough old spinster who also lives with them. She is fairly hard on Huck, causing him to resent her a good deal. Mark Twain may have drawn inspiration for this character from several people he knew in his life.
 * Jim is Miss Watson's physically large but mild-mannered slave. Huck becomes very close to Jim when they reunite after Jim flees Miss Watson's household to seek refuge from slavery, and Huck and Jim become fellow travelers on the Mississippi River. Jim is shown to be honorable, perceptive, and intelligent, despite his lack of education and prejudice he faces.
 * "Pap" Finn is Huck's father, a brutal alcoholic drifter. He resents Huck getting any kind of education. His only genuine interest in his son involves begging or extorting money to feed his alcohol addiction.
 * Judith Loftus plays a small part in the novel — as the kind and perceptive woman whom Huck talks to in order to find out about the search for Jim — but many critics believe her to be the best drawn female character in the novel.
 * The Grangerfords, an aristocratic Kentuckian family headed by the sexagenarian Colonel Saul Grangerford, take Huck in after he is separated from Jim on the Mississippi. Huck becomes close friends with the youngest male of the family, Buck Grangerford, who is Huck's age. By the time Huck meets them, the Grangerfords have been engaged in an age-old blood feud with another local family, the Shepherdsons.
 * The Duke and the King are two otherwise unnamed con artists whom Huck and Jim take aboard their raft just before the start of their Arkansas adventures. They pose as the long-lost Duke of Bridgewater and the long-dead Louis XVII of France in an attempt to over-awe Huck and Jim, who quickly come to recognize them for what they are, but cynically pretend to accept their claims to avoid conflict.
 * Doctor Robinson is the only man who recognizes that the King and Duke are phonies when they pretend to be British. He warns the townspeople, but they ignore him.
 * Mary Jane, Joanna, and Susan Wilks are the three young nieces of their wealthy guardian, Peter Wilks, who has recently died. The Duke and the King try to steal their inheritance by posing as Peter's estranged brothers from England but are eventually thwarted.
 * Aunt Sally and Uncle Silas Phelps buy Jim from the Duke and the King. She is a loving, high-strung "farmer's wife", and he a plodding old man, both a farmer and a preacher.

Themes
Adventures of Huckleberry Finn explores themes of race and identity; what it means to be free and civilized; and the ideas of humanity and social responsibility in the changing landscape of America. A complexity exists concerning Jim's character. While some scholars point out that Jim is good-hearted and moral, and he is not unintelligent (in contrast to several of the more negatively depicted white characters), others have criticized the novel as racist, citing the use of the word "nigger" and emphasizing the stereotypically "comic" treatment of Jim's lack of education, superstition and ignorance. This argument is supported by incidents early in the novel where Huck deliberately "tricks" Jim, taking advantage of his gullibility and Jim still remains loyal to him.

But this novel is also Huck's 'coming of age' story where he overcomes his initial biases and forms a deeper bond with Jim. Throughout the story, Huck is in moral conflict with the received values of the society in which he lives. Huck is unable consciously to rebut those values even in his thoughts but he makes a moral choice based on his own valuation of Jim's friendship and human worth, a decision in direct opposition to the things he has been taught. Twain, in his lecture notes, proposes that "a sound heart is a surer guide than an ill-trained conscience" and goes on to describe the novel as "a book of mine where a sound heart and a deformed conscience come into collision and conscience suffers defeat".

To highlight the hypocrisy required to condone slavery within an ostensibly moral system, Twain has Huck's father enslave his son, isolate him and beat him. When Huck escapes, he immediately encounters Jim "illegally" doing the same thing. The treatments both of them receive are radically different, especially in an encounter with Mrs. Judith Loftus who takes pity on who she presumes to be a runaway apprentice, Huck, yet boasts about her husband sending the hounds after a runaway slave, Jim.

Some scholars discuss Huck's own character, and the novel itself, in the context of its relation to African-American culture as a whole. John Alberti quotes Shelley Fisher Fishkin, who writes in her 1990s book Was Huck Black?: Mark Twain and African-American Voices, "by limiting their field of inquiry to the periphery," white scholars "have missed the ways in which African-American voices shaped Twain's creative imagination at its core." It is suggested that the character of Huckleberry Finn illustrates the correlation, and even interrelatedness, between white and Black culture in the United States.

Illustrations
The original illustrations were done by E. W. Kemble, at the time a young artist working for Life magazine. Kemble was hand-picked by Twain, who admired his work. Hearn suggests that Twain and Kemble had a similar skill, writing that: "Whatever he may have lacked in technical grace ... Kemble shared with the greatest illustrators the ability to give even the minor individual in a text his own distinct visual personality; just as Twain so deftly defined a full-rounded character in a few phrases, so too did Kemble depict with a few strokes of his pen that same entire personage."

As Kemble could afford only one model, most of his illustrations produced for the book were done by guesswork. When the novel was published, the illustrations were praised even as the novel was harshly criticized. E.W. Kemble produced another set of illustrations for Harper's and the American Publishing Company in 1898 and 1899 after Twain lost the copyright.

Publication's effect on literary climate

Twain initially conceived of the work as a sequel to The Adventures of Tom Sawyer that would follow Huckleberry Finn through adulthood. Beginning with a few pages he had removed from the earlier novel, Twain began work on a manuscript he originally titled Huckleberry Finn's Autobiography. Twain worked on the manuscript off and on for the next several years, ultimately abandoning his original plan of following Huck's development into adulthood. He appeared to have lost interest in the manuscript while it was in progress, and set it aside for several years. After making a trip down the Hudson River, Twain returned to his work on the novel. Upon completion, the novel's title closely paralleled its predecessor's: Adventures of Huckleberry Finn (Tom Sawyer's Comrade).

Mark Twain composed the story in pen on notepaper between 1876 and 1883. Paul Needham, who supervised the authentication of the manuscript for Sotheby's books and manuscripts department in New York in 1991, stated, "What you see is [Clemens'] attempt to move away from pure literary writing to dialect writing". For example, Twain revised the opening line of Huck Finn three times. He initially wrote, "You will not know about me", which he changed to, "You do not know about me", before settling on the final version, "You don't know about me, without you have read a book by the name of 'The Adventures of Tom Sawyer'; but that ain't no matter." The revisions also show how Twain reworked his material to strengthen the characters of Huck and Jim, as well as his sensitivity to the then-current debate over literacy and voting.

A later version was the first typewritten manuscript delivered to a printer.

Demand for the book spread outside of the United States. Adventures of Huckleberry Finn was eventually published on December 10, 1884, in Canada and the United Kingdom, and on February 18, 1885, in the United States. The illustration on page 283 became a point of issue after an engraver, whose identity was never discovered, made a last-minute addition to the printing plate of Kemble's picture of old Silas Phelps, which drew attention to Phelps' groin. Thirty thousand copies of the book had been printed before the obscenity was discovered. A new plate was made to correct the illustration and repair the existing copies.

In 1885, the Buffalo Public Library's curator, James Fraser Gluck, approached Twain to donate the manuscript to the library. Twain did so. Later it was believed that half of the pages had been misplaced by the printer. In 1991, the missing first half turned up in a steamer trunk owned by descendants of Gluck's. The library successfully claimed possession and, in 1994, opened the Mark Twain Room to showcase the treasure.

In relation to the literary climate at the time of the book's publication in 1885, Henry Nash Smith describes the importance of Mark Twain's already established reputation as a "professional humorist", having already published over a dozen other works. Smith suggests that while the "dismantling of the decadent Romanticism of the later nineteenth century was a necessary operation," Adventures of Huckleberry Finn illustrated "previously inaccessible resources of imaginative power, but also made vernacular language, with its new sources of pleasure and new energy, available for American prose and poetry in the twentieth century."

Critical reception and banning

While it is clear that Adventures of Huckleberry Finn was controversial from the outset, Norman Mailer, writing in The New York Times in 1984, concluded that Twain's novel was not initially "too unpleasantly regarded." In fact, Mailer writes: "the critical climate could hardly anticipate T. S. Eliot and Ernest Hemingway's encomiums 50 years later," reviews that would remain longstanding in the American consciousness.

Alberti suggests that the academic establishment responded to the book's challenges both dismissively and with confusion. During Twain's time and today, defenders of Adventures of Huckleberry Finn "lump all nonacademic critics of the book together as extremists and 'censors', thus equating the complaints about the book's 'coarseness' from the genteel bourgeois trustees of the Concord Public Library in the 1880s with more recent objections based on race and civil rights."

Upon issue of the American edition in 1885, several libraries banned it from their shelves. The early criticism focused on what was perceived as the book's crudeness. One incident was recounted in the newspaper the Boston Transcript: The Concord (Mass.) Public Library committee has decided to exclude Mark Twain's latest book from the library. One member of the committee says that, while he does not wish to call it immoral, he thinks it contains but little humor, and that of a very coarse type. He regards it as the veriest trash. The library and the other members of the committee entertain similar views, characterizing it as rough, coarse, and inelegant, dealing with a series of experiences not elevating, the whole book being more suited to the slums than to intelligent, respectable people.

Writer Louisa May Alcott criticized the book's publication as well, saying that if Twain "[could not] think of something better to tell our pure-minded lads and lasses he had best stop writing for them".

In 1905, New York's Brooklyn Public Library also banned the book due to "bad word choice" and Huck's having "not only itched but scratched" within the novel, which was considered obscene. When asked by a Brooklyn librarian about the situation, Twain sardonically replied: "I am greatly troubled by what you say. I wrote 'Tom Sawyer' & 'Huck Finn' for adults exclusively, & it always distressed me when I find that boys and girls have been allowed access to them. The mind that becomes soiled in youth can never again be washed clean. I know this by my own experience, & to this day I cherish an unappeased bitterness against the unfaithful guardians of my young life, who not only permitted but compelled me to read an unexpurgated Bible through before I was 15 years old. None can do that and ever draw a clean sweet breath again on this side of the grave."

Many subsequent critics, Ernest Hemingway among them, have deprecated the final chapters, claiming the book "devolves into little more than minstrel-show satire and broad comedy" after Jim is detained. Although Hemingway declared, "All modern American literature comes from" Huck Finn, and hailed it as "the best book we've had", he cautioned, "If you must read it you must stop where the Nigger Jim is stolen from the boys. That is the real end. The rest is just cheating." The African-American writer Ralph Ellison argued that "Hemingway missed completely the structural, symbolic and moral necessity for that part of the plot in which the boys rescue Jim. Yet it is precisely this part which gives the novel its significance." Pulitzer Prize winner Ron Powers states in his Twain biography (Mark Twain: A Life) that "Huckleberry Finn endures as a consensus masterpiece despite these final chapters", in which Tom Sawyer leads Huck through elaborate machinations to rescue Jim.

Controversy
In his introduction to The Annotated Huckleberry Finn, Michael Patrick Hearn writes that Twain "could be uninhibitedly vulgar", and quotes critic William Dean Howells, a Twain contemporary, who wrote that the author's "humor was not for most women". However, Hearn continues by explaining that "the reticent Howells found nothing in the proofs of Huckleberry Finn so offensive that it needed to be struck out".

Racial stereotyping
Much of modern scholarship of Huckleberry Finn has focused on its treatment of race. Many Twain scholars have argued that the book, by humanizing Jim and exposing the fallacies of the racist assumptions of slavery, is an attack on racism. Others have argued that the book falls short on this score, especially in its depiction of Jim. According to Professor Stephen Railton of the University of Virginia, Twain was unable to fully rise above the stereotypes of Black people that White readers of his era expected and enjoyed, and, therefore, resorted to minstrel show-style comedy to provide humor at Jim's expense, and ended up confirming rather than challenging late 19th-century racist stereotypes.

In one instance, the controversy caused a drastically altered interpretation of the text: in 1955, CBS tried to avoid controversial material in a televised version of the book, by deleting all mention of slavery and omitting the character of Jim entirely.

Use of the word "nigger"
Because of this controversy over whether Huckleberry Finn is racist or anti-racist, and because the word "nigger" is frequently used in the novel (a commonly used word in Twain's time that has since become vulgar and taboo), many have questioned the appropriateness of teaching the book in the U.S. public school system—this questioning of the word "nigger" is illustrated by a school administrator of Virginia in 1982 calling the novel the "most grotesque example of racism I've ever seen in my life". According to the American Library Association, Huckleberry Finn was the fifth-most frequently challenged book in the United States during the 1990s.

There have been several more recent cases involving protests for the banning of the novel. In 2003, high school student Calista Phair and her grandmother, Beatrice Clark, in Renton, Washington, proposed banning the book from classroom learning in the Renton School District, though not from any public libraries, because of the word "nigger". The two curriculum committees that considered her request eventually decided to keep the novel on the 11th grade curriculum, though they suspended it until a panel had time to review the novel and set a specific teaching procedure for the novel's controversial topics.

In 2009, a white Washington state high school teacher, John Foley, called for replacing Adventures of Huckleberry Finn with a more modern novel. In an opinion column that Foley wrote in the Seattle Post Intelligencer, he states that all "novels that use the 'N-word' repeatedly need to go." He states that teaching the novel is not only unnecessary, but difficult due to the offensive language within the novel with many students becoming uncomfortable at "just hear[ing] the N-word."

In 2016, Adventures of Huckleberry Finn was removed from a public school district in Virginia, along with the novel To Kill a Mockingbird, due to their use of racial slurs.

Expurgated editions
Publishers have made their own attempts at easing the controversy by way of releasing editions of the book with the word "nigger" replaced by less controversial words. A 2011 edition of the book, published by NewSouth Books, employed the word "slave" (although the word is not properly applied to a freed man). Their argument for making the change was to offer the reader a choice of reading a "sanitized" version if they were not comfortable with the original. Mark Twain scholar Alan Gribben said he hoped the edition would be more friendly for use in classrooms, rather than have the work banned outright from classroom reading lists due to its language.

According to publisher Suzanne La Rosa, "At NewSouth, we saw the value in an edition that would help the works find new readers. If the publication sparks good debate about how language impacts learning or about the nature of censorship or the way in which racial slurs exercise their baneful influence, then our mission in publishing this new edition of Twain's works will be more emphatically fulfilled." Another scholar, Thomas Wortham, criticized the changes, saying the new edition "doesn't challenge children to ask, 'Why would a child like Huck use such reprehensible language?'"

Film

 * Huck and Tom (1918 silent) by Famous Players–Lasky; directed by William Desmond Taylor; starring Jack Pickford as Tom, Robert Gordon as Huck and Clara Horton as Becky
 * Huckleberry Finn (1920 silent) by Famous Players–Lasky; directed by William Desmond Taylor; starring Lewis Sargent as Huck, Gordon Griffith as Tom and Thelma Salter as Becky
 * Huckleberry Finn (1931) by Paramount Pictures; directed by Norman Taurog; starring Jackie Coogan as Tom, Junior Durkin as Huck, and Mitzi Green as Becky
 * The Adventures of Huckleberry Finn (1939) by MGM; directed by Richard Thorpe; starring Mickey Rooney as Huck
 * The Adventures of Huckleberry Finn (1955), starring Thomas Mitchell and John Carradine
 * The Adventures of Huckleberry Finn (1960), directed by Michael Curtiz, starring Eddie Hodges and Archie Moore
 * Hopelessly Lost (1973), a Soviet film
 * Huckleberry Finn (1974), a musical film
 * Huckleberry Finn (1975), an ABC movie of the week with Ron Howard as Huck Finn
 * The Adventures of Con Sawyer and Hucklemary Finn (1985), an ABC movie of the week with Drew Barrymore as Con Sawyer
 * The Adventures of Huck Finn (1993), starring Elijah Wood and Courtney B. Vance
 * Tom and Huck (1995), starring Jonathan Taylor Thomas as Tom and Brad Renfro as Huck
 * Tomato Sawyer and Huckleberry Larry's Big River Rescue (2008), a VeggieTales parody
 *  (2012), a German film starring Leon Seidel and directed by Hermine Huntgeburth
 * Tom Sawyer & Huckleberry Finn (2014), starring Joel Courtney as Tom Sawyer, Jake T. Austin as Huckleberry Finn, Katherine McNamara as Becky Thatcher

Television

 * Huckleberry no Bōken, a 1976 Japanese anime with 26 episodes
 * Huckleberry Finn and His Friends, a 1979 series starring Ian Tracey
 * Adventures of Huckleberry Finn, a 1985 PBS TV adaptation directed by Peter H. Hunt, starring Patrick Day and Samm-Art Williams, with 4 one hour episodes(240 minutes)
 * Huckleberry Finn Monogatari (ハックルベリー・フィン物語), a 1994 Japanese anime with 26 episodes, produced by NHK

Other

 * The Adventures of Huckleberry Finn (1973), by Robert James Dixson – a simplified version
 * Big River: The Adventures of Huckleberry Finn, a 1985 Broadway musical with lyrics and music by Roger Miller
 * Manga Classics: Adventures of Huckleberry Finn, published by UDON Entertainment's Manga Classics imprint was released in November 2017.
 * Big Jim and the White Boy: An American Classic Reimagined, an upcoming graphic novel reimagining written and illustrated by David F. Walker and Marcus Kwame Anderson, and scheduled to be released in October 2024. Omitting Twain's negative portrayal of African Americans, Big Jim and the White Boy will expand the original novel by depicting Big Jim as the primary protagonist and Huckleberry Finn as his sidekick. The plot will be about Big Jim and Huck journeying through Civil War-era United States to rescue the former's enslaved wife and children and even becoming Underground Railroad agents, before going throughout the decades as generations of Big Jim's descendants fight for their rights.

Literature

 * Finn: A Novel (2007), by Jon Clinch – a novel about Huck's father, Pap Finn (ISBN 0812977149)
 * Huck Out West (2017), by Robert Coover – continues Huck's and Tom's adventures during the 1860s and 1870s (ISBN 0393608441)
 * James (2024), by Percival Everett – a novel narrated by Jim that reimagines the plot of Twain's 'Adventures of Huckleberry Finn' from his point of view. (ISBN 0385550367)
 * The Further Adventures of Huckleberry Finn (1983) by Greg Matthews – continues Huck's and Jim's adventures as they "light out for the territory" and wind up in the throes of the California Gold Rush of 1849
 * My Jim (2005), by Nancy Rawles – a novel narrated largely by Sadie, Jim's enslaved wife (ISBN 140005401X)

Music

 * Mississippi Suite (1926), by Ferde Grofe: the second movement is a lighthearted whimsical piece entitled "Huckleberry Finn"
 * Huckleberry Finn EP (2009), comprising five songs from Kurt Weill's unfinished musical, by Duke Special

Television

 * The New Adventures of Huckleberry Finn, a 1968 children's series produced by Hanna-Barbera combining live-action and animation

title: Adventures of Huckleberry Finn


text:
Harpsichord

A harpsichord (clavicembalo, clavecin, Cembalo; clavecín, cravo, клавеси́н ( tr. klavesín or klavesin), klavecimbel, klawesyn) is a musical instrument played by means of a keyboard. This activates a row of levers that turn a trigger mechanism that plucks one or more strings with a small plectrum made from quill or plastic. The strings are under tension on a soundboard, which is mounted in a wooden case; the soundboard amplifies the vibrations from the strings so that the listeners can hear it. Like a pipe organ, a harpsichord may have more than one keyboard manual, and even a pedal board. Harpsichords may also have stop buttons which add or remove additional octaves. Some harpsichords may have a buff stop, which brings a strip of buff leather or other material in contact with the strings, muting their sound to simulate the sound of a plucked lute.

The term denotes the whole family of similar plucked-keyboard instruments, including the smaller virginals, muselar, and spinet. The harpsichord was widely used in Renaissance and Baroque music, both as an accompaniment instrument and as a soloing instrument. During the Baroque era, the harpsichord was a standard part of the continuo group. The basso continuo part acted as the foundation for many musical pieces in this era. During the late 18th century, with the development of the fortepiano (and then the increasing use of the piano in the 19th century) the harpsichord gradually disappeared from the musical scene (except in opera, where it continued to be used to accompany recitative). In the 20th century, it made a resurgence, being used in historically informed performances of older music, in new compositions, and, in rare cases, in certain styles of popular music (e.g., Baroque pop).

History

The harpsichord was most likely invented in the late Middle Ages. By the 16th century, harpsichord makers in Italy were making lightweight instruments with low tension brass stringing. A different approach was taken in the Southern Netherlands starting in the late 16th century, notably by the Ruckers family. Their harpsichords used a heavier construction and produced a more powerful and distinctive tone with higher tension steel treble stringing. These included the first harpsichords with two keyboards, used for transposition.

The Flemish instruments served as the model for 18th-century harpsichord construction in other nations. In France, the double keyboards were adapted to control different choirs of strings, making a more musically flexible instrument (so-called 'expressive doubles'). Instruments from the peak of the French tradition, by makers such as the Blanchet family and Pascal Taskin, are among the most widely admired of all harpsichords, and are frequently used as models for the construction of modern instruments. In England, the Kirkman and Shudi firms produced sophisticated harpsichords of great power and sonority. German builders such as Hieronymus Albrecht Hass extended the sound repertoire of the instrument by adding sixteen-foot and two-foot choirs; these instruments have recently served as models for modern builders.

Around the year 1700 the first fortepiano was built by Bartolomeo Cristofori. The early fortepiano uses percussion, the strings being struck with leathered paper hammers instead of being plucked. The fortepiano is capable of changes in dynamic volume, giving it its name. This is unlike the harpsichord. By the late 18th century the harpsichord was supplanted by the piano and almost disappeared from view for most of the 19th century: an exception was its continued use in opera for accompanying recitative, but the piano sometimes displaced it even there.

Twentieth-century efforts to revive the harpsichord began with instruments that used piano technology, with heavy strings and metal frames. Starting in the middle of the 20th century, ideas about harpsichord making underwent a major change, when builders such as Frank Hubbard, William Dowd, and Martin Skowroneck sought to re-establish the building traditions of the Baroque period. Harpsichords of this type of historically informed building practice dominate the current scene.

Mechanism
Harpsichords vary in size and shape, but all have the same basic mechanism. The player depresses a key that rocks over a pivot in the middle of its length. The other end of the key lifts a jack (a long strip of wood) that holds a small plectrum (a wedge-shaped piece of quill, often made of plastic in the 21st century), which plucks the string. When the player releases the key, the far end returns to its rest position, and the jack falls back; the plectrum, mounted on a tongue mechanism that can swivel backwards away from the string, passes the string without plucking it again. As the key reaches its rest position, a felt damper atop the jack stops the string's vibrations. These basic principles are explained in detail below.

 * The keylever is a simple pivot, which rocks on a balance pin that passes through a hole drilled through the keylever.
 * The jack is a thin, rectangular piece of wood that sits upright on the end of the keylever. The jacks are held in place by the registers. These are two long strips of wood (the upper movable, the lower fixed), which run in the gap between pinblock and bellyrail. The registers have rectangular mortises (holes) through which the jacks pass as they can move up and down. The registers hold the jacks in the precise location needed to pluck the string.
 * In the jack, a plectrum juts out almost horizontally (normally the plectrum is angled upwards a tiny amount) and passes just under the string. Historically, plectra were made of bird quill or leather; many modern harpsichords have plastic (delrin or celcon) plectra.
 * When the front of the key is pressed, the back of the key rises, the jack is lifted, and the plectrum plucks the string.
 * The vertical motion of the jack is then stopped by the jackrail (also called the upper rail), which is covered with soft felt to muffle the impact.
 * When the key is released, the jack falls back down under its own weight, and the plectrum passes back under the string. This is made possible by having the plectrum held in a tongue attached with a pivot and a spring to the body of the jack. The bottom surface of the plectrum is cut at a slant; thus when the descending plectrum touches the string from above, the angled lower surface provides enough force to push the tongue backward.
 * When the jack arrives in fully lowered position, the felt damper touches the string, causing the note to cease.

Strings, tuning, and soundboard
Each string is wound around a tuning pin (also known as a wrest pin) at the end nearest the player. When rotated with a wrench or tuning hammer, the tuning pin adjusts the tension so that the string sounds the correct pitch. Tuning pins are held tightly in holes drilled in the pinblock or wrestplank, an oblong hardwood plank. Proceeding from the tuning pin, a string next passes over the nut, a sharp edge that is made of hardwood and is normally attached to the wrestplank. The section of the string beyond the nut forms its vibrating length, which is plucked and creates sound.

At the other end of its vibrating length, the string passes over the bridge, another sharp edge made of hardwood. As with the nut, the horizontal position of the string along the bridge is determined by a vertical metal pin inserted into the bridge, against which the string rests. The bridge itself rests on a soundboard, a thin panel of wood usually made of spruce, fir or—in some Italian harpsichords—cypress. The soundboard efficiently transmits the vibrations of the strings into vibrations in the air; without a soundboard, the strings would produce only a very feeble sound. A string is attached at its far end by a loop to a hitchpin that secures it to the case.

Multiple manuals and choirs of strings

While many harpsichords have one string per note, more elaborate harpsichords can have two or more strings for each note. When there are multiple strings for each note, these additional strings are called "choirs" of strings. This provides two advantages: the ability to vary volume and ability to vary tonal quality. Volume is increased when the mechanism of the instrument is set up by the player (see below) so that the press of a single key plucks more than one string. Tonal quality can be varied in two ways. First, different choirs of strings can be designed to have distinct tonal qualities, usually by having one set of strings plucked closer to the nut, which emphasizes the higher harmonics, and produces a "nasal" sound quality. The mechanism of the instrument, called "stops" (following the use of the term in pipe organs) permits the player to select one choir or the other. Second, having one key pluck two strings at once changes not just volume but also tonal quality; for instance, when two strings tuned to the same pitch are plucked simultaneously, the note is not just louder but also richer and more complex.

A particularly vivid effect is obtained when the strings plucked simultaneously are an octave apart. This is normally heard by the ear not as two pitches but as one: the sound of the higher string is blended with that of the lower one, and the ear hears the lower pitch, enriched in tonal quality by the additional strength in the upper harmonics of the note sounded by the higher string.

When describing a harpsichord it is customary to specify its choirs of strings, often called its disposition. To describe the pitch of the choirs of strings, pipe organ terminology is used. Strings at eight-foot pitch (8') sound at the normal expected pitch, strings at four-foot pitch (4') sound an octave higher. Harpsichords occasionally include a sixteen-foot (16') choir (one octave lower than eight-foot) or a two-foot (2') choir (two octaves higher; quite rare). When there are multiple choirs of strings, the player is often able to control which choirs sound. This is usually done by having a set of jacks for each choir, and a mechanism for "turning off" each set, often by moving the upper register (through which the jacks slide) sideways a short distance, so that their plectra miss the strings. In simpler instruments this is done by manually moving the registers, but as the harpsichord evolved, builders invented levers, knee levers and pedal mechanisms to make it easier to change registration.

Harpsichords with more than one keyboard (this usually means two keyboards, stacked one on top of the other in a step-wise fashion, as with pipe organs) provide flexibility in selecting which strings play, since each manual can be set to control the plucking of a different set of strings. This means that a player can have, for instance, an 8' manual and a 4' manual ready for use, enabling him to switch between them to obtain higher (or lower) pitches or different tone. In addition, such harpsichords often have a mechanism (the "coupler") that couples manuals together, so that a single manual plays both sets of strings.

The most flexible system is the French "shove coupler", in which the lower manual slides forward and backward. In the backward position, "dogs" attached to the upper surface of the lower manual engage the lower surface of the upper manual's keys. Depending on choice of keyboard and coupler position, the player can select any of the sets of jacks labeled in "figure 4" as A, or B and C, or all three.

The English "dogleg" jack system (also used in Baroque Flanders) does not require a coupler. The jacks labeled A in Figure 5 have a "dogleg" shape that permits either keyboard to play A. If the player wishes to play the upper 8' from the upper manual only and not from the lower manual, a stop handle disengages the jacks labeled A and engages instead an alternative row of jacks called "lute stop" (not shown in the Figure). A lute stop is used to imitate the gentle sound of a plucked lute. The use of multiple manuals in a harpsichord was not originally provided for the flexibility in choosing which strings would sound, but rather for transposition of the instrument to play in different keys (see History of the harpsichord).

Some early harpsichords used a short octave for the lowest register. The rationale behind this system was that the low notes F♯ and G♯ are seldom needed in early music. Deep bass notes typically form the root of the chord, and F♯ and G♯ chords were seldom used at this time. In contrast, low C and D, both roots of very common chords, are sorely missed if a harpsichord with lowest key E is tuned to match the keyboard layout. When scholars specify the pitch range of instruments with this kind of short octave, they write "C/E", meaning that the lowest note is a C, played on a key that normally would sound E. In another arrangement, known as "G/B', the apparent lowest key B is tuned to G, and apparent C-sharp and D-sharp are tuned to A and B respectively.

Case
The wooden case holds in position all of the important structural members: pinblock, soundboard, hitchpins, keyboard, and the jack action. It usually includes a solid bottom, and also internal bracing to maintain its form without warping under the tension of the strings. Cases vary greatly in weight and sturdiness: Italian harpsichords are often of light construction; heavier construction is found in the later Flemish instruments and those derived from them.

The case also gives the harpsichord its external appearance and protects the instrument. A large harpsichord is, in a sense, a piece of furniture, as it stands alone on legs and may be styled in the manner of other furniture of its place and period. Early Italian instruments, on the other hand, were so light in construction that they were treated rather like a violin: kept for storage in a protective outer case, and played after taking it out of its case and placing it on a table. Such tables were often quite high – until the late 18th century people usually played standing up. Eventually, harpsichords came to be built with just a single case, though an intermediate stage also existed: the false inner–outer, which for purely aesthetic reasons was built to look as if the outer case contained an inner one, in the old style. Even after harpsichords became self-encased objects, they often were supported by separate stands, and some modern harpsichords have separate legs for improved portability.

Many harpsichords have a lid that can be raised, a cover for the keyboard, and a music stand for holding sheet music and scores.

Harpsichords have been decorated in a great many different ways: with plain buff paint (e.g. some Flemish instruments), with paper printed with patterns, with leather or velvet coverings, with chinoiserie, or occasionally with highly elaborate painted artwork.

Virginals
The virginal is a smaller and simpler rectangular form of the harpsichord having only one string per note; the strings run parallel to the keyboard, which is on the long side of the case.

Spinet
A spinet is a harpsichord with the strings set at an angle (usually about 30 degrees) to the keyboard. The strings are too close together for the jacks to fit between them. Instead, the strings are arranged in pairs, and the jacks are in the larger gaps between the pairs. The two jacks in each gap face in opposite directions, and each plucks a string adjacent to the gap.

The English diarist Samuel Pepys mentions his "tryangle" several times. This was not the percussion instrument that we call triangle today; rather, it was a name for octave-pitched spinets, which were triangular in shape.

Clavicytherium
A clavicytherium is a harpsichord with the soundboard and strings mounted vertically facing the player, the same space-saving principle as an upright piano. In a clavicytherium, the jacks move horizontally without the assistance of gravity, so that clavicytherium actions are more complex than those of other harpsichords.

Ottavino
Ottavini are small spinets or virginals at four-foot pitch. Harpsichords at octave pitch were more common in the early Renaissance, but lessened in popularity later on. However, the ottavino remained very popular as a domestic instrument in Italy until the 19th century. In the Low Countries, an ottavino was commonly paired with an 8' virginals, encased in a small cubby under the soundboard of the larger instrument. The ottavino could be removed and placed on top of the virginal, making, in effect, a double manual instrument. These are sometimes called 'mother-and-child' or 'double' virginals.

Pedal harpsichord
Occasionally, harpsichords were built which included another set or sets of strings underneath and played by foot-operated pedal keyboard which trigger the plucking of the lowest-pitched keys of the harpsichord. Although there are no known extant pedal harpsichords from the 18th century or before, from Adlung (1758): the lower set of usually 8' strings "...is built like an ordinary harpsichord, but with an extent of two octaves only. The jacks are similar, but they will benefit from being arranged back to back, since the two [bass] octaves take as much space as four in an ordinary harpsichord Prior to 1980 when Keith Hill introduced his design for a pedal harpsichord, most pedal harpsichords were built based on the designs of extant pedal pianos from the 19th century, in which the instrument is as wide as the pedalboard. While these were mostly intended as practice instruments for organists, a few pieces are believed to have been written specifically for the pedal harpsichord. However, the set of pedals can augment the sound from any piece performed on the instrument, as demonstrated on several albums by E. Power Biggs.

Other variants
The archicembalo, built in the 16th century, had an unusual keyboard layout, designed to accommodate variant tuning systems demanded by compositional practice and theoretical experimentation. More common were instruments with split sharps, also designed to accommodate the tuning systems of the time.

The folding harpsichord was an instrument that could be folded up to make it more compact, thus facilitating travelling with it.

Compass and pitch range
On the whole, earlier harpsichords have smaller ranges than later ones, although there are many exceptions. The largest harpsichords have a range of just over five octaves, and the smallest have under four. Usually, the shortest keyboards were given extended range in the bass with a "short octave". The traditional pitch range for a 5-octave instrument is F1–F6 (FF–f‴).

Tuning pitch is often taken to be A4 = 415 Hz, roughly a semitone lower than the modern standard concert pitch of A4 = 440 Hz. An accepted exception is for French baroque repertoire, which is often performed with a = 392 Hz, approximately a semitone lower again. See Jean-Philippe Rameau's Treatise on Harmony (1722) [Dover Publications], Book One, chapter five, for insight into French baroque tuning; "Since most of these semitones are absolutely necessary in the tuning of organs and other similar instruments, the following chromatic system has been drawn up." Tuning an instrument nowadays usually starts with setting an A; historically it would commence from a C or an F. The harpsichord uses the bass clef (F clef).

Some modern instruments are built with keyboards that can shift sideways, allowing the player to align the mechanism with strings at either A = 415 Hz or A = 440 Hz. If a tuning other than equal temperament is used, the instrument requires retuning once the keyboard is shifted.

Classical period
The great bulk of the standard repertoire for the harpsichord was written during its first historical flowering, the Renaissance and Baroque eras.

The first music written specifically for solo harpsichord was published around the early 16th century. Composers who wrote solo harpsichord music were numerous during the whole Baroque era in European countries including Italy, Germany, England and France. Solo harpsichord compositions included dance suites, fantasias, and fugues. Among the most famous composers who wrote for the harpsichord were the members of English virginal school of the late Renaissance, notably William Byrd (c. 1540–1623). In France, a great number of highly characteristic solo works were created and compiled into four books of ordres by François Couperin (1668–1733). Domenico Scarlatti (1685–1757) began his career in Italy but wrote most of his solo harpsichord works in Spain; his most famous work is his series of 555 harpsichord sonatas. Perhaps the most celebrated composers who wrote for the harpsichord were Georg Friedrich Händel (1685–1759), who composed numerous suites for harpsichord, and especially J. S. Bach (1685–1750), whose solo works (for instance, The Well-Tempered Clavier and the Goldberg Variations), continue to be performed very widely, often on the piano. Bach was also a pioneer of the harpsichord concerto, both in works designated as such, and in the harpsichord part of his Fifth Brandenburg Concerto.

Two of the most prominent composers of the Classical era, Joseph Haydn (1732–1809) and Wolfgang Amadeus Mozart (1756–1791), wrote harpsichord music. For both, the instrument featured in the earlier period of their careers,

Revival
Through the 19th century, the harpsichord was almost completely supplanted by the piano. In the 20th century, composers returned to the instrument, as they sought out variation in the sounds available to them. Under the influence of Arnold Dolmetsch, the harpsichordists Violet Gordon-Woodhouse (1872–1951) and in France, Wanda Landowska (1879–1959), were at the forefront of the instrument's renaissance. Concertos for the instrument were written by Francis Poulenc (the Concert champêtre, 1927–28), and Manuel de Falla. Elliott Carter's Double Concerto is scored for harpsichord, piano and two chamber orchestras. For a detailed account of music composed for the revived harpsichord, see Contemporary harpsichord.

title: Harpsichord