172-634: The idea of the Panama Canal dates back to 1513, when the Spanish conquistador Vasco Núñez de Balboa first crossed the Isthmus of Panama . This narrow land bridge between North and South America was a fine location to dig a water passage between the Atlantic and Pacific Oceans. The earliest European colonists recognized this, and several proposals for the construction of a canal were made. By
344-551: A caribou herd. For a mosquito to transmit disease, there must be favorable seasonal conditions, primarily humidity, temperature, and precipitation. El Niño affects the location and number of outbreaks in East Africa, Latin America, Southeast Asia and India . Climate change impacts the seasonal factors and in turn the dispersal of mosquitoes. Climate models can use historic data to recreate past outbreaks and to predict
516-1239: A family of the true flies (order Diptera) : the Culicidae (from the Latin culex , genitive culicis , meaning "midge" or "gnat"). They are members of the infraorder Culicomorpha and superfamily Culicoidea . The phylogenetic tree is based on the FLYTREE project. Ptychopteromorpha (phantom and primitive crane-flies) [REDACTED] Chironomidae (non-biting midges) [REDACTED] Simulioidea (blackflies and biting midges) [REDACTED] Dixidae (meniscus midges) [REDACTED] Corethrellidae (frog-biting midges) Chaoboridae (phantom midges) [REDACTED] Culicidae [REDACTED] other midges and gnats [REDACTED] all other flies, inc. Brachycera [REDACTED] The two subfamilies of mosquitoes are Anophelinae , containing three genera and approximately 430 species, and Culicinae , which contains 11 tribes, 108 genera and 3,046 species. Kyanne Reidenbach and colleagues analysed mosquito phylogenetics in 2009, using both nuclear DNA and morphology of 26 species. They note that Anophelinae
688-586: A US-controlled canal across Central America was a vital strategic interest of the country. This idea gained wide circulation after the destruction of the USS Maine in Cuba on February 15, 1898. Reversing a Walker Commission decision in favor of a Nicaraguan canal, Roosevelt encouraged the acquisition of the French Panama Canal effort. George S. Morison was the only commission member who argued for
860-429: A blood meal, and avoiding being killed by their vertebrate hosts. The eggs of most mosquitoes are laid in stagnant water, which may be a pond, a marsh, a temporary puddle, a water-filled hole in a tree, or the water-trapping leaf axils of a bromeliad . Some lay near the water's edge while others attach their eggs to aquatic plants. A few, like Opifex fuscus , can breed in salt-marshes. Wyeomyia smithii breeds in
1032-419: A blood meal. The mosquito's saliva is transferred to the host during the bite, and can cause an itchy rash . In addition, blood-feeding species can ingest pathogens while biting, and transmit them to other hosts. Those species include vectors of parasitic diseases such as malaria and filariasis , and arboviral diseases such as yellow fever and dengue fever . By transmitting diseases, mosquitoes cause
1204-795: A canal across the isthmus, with some favoring a canal across Nicaragua and others advocating the purchase of the French interests in Panama. Bunau-Varilla , who was seeking American involvement, asked for $ 100 million, but accepted $ 40 million in the face of the Nicaraguan option. In June 1902, the US Senate voted in favor of the Spooner Act , to pursue the Panamanian option, provided the necessary rights could be obtained. On 22 January 1903,
1376-548: A canal commission with researching possible construction; Nicaragua was chosen as the location both times. Although the Nicaraguan canal proposal was made redundant by the American takeover of the French Panama Canal project, increases in shipping volume and ship sizes have revived interest in the project. A canal across Nicaragua accommodating post- Panamax ships or a rail link carrying containers between ports on either coast have been proposed. Theodore Roosevelt believed that
1548-715: A canal. Numerous canals were built in other countries in the late 18th and early 19th centuries. The success of the Erie Canal through central New York in the United States in the 1820s and the collapse of the Spanish Empire in Latin America resulted in growing American interest in building an inter-oceanic canal. Beginning in 1826, US officials began negotiations with Gran Colombia (present-day Colombia, Venezuela, Ecuador, and Panama), hoping to gain
1720-538: A classic example of the era of gunboat diplomacy . The leaders of the new government in breakaway Panama felt they had no choice but to accept the canal treaty. Had the U.S. withdrawn its warships, the Colombian army would have returned to Panama and executed the members of the new government. "The notion that Roosevelt would abandon Panama at this point, that he would leave the junta to the vengeance of Colombia, that he would now suddenly turn around and treat with Bogota,
1892-533: A concession to build a canal. Jealous of their newly gained independence and fearing domination by the more powerful United States, president Simón Bolívar and New Granada officials declined American offers. After the collapse of Gran Colombia, New Granada remained unstable under constant government intrigue. Great Britain attempted to develop a canal in 1843. According to the New-York Daily Tribune , 24 August 1843, Barings Bank of London and
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#17327656149632064-734: A dam across the Chagres River in Gatún , near the Atlantic, and another on the Rio Grande , near the Pacific, to create an artificial lake accessed by locks. Digging less and avoiding unsanitary work and the danger of flooding was his priority, with an estimated lower cost of $ 100,000,000 (equivalent to $ 3,157,241,379 in 2023) and 50,000 lives saved, as mentioned in the motivation for his negative review of Lesseps' plan. The bankruptcy of
2236-459: A domestic form and an animal-biting form of the mosquito Aedes aegypti showed that the evolution of preference for human odour is linked to increases in the expression of the olfactory receptor AaegOr4. This recognises a compound present at high levels in human odour called sulcatone . However, the malaria mosquito Anopheles gambiae also has OR4 genes strongly activated by sulcatone, yet none of them are closely related to AaegOr4, suggesting that
2408-533: A form of parasitism ; in Edward O. Wilson 's phrase "Parasites ... are predators that eat prey in units of less than one." Micropredation is one of six major evolutionarily stable strategies within parasitism. It is distinguished by leaving the host still able to reproduce, unlike the activity of parasitic castrators or parasitoids ; and having multiple hosts, unlike conventional parasites. From this perspective, mosquitoes are ectoparasites , feeding on blood from
2580-435: A host observed by the mosquito allows it to select a host to feed on. This occurs when a mosquito notes the presence of CO 2 , as it then activates odour and visual search behaviours that it otherwise would not use. In terms of a mosquito’s olfactory system, chemical analysis has revealed that people who are highly attractive to mosquitoes produce significantly more carboxylic acids . A human's unique body odour indicates that
2752-522: A mosquito's visual search system includes sensitivity to wavelengths from different colours. Mosquitoes are attracted to longer wavelengths, correlated to the colours of red and orange as seen by humans, and range through the spectrum of human skin tones. In addition, they have a strong attraction to dark, high-contrast objects, because of how longer wavelengths are perceived against a lighter-coloured background. Different species of mosquitoes have evolved different methods of identifying target hosts. Study of
2924-478: A nascent independence movement among the Panamanian people, led to a revolution in Panama and to the negotiation of the Hay–Bunau-Varilla Treaty , thus simultaneously securing independence for Panama and an opportunity for the U.S. to lead a renewed effort to construct the canal. Colombia's response to the Panamanian independence movement was tempered by an American military presence; this is often cited as
3096-513: A reservoir for the canal. The layout of the canal as seen by a ship passing from the Atlantic to the Pacific is: Thus, the total length of the canal is 80 km (50 mi). In 2017 it took ships an average of 11.38 hours to pass between the canal's two outer locks. Mosquito Mosquitoes , the Culicidae , are a family of small flies consisting of 3,600 species . The word mosquito (formed by mosca and diminutive -ito )
3268-560: A sea-level canal (like the Suez), but he visited the site only a few times, during the dry season which lasts only four months of the year. His men were unprepared for the rainy season, during which the Chagres River , where the canal started, became a raging torrent, rising up to 10 m (33 ft). The dense jungle was alive with venomous snakes, insects, and spiders, but the worst challenges were yellow fever , malaria , and other tropical diseases, which killed thousands of workers; by 1884,
3440-593: A sea-level canal, as had been attempted by the French and temporarily abandoned by them in 1887 for a ten locks system designed by Philippe Bunau-Varilla, and definitively in 1898 for a lock-and-lake canal designed by the Comité Technique of the Compagnie Nouvelle de Canal de Panama as conceptualized by Adolphe Godin de Lépinay in 1879. But in 1906 Stevens, who had seen the Chagres in full flood,
3612-715: A self-educated engineer who had built the Great Northern Railroad . Stevens was not a member of the ICC; he increasingly viewed its bureaucracy as a serious hindrance, bypassing the commission and sending requests and demands directly to the Roosevelt administration in Washington, DC. One of Stevens' first achievements in Panama was in building and rebuilding the housing, cafeterias, hotels, water systems, repair shops, warehouses, and other infrastructure needed by
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#17327656149633784-666: A settlement began and resulted in the Torrijos–Carter Treaties . On 7 September 1977, the treaty was signed by President of the United States Jimmy Carter and Omar Torrijos , de facto leader of Panama. This mobilized the process of granting the Panamanians free control of the canal so long as Panama signed a treaty guaranteeing the permanent neutrality of the canal. The treaty led to full Panamanian control effective at noon on 31 December 1999, and
3956-495: A sitting president. Whether contract employees or government workers would build the canal was controversial. Bids for the canal's construction were opened in January 1907, and Knoxville , Tennessee-based contractor William J. Oliver was the low bidder. Stevens disliked Oliver, and vehemently opposed his choice. Although Roosevelt initially favored the use of a contractor, he eventually decided that army engineers should carry out
4128-537: A treaty, in the name of the Société civile internationale du Canal interocéanique par l'isthme du Darien headed by general Étienne Türr, with the Colombian government, known as the Wyse concession, to build an interoceanic canal through Panama. The first attempt to construct a canal through what was then Colombia's province of Panama began on 1 January 1881. The project was inspired by the diplomat Ferdinand de Lesseps , who
4300-874: Is Spanish and Portuguese for little fly . Mosquitoes have a slender segmented body , one pair of wings, three pairs of long hair-like legs, and specialized, highly elongated, piercing-sucking mouthparts . All mosquitoes drink nectar from flowers ; females of some species have in addition adapted to drink blood. The group diversified during the Cretaceous period. Evolutionary biologists view mosquitoes as micropredators , small animals that parasitise larger ones by drinking their blood without immediately killing them. Medical parasitologists view mosquitoes instead as vectors of disease , carrying protozoan parasites or bacterial or viral pathogens from one host to another. The mosquito life cycle consists of four stages: egg , larva , pupa , and adult . Eggs are laid on
4472-768: Is known from Canadian amber from Alberta, Canada, which dates to the Campanian age of the Late Cretaceous, around 79 million years ago. P. burmanicus has been assigned to the Anophelinae , indicating that the split between this subfamily and the Culicinae took place over 99 million years ago. Molecular estimates suggest that this split occurred 197.5 million years ago, during the Early Jurassic , but that major diversification did not take place until
4644-482: Is short. Different mosquito species favor amphibians , reptiles including snakes , birds , and mammals . For example, Culiseta melanura sucks the blood of passerine birds, but as mosquito numbers rise they attack mammals including horses and humans, causing epidemics of Eastern equine encephalitis virus in North America. Loss of blood from many bites can add up to a large volume, occasionally causing
4816-402: Is sometimes misinterpreted as the "99-year lease" because of misleading wording included in article 22 of the agreement. Almost immediately, the treaty was condemned by many Panamanians as an infringement on their country's new national sovereignty. This would later become a contentious diplomatic issue among Colombia, Panama, and the United States. President Roosevelt famously stated, "I took
4988-535: Is unpredictable, freezing but often warming suddenly in mid-winter, making mosquitoes emerge from pupae in diapause, and then freezing again before they can complete their life cycle. Eggs of temperate zone mosquitoes are more tolerant of cold than the eggs of species indigenous to warmer regions. Many can tolerate subzero temperatures, while adults of some species can survive winter by sheltering in microhabitats such as buildings or hollow trees. In warm and humid tropical regions, some mosquito species are active for
5160-617: The Asteraceae , Rosaceae and Orchidaceae are pollinated by mosquitoes, which visit to obtain sugar-rich nectar . They are attracted to flowers by a range of semiochemicals such as alcohols, aldehydes, ketones, and terpenes. Mosquitoes have visited and pollinated flowers since the Cretaceous period. It is possible that plant-sucking exapted mosquitoes to blood-sucking. Ecologically, blood-feeding mosquitoes are micropredators , small animals that feed on larger animals without immediately killing them. Evolutionary biologists see this as
5332-532: The Atlantic Ocean with the Pacific Ocean , cutting across the Isthmus of Panama , and is a conduit for maritime trade. Locks at each end lift ships up to Gatun Lake , an artificial fresh water lake 26 meters (85 ft) above sea level , created by damming up the Chagres River and Lake Alajuela to reduce the amount of excavation work required for the canal. Locks then lower the ships at
History of the Panama Canal - Misplaced Pages Continue
5504-565: The Culebra Cut (known as the Gaillard Cut from 1915 to 2000), which involved cutting 8 miles (13 km) across the continental divide down to 12 meters (39 feet) above sea level. By August 1907, 765,000 m (1,001,000 cu yd) per month was being excavated; this set a record for the rainy season; soon afterwards this doubled, before increasing again. At the peak of production, 2,300,000 m (3,000,000 cu yd)
5676-487: The Culebra Cut , valued at about $ 1.00 per cubic yard. The United States also paid the new country of Panama $ 10 million and a $ 250,000 payment each following year. In 1921, Colombia and the United States entered into the Thomson–Urrutia Treaty , in which the United States agreed to pay Colombia $ 25 million: $ 5 million upon ratification, and four $ 5 million annual payments, and grant Colombia special privileges in
5848-685: The Drake Passage , the Strait of Magellan or the Beagle Channel . It is one of the largest and most difficult engineering projects ever undertaken. Colombia , France, and later the United States controlled the territory surrounding the canal during construction. France began work on the canal in 1881, but stopped because of lack of investors' confidence due to engineering problems and a high worker mortality rate . The US took over
6020-760: The Hay–Herrán Treaty was signed by United States Secretary of State John M. Hay and Colombian Chargé Tomás Herrán . For $ 10 million and an annual payment, it would have granted the United States a renewable lease in perpetuity from Colombia on the land proposed for the canal. The treaty was ratified by the US Senate on 14 March 1903, but the Senate of Colombia unanimously rejected the treaty since it had become significantly unpopular in Bogotá due to concerns over insufficient compensation, threat to sovereignty, and perpetuity. Roosevelt changed tactics, based in part on
6192-617: The Illinois Central Railroad , as chief engineer of the Panama Canal Project. Overwhelmed by the disease-plagued country and forced to use often dilapidated French infrastructure and equipment, as well as being frustrated by the overly bureaucratic ICC, Wallace resigned abruptly in June 1905. The ICC brought on a new chairman, Theodore P. Shonts , and a new chief engineer was appointed, John Frank Stevens ,
6364-589: The Mallarino–Bidlack Treaty of 1846, and actively supported the separation of Panama from Colombia . Shortly after recognizing Panama, he signed a treaty with the new Panamanian government under terms similar to the Hay–Herrán Treaty. On 2 November 1903, US warships blocked sea lanes against possible Colombian troop movements en route to put down the Panama rebellion. Panama declared independence on 3 November 1903. The United States quickly recognized
6536-591: The Mallarino–Bidlack Treaty , negotiated between the US and New Granada, granted the United States transit rights and the right to intervene militarily in the isthmus. In 1848, the discovery of gold in California , on the West Coast of the United States, generated renewed interest in a canal crossing between the Atlantic and Pacific oceans. William Henry Aspinwall , who had won the federal subsidy to build and operate
6708-546: The Panama Canal Authority (ACP) assumed command of the waterway. The Panama Canal remains one of the chief revenue sources for Panama. Before this handover, the government of Panama held an international bid to negotiate a 25-year contract for operation of the container shipping ports located at the canal's Atlantic and Pacific outlets. The contract was not affiliated with the ACP or Panama Canal operations and
6880-530: The Republic of New Granada entered into a contract for the construction of a canal across the Isthmus of Darien (Isthmus of Panama). They referred to it as the Atlantic and Pacific Canal, and it was a wholly British endeavor. Projected for completion in five years, the plan was never carried out. At nearly the same time, other ideas were floated, including a canal (and/or a railroad) across Mexico's Isthmus of Tehuantepec . That did not develop, either. In 1846,
7052-595: The Secretary of State for the Colonies , Joseph Chamberlain , who had written that "in view of the possible connection of Malaria with mosquitoes, it is desirable to obtain exact knowledge of the different species of mosquitoes and allied insects in the various tropical colonies. I will therefore ask you ... to have collections made of the winged insects in the Colony which bite men or animals." Mosquitoes are members of
History of the Panama Canal - Misplaced Pages Continue
7224-519: The YMCA , with billiard, assembly and reading rooms, bowling alleys, darkrooms for camera clubs, gymnastic equipment, ice cream parlors, soda fountains and a circulating library . Member dues were ten dollars a year, with the remaining upkeep (about $ 7,000 at the larger clubhouses) paid by the ICC. The commission built baseball fields and arranged rail transportation to games; a competitive league soon developed. Semi-monthly Saturday-night dances were held at
7396-547: The cargo ship SS Ancon . The opening of the Panama Canal in 1914 caused a severe drop in traffic along Chilean ports due to shifts in maritime trade routes, despite the closure of the canal for nearly seven months after a landslide in the Culebra Cut on 18 September 1915. The burgeoning sheep farming business in southern Patagonia suffered a significant setback by the change in trade routes, as did
7568-547: The hypopharynx , and the labrum . The labium bends back into a bow when the mosquito begins to bite, staying in contact with the skin and guiding the stylets downwards. The extremely sharp tips of the labrum and maxillae are moved backwards and forwards to saw their way into the skin, with just one thousandth of the force that would be needed to penetrate the skin with a needle, resulting in a painless insertion. Mosquito saliva contains enzymes that aid in sugar feeding, and antimicrobial agents that control bacterial growth in
7740-505: The pupa are merged into a cephalothorax , with the abdomen curving around beneath it. The pupa or "tumbler" can swim actively by flipping its abdomen. Like the larva, the pupa of most species must come to the surface frequently to breathe, which they do through a pair of respiratory trumpets on their cephalothoraxes. They do not feed; they pass much of their time hanging from the surface of the water by their respiratory trumpets. If alarmed, they swim downwards by flipping their abdomens in much
7912-792: The 30 million cu yd (23 million m ) excavated by the French. As quickly as possible, the Americans replaced or upgraded the old, unusable French equipment with new construction equipment that was designed for a much larger and faster scale of work. 102 large, railroad-mounted steam shovels were purchased, 77 from Bucyrus-Erie , and 25 from the Marion Power Shovel Company . These were joined by enormous steam-powered cranes, giant hydraulic rock crushers , concrete mixers , dredges , and pneumatic power drills, nearly all of which were manufactured by new, extensive machine-building technology developed and built in
8084-671: The Americas in order to ease the voyage for ships traveling between Spain and Peru. The Spanish were seeking to gain a military advantage over the Portuguese. In 1668, the English physician and philosopher Sir Thomas Browne speculated in his encyclopedic work, Pseudodoxia Epidemica , that "some Isthmus have been eaten through by the Sea, and others cut by the spade: And if the policy would permit, that of Panama in America were most worthy
8256-497: The British and French West Indies, and these workers provided most of the manual labor on the canal. The Canal Zone originally had minimal facilities for entertainment and relaxation for the canal workers apart from saloons; as a result, alcohol abuse was a great problem. The inhospitable conditions resulted in many American workers returning home each year. A program of improvements was implemented. Clubhouses were built, managed by
8428-537: The Canal Zone. In return, Colombia recognized Panama as an independent nation. The US formally took control of the canal property on 4 May 1904, inheriting from the French a depleted workforce and a vast jumble of buildings, infrastructure, and equipment, much of it in poor condition. A US government commission, the Isthmian Canal Commission (ICC), was established to oversee construction; it
8600-492: The Chagres River above Gatun Lake. Completed in 1935, the dam created Madden Lake (later Alajuela Lake), which provides additional water storage for the canal. In 1939, construction began on a further major improvement: a new set of locks large enough to carry the larger warships that the United States was building at the time and planned to continue building. The work proceeded for several years, and significant excavation
8772-539: The Chagres River, with channels to drain water away from the canal. However, the Gamboa dam was later found impracticable and the Chagres River problem was left unsolved. Construction of the canal began on January 1, 1881, with digging at Culebra beginning on January 22. A large labor force was assembled, numbering about 40,000 in 1888 (nine-tenths of whom were afro-Caribbean workers from the West Indies ). Although
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#17327656149638944-488: The Colombian government after 99 years without compensation. Ferdinand de Lesseps , who was in charge of the Suez Canal construction, headed the project. His enthusiastic leadership and his reputation as the man who had built the Suez Canal persuaded speculators and ordinary citizens to invest nearly $ 400 million in the project. However, despite his previous success, Lesseps was not an engineer. The construction of
9116-534: The Colombians being unable to put down the Panamanian rebellion and expel the United States troops occupying what today is the independent nation of Panama. On 6 November 1903, Philippe Bunau-Varilla, as Panama's ambassador to the United States, signed the Hay–Bunau-Varilla Treaty , granting rights to the United States to build and indefinitely administer the Panama Canal Zone and its defenses. This
9288-470: The Cretaceous. Over 3,600 species of mosquitoes in 112 genera have been described . They are traditionally divided into two subfamilies, the Anophelinae and the Culicinae , which carry different diseases. Roughly speaking, protozoal diseases like malaria are transmitted by anophelines, while viral diseases such as yellow fever and dengue fever are transmitted by culicines. The name Culicidae
9460-406: The Culebra excavation while a team of engineers began a comprehensive study of the project. They eventually settled on a plan for a two-level, lock-based canal. The new effort never gained traction, mainly because of US speculation that a canal through Nicaragua would render one through Panama useless. The most men employed on the new project was 3,600 (in 1896), primarily to comply with the terms of
9632-442: The French effort and he was soon able to begin construction in earnest. Goethals divided the project into three divisions: Atlantic, Central and Pacific. The Atlantic Division, under Major William L. Sibert , was responsible for construction of the breakwater at the entrance to Bahía Limón , the Gatún locks and their 5.6 km (3.5 mi) approach channel, and the Gatun Dam . The Pacific Division (under Sydney B. Williamson,
9804-412: The French manager of the New Panama Canal Company, eventually managed to persuade Lesseps that a lock-and-lake canal was more realistic than a sea-level canal. The Comité Technique, a high level technical committee, was formed by the Compagnie Nouvelle to review the studies and work—that already finished and that still ongoing—and come up with the best plan for completing the canal. The committee arrived on
9976-448: The French property connected to the canal on May 4, 1904, when Lieutenant Mark Brooke of the United States Army was presented with the keys during a small ceremony. The new Panama Canal Zone Control was overseen by the Isthmian Canal Commission (ICC) during construction. The first step taken by the US government was to place all the canal workers under the new administration. The operation was maintained at minimum strength to comply with
10148-519: The French were willing to sell their holdings for $ 40 million. The recommendation became law on June 28, 1902, and the New Panama Canal Company was compelled to sell at that price. Although the French effort was effectively doomed to failure from the beginning due to disease and a lack of understanding of the engineering difficulties, it was not entirely futile. The old and new companies excavated 59,747,638 m (78,146,960 cu yd) of material, of which 14,255,890 m (18,646,000 cu yd)
10320-422: The Hotel Tivoli, which had a spacious ballroom. These measures influenced life in the Canal Zone; alcohol abuse fell, with saloon business declining by 60 percent. The number of workers leaving the project each year dropped significantly. The work done thus far was preparation, rather than construction. By the time Goethals took over, the construction infrastructure had been created or overhauled and expanded from
10492-534: The Isthmus in February 1896 and went immediately, quietly and efficiently about their work of devising the best possible canal plan, which they presented on 16 November 1898. Many aspects of the plan were similar in principle to the canal that was finally built by the Americans in 1914. It was a lock canal with two high level lakes to lift ships up and over the Continental Divide. Double locks would be 738 feet long and about 30 feet deep (225 m × 9 m); one chamber of each pair would be 82 feet (25 m) wide,
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#173276561496310664-407: The Isthmus, started the canal and then left Congress not to debate the canal, but to debate me." Several parties in the United States called this an act of war on Colombia: The New York Times described the support given by the United States to Bunau-Varilla as an "act of sordid conquest". The New York Evening Post called it a "vulgar and mercenary venture". The US maneuvers are often cited as
10836-400: The Lesseps project is described clearly, without ambiguity. It will be technical and financial, as Godin de Lépinay had planned. Unfortunately, his plan received no serious attention. Had it been adopted, the Panama Canal might well have been completed by the French instead of by the United States. Following the congress, the Compagnie Universelle du Canal Interocéanique de Panama, in charge of
11008-457: The Pacific mail steamships at around the same time, benefited from the gold discovery. Aspinwall's route included steamship legs from New York City to Panama, and from Panama to California, with an overland portage through Panama. This route with an overland leg in Panama was soon frequently traveled, as it provided one of the fastest connections between San Francisco, California, and the East Coast cities, about 40 days' transit in total. Nearly all
11180-414: The Pacific side is about a third of a degree east of the Colón end on the Atlantic side. Still, in formal nautical communications, the simplified directions "southbound" and "northbound" are used. The canal consists of artificial lakes , several improved and artificial channels, and three sets of locks . An additional artificial lake, Alajuela Lake (known during the American era as Madden Lake), acts as
11352-419: The Panama Railway) to cross the isthmus; it opened in 1855. This overland link became a vital piece of Western Hemisphere infrastructure, greatly facilitating trade. The later canal route was constructed parallel to it, as it had helped clear dense forests. An all-water route between the oceans was still the goal. In 1855, William Kennish , a Manx -born engineer working for the United States government, surveyed
11524-437: The Panama location. The purchase of the French-held land for $ 40 million was authorized by the June 28, 1902 Spooner Act . Since Panama was then part of Colombia , Roosevelt began negotiating with that country to obtain the necessary rights. In early 1903 the Hay–Herrán Treaty was signed by both nations, but the Senate of Colombia failed to ratify the treaty. Roosevelt implied to Panamanian rebels that if they revolted,
11696-426: The Suez Canal, essentially a ditch dug through a flat, sandy desert, presented few challenges. Although Central America's mountainous spine has a low point in Panama, it is still 110 meters (360.9 ft) above sea level at its lowest crossing point. The sea-level canal proposed by de Lesseps would require a great deal of excavation through a variety of unstable rock, rather than Suez's sand. Less-obvious barriers were
11868-437: The U.S. continuing the project. The U.S. first sought to construct a canal through Nicaragua instead. French engineer and financier Philippe-Jean Bunau-Varilla played a key role in changing American attitudes. Bunau-Varilla had a large stake in the failed French canal company and stood to profit on his investment only if the Panama Canal was completed. His extensive lobbying of American lawmakers, coupled with his support of
12040-420: The US Army Corps of Engineers. Gaillard was placed in charge of the canal's Central Division, which stretched from the Pedro Miguel locks to the Gatun Dam , and dedicated himself to getting the Culebra Cut (as it was then known) excavated. The scale of the work was massive. 6 thousand men worked in the cut, drilling holes in which a total of 27,000 t (60,000,000 lb) of dynamite were placed to break up
12212-399: The US Navy would assist their fight for independence. Panama declared its independence on November 3, 1903, and the USS Nashville impeded Colombian interference. The victorious Panamanians gave the United States control of the Panama Canal Zone on February 23, 1904, for $ 10 million in accordance with the November 18, 1903 Hay–Bunau-Varilla Treaty . The United States took control of
12384-400: The US army troops that were supporting the Panamanian rebels. The reason an army of conscripts was sent was that it was the best response the Colombians could muster, as Colombia still was recovering from a civil war between Liberals and Conservatives from October 1899, to November 1902, known as the " Thousand Days War ". The US was fully aware of these conditions and even incorporated them into
12556-752: The United States to hand over the canal to Panama increased after the Suez Crisis in 1956, when the United States used financial and diplomatic pressure to force France and the UK to abandon their attempt to retake control of the Suez Canal , previously nationalized by the Nasser regime in Egypt. Panamanian unrest culminated in riots on Martyr's Day , 9 January 1964, when about 20 Panamanians and 3–5 US soldiers were killed. A decade later, in 1974, negotiations toward
12728-496: The United States. The railroad also had to be comprehensively upgraded with heavy-duty, double-tracked rails over most of the line to accommodate new rolling stock . In many places, the new Gatun Lake flooded over the original rail line, and a new line had to be constructed above Gatun Lake's waterline. Between 1912 and 1914 there was a controversy about the tolls for the canal . In 1907, Stevens resigned as chief engineer. His replacement, appointed by President Theodore Roosevelt,
12900-571: The attempt: it being but few miles over, and would open a shorter cut unto the East Indies and China". Given the strategic location of Panama, and the potential of its narrow isthmus separating two great oceans, other trade links in the area were attempted over the years. One early example of this was ill-fated Darien scheme , launched by the Kingdom of Scotland in 1698 to set up an overland trade route. Generally inhospitable conditions thwarted
13072-420: The blood proteins into free amino acids . These are used in the synthesis of vitellogenin , which in turn is made into egg yolk protein. Mosquitoes have a cosmopolitan distribution , occurring in every land region except Antarctica and a few islands with polar or subpolar climates , such as Iceland , which is essentially free of mosquitoes. This absence is probably caused by Iceland's climate. Its weather
13244-440: The blood separate from anything else in the stomach. Like many Hemiptera that survive on dilute liquid diets, many adult mosquitoes excrete surplus liquid even when feeding. This permits females to accumulate a full meal of nutrient solids. The blood meal is digested over a period of several days. Once blood is in the stomach, the midgut synthesizes protease enzymes, primarily trypsin assisted by aminopeptidase , that hydrolyze
13416-419: The blood; and decrease cytokine production. Females of many blood-feeding species need a blood meal to begin the process of egg development. A sufficiently large blood meal triggers a hormonal cascade that leads to egg development. Upon completion of feeding, the mosquito withdraws her proboscis , and as the gut fills up, the stomach lining secretes a peritrophic membrane that surrounds the blood. This keeps
13588-414: The bulk of the excavation of the canal, including appointing Major David du Bose Gaillard to oversee the most daunting project, the Culebra Cut through the roughest terrain on the route. Almost as important as the engineering advances were the healthcare advances made during the construction, led by William C. Gorgas , an expert in controlling tropical diseases such as yellow fever and malaria . Gorgas
13760-512: The canal concession and keep the machinery in working order. The US inherited a small workforce and an assortment of buildings, infrastructure and equipment, much of which had been neglected for fifteen years in the humid jungle environment. There were no facilities in place for a large workforce, and the infrastructure was crumbling. Cataloguing assets was a large job; it took many weeks to card-index available equipment. About 2,150 buildings had been acquired, many of which were uninhabitable; housing
13932-509: The canal remained a territory of the United States until 1977, when the Torrijos–Carter Treaties began the process of transferring territorial control of the Panama Canal Zone to Panama, a process which was finally completed on 31 December 1999. The Panama Canal continues to be a viable commercial venture and a vital link in world shipping, and is periodically upgraded. A Panama Canal expansion project started construction in 2007 and began commercial operation on 26 June 2016. The new locks allow
14104-520: The canal was completed in 1914, 401 years after Panama was first crossed overland by the Europeans in Vasco Núñez de Balboa 's party of conquistadores . The United States spent almost $ 500 million (roughly equivalent to $ 15.2 billion in 2023) to finish the project. This was by far the largest American engineering project to date. The canal was formally opened on 15 August 1914, with the passage of
14276-579: The canal. In 2017, it took ships an average of 11.38 hours to pass between the canal's two outer locks. The American Society of Civil Engineers has ranked the Panama Canal one of the Seven Wonders of the Modern World . The earliest record regarding a canal across the Isthmus of Panama was in 1534, when Charles V , Holy Roman Emperor and King of Spain, ordered a survey for a route through
14448-509: The chosen plan, and only one of those had actually visited Central America. While the Americans abstained because of their own plan through Nicaragua, the five delegates from the French Society of Engineers all refused. Among them were Gustave Eiffel and Adolphe Godin de Lépinay [ fr ] , the general-secretary of the Société de Géographie , who was the only one to propose a lake-and-locks project. Designer in particular of
14620-609: The classic example of US gunboat diplomacy in Latin America, and the best illustration of what Roosevelt meant by the old African adage, "Speak softly and carry a big stick [and] you will go far." After the revolution in 1903, the Republic of Panama became a US protectorate until 1939. In 1904, the United States purchased the French equipment and excavations, including the Panama Railroad , for US$ 40 million, of which $ 30 million related to excavations completed, primarily in
14792-437: The concession and to maintain the existing excavation and equipment in saleable condition. The company had already begun looking for a buyer, with an asking price of $ 109 million. In the US, a congressional Isthmian Canal Commission was established in 1899 to examine possibilities for a Central American canal and recommend a route. In November 1901, the commission reported that a US canal should be built through Nicaragua unless
14964-549: The construction company to the Panama Canal Zone government. The outbreak of World War I caused the cancellation of any official "grand opening" celebration, but the canal officially opened to commercial traffic on 15 August 1914 with the transit of the SS Ancon . During World War II, the canal proved vital to American military strategy, allowing ships to transfer easily between the Atlantic and Pacific. Politically,
15136-586: The construction of tunnels and locks. A second Isthmian exploratory visit began on 6 December 1877, where two routes were explored in Panama, the San Blas route and a route from Bahía Limón to Panama City, the current Canal route. The French had achieved success in building the Suez Canal in the Middle East. While it was a lengthy project, they were encouraged to plan for a canal to cross the Panamanian isthmus. Wyse went to Bogotá and on 20 March 1878, signed
15308-642: The construction, whose president was Lesseps, acquired the Wyse Concession from the Société Civile. The engineering congress estimated the Lesseps project's cost at $ 214 million; on February 14, 1880, an engineering commission revised the estimate to $ 168.6 million. Lesseps further reduced this estimate twice, with no apparent justification: on February 20 to $ 131.6 million and on March 1 to $ 120 million. The congress estimated seven or eight years as
15480-632: The continental divide to connect Gatun Lake to the Pacific Panama Canal locks . On 10 October 1913, President Woodrow Wilson sent a signal from the White House by telegraph which triggered the explosion that destroyed the Gamboa Dike. This flooded the Culebra Cut, thereby joining the Atlantic and Pacific oceans via the Panama Canal. Alexandre La Valley (a floating crane built by Lobnitz & Company and launched in 1887)
15652-436: The corruption, and Jean Jaurès was commissioned by the French parliament to conduct an inquiry which was completed in 1893. It soon became clear that the only way to recoup expenses for the stockholders was to continue the project. A new concession was obtained from Colombia, and in 1894 the Compagnie Nouvelle du Canal de Panama was created to finish the canal. To comply with the terms of the contract, work began immediately on
15824-616: The death of livestock as large as cattle and horses . Malaria -transmitting mosquitoes seek out caterpillars and feed on their haemolymph, impeding their development. Most mosquito species are crepuscular , feeding at dawn or dusk, and resting in a cool place through the heat of the day. Some species, such as the Asian tiger mosquito , are known to fly and feed during daytime. Female mosquitoes hunt for hosts by smelling substances such as carbon dioxide (CO 2 ) and 1-octen-3-ol (mushroom alcohol, found in exhaled breath) produced from
15996-463: The death rate was over 200 per month. Public health measures were ineffective because the role of the mosquito as a disease vector was then unknown. Conditions were downplayed in France to avoid recruitment problems, but the high mortality rate made it difficult to maintain an experienced workforce. Workers had to continually widen the main cut through the mountain at Culebra and reduce the angles of
16168-423: The deaths of over 725,000 people each year. Like all flies, mosquitoes go through four stages in their life cycles: egg , larva , pupa , and adult . The first three stages—egg, larva, and pupa—are largely aquatic, the eggs usually being laid in stagnant water. They hatch to become larvae , which feed, grow, and molt until they change into pupae . The adult mosquito emerges from the mature pupa as it floats at
16340-591: The economy of the Falkland Islands . Throughout this time, Ernest "Red" Hallen was hired by the Isthmian Canal Commission to document the progress of the work. In 1914, steam shovels from the Panama Canal were purchased and put to use in Chuquicamata copper mine of northern Chile. By the 1930s, water supply became an issue for the canal, prompting construction of the Madden Dam across
16512-531: The effort, and it was abandoned in April 1700. In 1788, Americans suggested that the Spanish should build the canal, since they controlled the colonies where it would be built. They said that this would be a less treacherous route for ships than going around the southern tip of South America, and that tropical ocean currents would naturally widen the canal after construction. During an expedition from 1788 to 1793, Alessandro Malaspina outlined plans for construction of
16684-506: The engineering and excavation work into three divisions: Atlantic, Central, and Pacific. The Atlantic Division, under Major William L. Sibert , was responsible for construction of the massive breakwater at the entrance to Bahía Limón , the Gatun locks , and their 3 + 1 ⁄ 2 -mile (5.6 km) approach channel, and the immense Gatun Dam. The Pacific Division, under Sydney B. Williamson (the only civilian member of this high-level team),
16856-464: The ensuing scandal, known as the Panama affair , some of those deemed responsible were prosecuted, including Gustave Eiffel . Lesseps and his son Charles were found guilty of misappropriation of funds and sentenced to five years' imprisonment. This sentence was later overturned, and the father, at age 88, was never imprisoned. In 1894, a second French company, the Compagnie Nouvelle du Canal de Panama,
17028-431: The entire year, but in temperate and cold regions they hibernate or enter diapause . Arctic or subarctic mosquitoes, like some other arctic midges in families such as Simuliidae and Ceratopogonidae may be active for only a few weeks annually as melt-water pools form on the permafrost. During that time, though, they emerge in huge numbers in some regions; a swarm may take up to 300 ml of blood per day from each animal in
17200-662: The female to lay more eggs. Both plant materials and blood are useful sources of energy in the form of sugars. Blood supplies more concentrated nutrients, such as lipids , but the main function of blood meals is to obtain proteins for egg production. Mosquitoes like Toxorhynchites reproduce autogenously, not needing blood meals. Disease vector mosquitoes like Anopheles and Aedes are anautogenous , requiring blood to lay eggs. Many Culex species are partially anautogenous, needing blood only for their second and subsequent clutches of eggs. Blood-sucking mosquitoes favour particular host species, though they are less selective when food
17372-463: The financing of the massive project, the canal was only partly completed. Interest in a U.S.-led canal effort picked up as soon as France abandoned the project. Initially, the Panama site was politically unfavorable in the U.S. for a variety of reasons, including the taint of the failed French effort and the unfriendly attitude of the Colombian government (at the time, the owner of the land) towards
17544-499: The genus Toxorhynchites , at up to 18 mm (0.71 in) in length and 24 mm (0.94 in) in wingspan. Those in the genus Aedes are much smaller, with a wingspan of 2.8 to 4.4 mm (0.11 to 0.17 in). Mosquitoes can develop from egg to adult in hot weather in as few as five days, but it may take up to a month. At dawn or dusk, within days of pupating, males assemble in swarms , mating when females fly in. The female mates only once in her lifetime, attracted by
17716-419: The gold that was shipped out of California went by the fast Panama route. Several new and larger paddle steamers were soon plying this new route, including private steamship lines owned by American entrepreneur Cornelius Vanderbilt that made use of an overland route through Nicaragua, and the unfortunate SS Central America . In 1850, the United States began construction of the Panama Railroad (now called
17888-403: The host, and through visual recognition. The semiochemical that most strongly attracts Culex quinquefasciatus is nonanal . Another attractant is sulcatone . A large part of the mosquito's sense of smell, or olfactory system, is devoted to sniffing out blood sources. Of 72 types of odor receptors on its antennae, at least 27 are tuned to detect chemicals found in perspiration. In Aedes ,
18060-551: The isthmus and issued a report on a route for a proposed Panama Canal. His report was published as a book entitled The Practicability and Importance of a Ship Canal to Connect the Atlantic and Pacific Oceans . In 1876, Lucien Napoléon Bonaparte Wyse and his chief assistant Armand Réclus, both officers and engineers of the French Navy , explored several routes in the Darien-Atrato regions and made proposals including
18232-405: The large-gauge canal between Bordeaux and Narbonne, the road between Sétif and Bougie , and of the railway lines connecting Philippeville to Constantine, Algeria , Algiers to Constantine, and Athens to Piraeus , he also supervised the construction of a rail link between Veracruz and Córdoba, Mexico , losing two-thirds of his workers to tropical disease. Godin de Lépinay's plan was to build
18404-462: The late nineteenth century, technological advances and commercial pressure allowed construction to begin in earnest. Noted canal engineer Ferdinand de Lesseps , builder of the Suez Canal , led the initial attempt by France to build a sea-level canal. Beset by cost overruns due to the severe underestimation of the difficulties in excavating the rugged terrain, heavy personnel losses to tropical diseases , and political corruption in France surrounding
18576-407: The later American effort. The French lowered the summit of the Culebra Cut along the canal route by five meters (16 feet), from 64 to 59 metres (210 to 194 ft). An estimated 22,713,396 m (29,708,000 cu yd) of excavation, valued at about $ 25.4 million, and equipment and surveys valued at about $ 17.4 million were usable by the Americans. The 1848 discovery of gold in California and
18748-862: The many aquatic insects that catch mosquito larvae are dragonfly and damselfly nymphs, whirligig beetles , and water striders . Vertebrate predators include fish such as catfish and the mosquitofish , amphibians including the spadefoot toad and the giant tree frog , freshwater turtles such as the red-eared slider , and birds such as ducks. Emerging adults are consumed at the pond surface by predatory flies including Empididae and Dolichopodidae , and by spiders . Flying adults are captured by dragonflies and damselflies, by birds such as swifts and swallows , and by vertebrates including bats . Mosquitoes are parasitised by hydrachnid mites, ciliates such as Glaucoma , microsporidians such as Thelania , and fungi including species of Saprolegniaceae and Entomophthoraceae . Several flowers including members of
18920-460: The new nation. This happened so quickly that by the time the Colombian government in Bogotá launched a response to the Panamanian uprising US troops had already entered the rebelling province. The Colombian troops dispatched to Panama were hastily assembled conscripts with little training. While these conscripts may have been able to defeat the Panamanian rebels, they would not have been able to defeat
19092-525: The only civilian division head) was responsible for the Pacific entrance to the canal, including a 4.8 km (3.0 mi) breakwater in Panama Bay, the approach channel, and the Miraflores and Pedro Miguel locks and their associated dams. The Central Division, under Major David du Bose Gaillard , was responsible for everything in between. It had arguably the project's greatest challenge: excavating
19264-524: The other 59 ft (18 m). There would be eight sets of locks, two at Bohio Soldado and two at Obispo on the Atlantic side; one at Paraiso, two at Pedro Miguel, and one at Miraflores on the Pacific. Artificial lakes would be formed by damming the Chagres River at Bohio and Alhajuela, providing both flood control and electric power. At this time, US President Theodore Roosevelt and the United States Senate were interested in establishing
19436-409: The other end. An average of 200,000,000 L (52,000,000 US gal) of fresh water is used in a single passing of a ship. The canal is threatened by low water levels during droughts. The Panama Canal shortcut greatly reduces the time for ships to travel between the Atlantic and Pacific oceans, enabling them to avoid the lengthy, hazardous route around the southernmost tip of South America via
19608-588: The outside of their hosts, using their piercing mouthparts, rather than entering their bodies. Unlike some other ectoparasites such as fleas and lice , mosquitoes do not remain constantly on the body of the host, but visit only to feed. A 2023 study suggested that Libanoculex intermedius found in Lebanese amber , dating to the Barremian age of the Early Cretaceous, around 125 million years ago
19780-493: The passage of Panamax ships. A third, wider lane of locks was constructed between September 2007 and May 2016. The expanded waterway began commercial operation on 26 June 2016. The new locks allow transit of larger, Neopanamax ships. Annual traffic has risen from about 1,000 ships in 1914, when the canal opened, to 14,702 vessels in 2008, for a total of 333.7 million Panama Canal/Universal Measurement System (PC/UMS) tons . By 2012, more than 815,000 vessels had passed through
19952-426: The pheromones emitted by the male. As a species that need blood for the eggs to develop, the female finds a host and drinks a full meal of blood. She then rests for two or three days to digest the meal and allow her eggs to develop. She is then ready to lay the eggs and repeat the cycle of feeding and laying. Females can live for up to three weeks in the wild, depending on temperature, humidity, their ability to obtain
20124-694: The pitchers of pitcher plants , its larvae feeding on decaying insects that have drowned there. Oviposition , egg-laying, varies between species. Anopheles females fly over the water, touching down or dapping to place eggs on the surface one at a time; their eggs are roughly cigar-shaped and have floats down their sides. A female can lay 100–200 eggs in her lifetime. Aedes females drop their eggs singly, on damp mud or other surfaces near water; their eggs hatch only when they are flooded. Females in genera such as Culex , Culiseta , and Uranotaenia lay their eggs in floating rafts. Mansonia females in contrast lay their eggs in arrays, attached usually to
20296-493: The planning of the Panama intervention as the US acted as an arbitrator between the two sides. The peace treaty that ended the "Thousand Days War" was signed on the USS Wisconsin on 21 November 1902. While in port, the US also brought engineering teams to Panama with the peace delegation to begin planning the canal's construction before the US had even gained the rights to build the canal. All these factors would result in
20468-566: The project attracted good, well-paid French engineers, retaining them was difficult due to disease. The death toll from 1881 to 1889 was estimated at over 22,000, of whom as many as 5,000 were French citizens. By 1885 it had become clear to many that a sea-level canal was impractical, and an elevated canal with locks was preferable; de Lesseps resisted, and a lock canal plan was not adopted until October 1887. By this time increasing mortality rates, as well as financial and engineering problems coupled with frequent floods and mudslides , indicated that
20640-464: The project in 1904 and opened the canal in 1914. The US continued to control the canal and surrounding Panama Canal Zone until the Torrijos–Carter Treaties provided for its handover to Panama in 1977. After a period of joint American–Panamanian control, the Panamanian government took control in 1999. It is now managed and operated by the Panamanian government-owned Panama Canal Authority . The original locks are 33.5 meters (110 ft) wide and allow
20812-475: The project was in serious trouble. Work continued under the new plan until May 15, 1889, when the company went bankrupt and the project was suspended. After eight years the canal was about two-fifths completed, and about $ 234.8 million had been spent. The company's collapse was a scandal in France , and the antisemitic Edouard Drumont exploited the role of two Jewish speculators in the affair. One hundred and four legislators were found to have been involved in
20984-567: The project. After two years of extensive work, the mosquito-spread diseases were nearly eliminated . Despite the monumental effort, about 5,600 workers died from disease and accidents during the US construction phase of the canal. Besides healthier and far better living conditions for the workers, another benefit given to American citizens working on the Canal was a medal for two years of service. Additional bars were added for each two-year period after that. Designed by Victor D. Brenner and featuring
21156-487: The purpose of this congress was only to launch fundraising by legitimizing Lesseps' own decision, based on the Lucien Bonaparte-Wyse and Armand Réclus plan, through a so-called international scientific approval, since he was convinced that a sea-level canal, dug through the mountainous spine of Central America, could be completed at least as easily as the Suez Canal. In reality, only 19 engineers approved
21328-455: The railway, which was to prove crucial in transporting millions of tons of soil from the cut through the mountains to the dam across the Chagres River. Colonel William C. Gorgas had been appointed chief sanitation officer of the canal construction project in 1904. Gorgas implemented a range of measures to minimize the spread of deadly diseases, particularly yellow fever and malaria , which had recently been shown to be mosquito-borne following
21500-413: The rainy climate. In France, Lesseps kept the investment and supply of workers flowing long after it was obvious that the targets were not being met, but eventually the money ran out. The French effort went bankrupt in 1889 after reportedly spending US$ 287,000,000; an estimated 22,000 men died from disease and accidents, and the savings of 800,000 investors were lost. Work was suspended on May 15, and in
21672-410: The relative merits of both types in cost and time. Although the engineers voted eight to five in favor of a sea-level canal, Stevens and the ICC opposed the plan; Stevens' report to Roosevelt was instrumental in convincing the president of the merits of a lock canal and Congress concurred. In November 1906 Roosevelt visited Panama to inspect the canal's progress, the first trip outside the United States by
21844-481: The risk of vector-borne disease, based on an area's forecasted climate. Mosquito-borne diseases have long been most prevalent in East Africa, Latin America, Southeast Asia, and India . An emergence in Europe was observed early in the 21st century. It is predicted that by 2030, the climate of southern Great Britain will be suitable for transmission of Plasmodium vivax malaria by Anopheles mosquitoes for two months of
22016-538: The rivers crossing the canal, particularly the Chagres , which flows strongly during the rainy season. Since the water would be a hazard to shipping if it drained into the canal, a sea-level canal would require the river's diversion. The most serious problem was tropical diseases , particularly malaria and yellow fever , whose methods of transmission were unknown at the time. The legs of hospital beds were placed in cans of water to keep insects from crawling up them, but
22188-457: The rock (which was then removed by as many as 160 trains per day). Landslides were frequent, due to the oxidation and weakening of the rock's underlying iron strata . Although the scale of the job and the frequent, unpredictable slides generated chaos, Gaillard provided quiet, clear-sighted leadership. Panama Canal The Panama Canal (Spanish: Canal de Panamá ) is an artificial 82-kilometer (51-mile) waterway in Panama that connects
22360-639: The rush of would-be miners stimulated US interest in building a canal between the oceans. In 1887, a United States Army Corps of Engineers regiment surveyed canal possibilities in Nicaragua. Two years later, the Maritime Canal Company was asked to begin a canal in the area and chose Nicaragua. The company lost money in the panic of 1893 , and its work in Nicaragua ceased. In 1897 and 1899, the United States Congress charged
22532-405: The same way as the larvae. If undisturbed, they soon float up again. The adult emerges from the pupa at the surface of the water and flies off. Both male and female mosquitoes feed on nectar , aphid honeydew, and plant juices, but in many species the females are also blood-sucking ectoparasites . In some of those species, a blood meal is essential for egg production; in others, it just enables
22704-455: The search for a host takes place in two phases. First, the mosquito flies about until it detects a host's odorants; then it flies towards them, using the concentration of odorants as its guide. Mosquitoes prefer to feed on people with type O blood , an abundance of skin bacteria, high body heat, and pregnant women. Individuals' attractiveness to mosquitoes has a heritable , genetically controlled component. The multitude of characteristics in
22876-420: The skin, creating large cues for mosquitoes as it increases the attractiveness of an odour blend, imitating a "healthy" human odour. Infected individuals produce larger amounts of aldehydes heptanal , octanal , and nonanal . These compounds are detected by mosquito antennae. Thus, people infected with malaria are more prone to mosquito biting. Contributing to a mosquito's ability to activate search behaviours,
23048-506: The slopes to minimize landslides into the canal. Steam shovels were used in the construction of the canal, purchased from Bay City Industrial Works, a business owned by William L. Clements in Bay City, Michigan . Bucket chain excavators manufactured by both Alphonse Couvreux and Wehyer & Richemond and Buette were also used. Other mechanical and electrical equipment was limited in capabilities, and steel equipment rusted rapidly in
23220-407: The somewhat similar Chironomid midges hold these legs forwards. Anopheles mosquitoes can fly for up to four hours continuously at 1 to 2 km/h (0.62 to 1.24 mph), traveling up to 12 km (7.5 mi) in a night. Males beat their wings between 450 and 600 times per second, driven indirectly by muscles which vibrate the thorax. Mosquitoes are mainly small flies; the largest are in
23392-568: The stagnant water was an ideal breeding place for mosquitoes (carriers of the diseases). In May 1879, the Congrès International d'Etudes du Canal Interocéanique (International Congress for Study of an Interoceanic Canal), led by Lesseps, convened in Paris. Among the 136 delegates of 26 countries, 42 were engineers and made technical proposals before the congress. The others were speculators, politicians, and friends of Lesseps, for whom
23564-728: The sugar meal. For a mosquito to obtain a blood meal, it must circumvent its vertebrate host's physiological responses. Mosquito saliva blocks the host's hemostasis system, with proteins that reduce vascular constriction , blood clotting , and platelet aggregation, to ensure the blood keeps flowing. It modulates the host's immune response via a mixture of proteins which lower angiogenesis and immunity ; create inflammation ; suppress tumor necrosis factor release from activated mast cells ; suppress interleukin (IL)-2 and IFN-γ production; suppress T cell populations; decrease expression of interferon −α/β, making virus infections more severe; increase natural killer T cells in
23736-533: The target is actually a human host rather than some other living warm-blooded animal (as the presence of CO 2 shows). Body odour, composed of volatile organic compounds emitted from the skin of humans, is the most important cue used by mosquitoes. Variation in skin odour is caused by body weight, hormones, genetic factors, and metabolic or genetic disorders. Infections such as malaria can influence an individual’s body odour. People infected by malaria produce relatively large amounts of Plasmodium -induced aldehydes in
23908-406: The then-current president they were popularly known as The Roosevelt Medal. A total of 7189 were ultimately issued, with a few people receiving as many as four bars. Certificates are available today. In 1905, a US engineering panel was commissioned to review the canal design, which had not been finalized. In January 1906 the panel, in a majority of eight to five, recommended to President Roosevelt
24080-492: The thousands of incoming workers. Stevens began the recruitment effort to entice thousands of workers from the United States and other areas to come to the Canal Zone to work. Workers from the Caribbean—called " Afro-Panamanians "—came in large numbers and many settled permanently. Stevens tried to provide accommodation in which the workers could work and live in reasonable safety and comfort. He also re-established and enlarged
24252-443: The time required to complete the canal; Lesseps reduced this estimate to six years (the Suez Canal had required ten). The proposed sea-level canal would have a uniform depth of 9 meters (29.5 ft), a bottom width of 22 meters (72.2 ft) and a width at water level of about 27.5 meters (90.2 ft); the excavation estimate was 120,000,000 m (157,000,000 cu yd). A dam was proposed at Gamboa to control flooding of
24424-459: The transit of larger Post-Panamax and New Panamax ships, which have greater cargo capacity than the original locks could accommodate. The idea of a canal across Central America was revived during the early 19th century. In 1819, the Spanish government authorized the construction of a canal and the creation of a company to build it. Although the project stalled for some time, a number of surveys were made between 1850 and 1875. They indicated that
24596-546: The two most-favorable routes were across Panama (then part of Colombia) and Nicaragua , with a third route across the Isthmus of Tehuantepec in Mexico another option. The Nicaraguan route was surveyed. After the 1869 completion of the Suez Canal , the French government believed that an apparently similar project to connect the Atlantic and Pacific Oceans could be carried out with little difficulty. In 1876 an international company, La Société internationale du Canal interocéanique,
24768-497: The two species have evolved to specialise in biting humans independently. Female mosquito mouthparts are highly adapted to piercing skin and sucking blood. Males only drink sugary fluids, and have less specialized mouthparts. Externally, the most obvious feeding structure of the mosquito is the proboscis, composed of the labium , U-shaped in section like a rain gutter , which sheaths a bundle (fascicle) of six piercing mouthparts or stylets. These are two mandibles , two maxillae ,
24940-477: The under-surfaces of waterlily pads. Clutches of eggs of most mosquito species hatch simultaneously, but Aedes eggs in diapause hatch irregularly over an extended period. The mosquito larva's head has prominent mouth brushes used for feeding, a large thorax with no legs, and a segmented abdomen . It breathes air through a siphon on its abdomen, so must come to the surface frequently. It spends most of its time feeding on algae , bacteria, and other microbes in
25112-529: The water from the lake. Gatun Lake would connect to the Pacific through the mountains at the Gaillard (Culebra) Cut. Unlike Godin de Lépinay with the Congrès International d'Etudes du Canal Interocéanique, Stevens successfully convinced Roosevelt of the necessity and feasibility of this alternative scheme. The construction of a canal with locks required the excavation of more than 17 million cu yd (13 million m ) of material over and above
25284-442: The water surface. Mosquitoes have adult lifespans ranging from as short as a week to around a month. Some species overwinter as adults in diapause . Mosquitoes have one pair of wings, with distinct scales on the surface. Their wings are long and narrow, while the legs are long and thin. The body, usually grey or black, is slender, and typically 3–6 mm long. When at rest, mosquitoes hold their first pair of legs outwards, whereas
25456-464: The water surface; they hatch into motile larvae that feed on aquatic algae and organic material . These larvae are important food sources for many freshwater animals, such as dragonfly nymphs , many fish, and some birds. Adult females of many species have mouthparts adapted to pierce the skin of a host and feed on blood of a wide range of vertebrate hosts, and some invertebrates , primarily other arthropods . Some species only produce eggs after
25628-436: The water's surface layer. It dives below the surface when disturbed. It swims either by propelling itself with its mouth brushes, or by jerkily wriggling its body. It develops through several stages, or instars , molting each time, after which it metamorphoses into a pupa . Aedes larvae, except when very young, can withstand drying; they go into diapause for several months if their pond dries out. The head and thorax of
25800-744: The work and appointed Major George Washington Goethals as chief engineer (under Stevens' direction) in February 1907. Stevens, frustrated by government inaction and the army involvement, resigned and was replaced by Goethals. The US relied on a stratified workforce to build the canal. High-level engineering jobs, clerical positions, skilled labor and jobs in supporting industries were generally reserved for Americans, with manual labor primarily by cheap immigrant labor. These jobs were initially filled by Europeans, primarily from Spain, Italy and Greece, many of whom were radical and militant due to political turmoil in Europe. The US then decided to recruit primarily from
25972-496: The work of Cuban epidemiologist, Carlos Finlay and American pathologist, Walter Reed . Investment was made in extensive sanitation projects, including city water systems, fumigation of buildings, spraying of insect-breeding areas with oil and larvicide, installation of mosquito netting and window screens, and elimination of stagnant water. Despite opposition from the commission (one member said his ideas were barmy), Gorgas persisted, and when Stevens arrived, he threw his weight behind
26144-594: The year, and that by 2080, the same will be true for southern Scotland. Dengue fever , too, is spreading northwards with climate change. The vector, the Asian tiger mosquito Aedes albopictus , has by 2023 established across southern Europe and as far north as much of northern France, Belgium, Holland, and both Kent and West London in England. Mosquito larvae are among the commonest animals in ponds, and they form an important food source for freshwater predators . Among
26316-462: Was US Army Major George Washington Goethals of the US Army Corps of Engineers . Soon to be promoted to lieutenant colonel and later to general, he was a strong, West Point -trained leader and civil engineer with experience in canals (unlike Stevens). Goethals directed the work in Panama to a successful conclusion in 1914, two years ahead of the target date of 10 June 1916. Goethals divided
26488-485: Was able to raise considerable funds in France as a result of the huge profits generated by his successful construction of the Suez Canal . Although the Panama Canal needed to be only 40 percent as long as the Suez Canal, it was much more of an engineering challenge because of the combination of tropical rain forests, debilitating climate, the need for canal locks, and the lack of any ancient route to follow. Lesseps wanted
26660-559: Was an early problem, and the Panama Railway was in a state of decay. However, much equipment (such as locomotives, dredges and other floating equipment) was still serviceable. Although chief engineer John Findley Wallace was pressured to resume construction, red tape from Washington stifled his efforts to obtain heavy equipment and caused friction between Wallace and the ICC. He and chief sanitary officer William C. Gorgas were frustrated by delay, and Wallace resigned in 1905. He
26832-505: Was being excavated per month (the equivalent amount of spoil from the Channel Tunnel every 3½ months). One of the greatest barriers to a canal was the continental divide , which originally rose to 110 metres (360.9 ft) above sea level at its highest point. The effort to cut through this barrier of rock was one of the greatest challenges faced by the project. Goethals arrived at the canal with Major David du Bose Gaillard of
27004-499: Was carried out on the new approach channels, but the project was canceled after World War II. After World War II, US control of the canal and the Canal Zone surrounding it became contentious; relations between Panama and the United States became increasingly tense. Many Panamanians felt that the Zone rightfully belonged to Panama; student protests were met by the fencing-in of the zone and an increased military presence there. Demands for
27176-537: Was controlling the diseases which had decimated workers and management alike under the original French attempt. The Americans' chief engineer John Frank Stevens (the second Chief Engineer of the American-led project after John Finlay Wallace resigned out of frustration with the bureaucracy in 1905) built much of the infrastructure necessary for later construction; slow progress on the canal itself led to his replacement by George Washington Goethals . Goethals oversaw
27348-546: Was created to take over the project. A minimal workforce of a few thousand people was employed primarily to comply with the terms of the Colombian Panama Canal concession, to run the Panama Railroad , and to maintain the existing excavation and equipment in salable condition. The company sought a buyer for these assets, with an asking price of US$ 109,000,000. In the meantime, they continued with enough activity to maintain their franchise. Phillipe Bunau-Varilla ,
27520-432: Was created to undertake its construction; two years later, it obtained a concession from the Colombian government (since Panama was a Colombian province) to dig a canal across the isthmus. On March 20, 1878, the Société Civile obtained an exclusive 15 years concession from the Colombian government to build a canal across the isthmus of Panama, which at the time was a Department of Colombia; the waterway that would revert to
27692-412: Was given control of the Panama Canal Zone, over which the United States exercised sovereignty. The commission reported directly to Secretary of War William Howard Taft and was directed to avoid the inefficiency and corruption that had plagued the French 15 years earlier. On 6 May 1904, President Theodore Roosevelt appointed John Findley Wallace , formerly chief engineer and finally general manager of
27864-536: Was introduced by the German entomologist Johann Wilhelm Meigen in his seven-volume classification published in 1818–1838. Mosquito taxonomy was advanced in 1901 when the English entomologist Frederick Vincent Theobald published his 5-volume monograph on the Culicidae. He had been provided with mosquito specimens sent in to the British Museum (Natural History) from around the world, on the 1898 instruction of
28036-565: Was not simply without foundation, but ridiculous to anyone the least familiar with the man or the prevailing temper in Washington. Nothing of the kind was ever even remotely contemplated at the White House or the State Department." The Americans' success hinged on two factors. First was converting the original French sea-level plan (which required extremely large excavations) to a more realistic lock -controlled canal. The second
28208-401: Was one of the first to recognize the role of mosquitoes in the spread of these diseases and, by focusing on controlling the mosquitoes, greatly improved worker conditions. On 7 January 1914, the French crane boat Alexandre La Valley became the first to traverse the entire length of the canal, and on 1 April 1914 the construction was officially completed with the hand-over of the project from
28380-487: Was replaced by John Frank Stevens , who arrived on July 26, 1905. Stevens quickly realized that serious investment in infrastructure was necessary and determined to upgrade the railway, improve sanitation in Panama City and Colón , renovate the old French buildings and build hundreds of new ones for housing. He then began the difficult task of recruiting the large labor force required for construction. Stevens' approach
28552-536: Was similarly responsible for the Pacific 3-mile (4.8 km) breakwater in Panama Bay , the approach channel to the locks, and the Miraflores and Pedro Miguel locks and their associated dams and reservoirs. The Central Division, under Major David du Bose Gaillard of the United States Army Corps of Engineers , was assigned one of the most difficult parts: excavating the Culebra Cut through
28724-501: Was summoned to Washington; he declared a sea-level approach to be "an entirely untenable proposition". He argued in favor of a canal using a lock system to raise and lower ships from a large reservoir 85 ft (26 m) above sea level. This would create both the largest dam (Gatun Dam) and the largest human-made lake (Gatun Lake) in the world at that time. The water to refill the locks would be taken from Gatun Lake by opening and closing enormous gates and valves and letting gravity propel
28896-426: Was taken from the Culebra Cut . The old company dredged a channel from Panama Bay to the port at Balboa , and the channel dredged on the Atlantic side (known as the French canal) was useful for bringing in sand and stone for the locks and spillway concrete at Gatún . Detailed surveys and studies (particularly those carried out by the new canal company) and machinery, including railroad equipment and vehicles, aided
29068-415: Was the first self-propelled vessel to transit the canal from ocean to ocean. This vessel crossed the canal from the Atlantic in stages during construction, finally reaching the Pacific on 7 January 1914. SS Cristobal (a cargo and passenger ship built by Maryland Steel , and launched in 1902 as SS Tremont ) on 3 August 1914, was the first ship to transit the canal from ocean to ocean. The construction of
29240-517: Was the oldest known mosquito. However its identification as a mosquito is disputed, with other authors considering it to be a chaoborid fly instead. Three other unambiguous species of Cretaceous mosquito are known. Burmaculex antiquus and Priscoculex burmanicus are known from Burmese amber from Myanmar, which dates to the earliest part of the Cenomanian age of the Late Cretaceous, around 99 million years ago. Paleoculicis minutus ,
29412-435: Was to press ahead first and obtain approval later. He improved drilling and dirt-removal equipment at the Culebra Cut for greater efficiency, revising the inadequate provisions in place for soil disposal. No decision had been made about whether the canal should be a lock or a sea-level one; the ongoing excavation would be useful in either case. In late 1905, President Roosevelt sent a team of engineers to Panama to investigate
29584-498: Was won by the firm Hutchison Whampoa , a Hong Kong–based shipping interest owned by Li Ka-shing . While globally the Atlantic Ocean is east of the isthmus and the Pacific is west, the general direction of the canal passage from the Atlantic to the Pacific is from northwest to southeast, because of the shape of the isthmus at the point the canal occupies. The Bridge of the Americas ( Spanish : Puente de las Américas ) at
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