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Jacen Solo

Jacen Solo is a fictional character in literature based on the Star Wars film series, set in what is now designated as the original-canon Star Wars Legends continuity. The son of Han Solo and Leia Organa Solo, as well as the nephew of Luke Skywalker, he is a major character in several novels, particularly the New Jedi Order series. He becomes the antagonist of the Legacy of the Force series under the name Darth Caedus. Jacen's other familial connections of note to his native continuity include being the brother of Jaina Solo and Anakin Solo as well as the cousin of Ben Skywalker.

Jacen has been noted as an influence for Kylo Ren, the canonical son of Han and Leia and villain of the Star Wars sequel trilogy, and Jacen Syndulla, the canonical son of Kanan Jarrus and Hera Syndulla from the epilogue series finale of Star Wars Rebels, later portrayed by Evan Whitten in Ahsoka.

Childhood
Jacen Solo was created for the Thrawn trilogy of novels by Timothy Zahn, set about five years after Return of the Jedi. He is introduced as one of an unnamed pair of twins Leia is pregnant with in the first installment of the trilogy, the 1991 novel Heir to the Empire. In the third installment, the 1993 novel The Last Command, he is born five minutes after his sister Jaina on Coruscant. The twins, and eventually their younger brother Anakin, were sent to live at various safe havens, under the protection of Leia's handmaiden, Winter.

In Jedi Search, the twins returned to Coruscant at age three and had many adventures there. Once, they became lost in the underworld of Imperial City with C-3PO, but they were quickly rescued and returned to their mother, the Chief of State of the New Republic.

In The Crystal Star, all three children were abducted, together with many other children with Force abilities, by Hethrir. Hethrir tried to brainwash them into becoming Dark Jedi in order to bring about the rebirth of the Galactic Empire, but the children defeated their captor.

Jedi Academy years
In the Young Jedi Knights series, Jacen travels to Yavin 4 with his sister to begin his Jedi training. Jacen discovers a strong connection to the Living Force — the concentration on the present moment — and can communicate with and calm many of the jungle creatures near the Academy. He even keeps a small menagerie of animals in his room in the Great Massassi Temple. He and his sister befriend the Wookiee Lowbacca (nicknamed Lowie by his friends) and the warrior princess Tenel Ka.

In Heirs of the Force and Shadow Academy, Jacen and Jaina discover a crashed TIE fighter from the Battle of Yavin. Jaina installs a hyperdrive in the downed starfighter and begins fixing it to fly again. Jacen, Lowbacca, and Tenel Ka help her to practice their Force skills until all are held captive by the TIE's original pilot, Qorl, who had been living in the jungle for two decades. They eventually escape, but so does Qorl, leaving the jungle moon behind and searching for any remnants of the Galactic Empire. Qorl discovers the Shadow Academy, a training ground for Dark Jedi commanded by one of Luke Skywalker's fallen students, Brakiss, along with the remains of the Dathomiri Nightsisters. These elements of the so-called Second Imperium kidnap Jacen, Jaina and Lowbacca, but they resist the dark side and are rescued by Luke Skywalker and Tenel Ka.

The friends return to Coruscant for a short vacation, and are reunited with the twins' childhood friend Zekk. They are forced to fight Jacen and Jaina several times, and the twins and their friends finally progress far enough to be tasked with building their first lightsabers. Jacen uses a corusca gem he had gained earlier for his focusing crystal.

Jacen's hard-learned lesson hits home once again in Lightsabers, when Tenel Ka rushes to complete her lightsaber to keep up with her friends. She uses an imperfect crystal and her blade shorts out in a sparring match with Jacen. His lightsaber passes through thin air where her weapon had been seconds before and severs the young woman's arm. Though she bears him no ill will for the accident, Jacen is wracked with guilt.

In Darkest Knight, the twins and Tenel Ka go to Kashyyyk with Lowbacca to witness his sister's adulthood rites. In Jedi Under Siege, the Jedi trainees and the Shadow Academy have their final confrontation on Yavin 4. The twins, with help from Luke and Zekk, bring down the Shadow Academy and the Second Imperium forever.

Throughout the series, Jacen and Jaina continue their training at Yavin 4, meeting new friends like Raynar Thul. They cannot convince Zekk to stay at the Academy with them, but Jacen and Jaina remain friends with him. With his and Raynar's help, they discover a threat to the New Republic: the Diversity Alliance, an alien, anti-human group. The Alliance is building up massive support among peoples that had been oppressed by the Empire. They are led by a Twi'lek Nolaa Tarkona, the sister of Oola, who was murdered by Jabba the Hutt in Return of the Jedi.

In Jedi Bounty, Jacen, Jaina, and their friends are briefly held captive on Ryloth and have to escape to its harsh surface. They have gone there in an attempt to rescue Lowbacca, who had misguidedly joined the anti-human Diversity Alliance. In the following book, The Emperor's Plague, they get to the bottom of a plot they had suspected all along, and catch up with Raynar's father, Bornan Thul, to race the Diversity Alliance fleet to an Imperial storehouse hidden in the deep core. There is hidden a supply of deadly diseases created by General Evir Derricote almost two decades before. Tarkona wishes to unleash a plague against humans and wipe them all out, but the Jedi and Alliance dissidents defeat her. She succumbs to one of the diseases herself on a faraway planet. Bornan Thul dies from one of the plagues right before his son's eyes.

In Return to Ord Mantell, they go on a trip with their father to the titular planet to watch a race. There, they run into Czethros, a bounty hunter who once hunted Han. They are ambushed by Black Sun agents, but are helped by Anja Gallandro, a young woman who wields a lightsaber, though she is not a Jedi. Although attracted to Tenel Ka, Jacen becomes infatuated with the older woman. Anja had blamed Han Solo for killing her father, but Solo reveals that her father died in a trap while finding treasure.

In Trouble on Cloud City, they discover Czethros is a minor leader of Black Sun, and is trying to gather enough power to overcome the New Republic. Jacen, Tenel Ka, and Lowbacca are ambushed by several Black Sun mercenaries, and Jacen is almost killed.

In Crisis at Crystal Reef, Jaina attempts to help Kessel and capture Czetheros while Jacen rushes to help Anja with her spice addiction and help her with Black Sun. With help, Anja beats her addiction and accepts her father's death. Jacen thinks Anja has Jedi potential, but it turns out she didn't. He gets over his infatuation with Anja when she goes to work for Lando.

Yuuzhan Vong War
In the New Jedi Order series, Luke takes Jacen as his Jedi apprentice. Jacen learns much from Luke, though they disagree on many philosophical issues. Jacen believes in the Force not only as a tool, but as part of something greater. He tells his brother Anakin that the Force is a guide to find one's place in destiny.

When the Yuuzhan Vong attack the New Republic in Dark Tide: Onslaught, Jacen comes to believe that many Jedi are handling the threat too aggressively. He abandons his powers temporarily to contemplate the Force and butts heads with his father over the morality of 'pirate' attacks on Peace Brigade vessels. Only his love for his mother brings Jacen back into the front lines of the battle. Eventually, Han and Jacen make their peace, the former declaring that while he doesn't always understand his son, he is proud of him.

In Star by Star Jacen joins a daring mission to Myrkr. A Jedi strike force, led by Anakin, is to infiltrate a Yuuzhan Vong cloning facility where the invaders craft deadly Jedi-hunting beasts called Voxyn. The mission is a disaster, ending with Anakin's death, in which Jaina reacts by touching the dark side of the Force. Forced into the leadership position, Jacen uses the Force Meld to bind the team together into a cohesive fighting unit. After destroying the voxyn queen, Jacen is captured by the Yuuzhan Vong army under the command of Vergere and Nom Anor. Jacen disappears, along with his presence in the Force.

In Traitor, Jacen awakes to find himself in the Embrace of Pain, a rack-like torture device favored by the Yuuzhan Vong. The torture nearly breaks Jacen's spirit, until he learns to use the pain he suffers to sustain himself. He remains under the care and tutelage of the avian Vergere, who he learns had once been a Jedi of the Old Republic, and who had even met his grandfather, Anakin Skywalker. He is put to work on Yuuzhan Vong ship, where he uses a number of herbs to heal slaves and get his captors to trust him. Using the implanted slave seed beneath his flesh as a conduit, Jacen communicates with the living instruments of Yuuzhan Vong technology. He uses this connection to stage a daring escape from captivity, commanding Yuuzhan Vong amphistaffs to surround him like living armor.

Jacen and Vergere flee to Coruscant. The planet's entire surface is undergoing a radical transformation. Yuuzhan Vong organic growths cover the once gleaming metropolis, remaking the planet into a Yuuzhan Vong paradise. The world is to be their new capital, a recreation of the planet that had spawned them, Yuuzhan'tar.

Vergere removes the slave seed from Jacen, but he can still sense the Yuuzhan Vong. Jacen is later surrounded by Yuuzhan Vong warriors whom Vergere had led to him. Wanting revenge, Jacen channels his hatred for Vergere into Force lightning; he is frightened by this connection to the dark side, however, and runs away. Vergere finds him in his destroyed home and gives him back full use of the Force. He is once again surrounded by Yuuzhan Vong captors; left with no choice, he surrenders and agrees to join their cause. He becomes the "khattazz al'Yun," or Avatar of God. Nom Anor intends to use Jacen to sacrifice Jaina, thus fulfilling an ancient Yuuzhan Vong prophecy.

Jacen's true allegiance is his own, however. During a test of Jacen's faith, the Yuuzhan Vong orders him to sacrifice captured Jedi Ganner Rhysode. Instead, the two Jedi turn against their captors. As Ganner holds off the Yuuzhan Vong, Jacen confronts the World Brain. The malevolent entity remembers the bond that Jacen had forged earlier, and Jacen suggests to it to work against the Yuuzhan Vong.

Ganner dies that day, though Jacen escapes with Vergere. He returns to the dwindling New Republic territories a different man: haggard, thin and hardened. He goes on a much needed vacation, but returns to frontline combat aboard the cruiser Ralroost. His ability to start the Jedi Meld is a large asset to Admiral Kre'fey, and Jacen joined the Alliance Fleet with elements of Garm Bel Iblis's forces in a large-scale deception at Ebaq 9. The battle ends in a victory, but results in Vergere's death. Her spectral form appears to him soon after.

As the newly formed Galactic Alliance emerged, Jacen accompanied his uncle Luke Skywalker into the Unknown Regions to seek a solution to the Yuuzhan Vong menace. Jacen would be instrumental in the search for Zonama Sekot and in the efforts to convince the living planet to join the fight against the Yuuzhan Vong. Jacen kills Supreme Overlord Onimi, who had been using Supreme Overlord Shimrra as a puppet, in a spectacular confrontation where the Force uses Jacen as a conduit to defeat Onimi, considering that Jacen was almost killed with just one hit by Shimrra himself, and in that moment Jacen started believing that he is beyond good and evil, marking the beginning of his fall. After the grueling final confrontation and the war's end, Jacen tells Luke that he had decided to travel the galaxy to learn more about the Force. While on his five-year journey Jacen enters a realm of the Force known as beyond shadows, thanks to his training with a sect called the Mind Walkers. In this realm Jacen gazes into the Pool of Knowledge that holds the Throne of Balance, (where in all future events are shown) Jacen sees a dark man ruling the Galaxy and becomes determined to prevent this evil future. Following this experience, Jacen begins his descent to the dark side of the Force.

Dark Nest Crisis
In Dark Nest, Jacen feels an urge through the Force and follows his sister to the Unknown Regions to help the insectoid Killik against an invading Chiss force. He returns to Republic space after his parents, resulting in his uncle and aunt to come for him, Jaina, and the other Jedi. He then travels to the Hapes Cluster to ask Tenel Ka to assist with the Chiss/Killik conflict, believing that the fleet could act as a buffer between the two armies. She obliges and sends a fleet of Hapan Battle Dragons to protect the Killiks.

In The Unseen Queen, Tenel Ka gives birth to his daughter, Allana, who is then attacked by the Gorog. Jacen successfully repels the attack and keeps his daughter safe. Possessed with a strong fear of his daughter or Tenel Ka being harmed, Jacen uses the Force to send Tenel Ka's grandmother (the person behind the attack) into a coma. Immediately afterward, he sees a vision of a neverending war that will destroy the galaxy, with the Killiks at the heart of it. Determined to save his daughter and the galaxy from his vision, he sets out to provoke the Chiss into destroying the Killiks. Jacen later reveals that he never knew who started the war in his vision.

In The Swarm War, Luke Skywalker takes his nephew's advice so many times that he even listens when Jacen tells him that he is not ready to face Lomi Plo, the Dark Queen of the Gorog. Jacen, Mara and Luke know that doubt and fear would make Lomi Plo invisible to her enemy. Jacen, along with R2-D2, helps Luke conquer some of his fears about Mara's involvement with the death of his mother, and then accompanies him to face Plo.

During the fight with Plo, Luke falters for a moment when Mara is injured, and doubt enters his mind. Plo then holds him in place, unable to move. In that instant, Jacen is critically wounded by Plo while saving Mara Skywalker's life. A well-placed shot from Mara injures Plo, after which Mara tends to Jacen's wounds. While he and Mara recover, Jacen beseeches Luke to embrace his darker emotions. Luke refuses and goes back to the true Jedi way, defeating the Dark Queen and Raynar Thul without using the dark side.

In the latter novel, Jacen joins his uncle in watching holovideos of his grandparents, Anakin Skywalker and Padmé Amidala; in particular, he sees Anakin fall to the dark side and Padmé die in childbirth partly as a result of Anakin's treachery. (These scenes are first portrayed in Star Wars: Episode III – Revenge of the Sith). Jacen actually sympathizes with Anakin's desire to protect his wife, and reminds Luke that Anakin was a fallible human being.

Legacy of the Force
In Betrayal, Jacen starts training his young cousin Ben in the ways of the Force. After a successful mission to Adumar that ends in a life-threatening attack, they return for a dinner party at his parents' new home. There, Han voices his concern over Corellia trying to gain independence. Luke orders Jacen and Ben to disable the Centerpoint Station, an ancient artifact that Corellian leader (and Han's cousin) Thrackan Sal-Solo is trying to use to his advantage. Ben disables the station while Jacen keeps Thrackan busy, ensuring the Galactic Alliance's partial victory as another fleet built in secret spoils the main attack.

While travelling to a subterranean base, Ben and Nelani, a Jedi Knight, are forced out of a mining car. Their guide, Brisha Syo creates a dark side phantom of Luke Skywalker, who attacks and very nearly kills Jacen. Eventually, Brisha stops the projections and takes Jacen to an office, where Darth Vectivus, the supposed Sith Lord they are hunting, lives. After fighting Force projections with Ben, Nelani catches up with them. Brisha is revealed to be Lumiya, the Dark Lady of the Sith. She reveals that Vergere is a Sith apprentice, and that Jacen has already received Sith training. Lumiya says that Jacen is going to become the next Sith Lord. Unsure of his next move, Jacen uses the Force to create visions of the future. In each vision in which Lumiya is arrested, the galaxy is consumed in an endless war that eventually places Jacen against Luke. In the vision, Jacen kills his uncle.

Horrified, Jacen spares Lumiya. Nelani then tries to arrest the Sith, but Jacen intervenes. Jacen realizes that Nelani will, if allowed to survive, possibly fulfill the dark vision he had seen. He then fights and kills her, asking her forgiveness before striking the fatal blow. He agrees to consider what Lumiya had said and leaves the asteroid with an unconscious Ben. Jacen then erases Ben's memories of Lumiya and tells him that both she and Nelani had been killed by dark side phantoms. They return to Coruscant; however, after Jacen departs, Lumiya says that she had won.

Fully pledged to Lumiya, Jacen becomes head of the GFFA's newly formed secret police, the Galactic Alliance Guard. With Ben at his side, he begins rounding up Corellians for internment and deportation. During an interrogation of a suspected assassin (who turns out to be Ailyn Vel, Boba Fett's daughter), Jacen tries to use the Force to extract information from her and kills her accidentally in the process.

Jacen also takes command of Rogue Squadron while it participates in the blockade of Corellia. He shoots down a civilian freighter that was attempting to run the blockade, and had fired on him, then relieves his sister from duty because she had refused to do it. He also uses the Anakin Solo to fire upon the Millennium Falcon, while both his sister and his parents are on board. He believes his parents to have been involved in a failed attempt to assassinate Tenel Ka; the Solos had in fact been set up by Dur Gejjen, Prime Minister of Corellia.

In Sacrifice, Lumiya says she is pleased by his progress, but instructs him that to truly become a Sith he would have to undergo the Trial of Sacrifice: to kill that which he loves most. Doing this, he believes, would allow him to use the powers of the Sith without becoming evil and would "immortalize his love" for his sacrifice. Jacen decides there is only one way to fulfill this last obstacle: he would have to kill Tenel Ka and their daughter Allana. Nevertheless, after Ben tells Mara that he overheard Jacen communicating with Lumiya, Mara tracks Jacen down in the Hapes Consortium. After a long and heated battle, Jacen kills Mara Jade; the sacrifice necessary to becoming a Sith Lord is not Jacen's love, but Ben's. Ben suspects Jacen almost immediately, upon meeting Jacen at his mother's body. Eventually, Jacen chooses the Sith name Darth Caedus.

By Fury, Darth Caedus is the principal antagonist of the series, and the declared enemy of nearly every other major character: His parents and sister have disowned him, Luke is sworn to redeem him, and Ben is driven to seek justice for his mother. In the novel, Caedus kidnaps Allana so Tenel Ka and the Hapans won't decide to leave the government, but Han, Leia, Luke, Jaina, Ben, and their allies save Allana. After saving Allana, Leia tells Caedus to become a Jedi again, but he refuses. Han and Leia later find out Allana is Caedus and Tenel Ka's child. At the end, Jaina plans to have training from Boba Fett to help her face off against Caedus, despite her parents once being foes with Fett.

In Revelation, Caedus takes on a new apprentice, Tahiri Veila to replace Ben and turns to the task of ending the war. He entices the Imperial Remnant to join him in an attack on the planet Fondor. Although Admiral Niathal wants to offer the planet the chance to surrender, Caedus is determined to make an example of Fondor by crippling the shipyards and its planetary government. After previously sharing military secrets, which leads to hundreds of deaths and compromises the battle plan at Fondor, Niathal arranges a cease-fire without consulting Caedus. Enraged at this treason, Caedus orders the fleet to ignore Niathal's orders and bombard the major cities. Niathal orders all ships loyal to her to attack the Anakin Solo. Two-thirds of the fleet side with Caedus, while the rest ally themselves with Niathal. When the Imperial Remnant refuses to assist Caedus, his new apprentice assassinates Imperial Head of State Gilad Pellaeon and turns control over to the Moffs who then come to aid Jacen. A mysterious fleet led by Admiral Daala, loyal to Pellaeon, appears, accompanied by one hundred Mandalorian mercenaries and together, owing to Daala's experimental weapons, they send the Galactic Alliance Fleet into retreat.

Caedus then takes control of Coruscant and claims sole control of the Galactic Alliance.

In Invincible, Jaina takes it upon herself to defeat her brother. Caedus's meditations are disrupted by Luke Skywalker, in an attempt to hide Jaina's attack. Jaina, accompanied by several Mandalorian commandos, confronts Caedus, who quickly dispatches the Mandalorians, while Jaina acts as a sniper. When she finally runs out of ammunition, she seizes a Mandalorian saber and severs Caedus' arm. Jaina withdraws, however, due to her own injuries. After escaping an attack led by Luke Skywalker on the bridge of the Anakin Solo, Caedus sees a vision of his daughter Allana on a white throne in a time of peace. This vision convinces Caedus that he has won — he would bring peace to the galaxy, and prevent his visions of war and suffering from coming true.

At the book's climax, Caedus and Jaina face off in a final lightsaber duel aboard Caedus' flagship, the Anakin Solo. In the midst of the duel, Caedus comes back to the light and attempts to persuade Jaina of his intentions to protect Tenel Ka and Allana. Jaina refuses to listen, however, and attacks him after he deactivates and holsters his lightsaber. She later slams the door shut in his face when he tries to leave the fight. After a grueling battle in which both are seriously injured, Jacen is defeated when Jaina severs his Achilles tendon and stabs him in the heart. As he dies, Jacen reaches out to both his former lover and his child through the Force, warning them to flee from an approaching bio-warfare attack designed by the Imperial Remnant to kill them. In this act of selflessness, Jaina sees the remnants of the good man her brother had once been. Following Caedus's death and the war's end, the Galactic Alliance emerges victorious over the Confederation and peace is restored to the galaxy, just as Jacen had foreseen through a vision in the Force.

Fate of the Jedi
Though Jacen makes few true appearances in the Fate of the Jedi, which follows the Legacy of the Force series, his legacy is felt throughout the series, as Luke Skywalker is arrested for negligence of duty and is sentenced to a ten-year exile, in which alongside his son Ben, he tries to ascertain the circumstances of how and why Jacen turned to the dark side.

Jacen's spirit makes its first appearance in Abyss, wherein he warns Luke and Ben about Abeloth, the main antagonist of the series.

Then, in the final novel Apocalypse, Jacen's spirit (along with Mara's) provides aid to Luke as he partners with Darth Krayt in the final battle against Abeloth. Following Abeloth's destruction, Jacen reveals that Krayt was the dark figure he saw in his vision of the future and the source of his downfall; he saw his daughter Allana standing next to Krayt. In response, Krayt insists that while Caedus's actions simply delayed the Sith, and they are eventually going to succeed in their planned takeover of the galaxy.

In aiding the Jedi against Abeloth, Jacen posthumously redeems himself; however, he still refers to his fate as damnation. While Luke does not forgive his nephew for his complicity in Mara's death, he does receive an understanding of what led Jacen to that point.

Star Wars: Legacy
The second volume of the Legacy comic series, set about 140 years after Return of the Jedi, features Jacen's descendant Ania Solo as the protagonist. In general, the descendants of Jacen, Jaina and Ben are main characters in this era, set when and after Darth Krayt takes over the galaxy. Although they themselves do not appear in person as spirits, older characters like Luke and Mara do.

Reception
IGN listed Jacen as #17 on their list of the top 100 Star Wars heroes, saying that he had a more "profound effect" than any of the other Solo children on the Star Wars setting. Jesse Schedeen, writing for IGN, also listed Darth Caedus as #5 in a reader-inspired list of top Star Wars villains, and called his "defining moment of villainy" his murder of Mara Jade. UGO.com listed Jacen as their top Star Wars expanded universe character, calling him "one of the most fearsome - and most tragic - villains in the Star Wars universe".

Legacy
With the sequel film Star Wars: The Force Awakens in production, in April 2014 most of the licensed Star Wars novels and comics produced since the 1977 film Star Wars were declared non-canon to the franchise. The epilogue of "Family Reunion – and Farewell", the series finale of Star Wars Rebels, introduced a character named Jacen Syndulla by series creator Dave Filoni in honor of Jacen Solo.

title: Jacen Solo


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Eduardo Frei Montalva

Eduardo Nicanor Frei Montalva (16 January 1911 – 22 January 1982) was a Chilean political leader. In his long political career, he was Minister of Public Works, president of his Christian Democratic Party, senator, President of the Senate, and the 27th president of Chile from 1964 to 1970. His eldest son, Eduardo Frei Ruiz-Tagle, also became president of Chile (1994–2000).

Frei's Christian Democratic Party supported the Armed Forces intervention to remove his successor Salvador Allende from office in 1973, after the Chamber of Deputies, on 22 August 1973, accused Allende of violating the Constitution. He was later a vocal opponent of the Augusto Pinochet regime. On 22 January 1982, Frei died in Santiago, Chile, following surgery. Assassination was suspected by some but has never been proven. On 18 August 2023, the Supreme Court ruled out the assassination charges and declared innocent all those accused.

Early life
Eduardo Frei Montalva was born in Santiago on 16 January 1911, the son of Eduard Frei Schlinz, a Swiss-born ethnic German from Feldkirch, Austria, and Victoria Montalva Martínez. In 1914, his family moved to Lontué, where his father had been hired as an accountant at a winery. In addition, his other two siblings, Arturo and Irene, were born. He attended the Escuela Pública de Lontué (Public School of Lontué). The winery San Pedro is still well known in Lontué and Molina 200 km south of Santiago and was founded in 1865 by the brothers Bonifacio and José Gregorio Correa Albano.

In 1919 the family returned to Santiago and Eduardo, as a young man, entered the boarding school Seminario Conciliar de Santiago where he remained until 1922. In 1923, he entered Instituto de Humanidades Luis Campino, where he graduated in 1928, at the age of 17.

As an 18-year-old, he entered Universidad Católica School of Law in 1929. For two years, he had been visiting María, the sister of his friend, Alfredo Ruiz-Tagle. He attended high school and went on to study law, graduating as a lawyer in 1933. He married María Ruiz-Tagle with whom he had 7 children. His eldest son, Eduardo Frei Ruiz-Tagle, was President of Chile from 1994 to 2000.

Political career
He began his political career in the Conservative Party, but was among a group of young men who founded their own party in 1938: the Falange Nacional. He was minister of Public Works in 1945, and in 1949, Frei was elected senator for Atacama and Coquimbo. The same year he published “Historia de los Partidos Políticos Chilenos” (“History of Chilean Political Parties”) in collaboration with Albert Edwards Vives. In 1950, he traveled to New York as a UN delegate. In 1952, at 41 years of age, Frei Montalva announced his first candidacy in the presidential elections.

The 1952 election was won by Carlos Ibáñez del Campo. Later, President Ibañez requested Frei to organize an executive committee. However, this never came to be. In 1954, the UN appointed him President of the Commission in charge of elaborating the report of the Conference of Chancellors held in Rio de Janeiro. Some of its members were: Carlos Lleras Restrepo, former President of Colombia, and Raúl Prebisch director of ECLAC. The report served as a basis for subsequent studies on economic development and the integration of Latin America. In 1956 he was elected Senator in Santiago by first majority.

On 27 July 1957, the Falange Nacional became the Christian Democratic Party of Chile, and he became the undisputed leader. Frei Montalva was offered once more the candidacy for president of the Republic in the 1958 elections. Jorge Alessandri Rodríguez was elected president while Eduardo Frei Montalva took only third place.

During these years he published three more books: “Sentido y Forma de una Política” (“Meaning and Shape of Politics”), “La Verdad Tiene Su Hora” (“Truth Has Its Time”), and “Pensamiento y Acción” (“Thought and Action”). In 1960, he lectured at conference “The Mission of Universities in Latin America” in Montevideo; a widely promoted conference at that time. In 1961, he was elected President of the First World Christian Democratic Party Congress, held in Santiago, Chile. The congress was attended by delegations from throughout Latin America, European, North American, and African countries. That year he was invited as special guest to a seminar on the problems of Developing Nations, held at Oxford University. The seminar was attended by delegates from all over the world.

Between 1960 and 1962, he lectured at Columbia University on problems in Latin America. In 1962, he gave a conference at Notre Dame University on the development and the integration of Latin American countries. He ran for president again in 1964. Declassified documents show that from 1962 through 1964, the CIA spent a total of $2.6 million to finance his presidential campaign and spent $3 million in anti-Allende propaganda "to scare voters away from Allende's FRAP coalition". The CIA considered its role in the victory of Frei a great success.

That year he was elected with his "Revolución en Libertad" ("Revolution in Liberty") slogan by a large margin (56%), defeating Socialist candidate Salvador Allende who only received 39% of the vote, but who subsequently won the 1970 Chilean presidential election.

Administration
Frei's administration began many reforms in Chilean society. "Promoción Popular" (Social Promotion), "Reforma Agraria" (Agrarian Reform), "Reforma Educacional" (Education Reform), and "Juntas de Vecinos" (Neighborhood Associations) were some of his main projects. He also took measures to rationalize drug supply. On 4 September 1964, having one of the highest turnouts in Chilean history, Frei Montalva was elected President of the Republic of Chile. He took office two months later, on November 4.

The Frei presidency did much to tackle poverty, as characterised by the growing share of wages as a proportion of GNP. By the end of the Frei presidency, the wage and salaried sector received close to 51% of GNP, compared with 42% at the end of the Alessandri presidency. This positive redistribution of wealth was encouraged by government policies, particularly in the rural sector, where wages rose by 40% in real terms. Between 1964 and 1970, total enrollment in education increased by 46%, while around 250,000 houses were built, mostly for the poor.

Frei's administration also introduced a wealth tax and carried out a property tax reassessment in order to make the taxation system more progressive. Taxes as a percentage of GNP increased 12.8% in 1964 to 21.2% in 1970. The social reforms introduced by Frei's government led to a huge increase in public expenditure, which rose as a proportion of GNP from 35.7% in 1965 to 46.9% in 1970. Expenditures on education, agriculture, and housing rose went up considerably, with spending on housing increasing by 70% in real terms in 1965 alone.

During Frei's six years in office, an average of 40,000 housing units were constructed each year, and a total of 100,000 lots were assigned. Investments in primary care clinics and hospitals were also carried out, with 20 clinics and 16 hospitals built between 1965 and 1969.

In 1965, he started a presidential tour through France, the United Kingdom, Federal Republic of Germany, Italy and the Vatican. During this time, he also visited countries in Latin America such as: Argentina, Brazil, Uruguay, Colombia, Peru, Ecuador, and Venezuela; places where he delivered important speeches on international issues.

On his return, he initiated important plans involving housing, education, reforestation, land reform, health, and the nationalization of copper. The Comisión Nacional de Cultura (National Culture Commission), the Consejería Nacional de la Promoción Popular and the Juntas de Vecinos (“Neighborhood Committees”) were also created.

One area of reform given high priority by the Frei Administration was the fostering of networks of local, self-help organisations (especially among the “unorganised” residents of the shantytowns), which was placed under a national supervisory council. As a result of the government's actions, mothers' centres, sports associations, youth clubs, residents’ committees, and parents' groups proliferated, with an estimated 20,000 units of this type in existence by 1970, according to government figures. Half of these new units were mothers' centres, with an estimated membership of 45,000 women, and the government claimed to have distributed 70,000 sewing machines to these centres. According to Frei, these measures had given “a new form of life and hope” to hundreds of thousands of people. Improvements were also made in areas such as housing, education and medical care. Between 1964 and 1970, around 260,000 houses were constructed (around a third by the state housing corporation CORVI) and about 200,000 housing solutions were claimed (referring to the provision of sites for self-help housing projects). The number of hospitals (and beds) doubled under the PDC, and spending on education as a proportion of public expenditure rose from one-seventh to one-fifth. Around 3,000 new schools were built throughout the country, and by 1970 95% of children in the relevant age group were covered by primary education. Expenditure on scholarships and school loans was doubled, and school enrollment was raised from 1.8 million to 2.9 million.

Expenditure on education doubled, the number of years of basic education was increased from six to eight, and a two-shift school-day was introduced that doubled the capacity of the country's system. Frei's initiatives in education led to increased rates of enrollment in both primary and secondary education, with primary school coverage reaching 90% in the majority of rural and urban areas by 1970, while secondary school coverage reached 49% in 1970, compared with 18% at the start of the 1960s.

A new law establishing work-accident and occupational disease insurance was signed into law in January 1968, providing for compulsory coverage of all salaried employees and wage earners, including apprentices and domestic servants. In March that year, a piece of legislation creating government-sponsored health insurance for public and private salaried employees and their dependents was signed into law.

Basic health services were expanded with the training of community health workers, the building of rural health clinics, and the shifting of financial and personnel resources from hospitals to community health centres. These efforts contributed to a steep decline in infant mortality in Chile during the 1960s–1970s.

Much attention was also given to the improvement of social and economic conditions in the countryside. Both rural unionisation and agrarian reform were accelerated, with the government starting to expropriate estates in a serious way. Family allowance for farmers was doubled, the agricultural minimum wage was raised to the same level as its urban equivalent, and an agrarian reform law signed by Frei in July 1967 made all farms of more than eighty “basic” hectares liable to expropriation. The Frei Administration had thus made a major start to land reform, a policy continued by the Allende Government.

The agrarian reform carried out by the Frei Government organized the reformed sector according to a temporary system established in the law, whereby the expropriated estates became asentamientos. This was a legal form in which the farm operated as a joint enterprise between the state and the peasants who had lived in the former latifundia (extensive agricultural estates), with the state providing the credits, land, and technical assistance, and the peasants their labor. After an indeterminate period, the land would be made available for subdivision into small private plots, if the peasants wished. According to one study, the percentage of the population living below the poverty line steadily fell; from 39% in 1965 to 17% in 1970.

During his administration 8 workers were killed in El Salvador mine and 11 squatters in the Massacre of Puerto Montt. His Minister of the Interior, Edmundo Pérez Zujovic was politically blamed for the deaths. On 21 October 1969 the Tacnazo insurrection, occurred—a brief non-violent demonstration of the Tacna artillery regiment in Santiago, led by General Roberto Viaux.

In 1966, the Andean Group, officially created through its Declaration, signed in January 1965. However, the group culminated with the famous speech delivered by Frei Montalva in Plaza Bolívar, Bogota. The same year the pacts on Chilean copper were signed.

In January 1967 the National Congress refused his constitutional permission to travel to the United States where he had been invited by President Lyndon B. Johnson. In April 1967, he participated in the Meeting of Presidents from American countries, carried out in Montevideo, Uruguay.

In 1970, he was awarded with the Doctor Honoris Causa title by the Pontificia Universidad Católica de Chile. On November 4, he left office, handing over the Presidency to Salvador Allende.

Support of the coup d'etat against Allende
After Allende's 1970 victory, Frei became convinced of what he called a "totalitarian project" to impose a Communist tyranny. In 1971, he gave conferences at universities in Dayton, Ohio, Boston, and the Council of the Americas in New York, denouncing in all of them the actions of the Allende government that were allegedly violating the Constitution and the laws of Chile.

In the March 1973 parliamentary elections he was elected Senator for Santiago by a first majority. He was afterwards elected President of the Senate and became the leader of the opposition to Allende. On 6 July 1973, he met with the executive directors of the industrialists’ association (SOFOFA). They told Frei that the country was disintegrating and that if urgent measures were not taken, Chile would fall under a bloody Cuban-style Marxist dictatorship. Frei responded: "There is nothing that can be done by myself, by the Congress, or by any civilian. Unfortunately, this problem can only be fixed with guns." Instead of going to the Congress, we should go to the regiments. "I fully share your apprehensions, and I advise you to state them plainly to commanders-in-chief of the Armed Forces, hopefully today."

On 11 September 1973, during the coup d’etát President Allende died by suicide in the presidential palace, La Moneda, as the Armed Forces seized power. Frei’s Christian Democratic Party supported the Armed Forces intervention to remove Allende from office in 1973, after the Chamber of Deputies, on 22 August 1973, accused Allende of violating the Constitution.

In November 1973 Frei wrote a historic letter to Mariano Rumor, President of the International Christian Democrats, endorsing the Armed Forces intervention and denouncing what he alleged was an attempt by Allende to impose a Communist dictatorship in Chile.

Between 1973 and 1977, Frei Montalva was invited to different countries and participated in conferences, such as the Atlantic Conference in 1976. In 1975 he published his book El Mandato de la Historia y las Exigencias del Porvenir (“The Mandate of History and Demands of the Future“), and in 1977 his quintessential book América Latina: Opción y Esperanza (“Latin America: Option and Hope”) which has been translated into several languages.

In the period between 1977 and 1982, he was invited to participate in the Brandt Commission, led by Willy Brandt. As a member, he attended meetings held in Germany, Switzerland, Mali, United States, Malaysia, France, Austria, Belgium, and Great Britain. As a Brandt Commission delegate he engaged with important executives from IDB, OAS, and ECLAC.

In 1980, he participated in the Meeting of Former Democrat Presidents of Latin America held in Caracas, Venezuela. In 1981, he was invited to the Club of Rome International Conference on the “Alternatives for Humanity: Latin America Mission” also held in Caracas. His last book El Mensaje Humanista (“The Humanist Message”) was published.

Later, Frei became an opponent of Pinochet's military government. He opposed the extension of Pinochet's presidency in 1981, leading a rally against it.

Death
In 1981 Frei was suffering from chronic acid reflux, stemming from a hiatal hernia, an unpleasant but not life-threatening condition. He was operated on for the condition, but died in Santiago on 22 January 1982, six days after his 71st birthday. His death at the time was attributed to septicaemia stemming from surgery. He was buried in the Cementerio General de Santiago.

It was later alleged that Frei had been poisoned by DINA, the intelligence service of the military government, with a toxin produced by biochemist Eugenio Berrios. After it was reported that researchers from the University of Ghent in Belgium had discovered traces of mustard gas in Frei's body, the former president's family filed a lawsuit.

Frei's personal doctor, Patricio Rojas, who was also his Minister of the Interior, denied the accusations. El Mercurio columnist Hermógenes Pérez de Arce disputed the existence of the Belgian report, citing a denial by the university's chief of communications, Tom de Smedt, that an investigation had been done at the university. Tissue samples sent to FBI labs and to the labs at the University of Ghent showed no evidence of toxic substances. A Chilean doctor reportedly found residues of sulfonic salts, which can be the result of the decomposition of mustard gas but can also be the result of the decomposition of a corpse.

In December 2009, six individuals were arrested for their roles in the alleged assassination.

Judge Alejandro Madrid based his decision on a report that determined that low doses of thallium and mustard gas were administered to Frei over an extended period while he was hospitalized at the Santa María Clinic in Santiago, and that these toxic substances had the effect of decreasing Frei's immune system, making him too weak to survive his surgery.

The report was widely criticized by the surgical team in El Mercurio and La Segunda, newspapers owned by the Edwards family, who had brokered the coup and maintains strong ties to the CIA and to Pinochet's government. The Appeals Court suspended Judge Madrid from the case, and the accused were freed on bail.

The case was re-opened in 2010 after a failed attempt to disqualify Judge Madrid.

On 30 January 2019, the six suspects were found guilty of homicide and given sentences ranging from 3 to 10 years in prison. On 25 January 2021, the convictions would be overturned by a Chile Appeals Court three judge panel which found that Montalva was not a homicide victim. The Supreme Court of Chile would also find that Frei was not a homicide victim on 18 August 2023 as well.

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

title: Eduardo Frei Montalva


text:
Anna Katharine Green

Anna Katharine Green (November 11, 1846 – April 11, 1935) was an American poet and novelist. She was one of the first writers of detective fiction in America and distinguished herself by writing well plotted, legally accurate stories. Green has been called "the mother of the detective novel".

Life and work
Green was born in Brooklyn, New York on November 11, 1846. She had an early ambition to write romantic verse and corresponded with Ralph Waldo Emerson. When her poetry failed to gain recognition, she produced her first and best known novel, The Leavenworth Case (1878), praised by Wilkie Collins, and the hit of the year. She became a bestselling author, eventually publishing 37 books over 40 years.

On November 25, 1884, Green married the actor and stove designer, and later noted furniture maker, Charles Rohlfs (1853 – 1936). Rohlfs toured in a dramatization of Green's The Leavenworth Case. After his theater career faltered, he became a furniture maker in 1897, and Green collaborated with him on some of his designs. Together they had one daughter and two sons: Rosamund Rohlfs, Roland Rohlfs, and Sterling Rohlfs. Her daughter Rosamund married Robert Twitty Palmer.

Green died on April 11, 1935, in Buffalo, New York, at the age of 88. Her husband died the following year.

Critical response
Though Green's book The Leavenworth Case is frequently cited as the first mystery written by an American woman, The Dead Letter by Seeley Regester was published earlier (1866).

In a discussion of women writers of detective fiction, scholar Ellen Higgins in 1994 chronicled the work of Green as popularizing the genre a decade before Arthur Conan Doyle brought out his first Sherlock Holmes story. "I only found out afterward that some people were a little upset with it because they don't want to hear about women competing with the master", Higgins said.

Green is credited with shaping detective fiction into its classic form, and developing the series detective. Her main character was detective Ebenezer Gryce of the New York Metropolitan Police Force, but in three novels he is assisted by the nosy society spinster Amelia Butterworth, the prototype for Miss Marple, Miss Silver and other creations. She also invented the 'girl detective': in the character of Violet Strange, a debutante with a secret life as a sleuth. Indeed, as journalist Kathy Hickman writes, Green "stamped the mystery genre with the distinctive features that would influence writers from Agatha Christie and Conan Doyle to contemporary authors of suspenseful "whodunits". In addition to creating elderly spinster and young female sleuths, Green's innovative plot devices included dead bodies in libraries, newspaper clippings as "clews", the coroner's inquest, and expert witnesses. Yale Law School once used her books to demonstrate how damaging it can be to rely on circumstantial evidence. Written in 1878, her first book, The Leavenworth Case: A Lawyer's Story, sparked a debate in the Pennsylvania State Senate over whether the book could "really have been written by a woman".

Green was in some ways a progressive woman for her time—succeeding in a genre dominated by male writers—but she did not approve of many of her feminist contemporaries, and she was opposed to women's suffrage.

Legacy
In 2002, Buffalo Literary Walking Tours began an annual series of weekend walking tours highlighting authors with local connections. Green is included along with Mark Twain, F. Scott Fitzgerald, Herman Melville, Taylor Caldwell, and others.

Green's short story "The Intangible Clue" featuring Violet Strange was adapted by Chris Harrald for the second series of BBC Radio 4's drama series The Rivals and starred Jeany Spark as Violet Strange.

Selected works

 * Detective and mystery novels

 * The Leavenworth Case (1878) Mr. Gryce #1
 * A Strange Disappearance (1880) Mr. Gryce #2
 * The Sword of Damocles: A Story of New York Life (1881) Mr. Gryce #3
 * Hand and Ring (1883) Mr. Gryce #4
 * Behind Closed Doors (1888) Mr. Gryce #5
 * A Matter of Millions (1891) Mr. Gryce #6
 * The Doctor, His Wife, and the Clock (1895) Mr. Gryce #7. Novellette, shorter than the others
 * That Affair Next Door (1897) (Amelia Butterworth I). Also Mr. Gryce #8
 * Lost Man's Lane: a Second Episode in the Life of Amelia Butterworth (1898) Also Mr. Gryce #9
 * The Circular Study (1900) (Amelia Butterworth III) Also Mr. Gryce #10
 * One of my Sons (1901) Mr. Gryce #11
 * Initials Only (color frontispiece by Arthur Keller) (1911) Mr. Gryce #12
 * The Mystery of the Hasty Arrow (1917) Mr. Gryce #13
 * X Y Z: A Detective Story (1883)
 * The Mill Mystery (1886)
 * 7 to 12: A Detective Story (1887)
 * One Hour More (1887)
 * Forsaken Inn (1890)
 * Cynthia Wakeham's Money (1892)
 * Miss Hurd: An Enigma (1894)
 * Doctor Izard (1895)
 * Agatha Webb (1899) Caleb Sweetwater #1
 * The Filigree Ball: Being a Full and True Account of the Solution of the Mystery Concerning the Jeffrey-Moore Affair (1903)
 * The Millionaire Baby (illustrations by Arthur I. Keller) (1905)
 * The Chief Legatee (1906)
 * The Woman in the Alcove (illustrations by Arthur I. Keller) (1906) Caleb Sweetwater #2
 * The Mayor's Wife (illustrations by Alice Barber Stephens (1907)
 * The House of the Whispering Pines (1910) Caleb Sweetwater #3
 * Three Thousand Dollars (1910)
 * Dark Hollow (1914)
 * The Step on the Stair (1923)

 * Other novels

 * The Defence of the Bride, and other Poems (1882)
 * Risifi's Daughter, a Drama (1887)
 * Marked "Personal", A Drama Within a Drama. (1893)
 * To the Minute; Scarlet and Black: Two Tales of Life's Perplexities (1916)

 * Short novels and short stories

 * The Old Stone House and Other Stories (1891) featuring:
 * "The Old Stone House"
 * "A Memorable Night"
 * "The Black Cross"
 * "A Mysterious Case"
 * "Shall He Wed Her?"
 * A Difficult Problem: The Staircase at the Heart's Delight, and Other Stories (1900) featuring:
 * "A Difficult Problem" (1900)
 * "The Grey Madam" (1899)
 * "The Bronze Hand" (1897)
 * "Midnight in Beauchamp Row" (1895)
 * "The Staircase at the Hearts delight" (1894)
 * "The Hermit of ― Street" (1898)
 * Room Number 3, and Other Detective stories (1913) featuring:
 * "Room Number 3"
 * "Midnight in Beauchamp Row"
 * "The Ruby and the Caldron"
 * "The Little Steel Coils"
 * "The Staircase at Heart's Delight"
 * "The Amethyst Box"
 * "The Grey Lady"
 * "The Thief"
 * "The House in the Mist"
 * Masterpieces of Mystery (1913)
 * Short story collection. The stories are also collected in Room number 3 and A Difficult Problem.
 * The Golden Slipper, and Other Problems for Violet Strange (1915) featuring:
 * "The Golden Slipper"
 * "The Second Bullet"
 * "The Intangible Clew"
 * "The Grotto Spectre"
 * "The Dreaming Lady"
 * "The House of Clocks"
 * "The Doctor, His Wife, and the Clock" *shorter version of the novella.
 * "Missing: Page Thirteen"
 * "Violet's Own"

title: Anna Katharine Green


text:
User:GTBacchus

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Selected articles that GTBacchus has worked on
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title: User:GTBacchus


text:
William Gilbert (physicist)

William Gilbert (24 May 1544? – 30 November 1603), also known as Gilberd, was an English physician, physicist and natural philosopher. He passionately rejected both the prevailing Aristotelian philosophy and the Scholastic method of university teaching. He is remembered today largely for his book De Magnete (1600).

A unit of magnetomotive force, also known as magnetic potential, was named the Gilbert in his honour; it has now been superseded by the Ampere-turn.

Life and work
[[File:Willian Gilbed M.D. demonstrating his experiments before queen Elizabeth A. Auckland Hunt.jpg|thumb| William Gilbert M.D. demonstrating his experiments before Queen Elizabeth I (painting by A. Auckland Hunt).
 * 300x300px]]

Gilbert was born in Colchester to Jerome Gilberd, a borough recorder. He was educated at St John's College, Cambridge. After gaining his MD from Cambridge in 1569, and a short spell as bursar of St John's College, he left to practice medicine in London and travelled on the continent. In 1573, he was elected a Fellow of the Royal College of Physicians. In 1600 he was elected President of the college. He was Elizabeth I's own physician from 1601 until her death in 1603, and James VI and I renewed his appointment.

His primary scientific work – much inspired by earlier works of Robert Norman – was De Magnete, Magneticisque Corporibus, et de Magno Magnete Tellure (On the Magnet and Magnetic Bodies, and on the Great Magnet the Earth) published in 1600. In this work, he describes many of his experiments with his model Earth called the terrella. From these experiments, he concluded that the Earth was itself magnetic and that this was the reason compasses point north (previously, some believed that it was the pole star (Polaris) or a large magnetic island on the north pole that attracted the compass). He was the first to argue that the centre of the Earth was iron, and he considered an important and related property of magnets, being that they can be cut, each forming a new magnet with north and south poles.

In Book 6, Chapter 3, he argues in support of diurnal rotation though he does not talk about heliocentrism, stating that it is an absurdity to think that the immense celestial spheres (doubting even that they exist) rotate daily, as opposed to the diurnal rotation of the much smaller Earth. He also posits that the "fixed" stars are at remote variable distances rather than fixed to an imaginary sphere. He states that, situated "in thinnest aether, or in the most subtle fifth essence, or in vacuity – how shall the stars keep their places in the mighty swirl of these enormous spheres composed of a substance of which no one knows aught?"

The English word "electricity" was first used in 1646 by Sir Thomas Browne, derived from Gilbert's 1600 Neo-Latin electricus, meaning "like amber". The term had been in use since the 13th century, but Gilbert was the first to use it to mean "like amber in its attractive properties". He recognized that friction with these objects removed a so-called "effluvium", which would cause the attraction effect in returning to the object, though he did not realize that this substance (electric charge) was universal to all materials.

"The electric effluvia differ much from air, and as air is the earth's effluvium, so electric bodies have their own distinctive effluvia; and each peculiar effluvium has its own individual power of leading to union, its own movement to its origin, to its fount, and to the body emitting the effluvium."

In his book, he also studied static electricity using amber; amber is called elektron in Greek, so Gilbert decided to call its effect the electric force. He invented the first electrical measuring instrument, the electroscope, in the form of a pivoted needle he called the versorium.

Like others of his day, he believed that crystal (quartz) was an especially hard form of water, formed from compressed ice:

"Lucid gems are made of water; just as Crystal, which has been concreted from clear water, not always by a very great cold, as some used to judge, and by very hard frost, but sometimes by a less severe one, the nature of the soil fashioning it, the humour or juices being shut up in definite cavities, in the way in which spars are produced in mines."

Gilbert argued that electricity and magnetism were not the same thing. For evidence, he (incorrectly) pointed out that, while electrical attraction disappeared with heat, magnetic attraction did not (although it is proven that magnetism does in fact become damaged and weakened with heat). Hans Christian Ørsted and James Clerk Maxwell showed that both effects were aspects of a single force: electromagnetism. Maxwell surmised this in his A Treatise on Electricity and Magnetism after much analysis.

Gilbert's magnetism was the invisible force that many other natural philosophers seized upon, incorrectly, as governing the motions that they observed. While not attributing magnetism to attraction among the stars, Gilbert pointed out the motion of the skies was due to Earth's rotation, and not the rotation of the spheres, 20 years before Galileo (but 57 years after Copernicus who stated it openly in his work De revolutionibus orbium coelestium published in 1543 ) (see external reference below). Gilbert made the first attempt to map the surface markings on the Moon in the 1590s. His chart, made without the use of a telescope, showed outlines of dark and light patches on the Moon's face. Contrary to most of his contemporaries, Gilbert believed that the light spots on the Moon were water, and the dark spots land.

Besides Gilbert's De Magnete, there appeared at Amsterdam in 1651 a quarto volume of 316 pages entitled De Mundo Nostro Sublunari Philosophia Nova (New Philosophy about our Sublunary World), edited – some say by his brother William Gilbert Junior, and others say, by the eminent English scholar and critic John Gruter – from two manuscripts found in the library of Sir William Boswell. According to John Davy, "this work of Gilbert's, which is so little known, is a very remarkable one both in style and matter; and there is a vigor and energy of expression belonging to it very suitable to its originality. Possessed of a more minute and practical knowledge of natural philosophy than Bacon, his opposition to the philosophy of the schools was more searching and particular, and at the same time probably little less efficient." In the opinion of Prof. John Robison, De Mundo consists of an attempt to establish a new system of natural philosophy upon the ruins of the Aristotelian doctrine.

William Whewell says in his History of the Inductive Sciences (1859):

Gilbert, in his work, De Magnete printed in 1600 has only some vague notions that the magnetic virtue of the earth in some way determines the direction of the earth's axis, the rate of its diurnal rotation, and that of the revolution of the moon about it. Gilbert died in 1603, and in his posthumous work (De Mundo nostro Sublunari Philosophia nova, 1631) we have already a more distinct statement of the attraction of one body by another. "The force which emanates from the moon reaches to the earth, and, in like manner, the magnetic virtue of the earth pervades the region of the moon: both correspond and conspire by the joint action of both, according to a proportion and conformity of motions, but the earth has more effect in consequence of its superior mass; the earth attracts and repels, the moon, and the moon within certain limits, the earth; not so as to make the bodies come together, as magnetic bodies do, but so that they may go on in a continuous course." Though this phraseology is capable of representing a good deal of the truth, it does not appear to have been connected... with any very definite notions of mechanical action in detail.

Gilbert died on 30 November 1603 in London. His cause of death is thought to have been the bubonic plague.

Gilbert was buried in his home town, in Holy Trinity Church, Colchester. His marble wall monument can still be seen in this Saxon church, now deconsecrated and used as a café and market.

Commentary on Gilbert
Francis Bacon never accepted Copernican heliocentrism and was critical of Gilbert's philosophical work in support of the diurnal motion of the Earth. Bacon's criticism includes the following two statements. The first was repeated in three of his works—In the Advancement of Learning (1605), Novum Organum (1620) and De Augmentis (1623). The more severe second statement is from History of Heavy and Light Bodies published after Bacon's death.

The Alchemists have made a philosophy out of a few experiments of the furnace and Gilbert our countryman hath made a philosophy out of observations of the lodestone. [Gilbert] has himself become a magnet; that is, he has ascribed too many things to that force and built a ship out of a shell.

Thomas Thomson writes in his History of the Royal Society (1812): The magnetic laws were first generalized and explained by Dr. Gilbert, whose book on magnetism published in 1600, is one of the finest examples of inductive philosophy that has ever been presented to the world. It is the more remarkable, because it preceded the Novum Organum of Bacon, in which the inductive method of philosophizing was first explained.

William Whewell writes in his History of the Inductive Sciences (1837/1859):

Gilbert... repeatedly asserts the paramount value of experiments. He himself, no doubt, acted up to his own precepts; for his work contains all the fundamental facts of the science [of magnetism], so fully examined, indeed, that even at this day we have little to add to them.

Historian Henry Hallam wrote of Gilbert in his Introduction to the Literature of Europe in the Fifteenth, Sixteenth, and Seventeenth Centuries (1848): The year 1600 was the first in which England produced a remarkable work in physical science; but this was one sufficient to raise a lasting reputation to its author. Gilbert, a physician, in his Latin treatise on the magnet, not only collected all the knowledge which others had possessed on that subject, but became at once the father of experimental philosophy in this island, and by a singular felicity and acuteness of genius, the founder of theories which have been revived after the lapse of ages, and are almost universally received into the creed of the science. The magnetism of the earth itself, his own original hypothesis, nova illa nostra et inaudita de tellure sententia [our new and unprecedented view of the planet]... was by no means one of those vague conjectures that are sometimes unduly applauded... He relied on the analogy of terrestrial phenomena to those exhibited by what he calls a terrella, or artificial spherical magnet. ...Gilbert was also one of our earliest Copernicans, at least as to the rotation of the earth; and with his usual sagacity inferred, before the invention of the telescope, that there are a multitude of fixed stars beyond the reach of our vision.

Walter William Bryant of the Royal Observatory, Greenwich, wrote in his book Kepler (1920): When Gilbert of Colchester, in his “New Philosophy,” founded on his researches in magnetism, was dealing with tides, he did not suggest that the moon attracted the water, but that “subterranean spirits and humors, rising in sympathy with the moon, cause the sea also to rise and flow to the shores and up rivers”. It appears that an idea, presented in some such way as this, was more readily received than a plain statement. This so-called philosophical method was, in fact, very generally applied, and Kepler, who shared Galileo’s admiration for Gilbert’s work, adopted it in his own attempt to extend the idea of magnetic attraction to the planets.

title: William Gilbert (physicist)


text:
Gilbert

Gilbert may refer to:

People and fictional characters

 * Gilbert (given name), including a list of people and fictional characters
 * Gilbert (surname), including a list of people

Australia

 * Gilbert River (Queensland)
 * Gilbert River (South Australia)

Kiribati

 * Gilbert Islands, a chain of atolls and islands in the Pacific Ocean

United States

 * Gilbert, Arizona, a town
 * Gilbert, Arkansas, a town
 * Gilbert, Florida, the airport of Winterhaven
 * Gilbert, Iowa, a city
 * Gilbert, Louisiana, a village
 * Gilbert, Michigan, and unincorporated community
 * Gilbert, Minnesota, a city
 * Gilbert, Nevada, ghost town
 * Gilbert, Ohio, an unincorporated community
 * Gilbert, Pennsylvania, an unincorporated community
 * Gilbert, South Carolina, a town
 * Gilbert, West Virginia, a town
 * Gilbert, Wisconsin, an unincorporated community
 * Mount Gilbert (disambiguation), various mountains
 * Gilbert River (Oregon)

Outer space

 * Gilbert (lunar crater)
 * Gilbert (Martian crater)

Arts and entertainment

 * Gilbert Collection, an art collection in the Victoria and Albert Museum
 * Gilbert (band), a name used by English composer and musician Matthew Gilbert Linley
 * Gilbert (film), a documentary on Gilbert Gottfried

Education

 * Gilbert Academy, a defunct private preparatory school for African Americans in Louisiana
 * Gilbert School, a privately endowed secondary school that serves as the public high school for Winchester, Connecticut

Ships

 * USC&GS Gilbert, a survey ship of the United States Coast and Geodetic Survey
 * US FWS Charles H. Gilbert, a fisheries research ship of the United States Fish and Wildlife Service and (as NOAAS Charles H. Gilbert) the National Oceanic and Atmospheric Administration

Other uses

 * A. C. Gilbert Company, an American toy company
 * Gilbert (unit), a CGS unit of magnetomotive force
 * Gilbert Building (disambiguation), several buildings on the American National Register of Historic Places
 * Gilbert Cell, a transistor circuit used in communication electronics
 * Gilbert Hill, a monolith column of black basalt rock in Andheri, India
 * Gilbert House (disambiguation), various buildings
 * Gilbert Model, a social class model
 * Gilbert Rugby, an English sporting-goods manufacturer
 * Gilbert Street, Adelaide, Australia
 * Gilbert's syndrome, a benign medical condition that may cause mild jaundice
 * Gilbert (typeface), a typeface created in honor of artist Gilbert Baker
 * Hurricane Gilbert, a 1988 Caribbean hurricane

title: Gilbert


text:
Metal detector

A metal detector is an instrument that detects the nearby presence of metal. Metal detectors are useful for finding metal objects on the surface, underground, and under water. A metal detector consists of a control box, an adjustable shaft, and a variable-shaped pickup coil. When the coil nears metal, the control box signals its presence with a tone, light, or needle movement. Signal intensity typically increases with proximity. A common type are stationary "walk through" metal detectors used at access points in prisons, courthouses, airports and psychiatric hospitals to detect concealed metal weapons on a person's body.

The simplest form of a metal detector consists of an oscillator producing an alternating current that passes through a coil producing an alternating magnetic field. If a piece of electrically conductive metal is close to the coil, eddy currents will be induced (inductive sensor) in the metal, and this produces a magnetic field of its own. If another coil is used to measure the magnetic field (acting as a magnetometer), the change in the magnetic field due to the metallic object can be detected.

The first industrial metal detectors came out in the 1960s. They were used for finding minerals among other things. Metal detectors help find land mines. They also detect weapons like knives and guns, which is important for airport security. People even use them to search for buried objects, like in archaeology and treasure hunting. Metal detectors are also used to detect foreign bodies in food, and in the construction industry to detect steel reinforcing bars in concrete and pipes and wires buried in walls and floors.

History and development

In 1841 Professor Heinrich Wilhelm Dove published an invention he called the "differential inductor". It was a 4-coil induction balance, with 2 glass tubes each having 2 well-insulated copper wire solenoids wound around them. Charged Leyden jars (high-voltage capacitors) were discharged through the 2 primary coils; this current surge induced a voltage in the secondary coils. When the secondary coils were wired in opposition, the induced voltages cancelled as confirmed by the Professor holding the ends of the secondary coils. When a piece of metal was placed inside one glass tube the Professor received a shock. This then was the first magnetic induction metal detector, and the first pulse induction metal detector.

In late 1878 and early 1879 Professor (of music) David Edward Hughes published his experiments with the 4-coil induction balance. He used his own recent invention the microphone and a ticking clock to generate regular pulses and a telephone receiver as detector. To measure the strength of the signals he invented a coaxial 3-coil induction balance which he called the "electric sonometer". Hughes did much to popularize the induction balance, quickly leading to practical devices that could identify counterfeit coins. In 1880 Mr. J. Munro, C.E. suggested the use of the 4-coil induction balance for metal prospecting. Hughes's coaxial 3-coil induction balance would also see use in metal detecting.

In July 1881 Alexander Graham Bell initially used a 4-coil induction balance to attempt to locate a bullet lodged in the chest of American President James Garfield. After much experimenting the best bullet detection range he achieved was only 2 inches. He then used his own earlier discovery, the partially overlapping 2-coil induction balance, and the detection range increased to 5 inches. But the attempt was still unsuccessful because the metal coil spring bed Garfield was lying on confused the detector. Bell's 2-coil induction balance would go on to evolve into the popular double D coil.

On December 16, 1881, Captain Charles Ambrose McEvoy applied for British Patent No. 5518, Apparatus for Searching for Submerged Torpedoes, &c., which was granted Jun 16 1882. His US269439 patent application of Jul 12 1882 was granted Dec 19 1882. It was a 4-coil induction balance for detecting submerged metallic torpedoes and iron ships and the like. Given the development time involved this may have been the earliest known device specifically constructed as a metal detector using magnetic induction.

In 1892 George M. Hopkins described an orthogonal 2-coil induction balance for metal detecting.

In 1915 Professor Camille Gutton developed a 4-coil induction balance to detect unexploded shells in farmland of former battlefields in France. Unusually both coil pairs were used for detection. The 1919 photo at the right is a later version of Gutton's detector.

Modern developments
The modern development of the metal detector began in the 1920s. Gerhard Fischer had developed a system of radio direction-finding, which was to be used for accurate navigation. The system worked extremely well, but Fischer noticed there were anomalies in areas where the terrain contained ore-bearing rocks. He reasoned that if a radio beam could be distorted by metal, then it should be possible to design a machine which would detect metal using a search coil resonating at a radio frequency. In 1925 he applied for, and was granted, the first patent for an electronic metal detector. Although Gerhard Fischer was the first person granted a patent for an electronic metal detector, the first to apply was Shirl Herr, a businessman from Crawfordsville, Indiana. His application for a hand-held Hidden-Metal Detector was filed in February 1924, but not patented until July 1928. Herr assisted Italian leader Benito Mussolini in recovering items remaining from the Emperor Caligula's galleys at the bottom of Lake Nemi, Italy, in August 1929. Herr's invention was used by Admiral Richard Byrd's Second Antarctic Expedition in 1933, when it was used to locate objects left behind by earlier explorers. It was effective up to a depth of eight feet. However, it was one Lieutenant Józef Stanisław Kosacki, a Polish officer attached to a unit stationed in St Andrews, Fife, Scotland, during the early years of World War II, who refined the design into a practical Polish mine detector. These units were still quite heavy, as they ran on vacuum tubes, and needed separate battery packs.

The design invented by Kosacki was used extensively during the Second Battle of El Alamein when 500 units were shipped to Field Marshal Montgomery to clear the minefields of the retreating Germans, and later used during the Allied invasion of Sicily, the Allied invasion of Italy and the Invasion of Normandy.

As the creation and refinement of the device was a wartime military research operation, the knowledge that Kosacki created the first practical metal detector was kept secret for over 50 years.

Beat frequency induction
Many manufacturers of these new devices brought their own ideas to the market. White's Electronics of Oregon began in the 1950s by building a machine called the Oremaster Geiger Counter. Another leader in detector technology was Charles Garrett, who pioneered the BFO (beat frequency oscillator) machine. With the invention and development of the transistor in the 1950s and 1960s, metal detector manufacturers and designers made smaller, lighter machines with improved circuitry, running on small battery packs. Companies sprang up all over the United States and Britain to supply the growing demand. Beat Frequency Induction requires movement of the detector coil; akin to how swinging a conductor near a magnet induces an electric current.

Refinements
Modern top models are fully computerized, using integrated circuit technology to allow the user to set sensitivity, discrimination, track speed, threshold volume, notch filters, etc., and hold these parameters in memory for future use. Compared to just a decade ago, detectors are lighter, deeper-seeking, use less battery power, and discriminate better.

State-of-the-art metal detectors have further incorporated extensive wireless technologies for the earphones, connect to Wi-Fi networks and Bluetooth devices. Some also utilize built in GPS locator technology to keep track of searching location and the location of items found. Some connect to smartphone applications to further extend functionality.

Discriminators
The biggest technical change in detectors was the development of a tunable induction system. This system involved two coils that are electro-magnetically tuned. One coil acts as an RF transmitter, the other as a receiver; in some cases these can be tuned to between 3 and 100 kHz. When metal is in their vicinity, a signal is detected owing to eddy currents induced in the metal. What allowed detectors to discriminate between metals was the fact that every metal has a different phase response when exposed to alternating current; longer waves (low frequency) penetrate ground deeper, and select for high-conductivity targets like silver, and copper; than shorter waves (higher frequency) which, while less ground penetrating, select for low-conductivity targets like iron. Unfortunately, high frequency is also sensitive to ground mineralization interference. This selectivity or discrimination allowed detectors to be developed that could selectively detect desirable metals, while ignoring undesirable ones.

Even with discriminators, it was still a challenge to avoid undesirable metals, because some of them have similar phase responses (e.g. tinfoil and gold), particularly in alloy form. Thus, improperly tuning out certain metals increased the risk of passing over a valuable find. Another disadvantage of discriminators was that they reduced the sensitivity of the machines.

New coil designs
Coil designers also tried out innovative designs. The original induction balance coil system consisted of two identical coils placed on top of one another. Compass Electronics produced a new design: two coils in a D shape, mounted back-to-back to form a circle. The system was widely used in the 1970s, and both concentric and double D type (or widescan as they became known) had their fans. Another development was the invention of detectors which could cancel out the effect of mineralization in the ground. This gave greater depth, but was a non-discriminate mode. It worked best at lower frequencies than those used before, and frequencies of 3 to 20 kHz were found to produce the best results. Many detectors in the 1970s had a switch which enabled the user to switch between the discriminate mode and the non-discriminate mode. Later developments switched electronically between both modes. The development of the induction balance detector would ultimately result in the motion detector, which constantly checked and balanced the background mineralization.

Pulse induction
At the same time, developers were looking at using a different technique in metal detection called pulse induction. Unlike the beat frequency oscillator or the induction balance machines, which both used a uniform alternating current at a low frequency, the pulse induction (PI) machine simply magnetized the ground with a relatively powerful, momentary current through a search coil. In the absence of metal, the field decayed at a uniform rate, and the time it took to fall to zero volts could be accurately measured. However, if metal was present when the machine fired, a small eddy current would be induced in the metal, and the time for sensed current decay would be increased. These time differences were minute, but the improvement in electronics made it possible to measure them accurately and identify the presence of metal at a reasonable distance. These new machines had one major advantage: they were mostly impervious to the effects of mineralization, and rings and other jewelry could now be located even under highly mineralized black sand. The addition of computer control and digital signal processing have further improved pulse induction sensors.

One particular advantage of using a pulse induction detector includes the ability to ignore the minerals contained within heavily mineralized soil; in some cases the heavy mineral content may even help the PI detector function better. Where a VLF detector is affected negatively by soil mineralization, a PI unit is not.

Uses
Large portable metal detectors are used by archaeologists and treasure hunters to locate metallic items, such as jewelry, coins, clothes buttons and other accessories, bullets, and other various artifacts buried beneath the surface.

Archaeology
Metal detectors are widely used in archaeology with the first recorded use by military historian Don Rickey in 1958 who used one to detect the firing lines at Little Big Horn. However archaeologists oppose the use of metal detectors by "artifact seekers" or "site looters" whose activities disrupt archaeological sites. The problem with use of metal detectors in archaeological sites or hobbyist who find objects of archeological interest is that the context that the object was found in is lost and no detailed survey of its surroundings is made. Outside of known sites the significance of objects may not be apparent to a metal detector hobbyist.

England and Wales
In England and Wales metal detecting is legal provided that the landowner has granted permission and that the area is not a Scheduled Ancient Monument, a site of special scientific interest (SSSI), or covered by elements of the Countryside Stewardship Scheme.

The Treasure Act 1996 governs whether or not items that have been discovered are defined as treasure. Finders of items that the Act defines as treasure must report their finds to the local coroner. If they discover items which are not defined as treasure but that are of cultural or historical interest, finders can voluntarily report them to the Portable Antiquities Scheme and the UK Detector Finds Database.

France
The sale of metal detectors is allowed in France. The first use of metal detectors in France which led to archaeological discoveries occurred in 1958: people living in the city of Graincourt-lès-Havrincourt who were seeking copper from World War I bombshell with military mine detector found a Roman silver treasure. The French law on metal detecting is ambiguous because it refers only to the objective pursued by the user of a metal detector. The first law to regulate the use of metal detectors was Law No. 89–900 of 18 December 1989. This last is resumed without any change in Article L. 542–1 of the code of the heritage, which states that "no person may use the equipment for the detection of metal objects, for the purpose of research monuments and items of interest prehistory, history, art and archeology without having previously obtained an administrative authorization issued based on the applicant's qualification and the nature and method of research."

Outside the research of archaeological objects, using a metal detector does not require specific authorization, except that of the owner of the land. Asked about Law No. 89–900 of 18 December 1989 by a member of parliament, Jack Lang, Minister of Culture at the time, replied by letter the following: "The new law does not prohibit the use of metal detectors but only regulates the use. If the purpose of such use is the search for archaeological remains, prior authorization is required from my services. Apart from this case, the law ask to be reported to the appropriate authorities an accidental discovery of archaeological remains." The entire letter of Jack Lang was published in 1990 in a French metal detection magazine, and then, to be visible on the internet, scanned with permission of the author of the magazine on a French metal detection website.

Northern Ireland
In Northern Ireland, it is an offence to be in possession of a metal detector on a scheduled or a State Care site without a licence from the Department for Communities. It is also illegal to remove an archaeological object found with a detector from such a site without written consent.

Republic of Ireland
In the Republic of Ireland, laws against metal detecting are very strict: it is illegal to use a detection device to search for archaeological objects anywhere within the State or its territorial seas without the prior written consent of the Minister for Culture, Heritage and the Gaeltacht, and it is illegal to promote the sale or use of detection devices for the purposes of searching for archaeological objects.

Scotland
Under the Scots law principle of bona vacantia, the Crown has claim over any object of any material value where the original owner cannot be traced. There is also no 300 year limit to Scottish finds. Any artifact found, whether by metal detector survey or from an archaeological excavation, must be reported to the Crown through the Treasure Trove Advisory Panel at the National Museums of Scotland. The panel then determines what will happen to the artifacts. Reporting is not voluntary, and failure to report the discovery of historic artifacts is a criminal offence in Scotland.

United States
The sale of metal detectors is allowed in the United States. People can use metal detectors in public places (parks, beaches, etc.) and on private property with the permission of the owner of the site. In the United States, cooperation between archeologists hunting for the location of colonial-era Native American villages and hobbyists has been productive.

As a hobby

There are various types of hobby activities involving metal detectors:
 * Coin shooting is specifically targeting coins. Some coin shooters conduct historical research to locate sites with potential to give up historical and collectible coins.
 * Prospecting is looking for valuable metals like gold, silver, and copper in their natural forms, such as nuggets or flakes.
 * Metal detectors are also used to search for discarded or lost, valuable man-made objects such as jewelry, mobile phones, cameras and other devices. Some metal detectors are waterproof, to allow the user to search for submerged objects in areas of shallow water.
 * General metal detecting is very similar to coin shooting except the user is after any type of historical artifact. Detectorists may be dedicated to preserving historical artifacts, and often have considerable expertise. Coins, bullets, buttons, axe heads, and buckles are just a few of the items that are commonly found by relic hunters; in general the potential is far greater in Europe and Asia than in many other parts of the world. More valuable finds in Britain alone include the Staffordshire Hoard of Anglo-Saxon gold, sold for £3,285,000, the gold Celtic Newark Torc, the Ringlemere Cup, West Bagborough Hoard, Milton Keynes Hoard, Roman Crosby Garrett Helmet, Stirling Hoard, Collette Hoard and thousands of smaller finds.
 * Beach combing is hunting for lost coins or jewelry on a beach. Beach hunting can be as simple or as complicated as one wishes to make it. Many dedicated beach hunters also familiarize themselves with tide movements and beach erosion.
 * Metal detecting clubs exist for hobbyists to learn from others, show off finds from their hunts and to learn more about the hobby.

Hobbyists often use their own metal detecting lingo when discussing the hobby with others.

Politics and conflicts in the metal detecting hobby in the United States
The metal detecting community and professional archaeologists have different ideas related to the recovery and preservation of historic finds and locations. Archaeologists claim that detector hobbyists take an artifact-centric approach, removing these from their context resulting in a permanent loss of historical information. Archaeological looting of places like Slack Farm in 1987 and Petersburg National Battlefield serve as evidence against allowing unsupervised metal detecting in historic locations.

Security screening

In 1926, two Leipzig, Germany scientists installed a walk-though enclosure at a factory, to ensure that employees were not exiting with prohibited metallic items.

A series of aircraft hijackings led the United States in 1972 to adopt metal detector technology to screen airline passengers, initially using magnetometers that were originally designed for logging operations to detect spikes in trees. The Finnish company Outokumpu adapted mining metal detectors in the 1970s, still housed in a large cylindrical pipe, to make a commercial walk-through security detector. The development of these systems continued in a spin-off company and systems branded as Metor Metal Detectors evolved in the form of the rectangular gantry now standard in airports. In common with the developments in other uses of metal detectors both alternating current and pulse systems are used, and the design of the coils and the electronics has moved forward to improve the discrimination of these systems. In 1995 systems such as the Metor 200 appeared with the ability to indicate the approximate height of the metal object above the ground, enabling security personnel to more rapidly locate the source of the signal. Smaller hand held metal detectors are also used to locate a metal object on a person more precisely.

Industrial metal detectors
Contamination of food by metal shards from broken processing machinery during the manufacturing process is a major safety issue in the food industry. Most food processing equipment is made of stainless steel, and other components made of plastic or elastomers can be manufactured with embedded metallic particles, allowing them to be detected as well. Metal detectors for this purpose are widely used and integrated into the production line.

Current practice at garment or apparel industry plants is to apply metal detecting after the garments are completely sewn and before garments are packed to check whether there is any metal contamination (needle, broken needle, etc.) in the garments. This needs to be done for safety reasons.

The industrial metal detector was developed by Bruce Kerr and David Hiscock in 1947. The founding company Goring Kerr pioneered the use and development of the first industrial metal detector. Mars Incorporated was one of the first customers of Goring Kerr using their Metlokate metal detector to inspect Mars bars.

The basic principle of operation for the common industrial metal detector is based on a 3-coil design. This design utilizes an AM (amplitude modulated) transmitting coil and two receiving coils one on either side of the transmitter. The design and physical configuration of the receiving coils are instrumental in the ability to detect very small metal contaminates of 1 mm or smaller. Today modern metal detectors continue to utilize this configuration for the detection of tramp metal.

The coil configuration is such that it creates an opening whereby the product (food, plastics, pharmaceuticals, etc.) passes through the coils. This opening or aperture allows the product to enter and exit through the three-coil system, producing an equal but mirrored signal on the two receiving coils. The resulting signals are summed together effectively nullifying each other. Fortress Technology innovated a new feature, that allows the coil structure of their BSH Model to ignore the effects of vibration, even when inspecting conductive products.

When a metal contaminant is introduced into the product an unequal disturbance is created. That creates a very small electronic signal. After suitable amplification a mechanical device mounted to the conveyor system is signaled to remove the contaminated product from the production line. This process is completely automated and allows manufacturing to operate uninterrupted.

Civil engineering
In civil engineering, special metal detectors (cover meters) are used to locate reinforcement bars inside walls.

The most common type of metal detector is a hand-held metal detector or coil-based detectors using oval-shaped disks with built-in copper coils. The search coil works as sensing probe and must be moved over the ground to detect potential metal targets buried underground. When the search coil detects metal objects, the device gives an audible signal via speaker or earphone. In most units, the feedback is an analog or digital indicator.

The metal detectors were first invented and manufactured commercially in the United States by Fisher Labs in the 1930s; other companies like Garrett established and developed the metal detectors in terms of technology and features in the following decades.

Military
The first metal detector proved inductance changes to be a practical metal detection technique, and it served as the prototype for all subsequent metal detectors.

Initially these machines were huge and complex. After Lee de Forest invented the triode in 1907 metal detectors used vacuum tubes to operate and became more sensitive but still quite cumbersome. One of the early common uses of the first metal detectors, for example, was the detection of landmines and unexploded bombs in a number of European countries following the First and Second World Wars.

Uses and benefits
Metal detectors can be used for several military uses, including:

 * Exposing mines planted during the war or after the end of the war
 * Detecting dangerous explosives and cluster bombs dangerous to people's lives
 * Hand-held metal detectors can be used to search people for weapons and explosives

War mine detection
Demining, also known as mine removal, is the method of clearing a field of landmines. The aim of military operations is to clear a path through a minefield as quickly as possible, which is mostly accomplished using equipment like mine plows and blast waves.

Humanitarian demining aims to clear all landmines to a certain depth and make the land secure for human use. Landmine detection techniques have been studied in various forms. Detection of mines can be done by a specially designed metal detector tuned to detect mines and bombs. Electromagnetic technologies have been used in conjunction with ground-penetrating radar. Specially trained dogs are often used to focus the search and confirm that an area has been cleared, mines are often cleared using mechanical equipment such as flails and excavators.

First idea
The first metal detector was likely the simple electric conduction metal detector ca. 1830. Electric conduction was also used to locate metal ore bodies by measuring the conductivity between metal rods driven into the ground.

In 1862 Italian General Giuseppe Garibaldi was wounded in the foot. It was difficult to distinguish between bullet, bone, and cartilage. So Professor Favre of Marseilles quickly built a simple probe that was inserted into the track of the bullet. It had 2 sharp points connected to a battery and a bell. Contact with metal completed the circuit and rang the bell. In 1867 Mr. Sylvan de Wilde had a similar detector and an extractor also wired to a bell. In 1870 Gustave Trouvé, a French electrical engineer also had a similar device however his buzzer made a different sound for lead and iron. The electric bullet locators were in use until the advent of X-rays.

Gerhard Fischer
Gerhard Fischer developed a portable metal detector in 1925. His model was first marketed commercially in 1931; he was responsible for the first large-scale hand-held metal detector development.

Gerhard Fisher studied electronics at the University of Dresden before emigrating to the United States. When working as a research engineer in Los Angeles, he came up with the concept of a portable metal detector while working with aircraft radio detection finders. Fisher shared the concept with Albert Einstein, who foresaw the widespread use of hand-held metal detectors.

Fisher, the founder of Fisher Research Laboratory, was contracted by the Federal Telegraph Company and Western Air Express to establish airborne direction finding equipment in the late 1920s. He received some of the first patents in the area of radio-based airborne direction finding. He came across some unusual errors in the course of his work; once he figured out what was wrong, he had the foresight to apply the solution to a totally unrelated area, metal and mineral detection."

Fisher received the patent for the first portable electronic metal detector in 1925. In 1931, he marketed his first Fisher device to the general public, and he established a famous Fisher Labs company that started to manufacture and develop hand-held metal detectors and sell it commercially.

Charles Garrett
Despite the fact that Fisher was the first to receive a patent for an electronic metal detector, he was only one of many who improved and mastered the device. Charles Garrett, the founder of Garrett Metal Detectors, was another key figure in the creation of today's metal detectors.

Garrett, an electrical engineer by profession, began metal detecting as a pastime in the early 1960s. He tried a number of machines on the market but couldn't find one that could do what he needed. As a result, he started developing his own metal detector. He was able to develop a system that removed oscillator drift, as well as many special search coils that he patented, both of which effectively revolutionized metal detector design at the time.

To present day
In the 1960s, the first industrial metal detectors were produced, and they were widely used for mineral prospecting and other industrial purposes. De-mining (the detection of landmines), the detection of weapons such as knives and guns (particularly in airport security), geophysical prospecting, archaeology, and treasure hunting are just some of the applications.

Metal detectors are also used to detect foreign bodies in food, as well as steel reinforcement bars in concrete and pipes. The building industry uses them to find wires buried in walls or floors.

Discriminators and circuits
The development of transistors, discriminators, modern search coil designs, and wireless technology significantly impacted the design of metal detectors as we know them today: lightweight, compact, easy-to-use, and deep-seeking systems. The invention of a tunable induction device was the most significant technological advancement in detectors. Two electro-magnetically tuned coils were used in this method. One coil serves as an RF transmitter, while the other serves as a receiver; in some situations, these coils may be tuned to frequencies ranging from 3 to 100 kHz.

Due to eddy currents induced in the metal, a signal is detected when metal is present. The fact that every metal has a different phase response when exposed to alternating current allowed detectors to differentiate between metals. Longer waves (low frequency) penetrate the ground deeper and select for high conductivity targets like silver and copper, while shorter waves (higher frequency) select for low conductivity targets like iron. Unfortunately, ground mineralization interference affects high frequency as well. This selectivity or discrimination allowed the development of detectors that can selectively detect desirable metals.

Even with discriminators, avoiding undesirable metals was difficult because some of them have similar phase responses (for example, tinfoil and gold), particularly in alloy form. As a result, tuning out those metals incorrectly increased the chance of missing a valuable discovery. Discriminators also had the downside of lowering the sensitivity of the devices.

title: Metal detector