* 1820 – Nadar, French photographer, caricaturist, journalist, novelist and balloonist ( d. 1910 )

In September of 1820, Ampère ’ s friend and eventual eulogist François Arago showed the members of the French Academy of Sciences the surprising discovery of Danish physicist Hans Christian Ørsted that a magnetic needle is deflected by an adjacent electric current.

* Alfonso Sanz y Martínez de Arizala ( 28 January 1880, Madrid – 1970 ), married in 1922 to María de Guadalupe de Limantour y Mariscal ( d. 1977, Marbella ), daughter of Julio de Limantour y Marquet ( 17 June 1863, Mexico City – 11 October 1909, Mexico City ) and wife Elena Mariscal y ..., paternal granddaughter of French Joseph Yves de Limantour y Rence de la Pagame ( 1812, Ploemeur – 1885, Mexico City ) and wife Adèle Marquet y Cabannes ( 1820, Bordeaux –?

A significant contribution to the chemistry of alkaloids in the early years of its development was made by the French researchers Pierre Joseph Pelletier and Joseph Bienaimé Caventou, who discovered quinine ( 1820 ) and strychnine ( 1818 ).

The Ilois, now called Chagos Islanders or Chagossians since the late 1990s, were descended primarily from slaves brought to the island from Madagascar by the French between 1793 and 1810, and Malay slaves from the slave market on Pulo Nyas, an island off the northwest coast of Sumatra, from around 1820 until the slave trade ended following the Slavery Abolition Act of 1833.

* 1820 – Athanase Coquerel, French theologian and preacher ( d. 1875 )

The islands were named after the first in the Russian ( Krusenstern ) and French ( Duperrey ) maps ( 1820 ), later in the English maps.

* 1820 – A. E. Becquerel, French physicist ( d. 1891 )

Quinine was isolated and named in 1820 by French researchers Pierre Joseph Pelletier and Joseph Bienaimé Caventou.

* August 24 – Henry, Count of Chambord, pretender to the French throne ( b. 1820 )

* October 25 – Émile Augier, French dramatist ( b. 1820 )

* May 21 – Joseph Fouché, French statesman ( d. 1820 )

In 1820, the statue which became known as the Venus de Milo was discovered on the Greek island of Milo and seen by a French naval officer, Emile Voutier.

Félix Nadar was the pseudonym of Gaspard-Félix Tournachon ( 1 April 1820, Paris – 23 March 1910 ), a French photographer, caricaturist, journalist, novelist and balloonist.

Between 1810 and 1820, several French Canadian fur traders, including Lamar Andie, Jean Baptiste Recollect, and Pierre Constant had established fur trading posts around Muskegon Lake.

One of the better known early residents was Captain Daniel Roe ( 1740 – 1820 ), who fought in the French and Indian War and served as a captain in the Revolutionary War, and for whom Captain Daniel Roe Highway is named.

Alexis Thérèse Petit ( 2 October 1791, Vesoul, Haute-Saône-21 June 1820 in Paris ) was a French physicist.

Mathilde Laetitia Wilhelmine Bonaparte, Princesse Française ( May 27, 1820 – January 2, 1904 ), was a French princess and Salon holder.

Abbé Augustin Barruel ( October 2, 1741 – October 5, 1820 ) was a French Jesuit priest.

The first recorded use of the name to describe the region, which until then had no officially sanctioned designation, was in 1820 when the name was given in York, Upper Canada by then Lieutenant-Governor Sir Peregrine Maitland, Maitland was a veteran of the British campaign against the French in Spain, called the Peninsular War, during the Napoleonic Wars where he served under the command of Wellington.

Pierre-Joseph Cambon ( 10 June 1756 – 15 February 1820 ) was a French statesman.

Although Braid was the first to use the terms hypnotism, hypnotize and hypnotist in English, the cognate terms hypnotique, hypnotisme, hypnotiste had been intentionally used by the French magnetist Baron Etienne Félix d ' Henin de Cuvillers ( 1755 – 1841 ) at least as early as 1820.

Justin Clinchant ( 24 December 1820, Thiaucourt-Regniéville – 20 March 1881 ) was a French Army general, entered the army from St Cyr in 1841.

Guillaume Victor Émile Augier (; 17 September 1820 – 25 October 1889 ) was a French dramatist.

In 1820, during the Battle of Navarino, which took place in Greece, the British fleet was based in Malta.

The Stone Frigate at Royal Military College of Canada in Kingston, Ontario was constructed in 1820 to store part of the dismantled fleet from the War of 1812.

The Stone Frigate, located at the Royal Military College in Kingston, Ontario, was constructed during 1820 to store part of the dismantled British fleet from the War of 1812, which had been dismantled pursuant to the Rush-Bagot Treaty of 1818.

In 1820 the city wall was torn down, with the exception of the individual towers and gates, and the defensive ditches were filled in.

Hegel, in his Elements of the Philosophy of Right ( 1820 ), gave it a philosophical justification that concurred with evolving contemporary political theory and the Protestant Christian view of natural law.

In 1820, the colony of Cape Breton Island was merged for the second time with Nova Scotia.

This statute replaced earlier statutes from 1820, 1823, 1838, 1841 and 1848 and has since been supplemented 11 times, with the latest supplement in 1995.

Poe moved back with the Allans to Richmond, Virginia in 1820.

* 1820 – The Chilean Navy under the command of Lord Cochrane completes the 2 day long Capture of Valdivia with just 300 men and 2 ships.

A late example of traditional Gothic is Melmoth the Wanderer ( 1820 ) by Charles Maturin which combines themes of Anti-Catholicism with an outcast Byronic hero ( Varma 1986 ).

Yet in 1820, weakened by illness and with a decreasing support for his authoritarian regime, he killed himself with a silver bullet rather than face a coup d ' état.

There were, however, also moves towards reunion, beginning with the unification of some secessionist churches into the United Secession Church in 1820, which united with the Relief Church in 1847 to form the United Presbyterian Church, which in turn joined with the Free Church in 1900 to form the United Free Church of Scotland.

The sons of Montgolfier obtained an English patent for an improved version in 1816, and this was acquired, together with Whitehurst's design, in 1820 by Josiah Easton, a Somerset-born engineer who had just moved to London.

The turning point came with the debate on the Missouri Compromise in 1820 when he broke with his friend John C. Calhoun, who became the most outspoken national leader in favor of slavery.

Posthumous Portrait of Percy Shelley | Shelley Writing Prometheus Unbound ( Shelley ) | Prometheus Unbound ( 1845 ) On 17 September 1820, Severn set sail onboard the Maria Crowther from England to Italy with the famous English poet John Keats.

Several other experiments followed, with André-Marie Ampère, who in 1820 discovered that the magnetic field circulating in a closed-path was related to the current flowing through the perimeter of the path ; Carl Friedrich Gauss ; Jean-Baptiste Biot and Félix Savart, both of which in 1820 came up with the Biot-Savart Law giving an equation for the magnetic field from a current-carrying wire ; Michael Faraday, who in 1831 found that a time-varying magnetic flux through a loop of wire induced a voltage, and others finding further links between magnetism and electricity.

In 1817 the British Wesleyans arrived in the Canadas from the Maritimes but by 1820 had agreed, with the Episcopal Methodists, to confine their work to Lower Canada ( present-day Quebec ) while the later would confine themselves to Upper Canada ( present-day Ontario ).

Other instruments associated with Paganini include the Antonio Amati 1600, the Nicolò Amati 1657, the Paganini-Desaint 1680 Stradivari, the Guarneri-filius Andrea 1706, the Le Brun 1712 Stradivari, the Vuillaume c. 1720 Bergonzi, the Hubay 1726 Stradivari, and the Comte Cozio di Salabue 1727 violins ; the Countess of Flanders 1582 da Salò-di Bertolotti, and the Mendelssohn 1731 Stradivari violas ; the Piatti 1700 Goffriller, the Stanlein 1707 Stradivari, and the Ladenburg 1736 Stradivari cellos ; and the Grobert of Mirecourt 1820 ( guitar ).

* List of oldest companies, as Nordea is the oldest bank in Sweden, with roots from 1820.

They sent pianos to both Joseph Haydn and Ludwig van Beethoven, and were the first firm to build pianos with a range of more than five octaves: five octaves and a fifth during the 1790s, six octaves by 1810 ( Beethoven used the extra notes in his later works ), and seven octaves by 1820.

The colony's new name honoured the fourth son of King George III, Prince Edward Augustus, the Duke of Kent ( 1767 – 1820 ), who subsequently led the British military forces on the continent as Commander-in-Chief, North America ( 1799 – 1800 ), with his headquarters in Halifax.