* 1838 – Nicaragua declares independence from the Central American Federation.

* 1838 – Non-laborer slaves in most of the British Empire are emancipated.

* 1770 – William Clark, American soldier, explorer, and politician ( d. 1838 )

* 1790 – Ferenc Kölcsey, Hungarian poet and politician ( d. 1838 )

* 1838 – The Wilkes Expedition, which would explore the Puget Sound and Antarctica, weighs anchor at Hampton Roads in 1838

A close relationship developed between Hasan Ali Shah and the British, which coincided with the final years of the First Anglo-Afghan War ( 1838 – 1842 ).

* 1838 – Léon Gambetta, French statesman ( d. 1882 )

* 1838 – Paul Emile Lecoq de Boisbaudran, French scientist ( d. 1912 )

* 1915 – John Labatt, Canadian businessman and brewer ( b. 1838 )

* 1838 – John Muir, Scottish-American environmentalist ( d. 1914 )

* Aleksandra von Engelhardt ( 1754 – 1838 ), Russian lady-in-waiting

The construction commenced around the courtyard with the East Wing ( The King's Library ) in 1823 – 1828, followed by the North Wing in 1833 – 1838, which originally housed among other galleries a reading room, now the Wellcome Gallery.

* Henry Sidgwick ( 1838 – 1900 )

* Tales of Angria ( written 1838 – 1839-a collection of childhood and young adult writings including five short novels )

* 1838 – Battle of Blood River: Voortrekkers led by Andries Pretorius and Sarel Cilliers defeat Zulu impis, led by Dambuza ( Nzobo ) and Ndlela kaSompisi in what is today KwaZulu-Natal, South Africa.

* 1838 – John Labatt, Irish-Canadian brewer ( d. 1915 )

* 1806 – Jean-Olivier Chénier, Canadian physician and patriote ( d. 1838 )

* 1838 – Émile Loubet, 7th President of France ( d. 1929 )

* 1838 – Edwin Abbott Abbott, English schoolmaster, theologian, and author ( d. 1926 )

* 1881 – August Senoa, Croatian writer ( b. 1838 )

In mathematical logic, there are two quantifiers, " some " and " all ", though as Brentano ( 1838 – 1917 ) pointed out, we can make do with just one quantifier and negation.

* The Narrative of Arthur Gordon Pym of Nantucket ( 1838 ) – Poe's only complete novel

Edwin Abbott Abbott ( 20 December 1838 – 12 October 1926 ), English schoolmaster and theologian, is best known as the author of the satirical novella Flatland ( 1884 ).

He had become passionate about the study of chemistry, matriculating at the University of Göttingen in the spring of 1838 in order to study with the famous chemist Friedrich Wöhler.

61 Cygni is significant because Friedrich Wilhelm Bessel determined its parallax in 1838, the first star to have a known parallax.

The principle of the fuel cell was discovered by German scientist Christian Friedrich Schönbein in 1838 and published in one of the scientific magazines of the time.

Further proofs were given by Laplace ( 1810, 1812 ), Gauss ( 1823 ), James Ivory ( 1825, 1826 ), Hagen ( 1837 ), Friedrich Bessel ( 1838 ), W. F. Donkin ( 1844, 1856 ), and Morgan Crofton ( 1870 ).

In a handwritten note on a reprint of his 1838 paper " Sur l ' usage des séries infinies dans la théorie des nombres ", which he mailed to Carl Friedrich Gauss, Johann Peter Gustav Lejeune Dirichlet conjectured ( under a slightly different form appealing to a series rather than an integral ) that an even better approximation to π ( x ) is given by the offset logarithmic integral function Li ( x ), defined by

The first direct measurement of the distance to a star ( 61 Cygni at 11. 4 light-years ) was made in 1838 by Friedrich Bessel using the parallax technique.

The term geochemistry was first used by the Swiss-German chemist Christian Friedrich Schönbein in 1838.

* 1838 — Thomas Henderson, Friedrich Struve, and Friedrich Bessel measure stellar parallaxes

In 1838 Henry Rawlinson, building on the 1802 work of Georg Friedrich Grotefend, was able to decipher the Old Persian section of the Behistun inscriptions, using his knowledge of modern Persian.

Mosselman had one daughter, Louise Le Hon ( 15 July 1838 – 9 February 1931 ), who married in Paris on 11 June 1856 Stanislaus August Friedrich Joseph Telemach Luci, later Poniatowski.

The first successful measurement of stellar parallax was made by Friedrich Bessel in 1838 for the star 61 Cygni using a Fraunhofer heliometer at Königsberg Observatory.

The first successful measurements of stellar parallax were made by Friedrich Bessel in 1838 for the star 61 Cygni using a heliometer.

A tour on the continent in 1817, when he visited Goethe at Weimar, was made possible by the publisher William Blackwood, who advanced money for a translation of Friedrich Schlegel's Lectures on the History of Literature, which was not published until 1838.

Three apparent proofs of the heliocentric hypothesis were provided in 1727 by Bradley, in 1838 by Friedrich Wilhelm Bessel and in 1851 by Foucault.

In regards to the stars, Tycho also believed that if the Earth orbited the Sun annually there should be an observable stellar parallax over any period of six months, during which the angular orientation of a given star would change thanks to Earth's changing position ( this parallax does exist, but is so small it was not detected until 1838, when Friedrich Bessel discovered a parallax of 0. 314 arcseconds of the star 61 Cygni in 1838 ).

Friedrich Christian Accum or Frederick Accum ( March 29, 1769 – June 28, 1838 ) was a German chemist, whose most important achievements included advances in the field of gas lighting, efforts to keep processed foods free from dangerous additives, and the promotion of interest in the science of chemistry to the general populace.

Christian Friedrich Schönbein ( 18 October 1799 – 29 August 1868 ) was a German-Swiss chemist who is best known for inventing the fuel cell ( 1838 ) and his discoveries of guncotton and ozone.

Doubts about the accuracy of his instruments kept him from publishing, however ( there had been previous, discredited attempts to claim a measurement of stellar parallax ), and eventually he was beaten to the punch by Friedrich Wilhelm Bessel, who published a parallax of 10. 4 light years ( 8. 8 % too small ) for 61 Cygni in 1838.

Its castellated top was designed by Karl Friedrich Schinkel in 1838 and is an example of Romantic architecture.

Georg Friedrich Julius Arthur von Auwers ( September 12, 1838 – January 24, 1915 ) was a German astronomer.

* 1838 – Friedrich Bessel: first successful measure of stellar parallax ( to star 61 Cygni )

Educated in his native town and later under Friedrich Schelling in Munich, he became a professor of philosophy at Lausanne ( 1838 to 1846 ), and later at Neuchâtel.