Dutch Guyana, a "state" formed by escaped slaves signs a treaty with the local governor. Marine chronometer invented as a means to accurately determine longitude. Matthew Boulton's Soho Manufactory opens in the midlands of England. The music for "Ah! vous dirai-je, maman" ("Ah, would I tell you Mom?") is first published in France by a Monsieur Bouin in his book Les Amusements d'une Heure et Demy; in 1806, English poet Jane Taylor publishes her poem, The Star, whose words fit the rhythm of the tune and become the children's song Twinkle Twinkle Little Star. Faber-Castell Company is founded by Kasper Faber in Nuremberg, Germany. Johann Heinrich Lambert finds a proof that π is irrational. l'Ordre des Chevaliers Maçons Élus Coëns de l'Univers is founded. Births January 17 – James Hall, Scottish geologist (d. 1832) February 1 – Christian Hendrik Persoon, South African mycologist (d. 1836) February 3 – Dorothea von Medem, Latvian diplomat, duchess of Courland (d. 1821) February 16 – Charles Pichegru, French general (d. 1804) February 22 – Erik Tulindberg, Finnish composer (d. 1814) March 6 – Antoine-Francois Andreossy, French general (d. 1828) May 3 – August von Kotzebue, German dramatist (d. 1819) June 3 – Henry Shrapnel, British Army officer and inventor (d. 1842) June 7 – John Rennie the Elder, Scottish-born civil engineer (d. 1821) October 21 – Louis Albert Guislain Bacler d'Albe, French painter and cartographer (d. 1824) October 27 – Matthew Baillie, Scottish physician and pathologist (d. 1823) November 4 – Bertrand Andrieu, French engraver of medals (d. 1822) November 13 – John Moore, British general (d. 1809) November 20 – Pope Pius VIII (d. 1830) December 1 – Marie Tussaud, French wax modeller (d. 1850) December 24 – Jean-Louis Pons, French astronomer (d. 1831) December 27 – Michael Andreas Barclay de Tolly, Russian military commander (d. 1818) Date unknown – Dido Elizabeth Belle, British slave heiress (d. 1804) Deaths January 4 – Stephen Hales, English physiologist, chemist, and inventor (b. 1677) January 7 – Darkey Kelly, Irish madam and serial murderer, executed by burning January 10 – Edward Boscawen, British admiral (b. 1711) January 26 – Charles Louis Auguste Fouquet, duc de Belle-Isle, French general and statesman (b. 1684) February 1 – Pierre François Xavier de Charlevoix, French historian (b. 1682) February 6 – Clemens August of Bavaria, Archbishop-Elector of Cologne (b. 1700) April 2 – William Sawyer, English cricketer (b. 1712) April