Slaves or Negroes in to the Province of Georgia of America and to keep and to use the same therein". August 20 – French astronomer Nicolas-Louis de Lacaille, by way of the Foreign Minister, the Marquis de Puisieulx and Netherlands ambassador to Paris Mattheus Lestevenon, sends a letter that ultimately persuades the States-General of the Dutch Republic to allow and partially finance Lacaille's stellar trigonometry mission to the Cape of Good Hope. The expedition departs Lorient on October 21 Thomas Maclear, Verification and Extension of La Caille's Arc of Meridian at the Cape of Good Hope (Mowry and Barclay, 1838) p58 September 30 – Crispus Attucks, an African-American slave who will later become the first person killed in the Boston Massacre of 1770, escapes from the Framingham, Massachusetts estate of slaveowner William Brown.KaaVonia Hinton, The Story of the Underground Railroad (Mitchell Lane Publishers, 2010) p24 In an unsuccessful attempt to recapture the fugitive, Brown runs an advertisement on October 2 in the Boston Gazette, but Attucks eludes recapture. October–December October 5 – Treaty of Madrid: Spain and Great Britain sign a treaty temporarily eliminating their hostility over their colonies in North and South America. In addition to both sides dropping their claims for damages against each other, Spain agrees to pay the South Sea Company £100,000 for damage claims. October 14 – The Louvre Museum is created in Paris four years after art critic Lafond de Saint-Yenne calls on the King to allow the display of the royal art collection to the general public. Abel-François Poisson, the Marquis de Marigny, arranges for the display of 110 of the Crown's paintings at the Palais du Luxembourg. November 11 – A riot breaks out in Lhasa after the murder of the regent of Tibet. November 18 – Westminster Bridge is officially opened in London. December 3 – What is described later as "The first documented presentation of a musical in New York" takes place one block east of Broadway, at the Nassau Street Theatre, when a resident company of actors stages The Beggar's Opera. December 25 – Prussia and Russia break off diplomatic relations after the Russians refuse to stop assisting the Electorate of Saxony. Five years later, the two Empires fight the Seven Years' War. December 29 – Two physicians in Jamaica, Dr. John Williams and Dr. Parker Bennet, fight a duel "with swords and pistols" after having had an argument