1787 in science

• January 11 – William Herschel discovers Titania and Oberon, the first moons of Uranus found. • February 19 – First light for William Herschel's 40-foot telescope under construction at Observatory House, Slough, England. • Caroline Herschel is granted an annual salary of £50 by King George III of Great Britain for acting as assistant to her brother William in astronomy. ==Biology==

• William Curtis begins publication of The Botanical Magazine; or Flower-Garden Displayed in London. As ''Curtis's Botanical Magazine'', it will still be published into the 21st century. • Spanish physician Francisco Xavier Cid publishes Tarantismo Observado en España, a study of tarantulas and the tarantella as a cure for their bite. • King George III of Great Britain, writing as Ralph Robinson of Windsor, contributes to Arthur Young's Annals of Agriculture. ==Chemistry==

• Guyton de Morveau, Jean-Henri Hassenfratz, Antoine François, Antoine Lavoisier, Pierre Adet and Claude Berthollet publish Méthode de nomenclature chimique in Paris. • Jacques Charles proposes Charles's law, a corollary of Boyle's law, describes relationship between temperature and volume of a gas. ==Physics==

• Ernst Chladni publishes Entdeckungen über die Theorie des Klanges, demonstrating modes of vibration. • Jean-Paul Marat publishes the first French translation of Newton's 'Opticks' ==Surveying==

• The first great theodolite constructed by Jesse Ramsden for the Anglo-French Survey (1784–1790) linking the observatories of Paris and Greenwich. ==Technology==

• June – William Symington patents improvements to the Watt steam engine. • c. July – John Wilkinson launches an iron barge in the English Midlands. • August 27 – Launching a steam-powered craft on the Delaware River, John Fitch demonstrates the first United States patent for his design. • December 3 – James Rumsey demonstrates a water-jet propelled boat on the Potomac. • First production of all-iron edge rail (for underground colliery rail transport), at Plymouth Ironworks, Merthyr Tydfil, South Wales. • First introduction of a plateway, underground at Sheffield Park Colliery, Yorkshire, England, by John Curr. • William Chapman designs a segmental skew arch at Finlay Bridge, Naas, on the Kildare Canal in Ireland. • Levi Hutchins of New Hampshire produces a mechanical alarm clock. ==Awards==

• Copley Medal: John Hunter ==Births==

• January 24 – Christophe-Paulin de La Poix de Fréminville (died 1848), French explorer and naturalist. • March 6 – Joseph von Fraunhofer (died 1826), Bavarian physicist. • March 8 – Karl Ferdinand von Graefe (died 1840), Polish-born German surgeon. • March 9 – Josephine Kablick (died 1863), Czech botanist and paleontologist. • March 28 – Claudius James Rich (died 1821), British archaeologist and anthropologist. • March 29 – Carl Philipp Sprengel (died 1859), German botanist. • April 24 – Mathieu Orfila (died 1853), Spanish-born French physician and chemist. • May 27 – Benjamin Valz (died 1867), French astronomer. • June 2 – Nils Gabriel Sefström (died 1845), Swedish chemist and mineralogist. • June 3 – Auguste Le Prévost (died 1859), French geologist, philologist, archaeologist and historian. • June 4 – Constant Prévost (died 1856), French geologist. • June 7 – William Conybeare (died 1857), English geologist. • June 27 – Thomas Say (died 1834), American naturalist. • August 16 – Jean Michel Claude Richard (died 1868), French botanist. • August 24 – James Weddell (died 1834), Flemish-born Anglo-Scots seal hunter and Antarctic explorer. • September 5 – François Sulpice Beudant (died 1850), French mineralogist et geologist. • September 15 – Guillaume-Henri Dufour (died 1875), Swiss engineer et topographer. • November 5 – John Richardson (died 1865), Scottish naturalist, explorer and surgeon. • November 9 – Johann Natterer (died 1843), Austrian naturalist. • November 18 – Louis Daguerre (died 1851), French inventor. • December 17 – John Forbes (died 1861), Scottish physician • December 17 (or 18) – Jan Evangelista Purkinje (died 1869), Czech anatomist et neurophysiologist. • Undated – Pierre Charles Alexandre Louis (died 1872), French physician. ==Deaths==

• February 13 – Ruđer Bošković, Ragusan physicist, mathematician and astronomer (born 1711) • May 10 – William Watson, English physician, botanist and physicist (born 1715) ==References==