1742 in science

Astronomy

• January 14 – Death of Edmond Halley; James Bradley succeeds him as Astronomer Royal in Great Britain.

  Mathematics

• June – Christian Goldbach produces Goldbach's conjecture.
• Colin Maclaurin publishes his Treatise on Fluxions in Great Britain, the first systematic exposition of Newton's methods.

  Metrology

• Anders Celsius publishes his proposal for a centigrade temperature scale originated in 1741.

  Physiology and medicine

• Surgeon Joseph Hurlock publishes his A Practical Treatise upon Dentition, or The breeding of teeth in children in London, the first treatise in English on dentition.

  Technology

• Benjamin Robins publishes his New Principles of Gunnery, containing the determination of the force of gun-powder and an investigation of the difference in the resisting power of the air to swift and slow motions in London, containing a description of his ballistic pendulum and the results of his scientific experiments into improvements in ballistics.
• The first large reflecting telescope is made, in Gregorian form, by James Short, for use by Charles Spencer, 3rd Duke of Marlborough, in London.

  Awards

• Copley Medal: Christopher Middleton.

  Births

• March 15 – John Stackhouse, English botanist.
• May 18 – Lionel Lukin, English inventor.
• December 3 – James Rennell, English geographer, historian and oceanographer.
• December 9 – Carl Wilhelm Scheele, Swedish chemist.
• December 26 – Ignaz von Born, Hungarian metallurgist.

  Deaths

• January 14 – Edmond Halley, English astronomer, geophysicist, mathematician, meteorologist, and physicist.
• February 28 – Willem 's Gravesande, Dutch polymath.
• May 13 – Nicolas Andry, French physician.
• September 22 – Frederic Louis Norden, Danish explorer.