1720 in science
# 1720 in science

The year 1720 in science and technology involved some significant events.

## Astronomy

* February 10 – Edmond Halley is appointed as Astronomer Royal of England.

## Medicine

* May – First patient admitted to the Westminster Public Infirmary, predecessor of St George's Hospital, London.
* Dr Steevens' Hospital is established at Kilmainham, Dublin.
* Great Plague of Marseille, the last major outbreak of bubonic plague in Europe.

## Physics

* Willem 's Gravesande publishes Physices elementa mathematica, experimentis confirmata, sive introductio ad philosophiam Newtonianam, an introduction to Newtonian physics, in Leiden.

## Technology

* A theodolite is developed by Jonathan Sisson of England.
* Pinchbeck is invented by English watchmaker Christopher Pinchbeck; it is an alloy of 83% copper and 17% zinc, creating a strong, hard-wearing metal which has the appearance and weight of 20 carat gold.
* An early chronograph is invented which has only mechanical parts in it.
* Henry de Saumarez (of the Channel Islands) produces an instrument called the Marine Surveyor intended to measure a ship's velocity.
* A single-action five-pedal harp is developed by Jacob Hochbrucker of Bavaria which can raise the pitch of the selected strings by a half step.
* approx. date – Joseph Williamson uses a differential gear in a clock.

## Births

* January 30 – Charles De Geer, Swedish industrialist and entomologist (died 1778)
* March 13 – Charles Bonnet, Genevan naturalist and philosophical writer (died 1793)
* July 18 – Gilbert White, English naturalist (died 1793)
* October 8 – Geneviève Thiroux d'Arconville, French novelist, translator and chemist (d. 1805)
* November 5 - Jean Baptiste Christophore Fusée Aublet, French pharmacist and botanist (died 1778)
* December ? – James Hargreaves, English inventor (died 1778)
* approx. date – Dmitry Ivanovich Vinogradov, Russian chemist and (died 1758)

## Deaths

* December 29 – Maria Margarethe Kirch, German astronomer (born 1670)
* David Gregory, Scottish physician and inventor (born 1625)
