1586 in science

	… 1576; 1577; 1578; 1579; 1580; 1581; 1582; ; 1583; 1584; 1585; 1586; 1587; 1588; 1589; ; 1590; 1591; 1592; 1593; 1594; 1595; 1596 …;
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The year 1586 in science and technology included a number of events, some of which are listed here.

Botany

Jacques Daléchamps publishes Historia generalis plantarum in Lyon, describing 2731 plants, a record number for this time.

Blaise de Vigenère publishes Traicté des chiffres ou secretes manières d'escrire in Paris, describing an autokey cipher of his invention.

July 21 - Thomas Cavendish sets out from Plymouth in the Desire on the first deliberately planned circumnavigation.^[1]

Francesco Barozzi publishes Admirandum illud geometricum problema tredecim modis demonstratum quod docet duas lineas in eodem plano designare, a treatise on the construction of parallel lines.

Timothy Bright publishes A Treatise of Melancholie; containing the causes thereof, & reasons of the strange effects it worketh in our minds and bodies: with the phisicke cure, and spirituall consolation... in London.

Galileo publishes La Billancetta, describing an accurate balance to weigh objects in air or water.^[2]
Simon Stevin publishes De Beghinselen der Weeghconst in Leiden, discussing static forces; and De Beghinselen des Waterwichts, discussing the weight of water.

^ Grun, Bernard (1991). The Timetables of History (3rd ed.). New York: Simon & Schuster. p. 261. ISBN 0-671-74919-6.
^ "Hydrostatic balance". The Galileo Project. Retrieved 2008-07-17.