Gottfried Kirch notices that Chi Cygni's brightness varies.
Edmund Halley establishes the relationship between barometric pressure and height above sea level.
Edmund Halley presents a systematic study of the trade winds and monsoons and identifies solar heating as the cause of atmospheric motions.
Isaac Newton uses a fixed length pendulum with weights of varying composition to test the weak equivalence principle to 1 part in 1000
May 24 - Gabriel Fahrenheit, physicist, inventor (+ 1736)
Nicolas Steno: pioneer in early-modern geology