1911 Encyclopædia Britannica/Donati, Giovanni Battista
DONATI, GIOVANNI BATTISTA (1826–1873), Italian astronomer, was born at Pisa on the 16th of December 1826. He entered the observatory of Florence as a student in 1852, became assistant to G. B. Amici in 1854, and was appointed in 1864 to succeed him as director. A new observatory at Arcetri near Florence, built under his supervision, was completed in 1872. During the ten years 1854–1864 Donati discovered six comets, one of which, first seen on the 2nd of June 1858, bears his name (see Comet). He observed the total solar eclipse of the 18th of July 1860, at Torreblanca in Spain, and in the same year began experiments in stellar spectroscopy. In 1862 he published a memoir, Intorno alle strie degli spettri stellari, which indicated the feasibility of a physical classification of the stars; and on the 5th of August 1864 discovered the gaseous composition of comets by submitting to prismatic analysis the light of one then visible. An investigation of the great aurora of the 4th of February 1872 led him to refer such phenomena to a distinct branch of science, designated by him “cosmical meteorology”; but he was not destined to prosecute the subject. Attending the International Meteorological Congress of August 1873 at Vienna, he fell ill of cholera, and died a few hours after his arrival at Arcetri, on the 20th of September 1873.