Upon completion of his studies in his native Pisa, Giovanni Battista Donati (1826-1873) was employed by the Florentine Observatory where he was intensely dedicated to the study of comets, discovering a few. There was a comet which, he himself discovered on 2 June 1858 – one of the most spectacular ever observed and also the first to be photographed – which brought him international fame. In 1860 he went to Torreblanca, in Spain, to observe the total eclipse of the Sun of 18 July. His studies of the stellar spectra were also important. With the death of Amici, which occurred in 1864, Donati succeeded him in directing the observatory. Giving life to a project that the two of them had conceived together, he established at the Technical Institute of Florence, an optical-mechanics laboratory that constituted the nucleus of the future Officine Galileo. Donati was given the duty of constructing the Observatory at Arcetri, inaugurated on 27 October 1872. He died less than one year later, infected with cholera, caught in Vienna, were he had gone for a meteorological convention.
Burning Lens,
Benedetto Bregans, Dresden; 1690; wood, glass
Gifted by Bregans to the Grande Duke Cosimo III, the lens was used in 1694-1695 by Giuseppe Averani and Cipriano Targioni for experiments in combustion, and in 1814, by Humphrey Davy to study diamonds.
Telescope tube for spectroscopy,
Giovanni Battista Donati, c. 1860; wood, iron
The tube is in sheet metal with a wooden mount. Upon the suggestion of Amici, Donati inserted into the spectroscope a field lens that rendered it useable with an objective of relative aperture the same as the lens of Bregans.
Spectroscope,
19th C.; brass, glass
Very similar to the one designed by Donati, this spectroscope disperses light by a series of five prisms.
Telescope,
Dollond, London; 18th C.; brass, glass
This refracting telescope has an aperture of 95 mm and provides a magnification of 50 times. The instrument was used by Donati, in Spain, to observe the total eclipse of the Sun of 18 July 1860.