With the Napoleonic occupation of Florence in 1799, Fontana was dismissed from his post as director. Only in 1807, Domenico de’ Vecchi, professor of physics at the University of Siena, was nominated director, who found the observatory in a grave state of deterioration. In 1825, he was succeeded by the Frenchman, Jean-Louis Pons, discoverer of a good 37 comets. It seems that Pons had had an extraordinary ability for memorising the stellar fields which he observed with a telescope and was therefore able to immediately individuate every eventual change. Upon his death in 1831, Giovanni Battista Amici assumed the direction of the observatory. He was followed by Giovanni Battista Dontai, who in 1864 presented a formal proposal to the government for the construction of a new observatory in the hills of Arcetri, which was inaugurated on 27 October 1872. Donati died in 1873, at only forty-seven years of age, and his successor, the German Ernst W.L. Tempel (1821-1889), was a great comet hunter too. Under the direction of Tempel the building manifested grave defects in construction.
Circle Dividing Engine,
First half of the 19th C.; Florence; marble, iron, brass
The toothed edge of a circular platform meshes with an endless screw attached to a handle equipped with a graduated drum. Each division of the drum corresponds with every fraction of a turn.
Refracting Telescope,
The beginning of the 19th C.; cardboard, wood, brass, glass
The telescope belonging to Pons, has a cardboard tube and two sections that, sliding one into the other, allowed for focusing. In the wooden breech is inserted the brass ocular housing.
Gregorian Telescope,
James Short, London; second half of the 18th C.; wood, brass, iron
The engraving on the breech “1 / 1309 = 61” signifies that this telescope is the first of these dimensions of 1309, until then created by Short and that the focal length of the primary mirror is of 61 inches.
Repeating Circle,
Georg F. von Reichenbach, Munich; first half of the 19th C.; wood, brass, glass
The repeating circles serve to determine with precision the celestial coordinates of the stars. This example created by von Reichenbach has an objective signed by Joseph von Fraunhofer.
Universal Instrument ,
Respold, Hamburg; 1839; brass, glass
This portable instrument constructed by the Respold company, was used in 1913-14 by members of the expedition in Caracorum lead by Filippo De Fillipi and in Florence to study the meridian line in the church of Santa Maria del Fiore.
Portrait of Jean-Louis Pons,
Ernesto Bonaiuti, Florence; 1830; pastel on paper
On the retro of the portrait is displayed a drawing of the Observatory with the upper part of the tower still under construction, and the epitaph for Pons, entombed in the church of San Marco.
Portable Refracting Telescopes,
Dollond, London; 18th C.; brass, glass
Here are two achromatic refracting telescopes, constructed by the Dollond company in London, of modest dimension and with a low power of enlargement.
Gregorian Telescope,
Navarre, Paris; 18th C.; brass
Around the middle of the 18th century, the Gregorian telescope was widely diffused thanks to the work of James Short, whose products were emulated by many opticians.