904 SEC. 20. COLLECTION OF APPARATUS AND PHOTOGKAPIIS 



the diamond and other precious stones. .Afterwards it served the 

 celebrated Sir Humphry Davy for his researches on the chemical 

 constitution of the diamond. 



Barometrograph of Fontana. 



Thermo-electrical Pile of Nobili, composed of 12 elements 

 disposed in rays. 



Thermo-electrical Pile of Nobili, divided into three 

 small ones of 12 elements each, to be combined at will. 



Thermo-electrical Pile of Nobili for the experiments 

 on radiant heat, composed of 37 elements, and furnished with a 

 conical mirror. 



Galvanometer of Nobili, with astatic system, and bobine 

 composed of eight threads to be united at pleasure. 



Galvanometer of Nobili, with astatic system for the hydro- 

 electrical current. 



Magnetoscope of Nobili, composed of an astatic system 

 suspended in a glass bell furnished with a graduated circle. 



Rose of Metallic Colours obtained by means of electricity 

 by Leopoldo Nobili. 



Magneto-electrical Machine of Leopoldo Nobili and 

 Vincenzo Antinori, which gave, on the 30th of January 1832, 

 the first spark, before Leopold II. 



Catadioptric Microscope of Amici. 

 Dioptric Microscope of Amici. 



Galvanometer for hydro-electrical currents, with which 

 Matteucci discovered, in 1844, the muscular current. 



Spectroscope of Donati, which served him in the observa- 

 tions of the eclipse of the sun, made in Agosta (Sicily) the 20th 

 of December 1870. 



Photographs of the Tribune of Galileo. 



1 . A view of the whole Tribune of Galileo. Galileo's statue was sculptured 

 by the Professor Aristodemo Costoli. In the lunette at the end is represented 

 Galileo while presenting his telescope to the Venetian Senate. The four 

 greater machines that can be observed in the angles of the middle part of the 

 tribune are, at the right hand the odometer of the Accademia del Cimento, 

 and the lens of Benedetto Bregans, at the left hand a Florentine astrolabe 

 and the quadrant of Rinaldini. The other parts of the tribune are explained 

 in the special photographs. 



2. The left side of the further end of the tribune. The lunette represents 

 Galileo observing the oscillations of the lamp in the Cathedral of Pisa. The 



