in Milan, 266 in Venice, 268 in Vienna. According to M. Lissajous, 

 in Paris, in 1856, the number of vibrations of the note A was 898 ; 

 while according to Sauveur in 1715 it was 810. This elevation is by 

 some supposed to be due to improvements made in the construction 

 of musical instruments. Professor Zantedeschi attributes it to a 

 molecular change which is gradually developed in the steel of which 

 tuning-forks are made. In order to eliminate this source of error, he 

 proposes to substitute for the tuning-fork a pipe such as is used at 

 the present time by tuners of instruments in the South of Italy. 

 He compared a number of tuning-forks and pitch-pipes known to be 

 more than fifty years old, and found that the former had become 

 higher, though unequally, when compared with the latter. In order to 

 secure the fixity of a note, he considers that it ought to be compared 

 with the syren of Cagnard de la Tour, or with the toothed wheel of 

 Savart. By these means, especially when combined with improve- 

 ments suggested by M. Zantedeschi, the stability of the note, or the 

 amount of its error, may at any time be ascertained. In France the 

 A has been lowered from 898 to 870 vibrations. 4. On the limits of 

 the sounds produced by free reeds, and on their harmonics, considered 

 in relation to the law of Bernoulli. 5. On the fundamental law of 

 the harmonics of a musical string, on the vibratory motion from which 

 they are derived, and on the interpolation of harmonics between the 

 notes of instruments sounded by means of a bow and those of the 

 human voice. 6. On the separation of waves corresponding to har- 

 monics, and on the coexistence of several vibratory waves in the same 

 aerial column. 7. On the lengths of the aerial waves, and on their 

 velocity in pipes, and on the influence which various circumstances 

 exert on the sound produced. 8. An experimental examination of 

 the method commonly followed in the determination of the nodes and 

 ventral segments of columns of air vibrating in tubes. 9. On the 

 fundamental laws of vibrating rods, and of the oscillation of air in 

 tubes. 



Professor Zantedeschi is in possession of a series of meteorological 

 observations embracing a very long period, by means of which he 

 hopes to be able to establish the constants of the climate of Italy. 



M. Schaub, Director of the Observatory, and Superintendent of 

 the Hydrographical Institution at Trieste, is occupied with the dis- 

 cussion of tide observations made during one whole year, beginning 



VOL. XI. E 



