15 



Boletin de la Socieda'd Economica de Amigos del Pais de Valencia. 



Ano 8°. Tomo 4°. Agosto, 1847. — From the Society. 

 Annals and Magazine of Natural History, including Zoology, Botany 



and Geology. Second Series. Vol. I. No. 2. Feb. 1848. — From 



Sir Wm. Jardine, Bart. 



ADDITIONS TO THE LIBRARY BY PUECHASE. 



London, Edinburgh, and Dublin Philosophical Magazine, and Journal 

 of Science. Third Series. No. 213. Feb. 1848. 



Astronomische Nachrichten. Nos. 622, 623, 624, and 625. Jan. 

 1848. Altona. 



Dr. F. Bache announced the death of Mr. Nicholas Carlisle, 

 of London, a member of this Society. 



Prof. Frazer read the following letter from Prof. Peirce, of 

 Cambridge, to Prof. Henry, of Washington. 



I have just completed the perturbations of Uranus by Neptune, and 

 am now certain that Neptune will account for these perturbations; so 

 completely, indeed, as to show that the former theories were some- 

 what defective, for they did not satisfy the observation of 1690, which 

 now appears to be as good as any other. The following table con- 

 tains the residual differences between the theoretical and observed 

 longitudes of Uranus, which are to be attributed to defects of theory 

 or to errors of observation. I have also, for the purpose of compari- 

 son, copied from Leverrier and Adams their outstanding differences 

 of the same kind, after the introduction of their hypothetical planets; 

 and I have, moreover, added a final column from Leverrier of the 

 residual perturbations which were originally to be accounted for, pro- 

 vided that orbit of Uranus is adopted which best coincides with mo- 

 dern observations. It will be perceived, from this table, that the 

 motions of Uranus contain no indication of another external planet, 

 or of any error in the mass of Saturn. Neptune stands, therefore, 

 in direct opposition to the proposition, that no planet, placed at a less 

 mean distance than 35 times the distance of the earth from the sun, 

 can possibly account for the observed irregularities in the motion of 

 Uranus to within 5" of arc for modern observations, and 10" for an- 

 cient ones. The table is computed from Walker's last elements of 

 Neptune as a basis. 



