264 M. Arago on G?-aham or Julia Island. 



of Puozzoli, seems well worthy of a serious examination. Let 

 us hope, remarked M. Arago, that the Neapolitan Government, 

 which has so magnificently supplied the necessary instruments 

 to the new Observatory of Capo di Monte, and more recently 

 still, has authorised M. Capocci to enrich the scientific institu- 

 tions of Naples with the first-rate instruments of every kind 

 which can be manufactured in France, England, and Germany, 

 will likewise supply to this able astronomer the means of pro- 

 secuting with assiduity so highly interesting a phenomenon con- 

 nected with the physical history of the globe. The annual ob- 

 servation of the levels, together with therraometrical observations 

 taken at great depths, would besides shew the estimate we 

 should form of Mr Babbage's ingenious idea ; according to which, 

 the variations on the surface of the earth, noticed in so many 

 places, may be owing to marked local changes of temperature 

 in the lower strata of the earth. Mr Babbage calculates that 

 a change of 100° Fahr. affecting a formation of sandstone to a 

 depth of five miles, would cause a movement upwards at the 

 surface to the extent of twenty-five feet. 



Considerations concerni^ig the Manner in lohicli was formed in 

 the Mediterranean, in July 1831, the New Island zchich has 

 successi-vely been called Ferdhiandia, Ilotham, Graham, Ne- 

 rita, and Jidia. By M. Arago. 



M. AiiAGo, after having given an account of the memoir just 

 noticed, in which M. Capocci establishes upon most important 

 historical documents, that at the epoch of the formation of Monte 

 Nuovo there had been a considerableelevation of all the surround- 

 ing grounds, communicated to the Academy, as a supplement to 

 his report, the considerations which have led him to think, con- 

 trary to the almost universal opinion of geologists, that in its 

 submerged portions, at least, Graham or Julia Island was caused 

 by the upraising of the solid and rocky bed of the ocean. 



These considerations are of two kinds; both of which we shall 

 successively analyze. In examining the Nautical Journal of 

 M. Lapierre, the commander of the brig La Flcche, M. Arago 



