190 Scientific Intelligence. — Geology. 



It results from these observations that the flattening of the ellipsoid of 

 revolution which may be considered as jjg, — the osculator of the sur- 

 face of the earth at Paris, touching the mean level of the ocean at Brest, 

 to which all the points of the map of France are referred, — cuts the sur- 

 face of the sea, which it leaves sometimes above and sometimes below 

 its own level. At Rochelle, Formentera, Macao, Madeira, Isle of France, 

 Ascension, &c., it is above ; but at Koenigsberg, St Petersburgh, Edin- 

 burgh, Sierra-Leone, &c., it is below. Hence there are very extensive 

 portions of continents which are lower than the true level of the sea, 

 without being overwhelmed by the latter ; which is to be ascribed to 

 gravitation retaining the waters in the position they now occupy. But 

 if, by any cause, gravitation should undergo considerable variations in 

 some points of the globe, and geological facts indicate that such variations 

 have taken place at different periods, the waters would overspread 

 parts of the continents, and ultimately again recede from them if gra- 

 vitation should afterwards vary in a contrary direction at these same 

 places. We thus find an explanation of many geological facts, such as 

 the successive returns of the sea into the basin of Paris, supposed by 

 MM. Brongniart and Cuvier to have taken place in order to account 

 for the alternation of marine and lacustrine formations in this basin ; 

 the deposits of marine shells to a great distance inland ; the immersions 

 and emersions of the temples of Serapis at Puzzuoli, &c. 



M. Rozet concludes his memoir by drawling attention to the fact that 

 the causes which have produced irregularities in the structure of the 

 globe have not yet ceased to act, as is proved by earthquakes, volcanic 

 eruptions, slow and continuous movements of the crust of the globe in 

 certain regions, &c. We may, therefore, yet see repeated the great 

 catastrophes which the surface of tlie earth has undergone anteriorly to 

 the historical period."' 



5. On Indications of the former higher Level of the Sea in the Man- 

 riiinft. — Having read in the instructions prepared by the Royal Society, 

 for the Antarctic Expedition under Captain James Ross, that tlie island 

 of Bourbon presents indications of the sea having formerly occupied a 

 higher level than at present, and having observed similar appearances 

 in the Mauritius, Captain Lloyd was induced to lay the following facts 

 before the Geological Society : — 



The island of Mauritius is belted by an enomious coral-reef through- 

 out its whole circumference, except for about ten miles of the broadest 

 and extreme southern side, or from Point Souffleur to Souillac, com- 

 monly called Port Savanne. Along that part of the island the coast is 



* L'lnstHut, No. 382, p. 136. 



