﻿1850.] MURCHISON SLATY ROCKS OF THE SICHON. 



13 



Great quantities of fragments of syenite are found in the ruins of 

 all the ancient towns of Egypt ; and the imagination is really tasked 

 when thinking of the difficulties presented in the cutting, polishing, and 

 transporting of so many gigantic monuments. The most celebrated 

 of these ruins are, according to De Roziere, those of the isles of 

 Philse and Elephantine, those of Thebes, Luxor, Heliopolis, and espe- 

 cially of Alexandria ; and although the syenite was extracted in the 

 country surrounding Syene, yet the fragments are more and more 

 abundant the further we descend the Nile towards the north ; which 

 is to be ascribed, as M. de Roziere has shown, to the fact that the 

 seats of government successively approached the Mediterranean, and 

 that the requisite material for the numerous sacred and palatial struc- 

 tures was wanting in that northern region of Egypt which is essen- 

 tially calcareous and gravelly. 



The syenite was of all rocks the one preferred by the Egyptians, 

 and they employed it for the construction of their most remarkable 

 monuments ; of these monuments there might be cited the obelisks, 

 the sphinxes, the sarcophagi found in all parts of Egypt, Pompey's 

 Pillar and Cleopatra's Needles, at Alexandria, both the inside and out- 

 side of the great pyramid of Cheops, and particularly the monolith 

 sanctuary of Sais. At Paris may be seen one of the Luxor obelisks, 

 and in the Egyptian Museum at the Louvre, the feet and head of a 

 colossal statue of Amenophis III., as well as a great number of 

 sculptures, which under the ever-pure sky of Egypt, for the greater 

 part have not suffered any alteration, even perfectly preserving their 

 polish, for nearly 4000 years. 



4. The Slaty Rocks of the Sichon, or Northern end of the Chain 

 of the Forez in Central France, shown to be of Carbonife- 

 rous Age. By Sir Roderick Impey Murchison, G-.C. St. S., 

 F.R.S., G.S., L.S., Hon. Mem. R.S. Ed., R.I.Ac., Mem. Imp. Ac. 

 Sc. St. Pet., Corr. Mem. Ac. France, Berlin, Turin, &c. &c. 



Long as the tertiary lacustrine deposits and extinct volcanos of 

 Central France have been explored and described, the true geological 

 age of the more ancient and crystalline rocks which form the margin 

 of that remarkable area have not yet been adequately developed. The 

 few observations I was enabled to make last summer, when a visitor 

 at the baths of Vichy, and of which I now give an account, will at 

 all events be sufficient to show how little acquainted we have hitherto 

 been with the age of the rocks that constitute the eastern boundary 

 of the Limagne d'Auvergne. At the same time let me do justice to 

 the author, who in the ' Memoires pour servir' has well described 

 the mineral structure of the tract to which I invite attention, and has 

 laid down the general outline on the geological map of France*. 

 The same district has also been specially dwelt upon by M. Visquenel, 



* M. Dufrenoy. See Mem. p. servir, vol. i. p. 260 et seq., and Carte Geol. de 

 la France. 



