Ohfervations &c. i']% 



fent back or confined; whereas in Summer, the whole Coun- 

 try being full of deep Chinks and Chafms, the inflammable Par- 

 ticles have an eafier Efcape. 



We cannot trace any of the preceeding Thenomena, (ox {c^rct no ^it^arrks 

 any other Branch of the Natural Hiftory ) much lower than the 

 Surface. Thofe Quarries of Marble " which are taken Notice 

 of by the Antients, are not known at prefent ; and indeed the 

 fmall Quantity of Marble that appears to have been made ufe 

 of in the moft fumptuous Buildings of this Country, would in- 

 duce us to believe, that either there never were fuch Quarries, 

 or that the Marble was fent away to other Places. For thej^^^^f^de 

 Materials that are made ufe of in all the antient Edifices of"J'i''"f"^'- 

 this Country, at Jol Ccefarea, Sittfi, Cirta, Carthage &c. are 

 not much different, either in their Colour or Texture, from the 

 foft and harder Kinds of the Heddington Stone near Oxford. 



Tlie Wells (except in Wadreag and fome other Parts oiih^rhe Layers cf 

 Sahara) are rarely of any great Depth ; and, in digging them, 

 I have often obferved, that after the Soil is removed, they 

 pafs through feveral different Layers of Gravel , and fome- 

 times, though rarely, of Clay, 'till they arrive at a foft fleaky stone. 

 Kind of Stone, the fure Indication of Water. When there is 

 neither Soil nor Gravel, as in feveral Places near Algiers 

 and Bona^ this fort of Stone lyeth immediately upon the Sur- 

 face, being frequently very beautifully guilded all over with Gold- cjd and sa- 

 like-Spangles ; as the Sparry Matter, which fiUeth up the Fiflures, glesf dS*''' 

 glittereth with Thofe that imitate Silver. I could not learn 

 that either Agates or Stones of the like Beauty and Conliftence, 

 were Natives of this Country. Even the common Flint Stone, 

 which moft other Nations have in Plenty, occurreth fo very 

 feldom in fome Parts of Barbary, that our Merchant Veflels 

 have received fome of them in the T)owns for Ballaft, and 

 difpofed of them at Algiers for feven Shillings the Quintal. 



The Selenites , which fometimes fpreads Itfelf over whole 

 Acres of the woody and mountainous Diftrifts ; a tranfparenr, 

 ftriated, yellow and flefh coloured Talk or Gypfum, that lyeth xaik and 

 often expanded, in thin Cakes, over the rocky Parts of the^^''^"'"' 

 Sahara^ fome chriftal-like Irides or Bri/lol-Stone% found in irides. 

 the Mountains of Boujeiah ', the dark-coloured douhle<oned DoMe.co»e,i 

 Chryftals from Zthhafs and Ellou-leejah ; with a Variety of ^'^ *''" 



I Exc. p. 21. cap,3. p. 23. cap. z6. &c. 



Nnn X Cawk 



