155 



6. AFRICA, 



Anon. La Verite sur les minerals de fer en Algerie. [The Truth 



respecting the Iron Ores of Algeria.] Echo cles Mines, t. i. nos. 8, 



9, 10, pp. 81, 129-131, &c. 



Describes the modes of occurrence of the ores, and gives a list of all 



the iron-mines, whether worked or not. Discusses their commercial 



value, and concludes against the probability of a future extension of 



iron-production in the colony, except as regards the magnetite found 



chiefly at Mokta el Hadid, &c. associated with the older rocks. G. A. L. 



The Proposed Submersion of North Africa by the Mediter- 



ranean Sea. Journ. Soc. Arts, vol. xxiv. no. 1237, pp. 883, 884. 

 Apparently a notice of a Report by Yice-Consul Dupuis. The pro- 

 ject is based on the fact of the occurrence of lakes in the line of the 

 great depressions, and the presumption that these lakes are the residue 

 of an inland sea, which disappeared through the formation of an isthmus, 

 cutting it off from the Mediterranean. Recent surveys, however, reject 

 the idea of former connexion with that sea, but indorse that of the 

 region having been under water. The isthmus is not a mere mass of 

 sand, but is chiefly composed of alternations of quartz and freestone 

 over Chalk. The disappearance of the water is thought to be owing to 

 the encroachment of the desert. W. W. 



Sokotra. Geogr. Mag. vol. iii. pp. 119-124. 



The island consists of limestone pierced by granite, diorite, and other 

 igneous rocks, the granite making mountains which rise to 24,656 ft. 



Barth, Baron H. de. Exploracao geologica na Africa Portugueza. 

 1 . . . , provincia de Angola. [Geological Exploration of Portu- 

 guese Africa, Angola.] Ann. Com. Ccntr. Geogr. no. 1, pp. 35-37. 



Coqnand, H. Sur les grcs rouge de la Nubie. [Red Sandstones of 

 Nubia.] Bull. Soc. Geol. France, 3 ser. t. iv. pp. 159, 160. 



Currey, John B. The Diamond Fields of Griqualand, and their 

 probable Influence on the Native Races of South Africa. Journ, 

 iSoc. Arts, vol. xxiv. no. 1217, pp. 372-381. 



Notices the history of the discovery and the methods of working. 



Czyszkowski, Stephen. Coup d'CEil Ge'ne'ral sur la Nature & lo 

 Gisement des Minerais de For en Algerie & Considerations Gene- 

 rales sur les Gisements metalliferes. Algerie — Pyrenees — Cor- 

 bieres — Montagne Noire — Region de Huelva (Espagne) — Cevennos 

 (Zone d'Alais). Essai de Classification des Gitcs Mineraux. Thai- 



