TRUE VOLCANOES. 333 



Biafra, and eastward of the Delta of the Kowara, or Niger, 

 emitted an eruption of lava- in the year 1838. The four 

 high volcanic islands of Annabon, St. Thomas, Isla do Prin- 

 cipe, and San Fernando Po, which run on a fissure in a di- 

 rect linear series from S.S.W. to N.N.E., point to the Came- 

 roons, which, according to the measurements of Captain Owen 

 and Lieutenant Boteler, rises to the great altitude of nearly 

 13,000 feet* 



A volcano (?) a little to the west of the snowy mountain 

 Kignea, in Eastern Africa, about 1 20 X S. lat., was discov- 

 ered by the missionary Krapf in 1849, near the source of the 

 River Dana, about 320 geographical miles northwest of the 

 coast of Mombas. In a parallel nearly two degrees more 

 southerly than the Kignea is situated another snowy mount- 

 ain, the Kiliiiiandjaro, which was discovered by the mis- 

 sionary Rebmunn in 1847, perhaps scarcely 200 geographical 

 miles from the fame coast. A little to the westward lies a 

 third snowy mountain, the Doengo Engai, seen by Captain 

 Short. The knowledge of the existence of these mountains 

 is the result of laborious and hazardous researches. 



Evidences of pre-liistorical volcanic action in the great con- 

 tinent, the interior of which between the seventh degree north 

 and the twelfth degree south latitude (the parallels of Ada- 

 maua and the Lubalo Mountain, which acts as a water-shed) 

 still remains so unexplored, are furnished, according to Riip- 

 pell, by the countiy surrounding the Lake Tzana, in the king- 

 dom of Gondar, as well as by the basaltic lavas, trachytes, 

 and obsidian strata of Shoa, according to Rochet d'PIericourt, 

 whose mineralogical specimens, quite analogous to those of 

 Cantal and Mont Dore, may have been examined by Dufre- 

 noy (Comptes rendus, t. xxii., p. 806810). Though the con- 

 ical mountain Koldghi, in Kordofan, is not now seen either in 

 a burning or smoking state, yet it appears that the existence 

 of a black, porous, and vitrified rock has been ascertained 

 there.f 



In Adamaua, south of the great Benue River, rise the iso- 

 lated mountain masses of Bagele and Alantika, which from 

 their conical and dome-like forms appeared to Dr. Barth, on 

 his journey from Kuka to lola, to resemble trachyte mount- 



* Gumprecht, Die Vulkanische TJiatigkeit avfdem Festlande von Af- 

 rika, in Arabien und aufden Inseln den liothen Meeres, 1849, s. 18. 



f Cosmos, vol. i., p. 245, note J. For the whole of the phenomena 

 hitherto known in Africa, see Laudgrebe, Naturgeschichte der Vuikane, 

 bd. i., s. 195-219. 



