NA TURE 



31 



THURSDAY, JULY 8, 1909. 



RUWENZORI AND CENTRAL AFRICA. 



(i) II Riiwenzori : parte scientifica: risultati delle 



ossen'azioni e studi compiuti sul matcriale raccolto 



dalla spcdizionc di S.A.R. il Principe Liiigi Amcdco 



di Savoia, Duca degli Abruzzi. Vol. i., Zoologia 



e Botanica. Pp. vii + 603; 74 plates. Vol. ii., 



Geologia, Petrografia e Mineralogia. Pp. xxi + 



286; 40 plates. (Milan: Ulrico Hoepli, igog.) 



Price, 2 vols, 50 lire. 



(2) Rdsultats scientifiqttes des Voyages en Afrique 



d'Edouard Foa. Publics sous les Auspices du 



Museum d'Histoire naturelle. Avec Preface de M. 



Edmond Perrier. Pp. xli + 742. (Paris : Imprimerie 



Nationale, and Plon-Nourrit et Cie., igoS.) 



(i) TN 1906 the Duke of the Abruzzi, already famous 



J- for his exploration of the lofty mountains of 



.Alaska, resolved to do what no other traveller had 



done — make a thorough examination of the range of 



snow mountains in equatorial .\frica known as 



" Ruwenzori." The number of snow peaks, their 



altitudes, extent of glaciation, and exact position on 



the map remained still unknown, although Ruwenzori 



had been revealed to geographical knowledge for 



nearly twenty years. Although no previous explorers 



had had the monetary resources of this prince of 



the House of Savoy, and consequently been able 



to fit out such a perfectly organised expedition, yet it 



must be noted that most of the Duke's predecessors 



suffered from sheer bad luck in the way of weather, or 



difficulties arising from the disturbed condition of the 



natives. Otherwise the Duke of the .Abruzzi might 



have been forestalled as conqueror of these virgin 



peaks. But in any case it is doubtful whether any 



previous traveller was so perfectly trained to make 



every use of his opportunities as the Duke of the 



Abruzzi, who, apart from his carefullv chosen staff, 



selected to deal specially with geology, biologv, and 



photography, was himself a highly trained surveyor, 



scientific geographer, and alpinist. 



The result has been, of course, a complete settle- 

 ment of the position, height, configuration, and petro- 

 logical structure of these " Mountains of the Moon " 

 — not, as we now learn, the highest point on the 

 African continent — in that respect they are only third 

 in rank — but surely the most impressive and remark- 

 able among African mountains. The general geo- 

 graphical and meteorological results of the expedition 

 were given in one large volume at the close of igo8 

 (published in English and Italian). In the two 

 volumes under review, the geological and biological 

 collections and observations of the Duke's expedition 

 are dealt with bv a large number of authors, the 

 whole work being edited bv Dr. Alessandro Roccati 

 (who has also written on the geology and petrology) 

 and published in Italian only. The volumes are mag- 

 nificently produced, and are of the highest importance 

 scientifically. Thev deal justlv, even generously, with 

 the work of previous explorers, or with the opinions 

 and researches of British, French, and German au- 

 thorities (inter alios) ; but why did not Dr. Roccati get 

 NO. 2071, VOL. 81] 



some one to go carefully through the proof sheets 

 with him before publication? The two volumes 

 abound in the most ridiculous press errors, wherever 

 the Latin, English, German, or French languages are 

 employed. English is the vi'orst maltreated. The 

 English authors quoted are sometimes made to express 

 themselves in a very puzzling manner. 



Ruwenzori was shown by the Abruzzi expedition to 

 be a mountain chain mainly of archaean, crystalline 

 rocks (gneiss, mica-schists, granite, &c.), cut athwart 

 by a curved band of Pateozoic volcanic greenstones 

 (amphibolite, diorite, diabase, &c.). In the upper 

 valleys of the Bujuku, Mubuku, Mahoma, and other 

 streams, born from the snow peaks and the glaciers, 

 there is a lacustrine alluvium (which ought to be in- 

 teresting of exploration for possible Pliocene or Pleis- 

 tocene fossils). There are two or three calcareous 

 deposits. The lower stream valleys are bordered by 

 ancient and recent moraines. At the southern base of the 

 Poital Peaks (south-east of Ruwenzori) there are three 

 small dykes of basalt. Elsewhere in the distant foot- 

 hills to the east and south of Ruwenzori there are plain 

 evidences of recent volcanic activity in the intrusions 

 of basalt, the stratified tuff, the craters of dead vol- 

 canoes (often filled with lovely crater lakes), the hot 

 springs and the frequent earthquakes. This volcanic 

 belt links on with the still smoking and devastated 

 region of Mfumbiro and Lake Kivu, and is no doubt 

 synchronous in origin with the volcanic activities of 

 equatorial East Africa and of North Nyasa. 



The work under review has much that is interesting 

 to record on the former extension of the Ruwenzori 

 glaciers. The volumes confirm the observations of 

 Scott-Elliott, Moore, the present writer, and other 

 travellers as to the signs of glacier action at com- 

 paratively low altitudes (7000 feet and less). If these 

 deductions be correct, similar signs ought to _ be 

 present (and should be looked for) on the Abyssinian, 

 North Nyasa, Mlanje, Rhodesian, and Drakensberg 

 Mountains. But if these indications of a Glacial 

 period or periods are found in tropical Africa, and if, 

 moreover, they are proved to be coincident in time 

 with the Glacial periods of Europe and North America, 

 will this not tend to dispose of the idea now in vogue 

 that there has been a gradual shifting of the poles of 

 the earth's axis, carrying with it the more or less 

 glacial conditions gathered round the poles to various 

 parts of the earth's surface? This last theory cer- 

 tainly explained more easily the former existence of a 

 vegetation in both the present polar regions sufficiently 

 dense to become transformed in course of time into 

 coal-measures, a vegetation which could not have 

 flourished with a six months' winter-night in every 

 yean 



Dr. Roccati thinks that Ruwenzori was at one time 

 a lofty island of archaean rocks rising up out of. the 

 waters of an immense fresh-water sea— the Victoria 

 Nyanza, Ibrahim (or Kioga), Albert Nyanza, Albert 

 Edward, Dweru, and Semliki combined. He attri- 

 butes this idea in its inception to the studies of Mr. 

 C. W. Hobley, a Commissioner in the British East 

 African service who has done so much to increase our 

 knowledge of Equatorial Africa. 



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