228 



NATURE 



[July 3, 1890 



map-makers for ignoring the work of the cartographers 

 of ancient times. We need not quarrel with his manner 

 of opening up a subject of great interest. What were 

 the relations of Egypt, and therefore of ancient Europe, 

 with Central Africa ? It is certainly a noteworthy fact 

 that, even in the oldest maps (whatever was the real 

 nature of these maps), we find the Nile coming out of 

 two lakes, and we find a range of mountains somewhere 

 in the neighbourhood, called the Mountains of the Moon. 

 It is not to be supposed that the people of Africa were 

 less restless in ancient times than they are now, nor 

 that the Egyptians did not make efforts to find out where 

 their great river came from. Expeditions into the heart 

 of Africa we read of in Herodotus and elsewhere. How- 

 ever the knowledge came — probably obtained through 

 traders or from natives brought down as slaves to Egypt— 



there can be no doubt that the Ptolemaic maps of Africa 

 bear some distant resemblance to reality. But all be- 

 came much exaggerated as time went on. The maps 

 of Africa became overcrowded with features the authority 

 for which it was impossible to find out ; the " Moun- 

 tains of the Moon " stretched themselves right across the 

 continent. That snowy Ruwenzori, Kilimanjaro, and 

 Kenia formed the original nucleus out of which these 

 mountains were evolved there can be little doubt. But 

 modern discoveries have proved how unlike the maps of 

 Africa, before d'Anvilie swept them clean, were to the 

 reality, and how essential it was to make a new start. 

 No one has done more than Mr. Stanley himself to fill 

 the map of Africa with authentic features. 



Mr. Stanley's pages teem with facts and suggestions of 

 interest to science ; we have only touched upon a few of 



South-west Extremity of Lake Victoria Nyanza. 



the more prominent topics referred to in the work. Here, 

 for example, are some curious data with regard to the 

 distribution of malaria : — 



" On the plateau of Kavalli and Undussuma, Messrs. 

 Jephson, Parke, and myself were successively prostrated 

 by fever, and the average level of the land was over 

 4500 feet above the sea. 



"On descending to the Nyanza plain, 2500 feet lower, 

 we were again laid up with fierce attacks. 



"At Banana Point, which is at sea-level, ague is only 

 too common. 



" At Boma, 80 feet higher, the ague is more common 

 still. 



" At Vivi, there were more cases than elsewhere, and 

 the station was about 250 feet higher than Boma, and not 

 a swamp was near it. 



NO. 1079, VOL. 42] 



"At Stanley Pool, about iioo feet above sea-level, fever 

 of a pernicious form was prevalent. 



" While ascending the Congo with the wind astern we 

 were unusually exempted from ague. 



" But descending the Upper Congo, facing the wind, we 

 were smitten with most severe forms of it. 



" While ascending the Aruwimi we seldom thought of 

 African fever, but descending it in canoes, meeting the 

 wind currents, and carried towards it by river-flow and 

 paddle, we were speedily made aware that acclimatization 

 is slow. 



" Therefore it is proved that from o to 5000 feet above 

 the sea there is no immunity from fever and ague ; that 

 over forty miles of lake water between a camp and the 

 other shore are no positive protection ; that a thousand 

 miles of river course may serve as a flue to convey 



