vi PREFACE. 



cattle become worn out ; his articles of exchange, 

 which are his money, expended ; and, indeed, the 

 medium of currency among the people he at last 

 reaches being unknown to him, has of course been 

 unprovided for. His clothes, necessaries, luxuries, 

 all become exliausted, and the capital out of which he 

 has to support himseK fast disappears. On the other 

 hand, infinite difficulty is found in acquiring the 

 confidence of a strange nation; a new language has 

 to be learnt ; native servants refuse, and are unfitted, 

 to accompany their master in countries strange and 

 probably hostile to them, and whom months of joint 

 labours had educated into a kind of sympathy with 

 his cause ; and so, when an explorer intends to cross 

 the frontier of a neighbouring tribe, he finds that all 

 his old travelling arrangements are more or less 

 broken up, and that the further progress of the 

 expedition will require nearly as many preparations 

 and as much delay as if it were then about quitting the 

 borders of civilisation. But his energies are reduced, 

 and his means become inadequate to the task, and 

 therefore no alternative is left him but to return 

 while it is still possible for him to do so. 



It is therefore not to be expected that any large 

 part of the vast unexplored region before us will 

 yield its secrets to a single traveller, but, rather, that 

 they will become known step by step through various 



