A question is commonly put to explorers, “Why could you not go further when you had already succeeded in going so far?” and the answer to this is, that several independent circumstances concur in stopping a man after he has been travelling for a certain time and distance. He _must_ refit, for his 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 exhausted, and the _capital_ out of which he has to support himself 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 successive discoveries; and as the experience of nearly a century corroborates these views, it is probable that for years to come there will still remain ample room in Africa for men inclined for adventure to carry out in them, if nowhere else, the _métier_ of explorers. FRANCIS GALTON. 8, ST. JAMES’S PLACE, _April 27th, 1853_. [Illustration: The four Mimosas that, to the exclusion of nearly every other tree or bush, form the vegetation of Damara-land.] DATES OF MY JOURNEYINGS.