VI PREFACE. 



He lays claim to no more credit than may attach to an 

 earnest desire to make himself useful and to further 

 the cause of science. 



It is more than probable that his career as an ex- 

 plorer and pioneer to civilization and commerce is term- 

 inated ; still he would fain hope that his humble exer- 

 tions may not be without their fruits. 



When he first arrived in Africa, he generally traveled 

 on foot throughout the whole of the day, regardless of 

 heat, and almost scorning the idea of riding on horse- 

 back, or using any other mode of conveyance ; indeed, 

 he was wont to vie with the natives in endurance ; but 

 now, owing to the severe hardships he has undergone, 

 his constitution is undermined, and the foundation of a 

 malady has been laid that it is feared he will carry with 

 him to the day of his death; yet such is the perverse- 

 ness of human nature that, did circumstances permit, 

 he would return to this life of trial and privation. 



