XXil INTRODUCTION. 
that its navigation was impeded by a cataract at no great 
distance from its mouth; but that was not considered as a 
reason why it should not again become navigable beyond it. 
Maxwell’s information from the slave dealers stated it to be 
so for six hundred miles above this cataract. 
In exploring the course of an unknown river upwards, 
there would obviously be less risk to the parties employed 
than in following the stream downwards. In the first case 
a retreat could always be secured when the navigation 
became no longer practicable, or the state of the coun- 
try rendered it unsafe to proceed ; in the second, every 
moment might be pregnant with unforeseen dangers from 
which there could be no retreat. The river might, for in- 
stance, suddenly and imperceptibly become bristled with 
rocks, and its rapid stream roll with such velocity as to 
sweep the unfortunate navigator to certain destruction down 
a cataract; or it might spread out its waters into a wide 
lake without an outlet, which, becoming in the dry season 
a boundless swamp, would equally doom him to inevitable 
destruction. No one can tell what the fate of Park may 
have been, but no one will believe that this enterprising 
traveller finished his career in the manner related by 
Isaaco, on the pretended authority of Amadou Fatima. 
Some persons indeed are still sanguine enough to suppose 
he may be living. It is just possible, and barely so, after 
such a lapse of time, that this unfortunate traveller may 
have been hurried down the stream of the Niger into the 
heart of Africa, and placed in a situation from whence 
he had neither the means of returning or of proceeding ; 
but what these obstacles may have been, whether moral or 
physical, or both, in the total absence of all imformation 
