xxxii INTRODUCTION, 



with the interior of the country through which it descends, by means of mission- 

 aries, and slave agents ; so confined indeed is our knowledge of the course of this 

 remarkable river, that the only chart of it, which can have any pretension to ac- 

 curacy, does not extend above 130 miles, and the correctness of this survey, as 

 it is called, is more than questionable. 



There can be httle doubt however, that a river, which runs more rapidly, and 

 discharges more water, than either the Ganges or the NUe, and which has this 

 peculiar quality of being, almost at all seasons of the year, in a flooded state, 

 must not only traverse a vast extent of country, but must also be supplied by 

 large branches flo^ving from different, and probably opposite directions ; so that 

 some one or more of them must, at all times of the year, pass through a tract 

 of country where the rains prevail. To ascertain the sources of these great 

 branches then, will be one of the principal objects of the present expedition : 

 but in the absence of more correct information, the instructions regarding the 

 conduct to be observed, can be grounded only on probable conjecture. 



The unusual phenomenon of the constant flooded state of the Zah-e, as men- 

 tioned by the old writers, and in part confirmed by more recent observations, 

 would seem to warrant the supposition, that one great branch, perhaps the 

 main trunk, descends from the tropical region to the northward of the Line ; 

 and if in your progress it should be found, that the general trending of its 

 course is from the north-east, it will strengthen the conjecture of that 

 branch and the Niger being one and the same river. 



It will be advisable therefore, as long as the main stream of the Zaire shall 

 lie found to flow from the north-east, or between that point and the north, 

 to give the preference to that stream ; and, to endeavour to follow it to its 

 source : at the same time, not to be drawn off by every large branch of the 

 river, that may fall into the main stream from the northward, but to adhere to 

 the main trunk, as long as it shall continue to flow from any point of the com- 

 pass, between the north and east. 



It is also probable that a very considerable branch of the Zaire will be found to 

 proceed from the east, or south-east ; as it has been ascertained, that all the 

 rivers of southern Africa, as far as this division of the continent has been tra • 

 A ersed from the Cape of Good Hope, northwards, flow from the elevated lands 

 on the eastern coast, across the continent, in a direction from west to north- 

 west: and it may perhaps be considered as a corroboration of the existence of 

 some easy water conveyance between the eastern and western coasts of south 

 Africa, that the language of Mosambique very nearly resembles the language 

 spoken on the banks of the Zaire. 



