GENERAL OBSERVATIONS. 343 
near the mouth of the river, the height of seven feet; with- 
out the velocity having much, if at all encreased ; and 
without a single shower having fallen that deserves to be 
noticed. ‘The little difference between the rise of seven 
feet, which then, took place in the dry season, while the 
sun was still to the northward of the line, and that of eleven 
feet in the wet season, during which the sun is twice verti- 
cal, affords a solid argument for its northern origin; and, 
when coupled with the particular moment at which it was 
first observed to rise, would seem to establish the fact, 
almost beyond a doubt, that one branch of the river, as 
was stated by the natives, must descend from some part 
of Africa to the northward of the Equator. 
We find in Captain Tuckey’s notes, after having ob- 
served the progressive rise of the river, the insertion of two 
words as a memorandum, ‘* hypothesis confirmed.” This 
hypothesis had previously been stated among the last notes 
of his Journal, which he did not live to reduce into a regu- 
lar narrative, under these words; ‘ extraordinary quiet 
rise of the river shows it to issue from some lake, which 
had received almost the whole of its water from the north 
of the line.” But in a private letter written from Yellala, 
and brought home in the Congo, he dwells more particular- 
ly on this hypothesis ; ** combining” he says ‘* my observa- 
tions with the information I have been able to collect from 
the natives, vague and trifling as it is, 1 cannot help think- 
ing that the Zaire will be found to issue from some large 
lake, or chain of lakes, considerably to the northward of 
the line ;’ and he contends that, so far from the low state 
