IN CENTRAL AFRICA. ^71 
difference of the orthography or the negligence of the 
transcriptions. Is not Couronia altered from Couronca 
Couranco) and Sangala, by the frequent mutation of 
the T into from Sangara ? The Wasselon, or Wassoulo^, 
should be placed much nearer to the ocean, the incontest- 
able consequence of M. Caillie's march ; and already this 
example affords a presentiment of the fact as relates to the 
course of the Dhioliba and all the districts which it tra- 
verses. This river having also been supposed too much 
to the east by three or four degrees, the result has been 
the necessity of lengthening all the distances in order to 
cover the space between it and Timbo, and the construc- 
tors of maps have scattered over this space the names of 
countries and places, made all the positions too remote from 
each other, and transformed hamlets into towns and towns 
into kingdoms. They have not sufficiently remarked the 
custom common to almost all travellers of lengthening 
distances by an exaggerated estimate, and have neglected 
to make allowance for the frequent curves and inflexions 
of the line of route : a double cause for throwing into the 
interior many countries much nearer to the sea than they 
are believed to be. 
This want of exactness in the compiling of itineraries, 
or in laying down those itineraries upon maps, is no novelty 
in geography ; the Ancients have furnished many exam- 
ples of it, and the maps designed after the positions of 
Ptolemy are nearly all tainted with this defect \ I shall 
mention Arabia alone as an example. But I must here 
