APPENDIX. 
xxxix 
detour may be taken at eight days more than the direct road (for Mr. Park 
furnishes the positions of Tisheet and Aroan veiy satisfactorily), whence 40 
remain, which at 16,3, produce 652 miles. 
Lasdy, although the following be a very vague kind of computation, it 
may not altogether be useless. Major Houghton's guide undertook to carry 
him to Tombuctoo, from Ferbanna in Bambouk, and to return again in 
ninety days. Ferbanna is much about the same distance, as St. Joseph, from 
Tombuctoo. Perhaps no more than ten days can well be allowed for rest 
and refreshment, and then forty days will be the length of the journey. 
The mean of the three first reports, is about 649 : and on the Map, the 
space between St. Joseph and Tombuctoo, according to Mr. Park's result, 
is 667, or 1 8 more. 
There is then, a difference of 31 only, on the accounts between Woolli 
and Sego : 1 8, between St. Joseph and Tombuctoo ; both pointing to an ex- 
cess, on the part of our traveller. I am however far from offering these 
results, on the ground of inducing a belief that such small differences can be 
ascertained by such coarse materials; but rather to shew that in the general 
scope of the authorities, there was more of coincidence, than of disagreement, 
if the circumstances are rightly appreciated. 
As it appears, however, that Mr. Park and Major Houghton formed dif- 
ferent estimates of the distance between Medina and the river Faleme ; and 
that the former exceeds by about 36 miles; and moreover, that on Mr. Park's 
return by the southern route, he found by the number and scale of his jour- 
nies, that he had allowed too great an extent to the space between the rivers 
Faleme and Gambia ; I say, it clearly appears that an excess may be admitted 
in this part. It may be added, that, according to the report of the African 
travellers, at Pisania, concerning the arrangement of the journies, there is an 
excess on the west of Kasson ; whilst the space on the east of it, agrees pretty 
well. Or, strictly speaking, perhaps the space is a little tnider-rated on the 
east, and much owr-rated on the west. If the mean of the differences between 
Pisania and Tombuctoo, Fort St. Joseph and Tombuctoo, 31, and 18, that 
is, 24 miles be taken off, the result will be satisfactory ; as it agrees pretty 
well with the.excess found in the southern route, on Mr. Park's return. 
