XXVI 
APPENDIX. 
Mr. Park's bearings and distances, and then to correct the bearings by his 
observed latitudes, as far as these extend : and beyond that, I have taken 
his bearing by compass, and allowed the supposed quantity of variation. 
The result of these calculations, together with the addition of his line of 
distance from Sego to Tombuctoo, was then compared with the popular re- 
port of the distance between the several stations of Woolli, Fort St. Joseph, 
Bambouk, and Tombuctoo. It was found that these reports did not mate- 
rially differ from the aggregate distance given by Mr. Park; although they 
fell short of it ; a difference which might naturally have been expected, and 
-which I have ventured to alter. The difference, however, does not exceed 
twenty-four geographic miles ; a mere trifle in African geography. The 
position of Tombuctoo, so obtained, differs only half a degree in latitude, 
and still less in longitude, from that arising from the intersection of the lines 
of distance from Morocco on the NW, and Fezzan on the NE: of which 
a particular account will be given in the sequel. 
A great part of Mr. Park's geographical memorandums are totally lost: 
but fortunately his bearings by compass during a great part of the way, are 
preserved. In other parts, he has preserved only the calculation of latitude 
and longitude, arising from them ; which, however, of course furnish the 
means of obtaining the bearings, if necessary. As he omitted to take obser- 
vations to determine the quantity of the variation of the compass, after he 
-lost the means of correcting his course by observations of latitude, which 
•was at Jarra, about midway in his route:* it becomes a question of some 
importance, what quantity to allow on those long lines of distance between 
Jarra and Silla ; Silla and Manding. 
It appears on inquiry, that the quantity of variation is no more known, 
any where within the continent of Africa, than within that of New Holland. 
And it happens moreover, that the lines of equal quantities of variation, do 
not run across Africa with that degree of regularity and parallelism, which 
takes place over great part of the Atlantic and Indian oceans (at least this 
is what appears clearly to my judgment).- so that it became necessary to 
inquire, what quantity prevails in the surrounding seas; and what the general 
* The places of observation are marked on the Map by asterisks. 
