S14 
REMARKS ON TRAVELS 
BEARINGS OF M. CAILLIE'S ROUTES. 
The reduction of the true north of our traveller's 
lines of route was one of the most important points ; and 
to arrive at their actual bearing, I was assisted by a single 
new datum only ; namely, the observation of the angle of 
the meridian shadow with the magnetic north. The 
travels furnish two of these observations : the one, of the 
30th of October 1827, gave the N. N. E. ; the other of 
the 1st of November, the N. J N. E., that is to say, 
the compass had on these days a declination of 22° 30' 
and 11° 15' to the east. I was then obliged to have re- 
course to other researches to determine between these two 
measures, and to avail myself of several observations 
taken by Mungo Park and other travellers. 
The following are the names of the places and obser- 
vations ; I omit their geographical situations : 
At Badoo, Mungo Park.* 14° 6' E. declin. 
On the Baling, idem 16 30 
On the Dhioliba, icZem. ........ , 16 36 
At Yamina, idem .. 17 11 
At Sansanding, idem 17 40 
At Bathurst, Captain Owen.f 17 06 
* The Journal of a Mission to the Interior of Africa, &c. p. 164. 
t A Chart of the River Gambia, &c. 
