82 
HINTS TO TRAVELLERS. 
only corrects liis distance travelled, and his latitude, but also corrects 
his estimated position in longitude. When travelling nearly east or 
west these remarks would not apply, as the angle between his line of 
march and the parallel of latitude would be too acute, and his position 
could only be corrected by such observations for latitude and longitude 
as are given in the portion of this book devoted to those subjects. 
The bearings given in the journal have been laid down on the 
annexed map, corrected for 20° easterly variation, and will serve to 
illustrate the manner in which this portion of the work is done. 
