112 MODE OF SURVEVLXG. 



Fortunately I was never surprised with the map, 

 and no one ever knew that I was sketching my 

 route. ^ My surveying instrument was a Schmalkalder 

 compass, which is usually fixed on a tripod stand ; 

 but as this would have excited suspicion and inter- 

 fered with the success of the expedition, I deter- 

 mined to do without it, and steadied the compass 

 in my hands. If the needle continued in motion 

 for more time than I could conveniently spare, I read 

 off the mean degrees between the extreme points 

 of oscillation. In measuring distances I reckoned 

 by the number of hours of travel and our rate of 

 progress.^ The scale of my map was lo versts to 

 the inch. I carried a small field-book for notine all 

 conspicuous objects, as it is never safe to trust to 

 one's memory in such work, where accuracy is of the 

 highest importance. At the end of every day's 

 journey I transferred the field survey to my diary, 

 keeping the map on ruled sheets carefully stowed 

 away in one of the boxes. 



My plan was this : After taking bearings in the 

 direction we were going and noting the time by my 

 watch, I drew a line in my pocket-book correspond- 

 ing as nearly as possible with that of our march ; at 

 the end of it I entered the degrees and marked off 

 the intersections with figures in their regular order. 



' The scale of the map accompanying this translation is reduced 

 to one-eighth of the scale of the original sketch map. — M. 



^ A pack animal averages two and a-half to three miles per hour, 

 according to the nature of the ground. The rate of travel varies so 

 much in a mountainous country that one has often to measure dis- 

 tances by the eye. 



