260 Instructions for 



for the time and resources to be employed in our present un- 

 dertaking It will, therefore, be advisable that the expedition 

 consider Klaar Water (GriquaTown), or Lattakoo, as the start- 

 ing point or base of their operations, and that its first effort 

 be the examination of the district from which issue the northern 

 branches of the Gariep and the streams which fall down to the 

 Indian Ocean, that then the dividing ridge be traced towards 

 the North, leaving it to the discretion of the Director to de- 

 termine at what parallel he should change his course, to the 

 North or Wcbt. Our present information leads us to esteem 

 it advisable that the Eastern side of the slope be examined 

 first, in order that if the great desert of Challahenga should 

 extend far to the eastward, so as to bar the progress of the 

 expedition towards the centre of the Continent, there may 

 remain the unexplored territory along the Western slope to 

 occupy its attention in returning. Much of the ultimate im- 

 portance and interest, as well as the security of guidance and 

 prospect of safe return of the Expedition, will of course de- 

 pend on obtaining an exact knov.dedge and preserving a faith- 

 ful record of its route, which can only be done by the aid of 

 Astronomical observations made with due regularity and pre- 

 caution, not only at strch stations as form the most interesting 

 features at tlie moment, in the eyes of those concerned, but at 

 every station where the Expedition may rest long enough to 

 permit observations to be taken deliberately, and with due 

 regard to safety both of the observer and instruments. The 

 track of a caravan on land, as of a ship at sea, is defined as 

 well by the less as the more remarkable points through which 

 it passes, and it may very easily happen that stations of the 

 highest interest in a commercial, political, or physical point of 

 view, may, by reason of that very interest, be inappropriate 

 for selection as principal observing stations, either from the 

 attention of every individual being distracted to duties of im- 

 mediate necessity or from the risk attending the exhibition of in- 

 struments in the unavoidable presence of a rude, curious, and 

 suspicious population. In all such cases it v.ill be proper to 

 connect by observations of a less elaborate nature, those 

 stations with others not far distant, which, although less in- 

 trinsically important, may be easier of exact determination. The 

 Committee would therefore recommend, that stations of obser- 

 vation be classed as either primaiy or secovdary ; those to be 

 considered primary stations whenever the circumstances may 

 ;appear particularly favourable, by reason of leisure from other 

 occupations, expected duration of halt, and freedom from an- 

 noyance, to afford a good determination of the longitude and 

 latitude, such as may serve to render them useful for Zero 

 points, to which the secondary stations may be referred, either 

 by dead reckoning of time and distance or by such less clabo- 



