48 On the Sehlagintweits'' [No. 1, 



But the Sehlagintweits express their doubts as to the correctness of 

 the determination of time at Le on the 11th July, and, therefore, do 

 not take it into account. Nevertheless, an error of no less than 10' 

 must, in all probability, be suspected in the longitude of the Karako- 

 ram pass as well as in the longitude of Le. It remains, consequently, 

 open to doubt, which longitude is to be accepted, that given by the 

 Sehlagintweits, or that previously adopted by Humboldt, which 

 Thompson, who visited this pass in 1848, found to be quite accurate. 

 Up to this point, the corrections are less than J°, and applied to the 

 map attached to the description of their journey, they excite curiosi- 

 ty, but not surprise ; but the upper portion of the map representing 

 Central Asia puzzles every one, by its marked difference to every 

 thing that has hitherto been known of these countries. It is sufficient 

 to say that the position of the three bases of the cartography of this 

 part of Asia, namely the towns of Khotan, Yarkand and Kashgar, 

 disagrees with those hitherto generally accepted, by nearly 180 versts, 

 for all the three points nearly equally lie 10' in latitude, and 130' in 

 longitude, more southward and westward, according to the dictum of 

 the Sehlagintweits. 



At the same time, the determinations of little Bokhara, which 

 belong to the Jesuits, cannot call forth strong doubts ; on the contrary, 

 there is strong reason for believing, that if these determinations are 

 not altogether correct, they are but very slightly incorrect. In Djun- 

 garia, there are several points determined by the Jesuits, and some sub- 

 sequently by me in 1859. From a comparison of these determina- 

 tions, it becomes evident that the latitudes given by the Jesuits are 

 correct to a minute. But the astronomical observations in Djungaria 

 were, in all probability, not made by the Jesuits themselves, but by 

 Chinese whom they had instructed. It must therefore be supposed, 

 that the points in little Bokhara, where the Jesuit fathers worked 

 themselves, are equally correct. As regards the longitudes, it is well 

 known that the existing itineraries coincide perfectly well with the 

 determinations of the Jesuits, though it must be acknowledged that 

 the marche-routes having almost a meridional direction, cannot point 

 out any appreciable error in the longitudes. Generally speaking, the 

 better acquainted we become with Chinese Turkestan, the more con- 

 vinced we are of the accuracy of the determinations of the Jesuits. 



