408 COURSE AND LEVELS 



The stations fixed from these are : 



(a) Duclu. 

 (J)) Gunass Pass. 

 (c) Childing Kona Pass.' 

 («/) Hangarang Pass. 

 (e) Tashigang. 



(a) At Dudo, the Magnetic bearing of Kedar Kanta was observed 

 150° 00'. The angle of elevation 3° 15' 45". The declination 3° easterly. 

 These data with the difference of latitude 597'', 4 give the longitude of Du- 

 du 78° 3' 39"; the elevation 8732 feet above the sea, 



(b) Gunass Pass. The three snowy peaks Ilaldang, the Needle, and L. 

 were observed here. The angle subtended by the first two was 44° 51' 30" 

 by the second two 13° 54' 30". These data afford excellent means of fix- 

 ing the Pass by using the elegant formula of Delambre. It would how- 

 ever in this case be necessary to calculate the respective distances of the 

 three peaks, on Avhich account, as well as the favorable situation of all three 

 points, I have chosen a less direct method by using the bearings and as- 

 suming a latitude for the pass. The place of Magnetic East and West on 

 the Limb was always observed with great care on these occasions, a magni- 

 fier being used to observe the coincidences of the Needle (which was fre- 

 quently made to oscillate) with the line of 90° in the compass box. In 

 every case the slow motion screw was used for making the coincidence 

 perfect ; and as the same precautions were taken in observing the decli- 

 nation of the Needle, it is evident that the Magnetic bearings for ncai ob- 

 jects were nearly as good as Azimuths. The true bearings then of these 

 three peaks observed as 1 have described were 53° 53' 98^; 44 30 and 112 

 39. The latitude of the pass is assumed to be 31° 21' 04". With these 

 data and the position of Raldang the longitude is found to be 78° 8' 27', 

 and with this longitude and the position of the Needle the latitude ap- 

 pears to be 31° 21' 03". With the same longitude and the position of L. we 



shall find the latitude 31° 21' 05". The elevations will be found 



