1856.] Beport on the Magnetic Survey. 3 



Ertel's universal instrument and a theodolite by Troughton and 

 Simms. 



The detail of these measurements has been combined with draw- 

 ings, in which a given angular value was made equal to a unit of 

 linear measure ; in the coloured drawings of Tonglo and Phulloot 

 one millemeter is equal to five minutes, and though by this scale 

 the full panorama of 360° extended to a length of 4.2 meters, it 

 allowed me, at the same time, to enter with full detail into the 

 topographical structure of the district.* 



I intended to proceed from Phulloot along the ridge, forming from 

 that place the boundary between Nepal and the Rajah of Sikkim's 

 territories, over the summits as far as possible to the central groups, 

 but we had been observed by the Nepalese (our fires during the 

 night being seen) and there came up first a few Nepalese sepoys, and 

 then a native officer with twenty sepoys, sent by Karak Bahadoor, 

 whose corps was stationed near the Wallanchoon Pass, on the frontier 

 of Thibet and Nepal. They at first seemed not disinclined to allow 

 at least a limited progress, but soon after leaving Phulloot we were 

 surprised by a man, who had evidently waited some days for our 

 passing, who brought fresh orders for the sepoys, who had come 

 up and were now accompanying us, absolutely forbidding them to 

 allow us to go on. 



After repeated negotiations, we succeeded in getting a few miles 

 further, to the Chungtaboo mountain, where we were obliged to 

 return, all supplies being denied us, and some of our coolies, who 

 were Nepalese, being threatened that they would be made prisoners, 



I returned to Darjiling after an absence of seven weeks and 

 continued my stay in British Sikkim till the 15th August, occupied 

 with another series of magnetic observations and in completing 

 the materials for a map of equi-distant horizontal contour lines for 

 British Sikkim. 



* The drawings of the same range of mountains having been made from different 

 points of known position, they form pictures complimentary to each other, like 

 stereoscopic pictures, allowing me to lay down roughly in a map many more points, 

 if required, than could be fixed by triangulation. 



The number of drawings in Sikkim now deposited in the Surveyor General's 

 Office is 100 to 120. 

 B 2 



