G Report on the 'Magnetic Survey. [No. 1. 



3. At Phulloot [11,900 ft.] besides the determination of the de- 

 clination, absolute intensity (by vibration and deflection), and dip, 

 the daily variations of these elements were observed during a succes- 

 sion of five days. 



4. For estimating the influence of height on the intensity of 

 magnetism more directly, the passage of the little Eungeet, which 

 lies between Phulloot and Darjiling, and which we reached a few 

 days after leaving Phulloot, was particularly favourable, and careful 

 observations of the deflection were made. 



6. In order to compare the Himalayan station with the plains, a 

 set of observations was made at Beriadangee, near Kissengunj on 

 the shore of the Mahanuddy, and only sixty-six miles distant from 

 the foot of the mountains in a direct line. 



7* Eampore Bauleah — dip and vibration ; the cloudy state of the 

 weather by day and night prevented the determination of the 

 declination.* 



8. Cherrapunji complete observations. 



9. Gowhatty * * 



In the following, I give an abridged account of some results of 

 these observations : 



The calculations of the absolute value of these elements depend 

 as well upon the change in the magnetism of the magnets employed, 

 as upon the regular changes of terrestial magnetism, corresponding 

 to the time of observation. 



The latter element must be deduced hereafter from the observatories 

 of Madras and Bombay ; in reference to the magnets, all care has 

 been taken to prevent irregular changes of magnetism, by a most 

 careful transport, and by keeping a pair in one box (in opposite 

 corners) the poles being in opposite directions. 



The declination in Sikkim varied between 3° 9 ; and 3° 15' for the 

 different places of observation. 



At Cherrapunji the declination was West, 2° 10', a very unex- 

 pected result, probably connected with the amount of magnetic iron 

 in the central parts of the Khosia hills, the sandstones of the plateau 



* I was assisted here by Mr. Herschel, Mr. Adams being laid up with remitting 

 fever. 



