18 Dr. Govan on the Natural History and Physical 



send out at different angles, give an appearance of parallelism 

 to the whole. 



The plains of Hindostan, at their northern extremity, 

 where they adjoin this part of the hilly tract, have an eleva- 

 tion, prohably of from about 800 to 1000 feet above the level 

 of the sea. Saharanpore is stated as 1013 feet, by Captain 

 Herbert, from an observation of the mean elevation of the 

 barometer during August, compared with the mean of the 

 same month in Calcutta. 



The data upon which the elevations of different points in 

 the Himalayan have been calculated, both barometrically and 

 trio-onometrically, are now before the public. From 15,000 

 to 1(5,000 feet above the level of the sea have been assigned 

 to the crests of the passes in the branch of the chain to the 

 southward of the Sutluj bed, (that which I have chiefly visit- 

 ed,) and which have been crossed by several different ob- 

 servers. From 3000 to 4000 feet more to the inaccessible 

 summits on either side. Upwards of 25,749 feet has been 

 stated by two eminent mathematicians, Captains Hodgson and 

 Herbert, as the elevation, trigonometric-ally ascertained, of 

 one of the Jowahir peaks. 



Lastly, two observers (Messrs. Gerards) of unquestioned 

 zeal, industry, and intelligence, in that part of the chain to 

 the northward of the Sutluj, have actually reached, with ba- 

 rometers in an efficient state, an elevation where the mercury 

 sunk to 15° 180, 15° 220 at mid-day, and 14° 675. T. 21°. 

 Thermometer standing at 23° and 24°. If the Sutluj bed, 

 not far from its reputed source in the lake Rawun Rhudd, 

 is nearly 15,000 feet, for which we have Captain Webbe's 

 calculation, the high level connecting this part of the Hima- 

 layah with the plains of Tartary, and separating the waters 

 of the Indus, the Ganges, the Sutluj, and the Burumpooter, 

 situated on such a base, may yet lead to loftier summits in 

 the interior. 



Perhaps it is yet necessary that some plan should be sug- 

 gested by which all the accuracy of which they are suscepti- 

 ble may be given to barometrical approximations under such 

 circumstances. 



Calculations have usually been founded either upon com- 

 parison with the medium height of the barometer in Calcut- 

 ta, or at the level of the sea (perhaps 1200 miles off) 



