HIMALAYAS ON THE PLUMB-LINE IN INDIA. 
73 
since, as observed in art. 30, ranges of mountains have not so important an influence, 
when distant, as table-lands of elevation. 
33. Before describing the country within these limits, I will give a general sketch 
of the parts which lie outside, from which it will appear that we may confine our 
calculations to this Enclosed Space. As the elevation of the Station A. is about 1000 
feet above the level of the sea, we shall take at this height the surface of reference 
parallel to the sea-level from which all altitudes are to be measured in our calcula- 
tions. The stations Kalianpur and Damargida are higher than Kaliana. In making 
the Kaliana-level our basis, while we consider A to be the station Kaliana itself, B 
and C must be considered to be points vertically below Kalianpur and Damargida 
and situated on the Kaliana-level. So that our calculation of the attraction at the 
middle and south end of the arc will strictly speaking apply to these points. The 
difference, however, of the attraction at these points and the stations under which 
they lie will be utterly inappreciable, unless the country around B and C, which we 
have left out of the account as having no sufficient elevation, produce a sensible 
effect*. 
34, Humboldt says in his ‘Aspects of Nature,’ that to the lowlands belong almost 
the whole of Northern Asia to the north-west of the volcanic range of the Thian- 
Schan, the steppes to the north of the Altai and of the Sayan range, the countries 
which extend from the mountains of Bolor or Bulyt-Tagh, from the upper Oxus to 
the Caspian, and from Tenghir or the Balkhash Lake through the Kirghis steppe, 
towards the sea of Aral and southern extremity of the Ural Mountains, “As com- 
pared,” he adds, “with high plains of 6000 and 10,000 feet above the level of the sea, 
it may well be permitted to use the expression lowlands for flats of little more than 
200 to 1200 feet of elevation.” Again, “the plains through which the upper Irtish 
flows [rising near K in fig. 4 and running north towards the north sea] are scarcely 
raisecl 850, or at most 1170 feet above the level of the sea.” The mountains about 
the river Aldan on the north-east and the Ural Mountains to the north-north- west — 
the former not averaging more than 2000 feet in height, and the latter 4000 — can 
have no influence owing to their great distance, as well as small elevation. In short, 
the whole country to the north, north-west, and north-east of the Enclosed Space is 
of so inconsiderable a height above the sea, that it may be left out of our reckonings. 
The same may be said of all to the west. Thus Sir Alexander Burnes assigns to 
Bokhara an elevation of only 1190 feet. The level of the Caspian is 83 feet below 
the Black Sea, and is the centre of an extensive depression — the Caucasus excepted. 
The Hindoo Koosh runs off at N, a short distance to the west, but soon descends 
into the generally-plain country, and at Herat is only 2558 feet high. The only 
* The actual heights above the sea are thus given in Colonel Everest’s work : — 
Height of Kaliana above the sea 942‘3 feet. 
Height of Kalianpur above the sea 1878"2 feet. 
Height of Damargida above the sea Q090'5 feet. 
