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Show ANNOTATIONS AND ADDITIONS. 89 the sacred Lake l\hnasa. and R.."tnnnhrada. (at an eleYation of 2345 toises, 1-!,995 Eogli h feet), in the vicinity of which the great river ri es, to Iskardo aud to the plateau of Deo-tsuh (at an elevation of 2032 toi e , 12,993 English feet), measured by Vigne, follows in the Thibetian highlands the same north-westerly direction as the Himalaya. Here is the summit of the Djawahir, long since well mea ured and known to be 4027 toises (25,750 English feet) in elevation, and the valley of Kashmeer, where, at an elevation of only 836 toises (5346 English feet), the Wulur Lake freezes every winter, and, from the perpetual calm, no wave ever curls its surface. Having thus described the four great mountain systems of Asia, which in their normal geognostic character are chains coinciding with parallels of lat.itude, I have next to speak of the series of elevations coinciding nearly with meridians (or, more precisely, having a SSE.NNW. direction), which, from Cape Comorin opposite to the Isbnd of Ceylon to the Icy Sea, alternate between the meridians of 66° and 77° E. long. from Greenwich. To this system, of which the alternations remind us of faults 1'n veins, belong to the Ghauts, the Soliman chain, the Paralasa, the Bolor, and the Ural. The interruptions of the series of elevations are so arranged that, beside their alternate position in respect to longitude, each new chain begins in a degree of latitude to which the preceding chain had not quite reached. The importance which the Greeks (although probably not before the second century) attached to these chains induced Agathademon and Ptolemy (tab. vii. and viii.) to represent to themselves the Bolar, under the name of Imaus, as an axis of elevation extending as far as 62° N. lat. into the low basin of the Lower Irtish and the Obi. (Asie Centrale, t. i. pp. 138, 154, and 198; t. ii. p. 367.) As the perpendicular elevation of mountain summits above the level of the sea (unimportant as in the eyes of the geologist the circumstances of the greater or less corrugation of the crust of the earth may be), is still, like all that is difficult of attainment, an object of popular curiosity, the following historical notice of the gradual progress of hypsometric knowledge may here find a suitable place. When I returned to Europe in 1804, after a four years' absence, not a single Asiatic snowy summit either in the Himalaya, the Rindu-Ooosh, or the Caucasus, had been measured with any exact- S* |