THE VALUE OF THE CHINESE OROGRAPHY. 33
What, then, have we learnt from the Chinese materials regarding the country north of the Tsangpo ? Looking at the results of the survey in Tibet during Kang Hi's and Chien Lung's time, as represented on d'Anville's and de Rhins' maps, we might be sure that the country is very rich in lakes and rivers situated between mountain ridges and ranges. But what is the value of this material ? During a long period it was accepted on European maps. But then the whole lot was suddenly abolished and the country north of the Tsangpo, except those peripheral parts which had been seen by Nain Sing, Littledale and the Tibet Frontier Commission, was left blank. When this new peripheral exploration had been in contact with the Chinese survey, the latter was found to be altogether too unreliable for use. And every bit of the Chinese survey disappeared, which, as Dutreuil de Rhins has proved, was the only right thing to do. Only two or three deplorable losses were made in this great general cleansing, namely, the sources of the two great rivers and the Tarok-tso. The sources of the Satlej and the Brahmaputra had therefore to be rediscovered. Nganglaring-tso and Teri-nam-tso were heard of by the Pundits, but as they were not entered on the Chinese maps, there was no ground for accepting the Tarok-tso either. Teri-nam-tso and Nganglaring-tso were visited for the first time in 1908, and if I had not, on the same journey, found the Tarok-tso as well, the fate of that lake would probably have been unsettled for a long time to come.
Regarding the Transhimalaya the Chinese maps have certainly considerably augmented our knowledge. But these maps as well as the Chinese texts only tells us clearly that mountains exist north of the Tsangpo. We could, however, be certain of their existence even without the Chinese affirmation. Already Desideri and della Penna had mentioned mountains to the north, although only on the extreme western and eastern wings of our region. The Chinese reports are more complete, but leave us in uncertainty regarding the situation and general arrangement. Of course mountains must exist in the north, as the northern tributaries of the Tsangpo were described as considerable rivers. If nothing else was known of the interior of Tibet one could, even two hundred years ago, be fairly sure that the country was very rich in mountains. And in the middle of the last century it would have been just as absurd to suggest a plain, a sand desert or a forest land north of the Tsangpo, as to suggest the existence of inland ice over the Congo basin. From the time of the first Chinese surveys some 190 years should pass before the first fundamental order was introduced into a great part of this labyrinth of mountains.
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IIIFカラー高解像度
