国立情報学研究所 - ディジタル・シルクロード・プロジェクト
『東洋文庫所蔵』貴重書デジタルアーカイブ

COLEBROOKE, WEBB AND RAPER ON THE SOURCE OF THE GANGES

hibited in d'Anville's map, and in the still ruder copy of the Lama's original delineation, published by SOUCIET (Vol. I, Pl. LIII), as intervening between their last station and the lake.

As I have shown before, such a view as o ebrooke s cannot be correct. But all he finds deducible as authentic information, is »that the lamas reached the

chain of mountains which forms the south-western boundary of Tibet; and halting at

the foot of the range, learned, from the inquiries which they there made, that the Ganges takes its rise in the opposite side of that chain of mountains. But the whole

of their sketch of the river's course, from the 36th degree of longitude (from Peking) where their route terminates, to the 43d, in which they make the two furthest branches of the Ganges turn due south after a westerly course, and thence return by an easterly course to the same longitude, with little difference of latitude, must be deemed vague and imaginary, being at best founded on oral information, and very imperfect notices, hastily collected in a season of danger and perturbation.»

Colebrooke regards Tieffenthaler's results and maps as not undeserving of attention. But he points out that Tieffenthaler had not surveyed in person the course of the Sarayu, although the Father made i t rise from the Manasarovar, nor had he seen the Ganges above Dévaprayåga, although he delineates its course to the Gangotri. Major Rennell believed that Tieffenthaler had himself taken the latitude 33° for Gangotri and accepted it on his map, where he tried to adjust to that position the supposed course of the Ganges as it carne out from the lake Mapama of the Lamas, »imagined to be the same with the Manasaråvara», and down to the cataract described by Tieffenthaler at Gangotri. Colebrooke finds it strange that Rennell could suppose that Tieffenthaler had visited Gangotri in person, as Anquetil du Perron positively says he did not. In the second edition of his Memoir, 1792, Rennell had detected the error in Tieffenthaler's report, and therefore distrusted the rest of his information. Rennell now concluded that Alaknanda was the chief branch of the Ganges, and had its source in the snowy mountains of Tibet. And as to the source of this river he regards Kang Hi's Lamas as the most reliable authority in existence. Their report is defective in geometrical exactness but in plain matter of fact it is trustworthy. And they had reported that the river issued from the lake Mapama and went westward. He thinks Tieffenthaler's messenger unintentionally corroborated this report.

In conformity with this notion, Colebrooke points out that most maps which had afterwards been published, as for instance ARROWSMITH's map of Asia in 18oî, and of India in 1804, represented the Ganges within the chain of snowy mountains flowing for hundreds of miles from lake Mapama to Gangotri. And both Colonel Colebrooke and H. T. Colebrooke suspected that this notion, founded on the Lamas' exploration, rested on very slender and unreliable information. They found it extraordinary that Desideri and Freyre, who stayed nearly two months in Ladak, should not even mention such a remarkable circumstance as the Ganges flowing past the