astronomical determinations accessible to me, and on a vast amount of orographic description, in which Chinese literature is beyond measure rich, examined at my request by Klaproth and Stanislas Julien. My map marks the _mean_ direction and the height of the mountain chains, and represents the leading features of the interior of the continent of Asia, from 30° to 60° degrees of north latitude, and between the meridians of Kherson and Pekin. It differs materially from any previously published map. The Chinese have enjoyed a threefold advantage towards the collection of so great an amount of orographic data in the highlands of Asia, and more especially in the regions (hitherto so little known in the west), north and south of the Celestial mountains, between the In-schan, the mountain lake Khuku-noor, and the banks of the Ili and the Tarim. The three advantages I allude to are,--the military expeditions towards the west, (under the dynasties of Han and Thang 122 years before our era, and again in the ninth century when conquerors advanced as far as Ferghana and to the borders of the Caspian), together with the more peaceful conquests of Buddhistic pilgrims;--the religious interest attaching to certain lofty mountain summits on account of sacrifices to be periodically offered there;--and the early and general use of the compass in giving the directions of mountains and of rivers. The knowledge and use of the “South pointing” of the magnetic needle twelve centuries before our era, has given to the orographic and hydrographic descriptions of countries by the Chinese, a great superiority over the descriptions of the same kind which Greek or Roman writers have bequeathed to us, and which are besides extremely few. The acute and sagacious Strabo, was alike imperfectly acquainted with the direction of the Pyrenees, and with those of the Alps and of the Apennines. (Compare Strabo, lib. ii. p. 71 and 128; lib. iii, p. 137; lib. iv. p. 199 and 202; lib. v. p. 211, Casaub.)