stream so large that it may be truly called a river. Tradition (the tradition found in almost every eastern country) says that this is the outlet of the inclosed lake Kara Kul, lying 75 miles to the southeast, on the Pamir, at an elevation of 12,400 feet.
The chief interest of the Alai basin lies in its old moraines and terraces, which will be discussed in due season. Of the regions seen by the writer in the heart of Asia none is more interesting than the Alai Valley. Its magnificent scenery and splendid climate on the one hand are only less excellent of their kind than are the opportunities for studying the epochs of the glacial period, the moraines and terraces which bear witness to them, and all the phenomena pertaining to glaciation, past and present. Not far to the southwest the salt deposits of Altyn Mazar are of the first importance geologically and economically, and various natural sections present fine opportunities for the study of the rock series ; while to the southeast Peak Kaufmann rises 23,000 feet, with Lake Kara Kul on the Pamir beyond it. Moreover, the Alai Valley is inhabited by a peaceable and most interesting folk, the nomadic Kirghiz, with whom it is well worth while to become acquainted. Besides all this, the valley is relatively accessible, as it is only three days' journey from the railroad at Marghilan ; and, lastly, it is practically virgin ground.
THE FERGANA BASIN.
In outward appearance the last of the four provinces differs widely from its companion, the Kashgar basin ; but the difference is only superficial, resulting from its moister climate. The Fergana basin seems green and prosperous ; its many streams are utilized by an irrigation system which sustains populous villages and cities. The Kashgar basin is chiefly a dreary desert. Yet in structure the two basins are so nearly identical that detailed description of the second would involve repetition of much that has been said about the first. The Fergana basin is an aggraded depression, due to local down-warping and burial of the Tertiary pene-plain. The mountains inclosing the basin are uplifted and more or less dissected portions of the sanie peneplain. As in the Kashgar basin, the warping by which the Fergana basin was formed seems to be a late phase of long-continued movements, during which the mountain area has encroached upon the basin area ; for the gradually rising mountains around the basin consist of granite and limestone in their higher parts and of weaker Mesozoic and Tertiary strata around the margin next
to the basin, all these having been folded and worn down to moderate relief before the present basin was formed. It is therefore quite possible that the down-warped floor, on which the Quaternary deposits of the Fergana basin lie, was not everywhere a peneplain of Tertiary erosion ; its central part may well have been an aggraded plain of Tertiary deposition.
The periphery of the Fergana basin is sheeted with gravel which grows gradually finer until it merges into the fine alluvium of the central plain ; the area of fine alluvium is much smaller than that of Kashgar and has no playas. Many streams cross the plain, with broad flood-plains of gravel between low terraces, while here and there rise hills more or less carved in masses of interstratified silt and gravel thrust up as folds in recent geological time.