58 EXPLORATIONS IN TURKESTAN.
The dune-covered area was abruptly cut off as we entered the irrigated fields of Charjui on the plain bordering the Amu on the south. The fields of the gently sloping plain are delicately graded to level surfaces, each fed by a little canal and bordered by a little dike next to its lower neighbor. The canals are divided and subdivided, like nerve endings, the smallest ones being hardly noticeable. Many of them are bordered with trees. The houses and the walls of inclosed gardens are of gray, sun-dried mud. There are no fences between the fields ; hence horses and cattle are tended or tethered while pasturing. Grain, lucern, and cotton were the principal crops noted. The change from the desolate sands to this thriving oasis was a beautiful example of the beneficent work of irrigation in the desert.
It was suggested by Professor Penck, during our conference with him at Vienna on the outward journey, that special attention should be given to deposits of loess, in order to determine in how far they are now in process of accumulation, or in how far they should be referred to some period of past time. This problem was made the more interesting by seeing at Krems, on the Danube, above Vienna, a well-defined deposit of loess from which some i 5,000 artifacts have been gathered by the patient work of Dr. Strobl. Some specimens of rudely chipped flints were kindly given to us to serve as samples of things to be searched for in the loess of Turkestan. Our hurried movements made it impossible to undertake any such search, or indeed to make any close examination of loess-covered areas ; but we passed certain loess deposits regarding which our observations, even though made only from train windows or from post-wagon, seem worth placing on record.
LOESS NEAR SAMARKAND,
On approaching Samarkand, June 15, the railroad crosses an extensive deposit of loess, at once seen to be unlike the gravelly piedmont slopes near Bokhara, and equally unlike the sea of sand-dunes on the plain south of the Ainu, but not easily distinguishable in a passing view from the fine silts of the Murg-ab and the Tejen plains, except that the surface of the deposit here was not level, but broadly undulating and sub-maturely dissected. A 3o-foot cut, where the railroad made its way between opposite valley heads, was unfortunately passed in the twilight. At Samarkand a deep valley is cut in loess, well seen a short distance east of the railroad station. A few miles farther on, near the ridge across the Zerafshan, the hill slopes are cloaked with loess, on which a thin cover of angular waste has crept down. All these deposits, therefore, seem to be and to have long been in process of dissection rather than of accumulation. It occurred to acne that even if other conditions were now favorable for the accumulation of loess in this district, the irrigation and cultivation of the Zerafshan flood plain is distinctly unfavorable to its accumulation; for the cultivation of crops and, perhaps even to a greater extent, the growth of trees, lifts the wind from the ground, and thus greatly diminishes the amount of fine silt that can be carried from the flood plain and deposited elsewhere. In the absence of cultivation the flood plain