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24 amidst the rugged wilds of Tartary, before quitting the broken lands and settling down into a peaceable and navigable stream. An American, writing of this river, says — "Down through the alternating table-lands and gorges of this tract it pours floods which are charged with a peculiar brownish-yellow loam, called by Mr. Pumpelly terrace deposit, and by Baron Eichthofen loess. In its original state it is of such constitution that, when a stream of water cuts down into it, vertical banks are left. Throughout the districts where it is found the inhabitants make houses in the cliffs, whole villages being constructed in this way completely out of sight of the traveller upon the plains above. When a river washes the foot of a wall of loess, the earth softens at the water's edge, and after a time a cleanly-cut section of the superincumbent mass drops into the flood, to be carried along until first the sandy and then the finer particles are deposited upon the plains below. A more slowly moving stream would be less charged with the loess, and would deposit it more rapidly. But the Yellow River can only carry the mass to the level country, and then struggle with the shallows and banks which it forms. The result is that the river is almost useless for navigation, and its floods, which are numerous, become peculiarly dangerous to the lower country. At low water there is about four feet of water on the bar at the mouth of the river, and there is no part of its course where steam vessels, excepting those of very light draught and small burthen, could be used."