246 THE POPULAR SCIENCE MONTHLY. 



ger of departing from the highway when in one of these deep cuts ; 

 after scrambling for miles along the broken loess above the road, he 

 only regained it when a further passage was cut off by a precipice on 

 the one side, while a jump of some thirty feet into the beaten track 

 was his only alternative upon the other. 



Difficult as may be such a territory for roads and the purposes of 

 trade, its advantages to a farmer are manifold. Wherever this deposit 

 extends, there the husbandman has an assured harvest two and even 

 three times in a year. It is easily worked, exceedingly fertile, and 

 submits to constant tillage, with no other manure than a sprinkling of 

 its own loam dug from the nearest bank. But loess performs still anoth- 

 er service to its inhabitants. Caves made at the bases of its straight 

 clefts afford homes to millions of people in the northern provinces. 

 Choosing an escarpment where the consistency of the earth is great- 

 est, the natives cut for themselves rooms and houses, whose partition- 

 walls, cement^ beds, and furniture are made in toto from the same loess. 

 Whole villages cluster together in a series of adjoining or superim- 

 posed chambers, some of which pierce the soil to a depth of often 

 more than two hundred feet. In costlier dwellings the terrace or suc- 

 cession of terraces thus perforated are faced with brick, as well as the 

 arching of rooms within. The advantages of such habitations consist 

 as well in imperviousness to changes of temperature without as in 

 their durability when constructed in properly selected places — many 

 loess dwellings outlasting six or seven generations. The capabilities 

 of defense in a country such as this, where an invading army must 

 inevitably become lost in the tangle of interlacing ways, and where 

 the defenders may always remain concealed, are very suggestive. 



There remains, lastly, a peculiar property of loess which is perhaps 

 more important than all other features when measured by its man- 

 serving efficiency. This is the manner in which it brings forth crops 

 without the aid of manure. From a period more than two thousand 

 years before Christ, to the present day, the province of Shansi has 

 borne the name of "Granary of the Empire," while its fertile soil, 

 hwang-tu^ or " yellow earth," is the origin of the imperial color. Spite 

 of this productiveness, which, in the fourteenth century, caused Friar 

 Odoric to admiringly call it "the second country in the world," its 

 present capacity for raising crops seems to be as great as ever. In 

 the nature of this substance lies the reason for this apparently inex- 

 haustible fecundity. Its remarkably porous structure must, indeed, 

 cause it to absorb the gases necessary to plant-life to a much greater 

 degree than other soils, but the stable production of those mineral 

 substances needful to the yearly succession of crops is in the ground 

 itself. The salts contained more or less in solution at the water-level 

 of the region are freed by the capillary action of the loess when rain- 

 water sinks through the spongy mass from above. Surface moisture, 

 following the downward direction of the tiny loess-tubes, establishes a 



