great part of the country was covered with waste tracts of sand. If the winds blew from the Caspian Sea, they swept the sand into high hills, under which not only did every trace of the road disappear, but travellers were at times overwhelmed; and, as if voyaging by sea, it was necessary to guide the course by the stars.[13] Strabo remarks, after Apollodorus of Artemita, that Bactria was the best part of East Iran (Ariana). In ancient times the Bactrians were hardly distinguished from nomads; but their land was extensive, and produced fruits of all kinds, with the exception of the vine. The fertility of the land enabled the Hellenic princes to make great conquests. Their cities were Bactra, traversed by the river of the same name, Darapsa, Aornus (_avarana_, _i.e._ protection), Kariata, and many others, and besides these cities, the Bactrians had citadels on lofty rocks.[14] According to Strabo, Bactra was also called Zariaspa, and Pliny asserts that at any rate in earlier times it was called by that name. In Arrian Zariaspa is the largest city of Bactria, while Ptolemy places Zariaspa to the north of Bactra, on the bank of the Oxus. Zariaspa means golden horse. A river might possibly be known by such a name, but hardly a city, unless it belonged to a tribe of the name of Zariaspians, and was inhabited by them. In fact Ptolemy places the tribe of the Zariaspians in his Zariaspa.[15] The air on these north-western terraces of the Hindu Kush is warm, and the soil sufficiently vigorous, under irrigation, to produce rice and southern fruits. Eight leagues below the snow-fields of the mountains, which resist even the hottest months of the year, two good leagues to the north of the place where the Dehas, after forcing a passage through the last heights, reaches the plains, lies the city of Balkh, on the banks of that river. At this day it is a town only partially inhabited; but the ruins of the ancient city are said to cover a circuit of several leagues. The adjacent soil is now well cultivated; the fields are thickly planted with trees, and beside old water-courses, now dried up, and extensive ruins of yet older aqueducts, eighteen channels still convey their rills to fields under active cultivation.[16]