DESERTS. 297 
Konshin believes to have followed the high Quaternary sea, is another, more 
ancient, and indicative of a different climate. 
Though thus forced to disbelieve that the Oxus ever flowed through the Usboi, 
we can not utterly discredit the writings of geographers and travelers so renowned 
as Ptolemy, Strabo, Pliny, and others. Assuming that during one or more periods 
of the past two millenniums water of the Oxus did flow to the Caspian, there 
are two alternatives: First, that the Usboi overflow, as a continuous waterway 
from the Caspian up the Oxus, might have been referred to as the Lower Oxus; 
second, that the Oxus may, in historic times, have flowed to the Caspian through 
some other channel. As both the Aral and Sari Kamish were through whole 
centuries omitted from writings and maps, it would seem that whatever waterway 
there was must have been far south of them or that they were dry. On the other 
hand, there appears to be little doubt that the Oxus recently flowed west from 
near Charjui through the Turkoman Trough and so into the Balkhan Gulf. This 
channel, the Kelif Usboi, or Ungus, indicated on Russian maps and known to the 
Turkoman, has not attracted government exploration as an engineering project, 
such as the Usboi of Ust-Urt, and must therefore remain only a possibility. 
However often the Oxus may have shifted, or whatever course it may have 
followed in reaching the Caspian or in contributing overflows to that sea, the 
total surface area of sea-water in the Aralo-Caspian basin would have been but 
little, if at all, affected by such oscillations. The River Don problem is more 
serious from this point of view. The Don, converging with the Volga to a point 
about 350 miles north of the Caucasus, now bends sharply away from there and 
flows to the Black Sea. There appears a possibility that it was once a branch of 
the Volga. The change of course may have resulted from faulting across the 
channel, and the river’s grade is very slight—only about 5 inches to the mile. 
But if it ever did flow to the Volga, the change to its present course was so long 
ago that time enough has elapsed to cut the present wide Don valley in con- 
solidated rocks. Assuming that Don water flowed to the Caspian before earth- 
movements forced it westward and to cut a deep channel in the plains, the sur- 
face area of Aralo-Caspian sea-water would not have been so much increased as 
might first appear the case. It is much smaller than the Amu and yet the Amu 
and Syr together maintain a surface area of only 26,300 square miles—that of the 
Aral. If the Don were now diverted to the Caspian, it might raise it till its surface 
area increased by perhaps 10,000 square miles. But that would change its present 
outlines but little except over the low marshes of its northern end, while the 
Kara Kum would be transgressed by some few miles. The Don, therefore, can 
not have effected any of those great changes we are discussing. 
