308 PHYSIOGRAPHY OF CENTRAL-ASIAN DESERTS AND OASES. 
for existence and shifted or died out at the hand of their change. Needs of 
exchange were always changing in degree and kind; new centers of trade were 
ever springing up and newly discovered routes opened in competition. Scores of 
miles of trail and sometimes whole routes were shifted by the work of rivers and 
avalanches, and others abandoned for lack of water and decrease of fodder during 
cycles of desiccation. And history and tradition and Oriental romance have 
emphasized how robber khans and nomad tribes made raid and others levied 
toll on passing caravans. It is easy to draw a line on the map, but quite another 
matter to follow it out in reality with pack-animals that can neither fly over 
canyons nor live without fodder and water, neither scale mountains nor swim 
bad rapids, nor pass unknown to watchful enemies; and it is hard enough to make 
such a risky enterprise profitable by having the right merchandise for the right 
market. 
ADVANTAGES OF THE ALAI VALLEY ROUTE. 
It is no surprise that within historic time there has been much shifting of 
the main trade-way between far East and West. Whether or not some of Bactria’s 
early trade passed over the Southern Pamir by way of Tash Kurgan to China, 
it does not seem likely that the much-spoken-of Terek Davan route to the north 
was ever of great importance. On it there are eight passes to be crossed within 
a distance of 250 miles—eight passes, most of them involving a steep rise of over 
2,000 feet, and to cross the Terek itself from the north, one must climb 6,000 feet 
in one day, all in less than 12 miles, 5 of which are up the bowlder-strewn bed of 
a torrent in which many a pack-horse has stumbled to drown. Of all the passes 
I crossed during 2,000 miles of travel through those mountains, the Terek Davan 
stands out as one of the two or three worst, not so much because of its height 
(13,500 feet, which is perhaps low for passes on those high ranges), but because 
of bad trail, or rather the utter lack of trail over many miles, especially on its 
northern side. Moreover, there is no indication of its ever having had a good trail 
or any trail at all. 
Beyond Irkeshtam (going westward), where it branches from the Alai valley 
route, there is on the Terek trail no trace of what we should expect to find on an 
important pathway of antiquity, no resemblance to one’s expectations of a one- 
time main way from Bactria to China. Beyond this junction there is no remnant 
stretch of graded way or cliff-cut, nor hoof-worn path in rock or loess, nor sign 
that ever caravansary or castle stood upon it. Though with their railroad built 
to Andijan and the military post at Irkeshtam, the Russians have had to better 
it as much as possible; it is still a decidedly bad trail. If such a route was used 
for Bactrian caravans instead of that through the Alai valley, over all its length 
contrasting in goodness, whole mountains must have heaved and gorges carved 
since then. 
From Kashgar to Bactra, via the Alai valley and Hissar, is only 600 miles, 
all of it good trail, well-engineered, and over 300 miles shorter than via the Terek 
Davan and Iron Door—3oo miles shorter, or but two-thirds of the distance by 
the other, and so good that, with a little improvement at a few points, light artillery 
