230 KURGANS OF THE MERV OASIS. 
evident that at the time of the kurgans, say 1,000 or 2,000 years ago, the Merv 
Oasis was more extensive than it is to-day. That this decrease is due to changes 
in the methods of irrigation is hardly possible. The earlier times, as we have seen, 
were characterized by a highly developed system of intensive irrigation, under 
which the distributaries were short, but highly branched, while the present is 
characterized by a poor system, now in process of rectification, under which the 
distributaries are long and but slightly branched. 
In other words, the change in the system of irrigation has been one which, 
other conditions remaining unchanged, would have caused an apparent increase 
in the size of the delta. Yet exactly the opposite result has taken place. The 
limits of the main canals have been drawn inward in spite of the fact that the 
number of side canals has decreased. Above Yelotan, so far as we know, the 
country along the upper Murg-ab is no more densely populated now than formerly. 
Therefore, the diminution in the cultivated area can not be due to the lessening 
of the water-supply of the Merv Oasis by the diversion of water farther upstream. 
Neither such diversion nor a change in the irrigation system can account for the 
lessening of the area capable of cultivation. The only other competent cause 
for such a diminution would seem to be a change in the amount of water furnished 
by the Murg-ab. Such a change would seem to require a corresponding variation 
in the climate of the mountains of northern Afghanistan, where the Murg-ab takes 
its rise. A change in the climate of northern Afghanistan would probably involve 
a similar change at Merv and elsewhere. Accordingly the ruins of Merv seem 
to be explicable only on the theory that in ancient times the climate of the country 
as a whole was more humid than it is to-day. 
If we approach the subject from another point of view, we arrive at the same 
result. The present population of the oasis of Merv behtow Yelotan comprises 
about 65,000 Turkomans, mostly cultivators of the soil who have recently given 
up nomadism, and a considerable number of townspeople of other nationalities, 
so that, at a liberal estimate, the total reaches 100,000. In ancient times the oasis 
is said to have contained a million people, and the size of Ghiaur Kala and of the 
other old cities, the number and character of the outlying and apparently contem- 
poraneous ruins, and the degree to which the traces of thickly populated villages 
extend into the desert, make this seem highly probable. Assuming, however, 
that the true figures are but half a million, could the oasis to-day support so large 
a number of people? 
At Bairam Ali on the Imperial Domain, under the direction, formerly of 
Mr. Dubosof, and now of Mr. Yeremief and Mr. Von Brandt, there is a portion 
of the oasis where the most modern and economical system of irrigation prevails, 
and where a given amount of water supports the maximum population. The 
water for the Domain is diverted from the Murg-ab by means of the Hindu-Kush 
dam, just south of Yelotan, which was completed in 1894. According to Mr. 
Nikrashevich, the superintendent of the dam, the minimum flow of the river at this 
point, before any of the canals of the oasis are taken off, amounts to 1,500 cubic 
feet per second, and of this the Imperial Domain has the right to divert 10 per cent. 
