l6 EXPLORATIONS IN TURKESTAN. 
It is the opinion of an important school of archeologists that the earliest 
prodncts of metallurgy in bronze and iron successi\-eh- progressed to the western 
world from the far East — a progress that in each case carried witli it a re\olution in 
civilizations. We do not know whether this region saw the birth of the metallnrgj' 
of those elemental substances which — beginning with copper and tin and progressing 
through bronze to iron and steel and the use of coal — marks the birth of civili- 
zation and its great revolutions. If it was not the birthplace of this art, and if it 
was a distributing center, it is a long step nearer to an\- far eastern source, whether 
this was China, Kast Turkestan, India, or Persia. 
RESULTS IN PHYSICAL GEOGRAPHY. 
Both our own obsen-atious and the excellent and extensive work of the 
Russian geologists show that the progressive desiccation of the region has 
greatly diminished both the area of cultivable land and the volume of water, and 
greatly reduced the population. Is this change a phase of cyclical phenomena — of 
c)-cles of long periodicit>- ? In what relation have the geologicall}- recent secular 
phenomena in central Asia stood to man and civilization in that region and to the 
outside world? 
One of the chief objects of the reconnaissance of the past season was to deter- 
mine whether a systematic investigation would be likely to throw light on these 
questions. Perhaps the most important result is our finding that successive physi- 
cal events have left such abundant records, written in large strokes, all o\-er the 
mountains and the plains. 
The work of this year has not onh* made a most promising beginning in this 
interpretation, but has shown that it is probably possible to correlate the different 
events among themselves and with the period of human occupation, and possibly 
with similar ph)sical e\-ents in Europe. 
As an interior region, central Asia is arid and dependent for its water almost 
wholh- on its bordering mountains. It is also self-contained, i. e.^ without drainage 
to the ocean. Changes of climate, resulting in great fluctuations of water supply, 
would therefore probably be recorded b)- old shorelines at different levels. They 
might also be more or less legibly recorded in the evidences of repeated glaciation 
and erosion in the high mountains. 
It will be seen from the report of Professor Davis that he has found traces of 
an old shoreline about 600 feet above the west shore of the Caspian Sea, and a \er>- 
distinctly marked one on the east side, at an elevation of 200 feet or more. Further 
search for shorelines was left to form the object of a more extended special stud>- 
than could be made in our general reconnaissance. 
In the eastern mountains, near Issik Kul and Son Kul, Professor Davis found 
clear evidence of two and probabh- three glacial epochs. Mr. Ellsworth Hunting- 
ton, working in the higher Tian Shan, found proof of three epochs, and later of five 
phases, in the successive moraines of a large number of glaciers studied by him in 
