032 E. HUXTIXGTOX SOLAR HYPOTHESIS OF CLIMATIC CHANGES 



In spite of this, however, if the earlier, less reliable portions of the curves 

 are omitted, the main features of the Asiatic curve agree in general with 

 those of the California curve. Both curves seem to point to the conclu- 

 sion that during the past two or three thousand years the climate of these 

 two far removed portions of the world has been subject to approximately 

 the same kind of climatic pulsations. The agreement of two such diverse 

 lines of evidence is one of the strongest reasons for accepting the pulsa- 

 tory hj^othesis. 



CLIMATIC PULSATIOXS ACCORDIXG TO CRITICS OF THE HTPOTHESIS OF 

 PROGRESSIVE DESICCATIOX 



Another reason for accepting it is found in the attitude of authors who 

 support the hypothesis of climatic uniformity. As examples of this I 

 shall take four who have written for the express purpose of controverting 

 the views which I have expressed in "Explorations in Turkestan,^' "The 

 Pulse of Asia," and "Palestine and its Transformation." Their argu- 

 ments, however, are not directed against the idea of pulsatory changes, 

 but against the idea that the climate of western and central Asia two 

 thousand years ago was moister than at present. These four authors — 

 Hedin, Gregory, Berg, and Herbette — state distinctly their acceptance of 

 the modern geological conclusion that since the Glacial period there have 

 been climatic pulsations of the t}'pe known as post-Glacial stages. They 

 hold, however, that by the beginning of the Bronze Age, say 1500 or 2000 

 B. C, these pulsations had come to an end. From that time onward for 

 3,000 or 4,000 years they state that the climate has been uniform. Xever- 

 theless they all qualify this by admitting that during the past 1,000 years, 

 more or less, there have been pulsations of greater magnitude than those 

 which can be observed during the life of a single individual. For in- 

 stance, the Swedish traveler Hedin-^ speaks of lakes Manasarowar and 

 Eakas-tal, in southwestern Tibet, as forming admirable rain gauges. 

 Both are without outlet most of the time. Manasarowar, however, over- 

 flows at fairly frequent intervals, perhaps in accordance with the Briick- 

 ner cycle, and sends a stream to Eakas-tal. This lower lake overflows 

 much more rarely and only in times of unusually marked precipitation. 

 Hence its occasional periods of overflow at intervals of a few hundred 

 years are taken by Hedin to indicate climatic pulsations having this dura- 

 tion. Hedin^^ also says that "the fact that the Caspian Sea was much 

 lower 750 years ago than it is now . . . proves more clearly than any- 

 thing else that the desiccation of the climate of central Asia and of the 

 lakes by no means follows a regular curve." Elsewhere he says that 



26 Sven Hedin : Trans-Himalaya, vol. 3, p. 234 ; see also p. 288. 

 ^ Sven Hedin : Overland to India, vol. 2, p. 209. 



