534 E, HUNTIXGTOX SOLAR HYPOTHESIS OF CLIMATIC CHANGES 



minor pulsations of one kind or another which are larger than those ob- 

 served during a single lifetime or than those recorded since accurate ob- 

 servations were possible on a large scale. In other words, a careful study 

 of the available facts has led these four authors to reject the hypothesis 

 of progressive changes and to accept the hypothesis of large pulsatory 

 changes previous to about 2000 B. C. and of small changes of the same 

 kind since about 600 A. D. The only point where their view differs 

 radically from the one advocated in this paper is in the interpretation of 

 the evidence from 2000 B. C. to the early part of the Christian era. ^Vere 

 the pulsations of that time of the small type which seems to have pre- 

 vailed during the last 1,500 years, or were they intermediate between 

 those and the larger ones of post- Glacial stages ? 



OBJECTJOXS TO THE HYPOTHESIS OF CLIMATIC CHAXGES 



Ancient droughts and famines. — Eeasons for believing that the pulsa- 

 tions were intermediate rather than small have already been 'mentioned 

 in our discussion of ruins and allied phenomena. It will now be advis- 

 able to consider the objections to this view. Only three of chief im- 

 portance can be taken up. The first is the unquestionable fact that 

 droughts and famines have occurred at periods which seem on other evi- 

 dence to have been moister than the present time. This argument has 

 been much used, "but it seems to have little force. If the rainfall of a 

 given region averages 30 inches and varies from 15 to 45, a famine will 

 ensue if the rainfall drops for a few years to the lower limit and does not 

 rise much above 20 for a few years. If the climate of the place changes 

 during the course of centuries, so that the rainfall averages only 20 

 inches, and ranges from T to 35, famine will again ensue if the rainfall 

 remains near 10 inches for a few years. The ravages of the first famine 

 might be as bad as those of the second. They might even be worse, be- 

 cause when the rainfall is larger the number of people is likeJy to be 

 greater and the distress due to scarcity of food would affect a larger num- 

 ber of people. Hence historic records of famines and droughts do not 

 indicate that the climate was either drier or moister than at present. 

 They merely show that at the time in question the climate was drier than 

 the normal for that particular period. 



The existence of deserts in ancient times — Alexander's marcli. — The 

 march of Alexander from India to ^Eesopotamia illustrates a second type 

 of objection which is often urged against the idea that the climate of that 

 time may have been moister than that of the present. Hedin gives an 

 excellent presentation of the case in the second volume of his "Overland 

 to India." He shows conclusively that Alexander's army suffered terribly 



