46 



BUEEAU OF AMEEICAN ETHNOLOGY 



[bull 54 



Argentina and Bolivia, and other instances as evidence of climatic 

 changes. Many travelers and explorers have brought forth evidence 

 from other regions that climatic changes have been in progress durmg 

 the last few thousand years. 



Ward ^ tells of recent desiccation of lakes in Africa, one lake 

 mapped as 30 miles long and 15 miles "wide having been reduced to a 

 few small ponds since 1859. Pope^ shows that Devil's Lake, in 

 North Dakota, has been materially reduced in area since 1883. 

 Similar reports come from other quarters. It is well to note, however, 

 that some travelers report encroachment of cultivated areas on 



Fig. 2.— Annual march of temperature, at St. Louis, Santa Fe, and Espanola. 



deserts, a condition which may indicate that in places at least desic- 

 cation is not going on and which even suggests that possibly a very 

 different interpretation may be placed on some of the evidence 

 adduced in support of the desiccation hypothesis.'^ The area of lakes 

 may be reduced by various causes other than change of climate, as, 

 for example, silting up, vegetal growths in case of shallow lakes, 



1 Ward, R. De C, A Disappearing Lake, in Science, n. s., xxv, 114-15, 1907; Changes of Climate in 

 Central Africa, ibid., xix, 740, 1904. 



2 Pope, Thomas E. B., Devil's Lake, North Dakota, Doc. No. 634, U. S. Bur. Fisheries, p. 4 and map, 

 1908. 



3 Ward, R. De C, Current Notes on Meteorology and Climatology, in Science, n. s., XXV, 794-95, 1907; 

 Changes of Climate in Central Africa, ibid., xxn, 251, 1905. 



