362 E. HUNTINGTON GLACIAL PERIOD IN NON-GLACIATED EEGIONS 



/ / / / 



Within, the master's deslj is seen, 



Deep scarred by raps otficial, 



/ / / ' 



The warping floor, the battered seats, 



The jaclc-linife's carved initial. 



We have here two strophes, or stanzas. Each consists of regularly 

 recurring arses and theses, or accented and unaccented syllables. The 

 metrical composition of the stanzas presents a close analogy to the course 

 of climate during geological time, as is illustrated in figure 2. In the 

 figure horizontal distance represents the course of time. An upward 

 curve indicates increasing moisture, diminishing temperature, or other 

 conditions pertaining to the phase of a climatic cycle known as glacial, 

 fluvial, lacustral, and so forth. The climax is the arsis, and the time 

 in which it occurs is an arsial epoch. The appropriateness of the term is 

 evident when one considers the stress which is commonly, and perhaps 



^M«oio ^.. INTER- STROPHE ---t-- STROPHE --1 



Figure 2. — DUiijyum iUiinfiotiiifj Frotjrcss of Changes of Clhiuitc ihiriiuj ncohigical Time. 



justly, laid upon the marked features of glacial or fluvial epochs as com- 

 pared with the less noticeable features of interglacial epochs. A downward 

 curve in the figure represents a tendency toward aridity or warmth, cul- 

 minating at what may be termed the thesis. The time when a thesis 

 occurs is a thesial epoch, which may be described as interglacial, or inter- 

 fiuvial, and so forth, when the agents which modify the earth's surface 

 are considered, or as intervegetal, interpluvial, and so forth, when other 

 ]3hases are considered. A group of climatic cycles consisting of alter- 

 nating accented or arsial epochs and unaccented or thesial epochs forms a 

 strophe, just as in poetry a succession of feet composed of arses and 

 theses forms a stanza. Thus we may speak of the Pleistocene strophe of 

 climatic change or the Permian strophe. An intervening period, when 

 changes of climate are less marked or less frequent than during the 

 strophes, would naturally be termed an i'nterstrophe. 



Importance op climatic Becords in arid Basins 



Eecords of climatic change are found chiefly in regions where ex- 

 tremes of one sort or another have prevailed. In a country where arsial 



