100 UNIFORMITY OF CLIMATE IN PAST AGES. 



The following is an abstract of a paper read, on the 



UNIFORMITY OF CLIMATE IN PAST GEOLOGICAL AGES. 



BY C. B. WARRING, PH.D. 



In geological times as late as the miocene and probably 

 the early pliocene, the climate in very high latitudes was 

 about the same as now in our southern states, as is shown 

 by abundant remains of animals and plants identical in 

 species with those of low latitudes. 



This condition is so unlike present polar climate that 

 it presents a problem of the greatest interest. 



To most persons — and to all writers hitherto — the prob- 

 lem has been summed up in one word, warmth. But 

 there are two other problems involved. Was the climate 

 uniform, or at least approximately so, as now in the trop- 

 ics % Was the supply of actinic influence subject to ex- 

 tremes ? Or, to put the two questions in another form, — 

 do the plants and animals that lived near the pole in 

 those remote times, indicate the presence or the absence 

 of long days and nights such as those of the present 

 period '. 



I assume that plants and animals were affected by heat 

 and cold, light and darkness, then as now. 



If the axis of the earth was inclined at that time 23^° 

 the days and nights must have varied as they do at pres- 

 ent. Hence in Spitsbergen, lat. 80°, and at Captain 

 Xaire's winter quarters, 81°-40' the mid-winter night 

 must have been four months long. Four months of un- 

 interrupted day would tend to raise the temperature 

 very high, while four months with no heat at all from 

 the sun, would make excessive cold. These extremes 

 were undoubtedly greatly modified by the capacity of 

 water to take up and give out heat, and the winters made 

 milder by the inflow of ocean currents. The same ca- 

 pacity, however, exists now, and ocean currents continue 



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