14 



been retarded by the moist climate of the locality, have 

 been necessary to keep the records. In making the 

 observations one has to traverse twenty degrees of lati- 

 tude, but the observations are only typical of what can 

 be observed in a few thousand feet of elevation upon the 

 slopes of Mt. Kenia, the Equadorian Andes, or other 

 glacier-crowned peak of any latitude. Above the tim- 

 ber line, the physical evidences of glacial retreat present 

 the same gradations of distinctness as we recede from 

 the active glacier. 



The fact that the evidence of glacial retreat grows 

 progressively fainter as we recede from the liv- 

 ing glacier, either in latitude or elevation, marks 

 a progressive retreat from the equator polewards 

 and from sea level upwards; since it is progress- 

 ive it must be accounted for by progressive laws now 

 active, and suppositions of upheaval and depression 

 and other hypotheses are not necessary. The areas 

 over which the ice invasions once extended may and 

 probably will be wrangled over for generations to come, 

 but no Geologist nor Physicist, who will take the trouble 

 to observe a single glacier and to read what others have 

 recorded, can dispute nor deny the fact that glacial ex- 

 tension has within a comparatively recent period been 

 vastly more extensive at all latitudes than it is at pres- 

 ent, and that successive retreat has been a marked char- 

 acteristic of glacial conditions during the present era of 

 geological time. The fact that glacial conditions are 

 giving place to milder temperatures is recorded in all 

 latitudes, and wherever glacial ice yet rests this record, 

 although a slightly fluctuating one, is being legibly in- 

 scribed. The bare citation of the facts establishes the 

 interpretation that solar energy is rewarming our planet 

 after the chill of the Ice Age — that the mean tempera- 



