1884- 95 Trans. N. V. Ac. Set. 



Tertiary times, it grew in Greenland. In Alaska, oaks once flourished 

 whose leaves were twelve to fifteen inches in length. The leaves of 

 trees were, as a whole, smaller than in the tropics, where at the pres- 

 ent day the largest leaves are found, such as those of the banana, etc. 



This flora, growing m a mild climate, was mostly destroyed by the 

 Ice period. This great change was probably caused by some cosmic 

 influence, and not by the elevation of high lands in the Arctic. 

 In the Tertiary age, the northern lands were deeply furrowed by val- 

 leys opening into the sea, thus producing the fjords to which the fimbri- 

 ated appearance of all the northern coasts has been due. There is 

 evidence of the occurrence of a great flood which afterward transported 

 the material from which the Champlain clays were separated, the 

 finest sediment having been deposited in bodies of still water. 

 These clays were synchronous with the coarser deposits of gravel 

 and boulders, on the higher lands. The elevation of the sea-level, 

 indicated by the Champlain deposits, amounted to about loo feet at 

 New York City, 200 feet at Albany, 500 feet at Montreal, 800 feet at 

 Labrador, 1,000 feet at Davis Strait, and finally reached, in the 

 Champlain clays of Polaris Bay, a height of 1,600 to 1,800 feet above 

 the sea. All these clays contained the remains of Arctic shells, and 

 these implied a low land level during the latter part of the Ice period. 



There is a difficulty in accepting the idea suggested by Prof. 

 Warring, that the axis of the earth was then perpendicular to the 

 ecliptic. No change in the constitution of the atmosphere could per- 

 mit the existence of a high temperature in the Arctic and its absence 

 in tropical regions. 



In the Cretaceous period, anterior to the luxuriant vegetation of the 

 Tertiary, a climate and vegetation of a temperate character had pre- 

 vailed here. The increase of carbonic acid in the atmosphere would 

 make conditions incompatible with these facts. It has been shown 

 that a vast amount of carbonic acid has been also withdrawn to pro- 

 duce all the deposits of limestone ; this would involve an enormous 

 percentage in the constitution of the original atmosphere of the globe. 

 To meet this difficulty, Winchell had suggested that there had been 

 a constant addition of carbonic acid to the atmosphere from space. 

 Sir Henry Siemens had also suggested, in Nature, about a year ago, 

 the constant addition of both aqueous vapor and carbonic acid from 

 space. 



We have testimony from the astronomers in general opposition to 

 the view of any change in the axis of the earth ; they have almost 

 unanimously pronounced against the probability of this idea. One or 

 two of the evidences, which have been cited, of the former existence 

 of a very high temperature at the north, are fallacious, e.g., the abun- 



