94 Mr. H. H. Howorth on 



larger quantity of water across the equatorial line into the 

 southern hemisphere, but this would be at once compensated 

 for by the fact that the stronger anti-trade winds in the 

 northern hemisphere would give the current which they 

 induced a greater impetus and a wider distribution than the 

 same current when under the pressure of the trades. If the 

 north-east trades were very powerful so must the south-west 

 anti-trades have been ; and if it were possible (as we have 

 tried to argue it was not) for the former winds to push the 

 equatorial current rather more to the south in the first part 

 of its course, it must also have followed that the latter winds 

 pushed them further north in the second part of its course, 

 and the Gulf Stream must have been correspondingly 

 faster and more widely diffused. In every way in fact, 

 in which we approach the problem from the meteorological 

 side, we must conclude that Dr. Croll's theory completely 

 fails to satisfy the drastic demands of the evidence. Let 

 us now turn to the more distinctly geological side. 



Dr. Croll's, like some other theories, wholly or partially 

 based upon astronomical evidence, includes the hypothesis 

 that either hemisphere has been subjected in turn to 

 glacial conditions, and that this alternating of glacial 

 climates with temperate ones, has been the law of all time, 

 and he, like Professor James Geikie, and others, professes 

 to find evidence of this in the geological record. In 

 addition, he has imported into the geology of the more 

 recent periods quite a portentous system of chronology based 

 upon the fact of recurring glacial periods coinciding with 

 periods of extreme eccentricity, and postulates of hundreds 

 of thousands of years have become quite an ordinary 

 demand upon our credulity. As I cannot accept any of 

 these conclusions, any more than I can his meteorological 

 view, I must now devote a little space to their discussion. 



In the first place, then, as to traces of a so-called glacial 

 period in the southern hemisphere. The so-called glacial 



