II PERMANENCE OF THE GREAT OCEANIC BASINS 39 



founded on incorrect data. For, surely, no one will sug- 

 gest that so vast a problem of terrestrial physics can be 

 held to be solved till we have exhausted all the evidence 

 at our command, and have shown that it largely prepon- 

 derates on one side or the other. 



The present article is intended to supply a hitherto 

 unnoticed class of arguments for oceanic permanence, and 

 these must of course be taken in connection with the 

 other evidence which has been summarised in the sixth 

 chapter of the writer's Island Life, and also with the 

 admirable " Summary " of the purely physical argument 

 in the second edition of Mr. O. Fisher's Physics of the 

 Earth's Crust. It is certainly a rcDiarkable fact that 

 writers approaching the subject from so many distinct 

 points of view — as have Professor Dana, Mr. Darwin, Sir 

 Archibald Geikie, Dr. John Murray, Rev. O. Fisher, and 

 myself — should yet arrive at what is substantially an 

 identical conclusion ; and this must certainly be held to 

 afford a strong presumption that that conclusion is a 

 correct one. 



