54 Geological Changes in Position of the Earth^s Crust. [Mar. 22, 



The former existence of cold in what are now warm latitudes might, and 

 probably did in part, arise from other causes than a change in the axis of 

 rotation, but no other hypothesis can well account for the existence of 

 traces of an almost tropical vegetation within the Arctic circle. 



Of the former existence of such a vegetation, the evidence, though 

 strong, is not conclusive. But if the fossil plants of Melville Island, in 

 iat. 75^ N.*, which appear to agree generically with those from the 

 English coal-measures, really grew upon the spot where they were now 

 discovered, they seem to afford conclusive evidence of a change in the 

 position of the pole since the period at which they grew, as such vegetation 

 must be considered impossible in so high a latitude. 



The corals and Orthoceratites from Griffiths Island and Cornwallis 

 Island, and the liassic Ammonites from Point Wilkie, Prince Patrick's 

 Island, tell the same story of the former existence of something like a sub- 

 tropical climate at places at present well within the Arctic circle. 



To use the words of the Rev. Samuel Haughtonf , in describing the fossils 

 ,€ollected by Sir F. L. M'^Clintock, '*The discovery of such fossils in situ^ 

 in 76'^ N. latitude, is calculated to throw considerable doubt upon the 

 -theories of climate, which would account for all past changes of temperature 

 by changes in the relative position of land and water on the earth's 

 surface and I think that all geologists will agree with this remark, aod 

 feel that if the possibility of a change in the position of the axis of rotation 

 4Df the crust of the earth were once admitted, it would smooth over many 

 difficulties they now encounter. 



That some such change is indeed taking place at the present moment 

 may not unreasonably be inferred from the observations of the Astronomer 

 Royal, who, in his Report to the Board of Visitors for 1861, makes use of 

 the following language, though "only for the sake of embodying his 

 .description of the observed facts," as he refers the discrepancies noticed 

 to '* some peculiarity of the instrument The Transit Circle and Colli- 

 mators still present those appearances of agreement between themselves 

 and of change with respect to the stars which seem explicable only on one 

 of two suppositions — that the ground itself shifts with respect to the 

 general Earth, or that the Axis of Rotation changes its position." 



March 22, 1866. 



Lieut.-General SABINE, President, in the Chair. 



The following communications were read : — 



* Lyell, ' Principles of aeology,' 1853, p. 88. 



t J ournal of the Eoyal Dublin Society, vol. i. p. 244. 



