40 The Origin of the 



strata there, crushing up the deep cavernous 

 structure, and so causing the sudden sinking of a 

 continent. That a former continent has actually 

 sunk to untold depths in the Pacific Ocean is 

 generally thought. Such an event, by shifting the 

 weight there nearer to the earth's central nucleus, 

 would, on the principle of the steelyard, alter the 

 balance, and under certain conditions, would demon- 

 strably produce a sudden change of the earth's axis ; 

 of the actual occurrence of which there is geological 

 and other evidence, Jamaica and Vienna having had 

 at one time nearly the same climate, 1 and therefore, 

 we may conclude, approximately the same parallel of 

 latitude, though now differing about thirty degrees. 

 I have said that under certain circumstances a 

 change of axis would demonstrably result. It is true 

 that the astronomers generally, with Sir Isaac 

 Newton and Laplace, have thought a change of the 

 earth's axis impossible, or so improbable that the 

 supposition could not be entertained ; but this they 

 have done in consequence of taking into account the 

 whole vast mass and weight of the earth as the 

 obstacle. But the mathematician Bond, and after 

 him Halley, the Astronomer- Royal of his day, who 

 was also the practical founder of the science of 

 Terrestrial Magnetism, deduced from the facts of 

 magnetism that there is a nucleus of the earth now 

 revolving differently from the main mass of the 

 earth ; and though men of science for a time 

 disparaged this opinion, yet the late Sir Edward 

 Sabine, who was preeminent in this department of 

 science, said in his presidential address to the Royal 

 Society, read May, 1864, 2 that he thought Halley' s 



1 Lyell, Prin. of Geol., 10th Ed., vol. ii. p. 201. 



2 Phil. Trans., p. 242. 



