138 Proceedings of the Royal Physical Society. 



Which, being greater than that of the immediately subjacent 

 mass, the crust so formed would necessarily sink. In like 

 manner it may be shown that all crusts under a certain 

 thickness would sink, whilst all above such a thickness would 

 float. It thus appears that the thin crusts originally formed 

 would sink and undergo total or partial re-fusion until a 

 certain thickness of solid matter was attained. By this 

 arrangement the refrigeration of the superficial parts of our 

 globe would proceed with far greater rapidity than if the 

 thin crust originally formed had maintained its position, as 

 in this case the heat from the interior could only have 

 reached the surface by the slow process of conduction 

 through a solid mass of very low conducting powers. In 

 this, then, there also appears evidence of design in hastening 

 the progress of our globe through its uninhabitable stages, 

 that it might be the sooner fitted for the habitation and 

 enjoyment of the sentient beings for whose use it was 

 destined. 



The deductions contained in the preceding paragraphs 

 are humbly -presented to the consideration of all who are 

 interested in the study of geological physics. Though some 

 of the assumptions founded upon may perhaps be called in 

 question, and although in the calculations many corrective 

 elements have not been taken into account, it is hoped that 

 at least glimpses of some important truths have been ob- 

 tained, sufficient to attract the attention of more competent 

 investigators. The astonishing progress which the physical 

 sciences have made within the last half century encourages 

 us to hope that the time is not far distant when sufficient 

 data shall be obtained to enable us to work out the solution 

 of many of the most important problems connected with 

 geological dynamics. Even now, in studying the phenomena 

 resulting from the refrigeration of our globe, we obtain a 

 clue to the nature and modus operandi of some of the causes 

 by which the varied configurations of the earth's surface 

 have, in the present as well as in the past geological epochs, 

 been produced. For example, in the fissures opened in 

 consequence of refrigeration, we see at once the origin of 

 mountain chains. We can imagine the gradually cooling 



