182 Geological Observation, 



ists among them, not only in the laws of their motions, but iii 

 the figure of their masses ; they have not failed to remark the 

 flattening at the poles, which can be observed in some of them, 

 similar to that of our globe, proving a similar state of fluidity 

 from which this figure has originated ; and thev have endeavoured 

 even to draw from the aspect which they exhil)it, indications of 

 the stage of progression in which they now are*. But they have 

 presented no pleasing prospect of the final adjustment of this 

 series of revolutions. Regardmg the planets as extinct suns, or 

 fragments of suns, or at least as masses which have been hot and 

 luminous, they have supjjosed them to be in a state of gradual 

 refrigeration, which will terminate in the total cessation of move- 

 ment and animated existence. The - ssumption on wbich this 

 gloomy hj'pothesis is built, — that of the unlimited escape of heat 

 from each planetary mass, — is fortunately as false, as the view to 

 which it leads is unworthy of the order and magnificence which 

 the system of nature displays ; and instead of this termination, 

 in what one of these philosophers emphatically calls the state of 

 ice and death, of silence and repose, we may with more confi- 

 dence look to the equal diffusion of heat through the ir.ass of 

 each planet, as the state of permanence under which it will exist, 

 and to the equal interchange of heat among all, as the peifectiou 

 of the system they form. 



XXXIII. Geological Ohserva.tions. By W. H, Gilby, M.D. 

 To Mr. Tdloch. 



Sir, — In the present communication, I shall offer a few observa- 

 tions as to the situation which the mountain limestone and red 

 sandstone usually associated with it hold in theWernerian system. 

 I shall then proceed to make some remarks upon tlie red ground, 

 chiefly for the purpose of showing how repeatedly the beds of 

 this formation have been confounded with the red sandstone ac- 

 companying the mountain limestone ; as also to point out the 

 great mistakes that prevail in regard to the beds which may be 

 considered as forming a part of the red ground. Such being the 

 object of my communication, if it is likely to be of any interest 

 to you or your readers, you will oblige me by inserting it. 



I am, sir. 



Yours very respectfully, 



W. H. Gilby, M.D. 



* HUloirc de I'Astronomie Moderne, torn. ii. p. 726. 



I BIJ^ 



