THE EARTH. 33 



ed together ; and these are, the solid or terrestrial 

 part, supported by a central body ; the aqueous 

 part, reduced to a spherical form by gravitation, 

 and become oblate by the earth's centrifugal 

 force ; and the atmosphere surrounding the whole, 

 evidently necessary for innumerable purposes of 

 life and vegetation. 



" Having thus considered the mechanism of 

 the globe, he proceeds to investigate the powers 

 by which it is upheld ; and these he supposes to 

 be the gravitating and projectile forces by which 

 the planets are guided ; the influence of light and 

 heat, cold and condensation, to which may be 

 added, electricity and magnetism. 



" He supposes the component parts of the world 

 to be in an alternate state of production and de- 

 cay ; and that, from a view of the present con- 

 struction and operations of nature, we may un- 

 derstand what has formerly passed in the original 

 formation of the globe. 



" Nine-tenths of the earth, he thinks, have been 

 formed by natural operations of the globe, in col- 

 lecting loose materials and depositing them at the 

 bottom of the sea, consolidating these collections 

 in various degrees, and either elevating these con- 

 solidated masses above the level on which they 

 were formed, or lowering the level of the sea. 

 The Doctor concludes that these materials have 

 been consolidated by heat and fusion, rather than 

 by aqueous solution, and that they produce, by 

 their several combinations, the different mineral 

 substances and solid strata of the globe. 



VOL. i. c 



