42 



THE WONDERS OF GEOLOGY. Lect. I. 



orbit of the most distant of the planets ; these bodies having 

 then no existence. Its temperature gradually diminished, 

 and contracting by refrigeration, the rotation increased in 

 rapidity, and zones of nebulosity were successively thrown 

 off, in consequence of the centrifugal force overpowering 

 the central attraction : the condensation of these separated 

 masses constituted the planets and satellites. This view of 

 the conversion of gaseous matter into planetary bodies is 

 not limited to our own system ; it extends to the formation 

 of the innumerable suns and worlds which are distributed 

 throughout the Universe ; for the discoveries of modern 

 astronomers have shown, that every part of the realms of 

 space abounds in large expansions of attenuated matter, 

 (termed nebulae,) which are irregularly reflective of light, 

 and of various figures, and in different states of conden- 

 sation, from that of a diffused luminous mass, to suns and 

 planets like the earth. 



It must be admitted that this hypothesis is astounding, — 

 and we may well demand if man, the ephemeron of the 

 material world, can indeed measure the vast epochs which 

 mark the progressive development of suns and systems ? 

 The master minds of Laplace and Herschel have effected 

 this wonderful achievement, and explained the successive 

 changes by which it seems probable that suns and planetary 

 systems are formed, through the agency of the sublime 

 laws of the Eternal. By laborious and unremitting ob- 

 servations, those illustrious philosophers have demon- 

 strated the progress of nebular condensation, not indeed 

 from the appearances presented by a single nebula, (for the 

 process, probably, can only become sensible through the 

 lapse of ages,) but by observations on the almost endless 

 series of related contemporaneous objects that appear in 

 every varied state of progression, from that of a cloud of 

 luminous vapour, to the most dense and mighty orbs that 

 appear in the firmament. As the naturalist in the midst of a 



