404 THEORY OF CONTRACTION. 



CHAPTER assumed to be of the samg age, or to belong to the same 

 epoch. How utterly the whole fair speculation vanishes 

 before one glance into the universe farther than our own 

 door-steps ! If the earth was cracked in this wise, so 

 must the moon have been ; but in the moon there is not 

 one instance of a chain l.ving along a great circle of the 

 sphere, or having connection with aught save the great 

 plains ; and there are no parallel ridges at all !" 

 Opinions of From these observations, the reader will see that astro- 

 observers. nomers have long been familiar with the illustrations 

 derivable from lunar phenomena, of the successive 

 changes through which our own planet has passed. He 

 will observe, moreover, that the speculations already re- 

 ferred to are only the revival of ideas previously advanced, 

 though now rendered more consistent, and confirmed by 

 much additional evidence, derived both from telescopic 

 observation, and from analytic experiments. We see, 

 however, in the remai'ks of Professor Nichol, in refer- 

 ence to the theory of De Beaumont, that the idea of de- 

 I^ression and upheaval being the result of the irregular 

 contraction of the whole earth's crust has not hitherto 

 been received without dispute, nor is it likely that it can 

 ExporiiiKu- now be accepted implicitly. It is not, however, to be 

 t.il rcsuiis. received in its latest form as a mere theory, but rather 

 as the result of conclusions forced on the mind of an in- 

 telligent and practical observer by the various pheno- 

 mena brought under his notice by the telescope, and con- 

 firmed by the analogies which his crucial experiments 

 elicited. Professor Nichol attaches importance to the 

 absence of a general parallelism in the striae on the 

 moon's surface, as an evidence of the fallacy of De Beau- 

 mont's theory, and in this he was so far justified, from 

 that ingenious theorist having assumed th:it such would 

 be the necessary result of tlie force which he sought to 

 account for. The experiments of Mr. Nasmyth, how- 

 ever, already referred to, bhow an entirely different re- 

 sult, completely corresjionding with the radiating striae 

 with which we are actually familiar on the surface of 



