GEOLOGICAL TIME. 29 



must have then been in the condition of soft mud or 

 ooze, which has gradually encased these shells, and as 

 time went on has become solidified, and finally converted 

 into rock. 



Now, when the attention of even the least instructed 

 man is called to these palpable facts, the inevitable 

 query is certain to arise How long did all this 

 take f 



To a great extent this must of course always remain 

 a matter of conjecture ; and as might be expected, 

 many learned works have been devoted to the discus- 

 sion of this abstruse and intricate problem with this 

 result, that though all the best authorities were practi- 

 cally unanimous in admitting that it must have taken 

 an enormous period of time geological time that is 

 still the tendency of all recent researches has been 

 to compel modern geologists to increase that enormous 

 period almost indefinitely. 



So that in geological time hundreds of millions of 

 years have now to be reckoned with. 



When we consider the extreme slowness with which 

 the sediment of still water accumulates, which certainly 

 only amounts to a few inches in a century. When we 

 consider that this is deposited in the form of soft mud, 

 reducible by pressure to almost infinitesimal propor- 

 tions : it is evident that the time which it must have 

 taken to build up the cretaceous rocks, which (be it 

 remembered) form only a small proportion of the whole 

 of the fossil-bearing strata known to science must 

 extend over a period wholly beyond the scope of our 

 finite understandings. 



The lesson therefore which these things seem to 

 teach us is, that while people glibly aquiesce in ad- 



