THE SURFACE OF THE GLOBE. 39 



the suiface (after having in a measure modified them) materials before 

 buried in the depths of the earth ; they form mountains ; they have, 

 in earlier ages, covered some parts of our continents with them ; they 

 have suddenly produced islands in the midst of the ocean ; but these 

 mountains, these islands are always composed of lava, all their mate- 

 rials have undergone the action of fire ; they are distributed as mate- 

 rials must be which emanate from an elevated spot. Volcanoes do not 

 elevate, nor overthrow the layers which lie along their apertures ; and 

 if certain causes have operated from their abysses and assisted in over- 

 throwing vast mountains, it has not been by means of volcanic agents 

 of which we have any knowledge. 



Thus, we repeat, it is in vain to seek amidst the forces now acting 

 on the surface of the earth ; for causes sufficiently powerful to produce 

 the revolutions and catastrophes of which its exterior bears traces ; 

 and if we have recourse to the external causes at present in action, we 

 shall not find them adapted for the purpose. 



Constant Astronomical Causes. 



The pole of the earth moves in a circle about the pole of the eclip- 

 tic ; its axis inclines more or less according to the ecliptic ; but these 

 two motions (which are well understood) are performed within known 

 directions and limits, and have no proportion to the effects, the extent 

 of which we have just considered. In every instance, their extreme 

 slowness would preclude the idea that they had any influence on the 

 catastrophe which we have proved to be violent and sudden. 



This latter reason is applied to all the slow agencies that have been 

 imagined, doubtlessly, in the hope that their existence could not be 

 denied, because it would be always easy to assert that their tardiness 

 made them imperceptible. True, or not, is of little consequence; they 

 explain nothing, for no slow causes can produce sudden results. There 

 may have been a gradual diminution of the waters, the sea may have 

 conveyed every kind of solid matter, the temperature of the globe may 

 have increased or diminished, but none of them have been the agents 

 which have disturbed our layers, which have clothed with ice great 

 quadrupeds with their flesh and skin ; which have thrown on dry land 

 those testaceous remains, still as perfect as if they contained living 

 fish ; which have, in fine, destroyed whole species and genera. 



These arguments have struck the majority of naturalists ; and, 

 amongst those who have sought to explain the present state of the globe, 

 there is scarcely one who has attributed it entirely to slow causes still 

 less to causes operating before our eyes. The necessity they have experi- 

 enced of discovering different causes from those now in action has 

 given rise to many extraordinary speculations, and has involved them 



