28 COSMOS. 



have the art of making science inaccessible." An edifice 

 cannot produce a striking effect until the scaffolding is re- 

 moved, that had of necessity been used during its erection. 

 Thus the uniformity of figure observed in the distribution of 

 continental masses, which all terminate towards the south in 

 a pyramidal form, and expand toAvards the north (a law that 

 determines the nature of climates, the direction of currents in 

 the ocean and the atmosphere, and the transition of certain 

 types of tropical vegetation towards the southern, temperate 

 zone), may be clearly apprehended without any knowledge of 

 the geodesical and astronomical operations by means of which 

 these pyramidal forms of continents have been determined. 

 In like manner, physical geography teaches us by how many 

 leagues the equatorial axis exceeds the polar axis of the 

 globe ; and shows us the mean equality of the flattening of 

 the two hemispheres, without entailing on us the necessity of 

 giving the detail of the measurement of the degrees in the 

 meridian, or the observations on the pendulum, which have 

 led us to know that the true figure of our globe is not 

 exactly that of a regular ellipsoid of revolution, and that this 

 irregularity is reflected in the corresponding irregularity of 

 the movements of the moon. 



The views of comparative geography have oeen specially 

 enlarged by that admirable work, Erdkunde im Verhdltniss 

 zur Natur und zur Geschichte, in which Carl Hitter so ably 

 delineates the physiognomy of our globe, and shows the 

 influence of its external configuration on the physical phe- 

 nomena on its surface, on the migrations, laws, and manners, 

 of nations, and on all the principal historical events enacted 

 upon the face of the earth. 



France possesses an immortal work, IS Exposition du 

 Systcme du Monde, in which the author has combined the 

 results of the highest astronomical and mathematical labours, 

 and presented them to his readers free from all processes of 

 demonstration. The structure of the heavens is here reduced 

 to the simple solution of a great problem in mechanics ; yet 

 Laplace's work has never yet been accused of incompleteness 

 and want of profundity. 



The distinction between dissimilar subjects, and the sepa- 

 ration of the general from the special are not only conducive 

 to the attainment of perspicuity in the composition of a 

 j bysical history of the universe, but are also the means by 



