LIMITS AND METHOD OF EXPOSITION OF THE PHYSICAL 

 DESCRIPTION OF THE UNIVEBSE. 



IN the preceding discourse, I have sought to make manifest, 

 and to illustrate by examples, how greatly the enjoyment of 

 nature, varying as it does in the inward sources from which 

 it springs, may be heightened by a clear insight into the 

 connection of phsenomena, and of the laws by which they are 

 regulated. I have now to examine more particularly the 

 spirit of the method of exposition, and to indicate the limits 

 of the science of physical cosmography, such as I have con- 

 ceived it, and have now endeavoured to display it, after 

 many years of preparatory studies in many regions of the 

 earth. Would, that in so doing, I might natter myself with 

 the hope of thereby justifying the bold title of my work, 

 and freeing it from the reproach of presumption ! 



Before entering on the view of nature, which forms the 

 larger portion of the present volume, T would touch on 

 some general considerations intimately connected with each 

 other, with the nature of our knowledge of the external 

 world, and with the relations which this knowledge presents, 

 at different epochs of history, to the different phases of the 

 intellectual cultivation of nations. These considerations 

 will have for their objects : 



1. The idea and the limits of physical cosmography as a 

 distinct and separate science. 



