PART IV. 



METEOROLOGY. 



CHAPTER I. 



METEOROLOGY is the science which treats of all the various 

 phenomena which take place in the atmosphere. " Under the 

 term meteorology, it is now usual to include, not merely the 

 accidental phenomena to which the name of meteor is applied, 

 but every terrestrial as well as atmospherical phenomenon, 

 whether accidental or permanent, depending on the action of 

 heat, light, electricity, and magnetism. In this extended 

 signification, meteorology comprehends climatology and the 

 greater part of physical geography ; and its object is to deter- 

 mine the diversified and incessantly changing influences of the 

 four great agents of nature now named, on land, in the sea, 

 and in the atmosphere." [Brande.] 



A meteor is any phenomenon of a transitory nature, which 

 appears in the atmosphere. The various conditions and changes 

 which take place in the air incessantly, with respect to heat, 

 cold, moisture, dryness, &c., are called weather. Observations 

 have been made in all ages of the world upon these phenomena, 

 in order to explain their causes and foretell the changes of 

 weather. But there are so many conditions to be considered, 

 and so many influences which probably can never be under- 



