SIR JOHN HERSCHEL. 321 



In reference to the 3rd and 4th rules it may 

 be observed, that the quantity of precipitation 

 and lightning are greatly diminished, cceteris pa- 

 ribus, by uniformity of temperature, as in the 

 tropical portions of the sea far from land, and 

 other parts of the world where the winds blow 

 long in one direction ; whereas changes of tem- 

 perature are indispensable to the condensation 

 of atmospheric vapour, and to the evolution of 

 its caloric in the concentrated form of lightning. 



CHAPTER II. 



Theory of Winds. 



Of all the subdivisions of General Philosophy, there is none 

 so little entitled to the name of science as Meteorology. 



MASON GOOD. 



THAT the reader may comprehend more fully 

 the connexion between caloric, evaporation, and 

 atmospheric electricity, it becomes necessary to 

 present a cursory view of atmospheric currents 

 generally. 



The unequal distribution of solar caloric over 

 the earth's surface, together with its annual and 

 diurnal revolutions, determine the periodical 

 movements of the atmosphere which surrounds it. 



Y 



