Lesson xxx.] SPRINGS. 



it is natural to inquire of what use they are. Ad 

 perhaps none will offer a more probable answer to 

 this inquiry, than those who say the waters of the 

 sea are by such means conveyed through subterra- 

 nean channels to the sides of mountains and hills, 

 whence they gush out at convenient apertures, and 

 form springs. 



Each of the hypotheses here advanced admits of 

 objections. To the first two it is objected that they 

 are not the only ways in which Springs are pro- 

 duced: for as causes may always be measured by 

 their effects, it is unphilosophical to conclude, that 

 an inconstant cause will produce a constant effect 

 and therefore Springs which constantly send forth 

 the same, or nearly the same quantities of water, 

 cannot be supplied in the manner pointed out 

 under the two first hypotheses, where the causes, as 

 pain, snow, or vapours, are inconstant or variable. 



Suppose the truth of this remark be allowed, it 

 does not follow from this, that all Springs are pro- 

 duced in some other way. Perhaps, if the nature 

 of Springs, and the nature of the hypothesis be 

 compared, we shall, by such comparison, be 

 brought to a very different conclusion. 



Let us consider the first hypothesis. Neither rain 

 nor snow continues without intermission : but 

 there are intervals between the showers, during 

 which neither rain nor snow descends. Is it not 

 probable, that those Springs which flow and stop 

 alternately, and are therefore called intermitting 

 Springs, are caused by these showers ? It may, 

 perhaps, be objected, that in such Springs, the- 



time 



