105 



If A B be taken iirertter than one liundrefl. while A D remains ten, 

 or if we have anj- similar relation between the two. it will l)e more ad- 

 A'autageoiis to use the Fourier's integral instead of the Fourier's series, 

 since for such a difference between A B and A D the area may be con- 

 sidered as an intinite strip. 



The results obtained are especially interesting in connection with the 

 motion of ground water, because of their bearing on the theory of ore 

 deposits, artesi.au wells and drainage flumes. The fact that sand through 

 which water is flowing, as before indicated, can he replaced by an ideal 

 liquid having a Aelocity-potential which is identical with the pressure 

 opens a new field of investigaiicn in Ir.drndyiiamies from which many 

 important results will be obtained. 



Tiq.-l 



