iji the Quantities of Water afforded by Sprt?igs. 293 

 Tabi-e V. 



From Tables IV. and IV'-, we also obtain the animal re- 

 sults contained in 



Table Vl.f 



These results are obviously dependent on two causes of va- 

 riation; — first, the variable quantity of rain; and, second, the 

 difference in depth at various times. . 



Having already discussed the former, we are enabled to 

 use the data obtained in Table III., having nothing better to 

 apply. Huel Rose and Huel Hope are compared, so far as 

 possible, with Unitetl Mines, being in the same stratum ; and 

 where the observations on the latter do not extend, I make 

 the comparison between the former and Dolcoath. Poldice 

 is also brougiit to the standard of Dolcoath. Huel Reeth (in 

 granite) is reduced to the ratio of Huel Damsel. 



I To coinplctc this, I have been compelled to interpolate from Tables 

 IV. IV^ and V. 



