102 



Prof. J. Prestwich. 



I 



Number 

 in 



list, 

 Table I. 



II 



-Li dblllKj Ul .Llilllt; cblVX U-LdjOt/. 



Ill 



im ature ox rocK. 



IV 



JLJUUl>LL. 









.Feet. 





England — continued. 







18 



Cornwall, average of six mines .... 



Granite and slate. 



700—750 





33 33 33 • • • • 



33 



Qf)0 Q£1 









1350—1400 



54 



and. Devon. ^ Various 



33 



180 





mines in ten districts. 













432 





33 33 33 



33 



762 





33 33 33 





1038 





33 33 33 



33 



1440 



4* 



„ average of 53 mines .... 





354 





33 3J 33 .... 





438 





}3 33 33 .... 



•• 



684 



130 





Carboniferous limestone. 



440 



158 





33 



660f 







33 



i04i|: 



636§ 







.. 



660—1041 



160 





33 



660(j 



1*2 





Syenite. 



324 









384 



115 





Silurian schists. 



552 



116 





JPalceozoic schists. 





IS* 





Carboniferous shales. 



840 





France. 







1 



Griromagny, near Belfort, Vosges . . 



Porphyritic rocks. 



332 





33 33 33 





1420 





33 33 33 





332 1420 



12 





Silurian slates. *^ 



230 







33 



781 







33 



230—781 



11 







459 





Switzerland. 







2 





Metamorphic rocks. 



721 



