404 



D. A. MacAUster—Cassiterite and Spectilar Iron 



Mine. 



Birch Tor and 

 Vitifer. 



Golden Dagger. 



New Birch Tor. 



Dressed 

 Black-Tin' 



Tons. 

 670 



170 



394 



Pekiod of Working. 



From 1852 to 1865; 

 1872 to 1882; 1887 

 to 1890 ; 1903 to 

 1907. 



From 1882 to 1906. 



From 1859 to 1874. 



Remarks. 



In 1882 the metal con- 

 tained in the Black-tin 

 amounted to 64 per 

 cent. 



In 1882 the metal con- 

 tained in the Black-tin 

 amounted to 55 per 

 cent. 



The lodes depicted in the illustration have been mapped on the 

 spot from such evidence as is afforded by open-cuts, lines of trial pits, 



^ ALLUVIUM & VALLEY GRAVEL 

 •\\AIORKED FOR STREAM-TIN. 



I 



CHALL/KCOMBt 



DOWN 



SCALE ^ 



/zMiLL. 



Fig. 



Geological Map of the Birch Tor Mining District, Dartmoor. 

 "• Coarse Forphyrine should read Coarse Porplujrltic. 



