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106 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [June 9, 



them are situated among the beds overlying, and therefore south of, 

 the so-called " calciferous slates." 



Ores of iron occur both in regular strata and in veins ; and it 

 is evident that they were known and worked by our forefathers, 

 although the common tradition of their having been opened by the 

 Romans, and the term "Eoman vein" attached to one locality, 

 would seem, I think, of less weight than the probabiKty of their 

 having been wrought about the time when Queen Elizabeth invited 

 German miners to England, supported as it is by the name Eyesen 

 Hill, by which one of the ancient workings is still known. 



The ores occurring in strata have been found (especially on the 

 flank of the Hangman Hill near Combe Martin, in the valley of the 

 Exe, north-east of Simonsbath, and in the North Eorest, Exmoor) 

 in nodules, generally of small size, and often tilted, with the shales 

 in which they occur, at such considerable angles as to render their 

 working difficult. An uncommon variety, of chocolate- or claret- 

 colour, and with an unusually high per-centage of iron, is seen in 

 the Worth Forest. 



The lodes, or iron -bearing veins of this country, course almost 

 uniformly about E. 10° S., incHning at an angle of from 45° to Q5> 

 southward, and hence appearing to hold so exact a parallelism with 

 the strata, as 'to have been regarded by some observers as stratified 

 deposits. A closer examination shows us slight deviations from 

 such parallelism, both in strike and dip, as well as those irregu- 

 larities of composition which are so characteristic of lodes. It is 

 owing to this latter variability, and to the want of familiarity with 

 similar capricious lode-phenomena, that some disappointment has 

 attended the operations hitherto attempted. Yery few of the works 

 have as yet been pushed to any considerable depth or length ; but 

 all the more extended excavations have exhibited an interesting 

 series of subjects for observation in addition to those above-men- 

 tioned. 



First, haematite- ore, or the anhydrous sesquioxide of iron, has 

 been obtained from near the surface of certain veins in the pro- 

 perty of Fred. Knight, Esq., M.P., especially from the Roman lode, 

 Cornham Ford, and Little Woolcombe, exhibiting small crystals of 

 specular iron, but with a structure throughout the mass distinctly 

 resembling that of sparry iron (carbonate). 



The analysis of that of Cornham Ford, by Mr. Riley of Dowlais, 

 is as foUows : — 



Peroxide of iron 98*41 



Sihca 1-01 



Oxide of manganese 0-29 



Magnesia 0*16 



Phosphorie acid 0*12 



Moisture 0*13 



Oxide of copper 0*04 



Nickel and alumina trace 



100-16 



