224 Analyses of Books. [MAitCH,. 



Breconfeike, as having formerly produced in some years 10,000 

 bings of ore, which would be 2250 tons of lead ; and, p. 232, 

 Hudgill Burn mine, is stated to be yielding 9000 bings, which 

 would be 2000 tons of lead. We have reason to think that the 

 produce of this rich mine has increased and is now near 3000 

 tons of lead. 



But even this has been exceeded by other lead mines, one ia 

 Hulkin mountain in Flintshire, the property of Earl Grosvenor, 

 produced within the last seven years 1900 tons of ore in a quar- 

 ter ; which would be at least 5000 tons of pig lead in the year. 

 And in the same mountain, in the late Earl's time, there was at 

 another mine at one period 3000 tons of ore dressed and 

 washed ready for smelting. 



We need not pursue this part of the subject further : we have 

 noticed it particularly because we are of opinion, that writers on 

 fluch subjects, who have it in their power, would render their 

 books useful and mteresting, if they would register facts which, 

 by affording just comparisons, would lead to great additions to 

 our statistical knowledge, the importance of which is so ob- 

 vious : and further, because errors, such as we have noticed, 

 are copied and distributed by other writers who quote them 

 ■without being able to judge as to the real state of the case. 



The great peculiarity of the country under consideration, is 

 a stratification strikingly uniform in its arrangement and con- 

 taining an extraordinary number of beds, which with unbroken 

 continuity, prevail over a large extent of ground. Some of 

 these beds are peculiar for the rich state of the lead veins that 

 traverse them, while others above or below, though enclosing 

 the same veins, -have produced little or no metal. 



A table exhibiting the relative productiveness of these beds, 

 or a section in which by a figure the proportion of lead in each 

 might have been shown, would have been a very interesting 

 thing. We mean of course, that all that could be thus exhibited 

 would be an approximation to the truth, which might, however, 

 have been collected from the experience and opinions of the 

 best miners. Mr. Forster tells us that the great limestone, which 

 appears to be 21 yards thick, '' (p. 103,) has been nearly as 

 productive of lead ore, as all the other strata taken together." 



The whole number of beds enumerated, which lie beneath 

 the coal measures, reckoning from the deepest stratum of that 

 series, down to the red sandstone, amounts to 148 ; and of 

 these, 122 are classed under the head of lead measures: they 

 consist principally of plate or shale, hazle or gritstone, and 

 limestone, alternating with each other. 



It appears to us from Mr. Forster's notice of the different 

 strata, that lead ore is not found abundantly much under the 

 tuft or water sill (a tender irregular gritstone) lying immediately 

 under the great limestone, and the 38th bed of the series, — hvX 

 this important fact, if it be so, is not explicitly stated, ^'i^ 



