ON THE LEAD MINING DISTRICTS OF YORKSHIRE. 173 
mostly carries considerable deposits, of mixed rich and poor earthy, compact, 
and crystallized Carbonates. 
In such ground, when the vein is very wide and encloses detached masses 
of Gritstone, or when the sides of the lode are much disturbed and broken, 
large crystals of the Carbonate are frequently found pressed flat upon the 
faces formed by the jointing and bedding planes of such Sandstone, for 
some distance from the body of the ore. 
The Limestone beds usually favour the deposits of rich Galena in self 
lumips, or nodules of various sizes. These self lumps are often coated with 
an earthy white Carbonate, which is also frequently found filling the small 
interstices in the adjacent rock, and likewise as a deposit in the nests formed 
by those sudden enlargements and contractions so usual in veins traversing 
the Limestone beds. Not many of the other Lead Ores (which are seldom 
met with, and consequently of little commercial value) have been found in 
our Yorkshire Mines. 
Minium is stated, in most Mineralogical works, to have been found on 
Grassington Moor; but I have never seen, nor heard of any from there, 
and certainly for twenty-six years past none has been found. The Phos- 
phate and Arsenio-phosphate were formerly found at Grassington, principally 
in the Gritstone. 
A small piece of native Lead has also been obtained from the Gritstone 
in those mines within the last four years. 
In each district we have numerous mines; some, that a few years ago 
_ were highly productive, are now nearly exhausted; others, though but 
recently opened, are yielding well; and there is no doubt there are many rich 
_ veins yet undiscovered in both districts. 
By far the greater portion of the present produce from the Northern dis- 
trict is from the Old Gang Mine, in Arkendale; and the Kell Head Mine, 
in Wensleydale; while the Grassington Mines in Wharfedale yield about 
two-thirds of the produce of the Southern district. The produce of the 
county in 1856 was 8933 tons of Pig Lead, or about tth of the total returns 
of the United Kingdom. 
The difficulties and uncertainties which attend mining for Metallic Minc- 
rals are not generally known. 
Many large and regular veins (although presenting very encouraging fea- 
tures) prove totally destitute of metallic mineral; others make rich deposits 
of ore, but of very limited extent; and in our most profitable mines, a con- 
siderable extent of barren ground must needs be opened, even on the best 
‘producing veins. 
At the Cononley Mines, for instance, although profitable for many years 
past, the levels (which are very extensive) have laid open more than 20 
fathoms of totally unmetalliferous, for every fathom of productive ground. 
__ The Sections produced tend to show that Lead Mining in the secondary 
formation is more uncertain in its character than in the more primitive 
rocks. When ore is discovered in the latter, it is reasonably expected to 
continue upwards and downwards to some considerable extent ; whereas, in a 
stratified country, and where the bearing beds are not individually thick, the 
ore at best will not exceed a few fathoms in height or depth, and moreover 
levels may be driven in certain beds without the slightest chance of success. 
_ In one respect the stratified district offers the advantage. The nature 
and thickness of the bearing beds, and the inclination of the strata being 
known, we can generally determine the elevation for commencing an Adit, 
or water level, to drain the productive parts of the veins; and thus avoid 
the cost of engine power for pumping, and other expenses, 
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