BLACK LEAD. 
473 
above the sea, and its depth about thirty. The 
strata of the mountain are very irregular and broken, 
and the black lead appears to have been found in 
the fissures. The mineral is described as lying in 
the mine in form resembling a tree, having a body 
or root, and veins, or branches, spreading from it 
in different directions : the root, or body, is the 
finest black lead; the branches, the worst; and even 
these decrease in quality in proportion as they are 
distant from the main trunk. The black lead is 
generally imbedded in a blue rock, which is often 
stained as black as the mineral itself to the depth 
of two or three feet. In the deepest mine the black 
lead lies in two veins, which cross each other, and 
the richest lead is said to be at the point of inter- 
section. These veins fall perpendicularly to the 
depth of forty fathoms. 
Tradition says that we owe the discovery of this 
valuable mine to a storm, which blew down a large 
oak, whose roots, tearing up several fragments of the 
rock where it had grown, discovered the lead. For 
some time after the mineral was found it was only 
used to mark sheep ; but as its properties became 
better known its value increased, and the price of 
course kept pace with the demand ; so that when 
Mr. Pennant visited Cumberland in the year 1 77 2 > 
the best kind might be obtained for twelve shillings 
a pound, which now sells for sixty. The mines are 
opened at intervals for a certain period, and then 
closed up again. Formerly this was only permitted 
to be done every seven years ; but it is said that 
