{ P75 ) 
and Rock over them, but differ in refped to their 
Courfe or Drift, as alfo in Thicknefs, Goodnefs, and 
Ufe. 
Now as Coal is here generally dug in Valleys, fo 
the Hills, which interfere between the feveral Works 
before mentioned, (eem alfb to obferve a regular Courfe 
in the Strata of Stone and Earth found in their Bowels: 
For in thefe Hills (I mean thofe only that aredifpers’d 
between the Coal-Works above mention’d) we find on 
the Summits a ftony Arable mixt with a fpungy yel- 
lowifli Earth and Clay ; under which are C^arries of 
lyas, in feveral Beds, to about eight or ten Feet deep, 
and fix Feet under that thro’ yellowilh Loem, you have 
a blue Clay enclinable to Marie, which is about a Yard 
thick : Under this is another Yard of whitifli Loom, 
and then a deep blue Marie fofr, far, and foapy, fix 
Feet thick; only at about two Feet thick, it is parted 
by a Marchafite about fix Inches thick. But as this 
fwells beyond the Bounds of a Letter, I mud defer the 
farther Defcription of thefe and fome Lead-Mines to 
another Opportunity ; only ’tis to be noted, that the(e 
Beds of Stom and Marie, different from Coal, lie all 
Horizontal. 
Tour humhle Servant, 
John Strachey. 
VL Sme 
Llllllll 2 
