( 39 5 ) 
I. An Account of the Strata in Coal-Mines , &c. 
y John Strachey, Ej<fa F. 3^. 5. 
I T was forae Time fince, that in a Letter to one of 
the Members of this Society, I gave an Account 
of the feveral Strata of Earths and Minerals, found 
in fome of the Coal-Works in Somerfetjhire , which 
was printed in PbiLTranfatlions , N° 360. But there 
is one great Error in the Print j for whereas I faid, 
that in thofe Parts they never meet with Freeftone 
over the Coal } the Printer, by miftake, calls it Fire - 
ft one ^ whereas Fireftone is always found in thofe 
Mines, contrary to the Works in Staffordshire , New- 
caftle , and Scotland , where Freeftone does, indeed, 
lie over the Coal. 1 have farther obferved the Strata 
of Stone, Clay, and Marie, of the interjacent Hills, 
where, under the black Marie, lies a fpongy yel- 
lowifh Earth ^ all this lies above the red Soil, which 
I have faid is generally the Surface of the Vallies, 
where the Coal is found. And as this red Mould on 
the Surface degenerates into Marie or Loom, fo, towards 
the North-Weft, beyond or without the Veins of Coal, 
about Winford , in the fame County, it turns to 
Ruddle, or Red-Okre, ufed chiefly for marking of 
Sheep, and for ground Colours or Priming, inftead of 
Spaniff Brown ; and often counterfeits Bole Armoniack. 
But as I never heard any Coal was found to the 
Weft or South of Me n dip -hills ; fo Cotfwold, to the 
North-Eaft,and theChalk-Hills of Marlborough -Downs 
and Salisbury Plains , feern to fet Bounds to the Coal 
Country, to the Eaftand South-Eaft of which Fig 1. 
K k k may 
