692 
of ore are a perfect mash of fossil shells of the genus 
Anthracosia, and the peculiar character thus given to the 
stone makes it easily recognisable. The alteration in 
character, change of name, and variable distance from the 
Park Gate of the Flockton Coal, would have made the 
tracing of the latter, over long distances, a matter of much 
uncertainty, but the constant presence above it of this 
marked stone enables us safely to identify at different parts 
of the field the coal beneath. 
At about twenty yards above the Flockton, is the Joan 
Coal, a very regular bed about two feet thick. 
About a hundred yards above the Flockton, lies a coa], or 
group of coals, about the identification of which in different 
parts of the field there is some uncertainty. Hereabouts we 
find a distinctly recognisable bed, called the Swallow Wood, 
with a dirt parting, altogether about 4' 6" thick. Though 
our information is very meagre, the bed seems to keep this 
character up to Tankersley, where it is worked for local 
purposes, and is about three feet thick. Hence as far as 
Barnsley we learn nothing definite about this coal, but about 
that town it seems to be the custom to bore down below 
the Barnsley Coal, and call the first bed that could by any 
possibility be supposed workable by the name of the Swallow 
Wood. Great confusion has thus crept in; but I believe that, 
though several different beds bear this name, a coal can 
pretty fairly be fixed upon as the equivalent of the true 
Swallow Wood of the Sheffield district; it has, however, 
fallen off very much in quality, and is so split up by dirt 
partings as to be little worth. Further north, between 
Darton and Netherton, there are two poor beds of coal, 
called the Netherton Thick and Thin, which hold about the 
same position in the measures as the Swallow Wood ; and 
still further on these seem to run together and form the 
valuable seam of the Haigh Moor ; but I am here getting 
beyond the present range of my knowledge. 
