C 459 3 
Bricks employed in building the Wind-Furnaces 
for melting Iron, for coating over the In (ides of Af- 
fay-Furnaces, ufed by the Workers on Metals, and 
on many Occafions of like kind at the Giafs-Houfes, 
both in England and other Nations. 
The Place where it is dug is Hedgerley before- 
mention'd, a fmall Village about 22 Miles from 
London , furrounded with Hills, under one of which 
this Loam lies. The Pits are about a Quarter of a 
Mile South-weft from the Town, and five Miles 
North of Windfor : They extend over four Acres of 
Ground, fituated on the Defcent of a Hill 5 and were 
intended to have been carried over much more 
Ground by the Perfon who now works them; but, 
on Trials, the Loam is found not to extend as was 
imagin'd. 
They dig, before they come at this, a very good 
common Brick-Clay, a Tile-Clay, and a Potter's 
Earth, a kind of Clay of a firmer Texture, and deeper 
Colour, than either of thofe 5 but the Strata of thefe 
are feldom pure or regular, and at the Boundaries of 
the Stratum of Loam a pure hard Sand evidently 
the fame with that in the Compofuion of the Loam, 
but left loofe, from there not having been Clay 
in the Way to bring it into the Condition of the 
perfect Mafs. They have already work'd the Stratum 
fo far as to find it bounded Eaft and Weft by Beds of 
this Sand, and Northward by Chalk, and are there- 
fore afraid it will be foon exhaufted 5 at leaft, what- 
ever they get hereafter muft be procur'd with more 
Labour and Expence, as they have no where to fearch 
for it but higher up in the Hill; from whence it 
muft be fetch'd at greater Depths, and much more 
Ooo Expence: 
