250 MIDLAND UNION OF NATURAL HISTORY SOCIETIES. Nov., 1891. 
are now. An engraving of 1821 shows an octagonal tower, 
which has since disappeared, indeed a considerable portion of 
the building was taken down many years ago for the con¬ 
venience of a manufactory, into which the tenantable remains 
were converted, and many now alive remember the fender 
works of Messrs. Marsh, of Burnt Tree, occupying this 
ground. The chain of fish ponds kept and preserved by the 
monks, as was common in olden time, can still be discerned. 
From this point brakes were provided to convey the party 
to the Wren's Nest. The programme supplied for the party 
very succinctly described the characteristics of this remarkable 
eminence. Its form is that of an elliptical dome, and the 
strata which compose and bind it round, rise on the east side 
at an angle of sixty degrees, and on the west side of forty- 
five degrees ; the limestone lies in two beds, the upper, called 
grey or crystalline, about eight yards in thickness, used as a 
flux in the blast furnaces of the district, and the lower, known 
to the miners and those engaged in working it, as blue, about 
thirteen yards in thickness, used for converting into lime, for 
building and agricultural purposes, and which is separated from 
the upper bed by strata of limestone shale, about thirty-three 
yards in thickness. Ingress is gained to the galleries—tiers 
of which run from end to end on either side—at the north and 
south ends where the workings extend to the surface, and on 
the west side by pits seventy-two yards in depth, the bottom 
of which is level with the wharves on either side of a canal 
basin, where the limestone won in the several galleries is 
loaded into boats for conveyance through a tunnel about 
two-tliirds of a mile in length driven through the centre of 
the hill, and showing the double stratification in its entirety. 
The canal joins the Birmingham system at its outlet at Castle 
Mill. The earliest reliable information of the quarrying of 
the limestone is that it was quarried in the outcrop and 
calcined into lime in kilns, placed for convenience as near as 
possible to the point quarried; traces of these kilns being 
visible in several places on the sides of the Hill. According 
to rumour, the coal required in the process was conveyed by 
means of panniers on horses’ backs. Befreshments were 
provided in that portion known as the Daylight Cavern, by 
the kindness of the Earl of Dudley. 
THE OPEN COAL WORKS. 
The open coal works at Foxyards were afterwards 
seen. The site of this work occurs at the north end 
of the glen, stretching away beyond the Castle and the 
Wren’s Nest Hill, the whole of which ground is in a 
disturbed and tangled condition as regards its strata, 
