274 THE GEOLOGIST. 



then taking a small lead/' on the walls of which some portions of 

 *'Brush"-or8 still remain, we crawl now into the ''Wide road" or 

 great " churn." The first thing that we see on raising our heads is a 

 rude pyramidal heap of stones, which will prove very useful to us here- 

 after, as it forms our directing-post to the Way out "—and without 

 some such indicator it is more than probable we might contribute a 

 future ossiferous interest to the caverns ! Separating from each other, 

 and holding our candles with upstrotched arms into the vault above, 

 we gather our first notion of the Sway-pole Hole" — a notion which 

 fills us with deepest wonder — which is even further heightened as we 

 gaze backwards and forwards along a vault where the roof and walls are 

 dimly discernable, and where 



" Beyond is all abyss^ 

 ^Tiose end no eye can reach." 



The dimensions of this " churn," however, are about 350 yards long, 

 by an average height of 14 yards, and 12 yards in breadth ; and, con- 

 sidering that it must have been filled with ore, which alone has been 

 removed, its cubic contents, on the calculation of one ton to the cubic 

 yard, equal nearly 60,000 tons, without including any branch-'' churns'* 

 or " pockets," which would probably raise the quantity to 100,000 

 tons. This "churn" follows the direction of the strike, but pitches 

 across the " bed" at the rate of about six inches in a yard ; the dip of the 

 measures is about one in three. Below, following the dip, there are 

 other churns of great magnitude, but their size diminishes with their 

 depth from the surface : indeed, the largest deposits of ore would seem 

 to have been formed near to the crop of the measures, and it is yet an 

 undetermined question whether "in the deep" the measures "make them- 

 selves," to use a mining term, as strongly as "in the land" : — certain 

 it is that the deep mines have not yet revealed any deposits to compare 

 either in magnitude or productiveness with such churns as the one I 

 have just described. 



The accompanying sketch (PI. YIII.) represents some partly emptied 

 churns, laid open by excavation to the light of day, which I am working at 

 Old Park, near Bream, and which will illustrate the relationship of the 

 overlying stratified rock and the un-stratified " crease," showing at the 

 same time the "leads" and general structure of the deposits. The 

 mystical appearance of the entrances to the excavations and the solitude 



