NOTES ON THE EARLY HISTORY OF STONEHOUSE. 373 
sound of the voice, or of a mallet within, might be distinctly heard 
without : In consequence of which, a very large opening has been made 
into it. At the bottom of this vault, in a place not readily observed, is 
another well of water, the depth of which, on account of its situation, 
cannot be well fathomed, nor the breadth of it ascertained. 
" While the miners were exploring those gloomy and grotesque regions, 
they were alarmed at a murmuring sound that seemed to come from the 
hollows of the cave ; and one of them, who chanced to be near the 
largest well with a candle in his hand, saw at that instant the water rise 
about half a foot. This phenomenon then could not be explained. But 
now we think that the several wells are nearly on a level, and that the 
waters shape their course towards the sea, and mix with it in Mill Bay, 
at the distance of four hundred and twelve feet. It is not certain 
whether those wells, though they lie below the extremity of the lime- 
stone, have a mutual communication or not ; but it is highly probable, 
as the bottom of the largest well is clay, and its sides are shelvy slate, 
that there are springs ; and it is certain that this shelvy vein of slate, 
nearly of the same kind and colour with some seen at Mount Edgecumbe, 
on the opposite shore, is continued even to the sea, where two openings 
at low water have been found, through which it is probable the water of 
the great well discharges itself. When the tide rises, it is presumed 
that the pressure of the sea without retards the course of the water 
within ; and this may account for the rise and fall so manifest at different 
times of sounding : And the same circumstance is observed also in a 
well near the old French prison, in the environs of Plymouth. 
" Each cavern has its arch ; each arch is strong, and in general curious. 
The way to the largest well is, in one part, roofed with solid and smooth 
stone, not unlike the arch of an oven. No one seemed to be affected 
by the damps till he came hither, and then the candles grew dim, and 
one of the investigators, as well as myself, felt unusual and uneasy 
sensations. However, since an opening has been made near the arch of 
the great wall [sic], and the air has had a much freer access, no such 
symptoms have been perceived. It is very likely that the hill itself is 
hollow ; some of the caverns have reciprocal communications ; but the 
clefts are often too narrow for accurate inspection or minute inquiry.. 
The water here and there is still dripping, and incrustations, usual in 
such grottos, coat the surface of the walls in some places. There are 
some whimsical likenesses, which the pen need not describe, nor the 
pencil delineate. Mr. Cookworthy of Plymouth, a very ingenious man, 
and an excellent chymist, has been so obliging as to analize the water of 
the three wells, and has found, by many experiments, that it is very 
soft, and fit for every purpose. 
" I therefore beg leave to congratulate your Lordship on the discovery 
of this water, which, though there was no want before, cannot fail to be 
