Mineralogy, Geology, &c. 41 
and S. W. and of its dip, which is to the east, at an angle 
generally over 45 degrees and often much larger. This 
marble is not all white; much of it is grey, of various 
shades, and near its junctions with the other primitive rocks, 
it is much mixed with the mica quartz, &c. which are found 
in them. ‘The Lanesborough marble is generally spoken 
of as the whitest in America ; probably its finest specimens 
are not surpassed in this country, but we were disappointed 
in finding that but a small part of it, comparatively, is ofa 
pure white ; the greater part is mixed with dark colours, 
and many extensive ledges are of a gray colour. We found 
the workmen quarrying it under circumstances of conside- 
table danger. The strata over their heads being in a sloping 
position like the roof, of a building, and being also com ws 
divided in the di mn of their length and breadth, b; 
ng only by the feeble adhesion of the : parts s of the stone 
iteolf at the bottom and ends of the uncovered layers ; 
these being of the extent of some yards in breadth, and of 
many yar ds i in length, presented, of course, an enormous un- 
supported mass, which gravity was constantly urging to its 
fall e remonstrated with them as to the danger, and 
suggested to them the obvious and effectual expedient of 
st of timber; they assented to the danger, but eons 
very little disposed to take any trouble to prevent the ac 
cidents, which are the more probable to occur from the c con- 
ea exertion of force, by implements and gun p wder 
ttom of these vast pendent ledges of marble. 
‘A small cavern. It is but a short time since a ae cav- 
ern was discovered between the strata of marble in one of 
great difficulty, in, feet first, by lying nearly flat on one 
side, and thas pushing ourselves patie by the bands: and el- 
bows. narrow passage is however = on a few feet in 
length, ‘and? when once entered, we could walk erect, with 
sufficient room in every direction. “This cavern is only one 
eats and fifty f feet in length, and would scarcely be 
orth ceurrence of caverns in re- 
sats of primitive limestone a. | comparatively rare cireum- 
stance ; they being amie more Ses ae in transition ape 
seconda ary regions. say ' 
Vor. IV.....No. 1. 6 
