Mineralogy, Geology, &c. 4} 
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 miea 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 aré of a gray colour. We found 
the workmen quarrying it under circumstances of conside- 
rable danger. ‘The strata over their heads being in a sloping 
position like the roof of a building, and being also completely 
divided in the direction of their length and breadth, by the 
natural seams between the strata, they were kept from fall- 
ing only by the feeble adhesion of the parts of the stone 
itself, at the bottom and ends of the uncovered layers ; 
these being of the extent of some yards in breadth, and of 
many yards in length, presented, of course, an enormous un- 
supported mass, which gravity was constantly urging to its 
fall. We remonstrated with them as to the danger, and 
suggested to them the obvious and effectual expedient of 
props of timber; they assented to the danger, but seemed 
very little disposed to take any trouble to prevent the ac- 
cidents, which are the more probable to occur from the con- 
stant exertion of force, by implements and gun powder, at 
the bottom of these vast pendent ledges of marble. | 
Al small cavern. tis but a short time since a small cav- 
ern was discovered between the strata of marble in one of 
the quarries at Lanesborough; they accidentally opened 
into it, but the orifice is so small, that we could only with 
great difficulty, pass in, feet first, by lying nearly flat on one 
side, and thus pushing ourselves down, by the hands and el- 
bows. ‘This narrow passage is however only a few feet in 
length, and when once entered, we could walk erect, with 
sufficient room in every direction. ‘This cavern is only one 
hundred and fifty feet in length, and would scarcely be 
worth mentioning, were not the occurrence of caverns in re- 
gions of primitive limestone a comparatively rare circum- 
stance ; they being much more frequent in transition and 
secondary regions. 
Vou. IV.....No. 1. 6 
