$28 TRAVELS THROUGH NORTH AMERICA t 
the purpose of getting salt-petre, with which 
the earth is strongly impregnated. The earthy 
after being dog up, is mixed with water, and 
when the grosser particles- fall to the bottom, 
the water is drawn off and evaporated; from 
the residue the salt-petre is procured. There 
are many other caverns in this- neighbourhood, 
and also farther to the westward, in Virginia* 
from all of them great quantities of salt-petre 
are thus obtained. The gunpowder made with 
it, in the back country, forms a principal ar¬ 
ticle of commerce, and is sent to Philadelphia 
in exchange for European manufactures. 
About two thirds of the way down this 
long passage, just described, is a large aper¬ 
ture in the wall on the right, leading to an¬ 
other apartment, the bottom of which is about 
ten feet below the floor of the passage, and 
it is no easy matter to get down into it, as 
the sides are very steep and extremely slippery* 
This is the largest and most beautiful room 
in the whole cavern ; it is somewhat of an oval 
form, about sixty feet in length, thirty in 
breadth, and in some parts nearly fifty feet 
high. The petrifactions formed by the water 
dropping from above are most beautiful, and 
bang down from the ceiling in the form of 
elegant drapery, the folds of which are similar 
to what those of large, blankets or carpets 
o 
