Copper Mines. 507 
view to supplying Jerusalem with water. This most de- 
sirable work is now completed. 
“Two lines of telegraph, wd Beyrout and Alexandria 
respectively, connect Jerusalem with Europe. 
“Jerusalem, Jan. 16, 1867.” 
COPPER MINES, NO. III 
(Continued from page 37 5.) 
HE expense of mining increase in proportion to the 
depth ; so that the same quantity of ore which, toa 
certain depth could be raised at a profit, would, at a greater 
depth, be not worth raising at all. These expenses consist 
chiefly in the various machinery required, but more parti- 
cularly steam-engines, of which, in a large mine, there are 
frequently not fewer than seven, eight, or ten. These are 
used partly for the raising of ore, and partly for clearing 
the mine of water, which would otherwise soon fill it en- 
tirely ; for in all mines there is a constant oozing of water 
from the sides, which to a certain depth proceeds from the 
rains and other aqeous collections on the surface, beyond 
that depth from springs. However inconvenient such 
waters may be considered, it is, nevertheless, attended with 
two advantages—one, that the stone is rendered less hard 
by its continual exudation, and the other, that the oxygen 
‘from it supplies, in some degree, the want of air. 
In many mines, the inconvenience of want of air is 
removed by cutting the levels or passages in a direction so 
as to admit the outer air. Thus, if the mine be upon an 
eminence, where there is a sloping side, or where there 
happens to be a ravine, cavern, hollow, or fissure, at no 
great distance, the passage which is made to open into it, 
is termed an Adit; but metal has too. frequently to be 
worked where this is impossible, such as under the sea, or 
quite in the bowels of the earth. 
Since the application of steam to the purposes of 
machinery, and since the improvements which have taken 
place in mechanics within the last fifty years, mines have 
been sunk much deeper than formerly; for prior to those 
improvements, it was impossible to excavate them with 
advantage, to any great depth, and many were consequently 
abandoned. Numbers of such abandoned mines have been 
