1divide it obliquely; however, my discourse is now
concerned mainly with
vena profunda, but most of all with the metallic material which it contains.
53[Figure 53]
vena profunda, but most of all with the metallic material which it contains.
THREE VERTICAL SHAFTS, OF WHICH THE FIRST, A, DOES NOT REACH THE TUNNEL; THE
SECOND, B, REACHES THE TUNNEL; TO THE THIRD, C, THE TUNNEL HAS NOT YET BEEN
DRIVEN. D—TUNNEL.
SECOND, B, REACHES THE TUNNEL; TO THE THIRD, C, THE TUNNEL HAS NOT YET BEEN
DRIVEN. D—TUNNEL.