A, C—Vena dilatata
CROSSING A vena profunda.
B—Vena profunda.
D, E—Vena
dilatata WHICH JUNCTIONS WITH A vena profunda. F—Vena profunda. G—Vena dilatata.
H, I—ITS DIVIDED PARTS. K—Vena profunda WHICH DIVIDES THE vena dilatata.
dilatata WHICH JUNCTIONS WITH A vena profunda. F—Vena profunda. G—Vena dilatata.
H, I—ITS DIVIDED PARTS. K—Vena profunda WHICH DIVIDES THE vena dilatata.
Finally, a vena profunda has
a “beginning” (origo), an “end” (finis), a
“head” (caput), and a “tail” (cauda). That part whence it takes its rise
is said to be its “beginning,” that in which it terminates the “end.” Its
“head”5 is that part which emerges into daylight; its “tail” that part
which is hidden in the earth. But miners have no need to seek the
“beginning” of veins, as formerly the kings of Egypt sought for the source
of the Nile, but it is enough for them to discover some other part of the vein
and to recognise its direction, for seldom can either the “beginning” or the
“end” be found. The direction in which the head of the vein comes into
the light, or the direction toward which the tail extends, is indicated by its
footwall and hangingwall. The latter is said to hang, and the former to lie.
The vein rests on the footwall, and the hangingwall overhangs it; thus,
when we descend a shaft, the part to which we turn the face is the foot
wall and seat of the vein, that to which we turn the back is the hanging
wall. Also in another way, the head accords with the footwall and the tail
with the hangingwall, for if the footwall is toward the south, the vein
extends its head into the light toward the south; and the hangingwall,
because it is always opposite to the footwall, is then toward the north.
Consequently the vein extends its tail toward the north if it is an inclined
vena profunda. Similarly, we can determine with regard to east and west
and the subordinate and their intermediate directions. A vena profunda
which descends into the earth may be either vertical, inclined, or crooked,
the footwall of an inclined vein is easily distinguished from the hangingwall,
but it is not so with a vertical vein; and again, the footwall of a crooked
vein is inverted and changed into the hangingwall, and contrariwise the
hangingwall is twisted into the footwall, but very many of these crooked
veins may be turned back to vertical or inclined ones.
“head” (caput), and a “tail” (cauda). That part whence it takes its rise
is said to be its “beginning,” that in which it terminates the “end.” Its
“head”5 is that part which emerges into daylight; its “tail” that part
which is hidden in the earth. But miners have no need to seek the
“beginning” of veins, as formerly the kings of Egypt sought for the source
of the Nile, but it is enough for them to discover some other part of the vein
and to recognise its direction, for seldom can either the “beginning” or the
“end” be found. The direction in which the head of the vein comes into
the light, or the direction toward which the tail extends, is indicated by its
footwall and hangingwall. The latter is said to hang, and the former to lie.
The vein rests on the footwall, and the hangingwall overhangs it; thus,
when we descend a shaft, the part to which we turn the face is the foot
wall and seat of the vein, that to which we turn the back is the hanging
wall. Also in another way, the head accords with the footwall and the tail
with the hangingwall, for if the footwall is toward the south, the vein
extends its head into the light toward the south; and the hangingwall,
because it is always opposite to the footwall, is then toward the north.
Consequently the vein extends its tail toward the north if it is an inclined
vena profunda. Similarly, we can determine with regard to east and west
and the subordinate and their intermediate directions. A vena profunda
which descends into the earth may be either vertical, inclined, or crooked,
the footwall of an inclined vein is easily distinguished from the hangingwall,
but it is not so with a vertical vein; and again, the footwall of a crooked
vein is inverted and changed into the hangingwall, and contrariwise the
hangingwall is twisted into the footwall, but very many of these crooked
veins may be turned back to vertical or inclined ones.
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