PROHEMIO

digging downward in the manner of wells, they followed it to the depth, and now here,
now there, according as it showed itself to them, they followed it. Concerning this,
it seemed appropriate to me to mention it to you, because to many such a way seems
much better and safer for finding [ore] than digging from the side (so as to always have
the ore original: "minera" before them, whether a little or a lot is found, like a thread for a guide to be able
to follow and go surely to find the main mass original: "massa grossa"—the primary, thickest part of the ore deposit. as if they saw it).
But whoever considers this well will recognize that the moderns have better understood the
necessity of such a thing, in respect (as is seen) to the many more
conveniences and safety that this method provides over the other: such as
the difficulties of descending and ascending in the pit, and the danger of being trapped
by the most frequent collapses, besides the greater labor of drawing out the ore and the
other fragments of the excavated stones; and above all, the inability to properly draw out
the water, of which so much very often overflows that it multiplies
expense and toil for the masters, because of the great number of assistants needed, and also
for the making of wheels, pumps original: "trombe", pipes, pistons original: "standussi"—likely referring to the suction valves or pistons in a reciprocating pump., and other similar instruments to draw it
out. Nor with all this can they often do enough so that they
are not stopped by it. So, to conclude, I say (as you can well understand) that it is
a much better and safer way to begin at the roots of the mountain, digging
and entering it little by little, than from the summit or from the upper ridge; both
to facilitate the exit of water and the transport of the workers, every ten canne A unit of measure; here likely representing a distance of about 20 to 30 meters. going with the
excavation rising very gently by half a braccio A "cubit" or arm's length, roughly 50-70 cm. This slight upward incline (about 1%) allows water to drain out of the tunnel by gravity., always observing the changing signs
that show themselves outside, using the helm original: "timon"—metaphorically used here for direction-finding. and compass just as sailors do,
so that they have reason to always keep the excavation on the straight path, and use
ingenuity and art to lead themselves to the location of the main mass, and where the
cause is that showed you the vapors and mineral signs on the surface. And to this
purpose, it seems right to tell you how in the Duchy of Austria, between Innsbruck original: "Ispruc" and
Hall original: "Alla", many years ago now, I saw an ample valley surrounded by a great number
of mountains, through the middle of which passes a river most copious with water, and in
the mountains that are around it, ore is dug in almost all of them: although
most are of copper or lead, even though in almost all it is found to contain some
particle of silver. And among said mountains I saw one in which certain locals
of the place, drawn by the sight of many signs, began to
dig one in the aforementioned manner, and digging they traveled (in my opinion)
little less than two miles forward before they saw a spark or shadow of ore; and
having almost arrived with the excavation perpendicularly under the signs that above
showed themselves, they encountered a vein of albazano A very hard, typically white rock—often quartz or a hard limestone—frequently encountered as "dead rock" in Alpine mines. stone, most hard
and thick in solid mass more than a canna and a half; which with strong and very hard
iron tools, tempered much more than such stone, with great labor and time they worked until they
passed through it, and having thus passed through it, they encountered a vein of copper ore
of the thickest sort, and of such strength that when I was there, looking between the one and
the other of the two, I saw there to be a wall of hardest albazano; made a va...