
fame would have happened in a ftone quarry, as well
as in a mine : moreover, the great number o f galleries,
filled with quantities o f decayed and rotten timber, produced
obnoxious vapours, and made a hanging vault of
the mine, replete with danger, from the large pieces
which continually tumbled in ; to prevent thefe inconveniences
in future, I laid before the miniftry the following
propofals.
That a new mine ihould be opened lower down, and
a general ihaft funk obliquely, following the direction of
the vein, and leaving a ftaircafe at every twenty feet, to
go up and down. That two galleries ihould be extended
on the vein, one to the right, and the other to the
left, continuing them in proportion as the ihaft went
deeper. That a fpace of three feet Ihould be left on the
vein, between one miner and another, in the nature of
fteps which the French call travailler en banquette. By this
means a file of workmen, from twenty, to a hundred,
might be placed commodioufly, and go as deep as
they pleafed without danger, becaufe the new excavations
are fupported with the ftone and rubbilh dug out o f
the mine, the props which ferve for this purpofe being
folid,and not liable to the fame inconveniences as timber.
The fame ihould be done in the fécond vein, and they
might continue their labours at pleafure ; when they go
deeper,
deeper, a gallery for a communication o f air, muft be
made from one vein to another, by which a conftant circulation
is kept up through the whole, as is always pfac-
tifed in well regulated mines.
My plan was well received by the miniftry, miners were
fent for front Germany, and the whole was tolerably executed.
About this time the Cinnabar mine o f Guanca-
velica, in Peru, had begun to decay, after fupplying the
mines of that kingdom for above two centuries paft with
a prodigious quantity o f quickfilver (a)y that of Almaden
only furniihing Mexico;for which purpofe they generally
extracted five or fix thoufand quintals per annum, but
the miniftry finding it was neceffary to fend more to
Peru, ordered a large quantity to be provided, fo that
from Almaden, and Ahnadcnejos, they extracted about
eighteen thoufand quintals per annum, but the greateit
part came from the mine worked by the Germans.
The Fuggers were the moft experienced; men of their
age, and their ihafts and galleries were according to the
ftriifteft rules o f a r t ; but they never undertook any thing
very; great, perhaps only confideriag themfelves as occasional
tenants, therefore endeavoured to get as much as
they couldat the cheapeft and eafieftrate, concluding their
■ la) The mine o f Guancaveliea was firft difcovered in 1563. See Noticias Americanasi-
Entretenimunto phyfïco hiilorico por Don Ant. de Ulloa» Madrid, 1772, 4to.
H h harvefk