Watertown republican. [volume] (Watertown, Wis.) 1860-1906, 1891-09-30
HOW MIRRORS ARE MADE.
The Best Are Now Backed With Plates OF
Pure Silver.

The Best Are Now Backed With Plates of
Pure Silver.
Probably few of those who find the
mirror so essential an article in the
home know that its manufacture is one
of the most closely guarded secrets in
the industrial world. It is asserted on
high authority that, simple as would
Seem the few processes required, even
those who have worked for years on
one portion of the production, know
nothing of the other branches. There
are but few manufactures in the
country; in fact, in all the great manu-
featuring region lying between New
York and Chicago but one firm pro-
duces plate glass mirrors.
So closely is the secret of fine mirror
making kept, it is said, that many of
the most valuable processes are not
even covered by patent, the procuring
of which would be attended with more
or less publicity. even in those cases
where patent might legally be claimed,
and the knowledge lives close locked
in the breasts of out few people in the
whole country. The plate glass which
the choicest description, as the slight
est flaw would be fatal 1t
is taken in the unfinished
form to the factory, where it is cut,
beveled, polished and silvered The
time REQUIRED IN the manufacture has
been greatly shortened by the recent
developments of the art of working, so
that what only a few years ago re-
CURED nearly a mouth in the accom-
plishment may now be completed with
in a single day.
The bevels are cut, first by the action
of sand and water, followed by the
open to public inspection till the polish
ing, through several additional pro-
cesses, has been completed. But it is
the silvering that the most delicate and
important steps are taken, as the most
carefully prepared glass is valueless if
the silvering be anywhere detective
Formerly the back OF the glass was
coated with mercury, or quicksilver,
from which the name OF the process
was derived; but the name is now even
more true, since the backs of fine
sheets Of pure silver-or it would be
more proper to say that they are
backed with plate Of silver. This is
a great Improvement in many ways, to
say nothing of the economy in the use
of quicksilver. Not few good house
wives will recall how provoking it has
been to find that patch Of the coating
had peeled from the mirror in the
''spare room,'' the loss rot being dis
covered till a valued and perhaps
slightly critical guest was expected as
an occupant for that very room, and
when there was no time, and perhaps
not the means, TO replace the now
worthless looking-glass. This can n6t
happen, of course, when the backing is
a solid sheet Of metal Another adj
vantage is in the greater reflective
powers OF the pure silver as now pre-
pared. Formerly reflection of two
thirds the light received was a very
fatjering result, and as low as sixty
per cent. was very satisfactory; now at
least ninety-ive per cent. of the light is
reflected from frst-class glasses New
ton Norton, in Jury.
-COuHteSS NyueHUfuch, cdltIly
Austrian lady, has sold one of her es-
tates in Karnthen, the old castle of
Tazenberg, which was built in the fif-
teenth century by the archbishop of
Salzburg This prelate was man of
queer and curious fancies, and after
bordering long and gravely as to what
should be the unique feature of his cas-
tie, he determined to make it a kind of
perpetual almanac by giving it as many
gates as the year has months, az many
rooms as the year has weeks, and as
many windows as the year has DAYS.