
~~~~~~~~~~~~~~~005r~~~~~~~~~~~~~~~


or linen & leave it thus for xx4
hours & it will be engraved. But if you should
want to engrave quickly, varnish all your work & boil it in the
aforesaid liquor, and it will engrave quickly.


Steel mirrors

+They are called of steel because in the
past they were commonly made of steel polished with
potée of emery. But more easily, various kinds are made
of cuivre franc, which is rosette, and
tin, because this can be cast in a mold & made
round, concave, convex & however you like, to produce various
forms.

So take half of rosette copper & half
of soft tin, that is to say fine, which has not yet been used.
Put them in a crucible, & first melt the copper
well. And once it is well melted, put in the tin and mix
together. Then cast in the mold, of white stone with no
eyelets, & grease the mold with oil, & let
the mold be moderately warm. Then, having
molded your mirror, you can polish it in this manner.

Set one of these in plaster in order that it holds firmly,
& then put the other one over it with thin sand in between,
& rub one against the other, whether hollow or flat, & thus you
will polish two at once. And if you want to polish them on both sides,
you only need to switch them, which means putting the one that was
polishing into the plaster & using the one that was in the
plaster to polish. After having polished them with the
arene you can soften them with tripoli
of Venice, which should not be sandy, & after with
potée. You polish with
arene using water, but polishing with
tripoli & potée is done
dry. Once polished, you can set it.


Concave mirrors

The concave mirror composed in the aforesaid form produces an
endless number of illusions which seem magic. If someone wants to see
oneself from behind, it is necessary to place the concave
mirror on the ground on its foot, & let it be at a slant;
after, look at it one step away. But if you
look at it closer up, it will show you the right way up but
with your face quite large & the hairs of your
beard as thick as

