rs a profound secret,
and the French were determined to get at the mystery. Several young
glass-makers went from France to Venice, and applied to all the
looking-glass makers of Venice for situations as workmen, that they
might learn the art. But all positively refused to receive them, and
kept their doors and windows tightly closed while they were at work,
that no one might see what they did. The young Frenchmen took
advantage of this, and climbed up on the roofs, and cautiously made
holes through which they could look; and thus they learned the
carefully-kept secret, and went back to France and commenced the
manufacture of glass mirrors. Twenty years after, a Frenchman invented
founding glass, which gave France such a great advantage that the
trade of Venice in looking-glasses was ruined.

You would be very much interested in watching this process of founding
glass. This is the way it is done. As soon as the glass is melted to
the proper consistency, the furnaces are opened, and the pots are
lifted into the air by machinery, and passed along a beam to an
immense table of cast iron. A signal is given, and the brilliant,
transparent liquid glass falls out and spreads over the table. At a
second signal a roller is passed by machinery over the red-hot glass,
and twenty men stand ready with long shovels to push the sheet of
glass into an oven, not very hot, where it can slowly cool. When taken
out of the oven the glass is thick, and not perfectly smooth, and it
has to be rubbed with sand, imbedded in plaster of Paris, smoothed
with emery, and polished by rubbing it with a woollen cloth covered
with red oxide of iron, all of which is done by machinery.

We know that cut glass is expensive, and the reason is that cutting it
is a slow process. Four wheels have to be used in succession, iron,
sandstone, wood, and cork. Sand is thrown upon these wheels in such a
way that the glass is finely and delicately cut. But this is imitated
in pressed glass, which is blown in a mould inside of which the design
is cut. This is much cheaper than the cut glass.

[Illustration]

A higher art than cutting is engraving on glass, by which the figures
are brought out in relief. Distinguished artists are employed to draw
the designs, and then skilful engravers follow the lines with their
delicate tools. If you will examine carefully the engraving on this
Bohemian goblet, you will see what a wonderful piece of workmanship it
is.

It seems a