ut pure gold and
silver could ever stand such treatment. It is melted again, dissolved
in nitric acid, squeezed under immense pressure, baked in a hot cellar,
and finally carried to this dingy-looking room, at the left of the
court-yard, where we have stood all this time. The metal is perfectly
pure now, but before the final melting one-tenth of its weight in
copper is added to it, to make it hard enough to bear the rough usage
which it will meet with in traveling about the world.

The room would be dark but for the fiery glow of the furnaces which
line one end of the place. On these are a number of small pots, filled
with red-hot liquid metal; and while we look, a workman lifts one after
another, with a pair of long tongs, and pours the glowing gold in
streams into narrow iron molds.

"This piece of gold," says the usher, taking up one of the yellow bars
from a cold mold, "is called an ingot, and is worth about 1,200
dollars."

One of the party asks why one end of the ingot is shaped like a wedge.

"That it may enter easily between the rollers," is the reply. "You will
see the rollers when we go upstairs."

The guide calls our attention to the curious false floor, made of iron
in a honey-comb pattern, and divided into small sections so that it can
be readily taken up to save the dust. He tells us that the sweepings of
these rooms have sometimes proved to be worth fifty thousand dollars in
a single year. The particles which adhere to the workmen's clothing are
also carefully saved, and there is an arrangement in the chimney for
arresting any light-minded atoms that may try to pass off in the smoke.

We would gladly remain longer, peering in at the glowing fires and the
swarthy figures of the workmen, but our guide is already half-way
across the court, and we reluctantly follow, stepping aside to make
room for a workman with his burden of silver bars, which he is carrying
to the next process.

This takes place in the rolling-room, where the short, thick ingots are
pressed between two steel rollers, again and again, till they are
rolled down into long thin ribbons of metal about the thickness of a
coin.

[Illustration: THE ROLLERS.]

The next step in the work is to draw the metal ribbons through a
"draw-plate," to bring them down to an exactly uniform thickness. This
pulling through a narrow slit in a steel plate hardens the metal, and
again and again it has to be put in the fire and brought to a light red
to