The letters are now taken and placed carefully on thin iron disks or
plates on the bench, where they remain until they are fired. It will
be remembered that we said at the outset that the factory was divided
into two large compartments, and it is into the second of these that
we now go.
Here are ranged the series of furnaces which convert the copper and
superincumbent enamel into one common body--fuse the one into the
other. An unwary step soon warns us that we are too near the furnace,
unless we want to run the risk of a premature cremation, and in the
interests of the readers of this journal we step back to a respectful
and proper distance, and watch the operations from afar.
There seems to be something innately picturesque about all furnaces
and those who work about them. Whether it is the Rembrandt effects
produced by the strong light and shade, or whether it is that the
necessary use of the long iron instruments, such as all furnace
workers employ, compels a certain dignity and grace of poise and
action, we know not; but certain it is that the grace is there in a
marked degree, and as we watched the men take their long-handled iron
tongs and place in or lift out the plates of hot metal, we could not
fail to be impressed with the charm of the physical action they
displayed.
The disk containing the enameled letters is taken at the end of a long
iron handle and carefully placed in a dome-shaped muffle. These
muffles are all heated from the outside; that is, the fire is all
round the chamber, but not in it, the fumes of the sulphur being
destructive of the enamel if they are allowed to come into contact
with it. So intense is the heat, however, that a muffle lasts only
about nine days, and at the end of that time has to be renewed.
[Illustration: FIRING THE LETTERS]
After the enamel is fused on to the copper, the disk is taken out and
placed on a side slab, where it is allowed to cool.
This process is repeated on the front side of the letter, when all
that remains to complete it is