The Opelousas courier., 1896-01-04
$500
ThE CAST or 4 EEats.

interesting Process tfnlch Few OuDOefS
Have Been Able to Master.
The e%petation of casting p bell is g
most interesting one. The Has'.
wherein and whereon the mold is made
consists of two parts, constructed of
plentifussv perforated with holes for
ESCAPING gas while casting, oba being
80 nush leas In size than it's fellow as
| to give SPACE for the liam forming the
mold between the two. The ''pattetn,"
as the term is generally used, is pro-
vided. The two parts of the mold are
"swept" by formers" accurately fin
ished from thin iron TO the form in
tended for the inner and outer surfaces
Of tbs bell; Thees tformers'' are
mounted and rotated over the applied
loari. Five. courses Of loan and clay
are suegess;selT applied, swept" and
baked, to complete each mold. H5tete
this work is done, however, the inner
flask is wound near the top with a rope
made Of hay. As the shrinkage is very
great rs the castings cool, difficulty
would be met with In getting the flask
and luaIi oat of the Hearty parallel In
side top; this ''Fifcif' is obEisted by
using this d~estructable base, which
permits the collapse Of the loan after
the heat of the metal has consumed
the hay.
The five courses laid on the TASKS
are: LOAN, d mixtsrs OF loan, fire
clay aid ManHrej two Successive eoat-
ings of powdered fire clay, and, lastly,
a thin coating of brick and fire clay
combined with foundry facing. Each of
these coatings is baked in IN oven be-
fore the succeeding one is applied. The
coatings are asWept'' by tic fHrr,ers,
as applied, both in the inner and outer
TASKS, by careful adjustments as to
thickness of materials. SO that when
the exterior mold is placed over the in
terror; a space corresponding to the in
tended thickness and shape of the bell
shall exist. Inscriptions Of ethbsllish"
ments to be made upon the bell arp
provided for with the last coating By
me cans of a "knurl" or wheel, having
the desired motto raised upon its peri
phsry, the wheel being carefully rolled
around the soft surface and leaving it's
imprint iii the clay. Other designs are
IMPRESSED from dies Of the required
ornament, add the usual beading
is accomplished by notcfies Id the edge
of the sweep.
The two parts of the fash being
placed together are firmly held in posi-
ton by many clamps, the tendency Of
hot bell metal TO squeeze through and
force a separation of TASKS being very
great As the mold rears completion
a fire il started In a nearby reverbera-
tory furnace; In which Ii placed the
desired charge Of copper, and when
the copper Is melted the tin is added in
its proportion. The melted metal be-
ing ready, the furnace is tapped, the
bright stream caught in a huge ladie
swung over the mold by a crane and
poured into the open mouth Of the
mold until it is filed. After cooling
and removal from the mold the bell is
usually polished with sand and water
in special revolving grinding machines.
The tongue and claprer, the yoke and
wheel are now attached and the whole
suspended In its frame. In making a
chime the bells are, after completion,
temporarily set up and regularly
tested by skilled bell ringers, from
the permanent Ginning stand of the
foundry.
A bell al such proportions as the
large one proposed for Milwaukee's
city hall hasto be molded and cast il
) pis-Mlwaukss wisconsin,