The Providence news. (Providence [R.I.]) 1891-1906, 1895-11-29
TAE CAST OF A BELL.
1t Il an Interesting se'rocess Which Few
Founders Have Mastered.

The operation OF casting "A bell is most
interesting one. Tho flask whereon and
wherein tho mold is made consists of two
parts constructed of boiler iron of "a gen.
eral bell form and plDltfully perforated
with holes for escaping gas while casting,
one being so much less In size than its fell
loy- as to give space for tho loan forming
around the mold between the two. No
"pattern," as the term is generally used,
Is provided. Tire two parts of the mold
nre swept by formers" accurately
finished from thin iron 20 the form intend
eel for the inncr and outer surfaces Of the
bell. These formers" are mounted and
rotated over the applied loan. Five courses
OF loan and clay are successfully applied,
"swept" and baked, TO complete each
mold. Before 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 as the castings cool, difficulty
would be met with in getting the flask
and loan out Of the nearly parallel inside
top. This pinch" is obyiated by using
this dcstructible base, which permits tho
collapse of the loam after the heat Of the
metal has consumed the hay.
Tho five courses laid on the TASKS are:
Loan, mixture of loan, fire clay and
dered fire clay, and, lastly, thin coating
of brick and fire clay combined with foun-
dry facing. Each of those coatings is baked
in an oven before the succeeding one is ap-
piled. The coatings are "swept" by the
formers, 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 interior a
space corresponding to the intended thick
ness and shape Of the Cell shall exist. In
scriptions or embellishments 60 be made
upon the bell are provided for with the
last coating by means of "knurl," OF
wheel, having the desired motto raised
upon its periphery, the wheel being care
fully rolled around the soft surface and
leaving its imprint in the clay. Other de-
signs arc impressed from dies of the re-
quired ornament, and the usual beading"
is accomplished by notches in the edge of
the sweep.
The two parts of the flask being placed
together ara FIRMLY held in position by
many clamps, the tendency of hot bell
metal 20 squeeze through and forco "a sep
aration of TASKS being very great. As the
mold nears completion fire Is started in
n near by revnrbcratory furnace, in which
is placed the desired charge of copper, and
when the copper Is melted the tin Is added
in It's proportion. The melted metal being
ready, the furnace is tapped the bright
stream caught i'm a huge ladle swung over
the mold by crane aud poured into the
open mouth Of the mold until 1t is hlled.
After cooling and removal from the mold
the bell is usually polished with sand and
water in special revolving grinding na-
chimes. The tongue and olnpper, the yoke
and wheel arc now attached and the whole
suspended i'm it's frame. In making
chime the bells arc, after completion, tenn
porarily set up and regularly tested by
skilled bell ringers, from the permanent
Ginning stand OF tho foundry .--Milwau-
kee Wisconsin.