The evening times., 1901-09-12
MAKING LAMP CHIMNEYs.
An Interesting Process From sand
to the Finished Globe.


Perhaps the most important feature in
the manufacturc OF lamp Chimneys, or.
indeed. the manufacture Of any form Of
glassware. is the mixing Of the iugredi-
oHts. As in the case Of plate glass. the
body Of the mixture consists Of a sand
which is as n-arIy pure silica rock as can
be- obtained. The sand is quarried from
silica rock, then thoroughly ground and
sifted through a f5-mcsh screen, the mate
rial being received at the works in the
prepared condition. The second most i'm
portaut Ingredient is Htharge; while pot
ash and soda are used as fuXes. When
the above mixture Is used for the best
quality of lamp cEimneys about 80 per
cent Of the total is silica The sand is
melted In what is known as the fur
mace. "a large COniCai structure which is
fired by gas from beneath and contains
some fourteen To sixteen large melting
pots. which are nodded from specially
prepared and very carefully kueadad pot
clay The melting pots are generally for
ty-i0Br inches In their largest diameter.
aud hlty inches IN height. They are ar
ranged IN a circle within the furnace. each
one opposite a UJcr. II takes rweuty-four
hours 10 melt the contents Of pot Of the
size Just described. Ordinarily the con-
tents are made up of part Of the prepared
mixture and part Cullet-that is. glass left
over from previous days Of Cp-rati0uss
The blowing is done with long iron
tube. known the blOWpiUe. which has
a mOuthpieCe at one end and is swelIed
out and thICkenCd into a beIl-mOUth form
at the lower end. In the process OF blow
ing. the operator dips the thickeued end
INTO lnc melting pot ana twists u around
until 10 has gathered up bali of molten
glass of desired size. The bl0wpipe
iS then Withdrawn from the furnace and
the BAH nt glass Is rolled out to a couiCal
shape on plate and slightly inflated by
blowing through The tube. The bIOwpipe
is then handed To the second operator.
who completes the operation of blowing.
The bubble. II We may so CaH 1t. Of glass
Is thicker and heavier at its lower end,
and 20 secure the elongated form neces-
sary ~ lamp chimueys the operator
swings the BIOWpIVr 10 and fro. thus Caus-
ing the bubble 20 stretch By its own
weight. BY thus alternately swinging
and blowing he brings the bubble to the
required diameter, and then places it
within a hinged mold. which is opened 10
receive it. either by himself or one Of his
assistants.
lie then twists the pipe and blows at
The same time. thus pressing the glass
against The inner walls Of the mold The
tube. with the nodded chimney attached.
Is then Withdrawn from the mold and
handed TO another operator. who. with
"a pair Of spring t0usS. forms the harUg
top OF the lamp chimney and marks
sharp depression just outside its base.
where ID is 20 be broken away from the
blnWblp'- AltEDugl a large amount OF
blowing is done Joy hand and mouth in
crsasing use is being made o. what is
kHu"u as the owens blowing machine.
which substitutes mechanical for hand
power Ihis consists Ct vertical stand
at th- base OF which IS circular table,
carry inS hdli a dozen of the hinged molca
already referred To- After the nrst ope-
E@l'r h1S blown and elongated the ball
OF glass 10 the desired shape. the blow
pipes aT" placed in the m0lu. with the up
per end ot the tubes secured in the clamp
near tho top OF the stand To each OF the
tubes Is connected rubber hose, which
Is supplied with air from small air
Iui--p located on ana forming part of
ln- W''hiHt me Japlc. with It's blow
ri''. Is rotated ana AR pressure is ep-
pine" tLi'Hsn lile nose Etll p o|zrN chin
"-lo D-liE lHuo blo"u anu H4lut4 al me
adli' 'i--.
me ,hlIllHtys arc G.Nt carried 10 the
"H5r'iHS furnace. mis- Is constructed
'HL'LEh III. '.. zee from sHu 70 end l1e
Chlnnel ar. ...d up thlckly upon IN.
b'lI ana tAi.i...t 'EIslSA the furnace ue
convey rT move F'ilnrl.ullE SLOWLY 70 sub
Jet '3Gh CHIMNEY 10 Jh' neat or the Iur-
mace i'F from lWtiNt Z" twenty -touT
hpnTs- AIJeT anhrLllnE lne chimney Is cut
down 10 lrhSth- rms cutting IS done by
i'l"JlhE lhr chimney horiz"nlaiy above
lNp INC lItths. rLse Sllts- through "hlch a
.l'--. ~ ga ny ~ 4-'P-.-hr9 3N tle
, EL.LNs - 'tIg tr pol-L "lleLe II Is 10 he cut
t'i n.5L m | S'lilll . So -p 9g ms iocti
u5-,i- e - - -, ,'I - - Dl'y 81
y 10 alltllA1 tLlf lb blt-h bLl ttlt-