The Irish standard., 1886-07-31
EXPLODING GLASSWARE.
How Chi,nneys and Tumblers Fly Into
Fragments Without Apparent Cause.

EAELOIlIN(1 1IAooVAnEs
How Chi,nneys and Tumblers Fly Into
Fragments Without Apparent Cause.
Spontaneous explosions Of glass;
ware?" said w. H. Roby, of the Boston
and Sandwich Glass Company in reply
to query. .'Oh, yes, have often
heard Of such a thing. It occurs not
infrequently in lamp chimneys, espec-
tally of the sort commonly known as
the s:unbreakable. y These chimneys
may be thrown or kicked about on the
floor with impunity, and will seldom
break by such usage They have even
been used as hammer to drive nails
with, and yet they will often explode
without any warning, and apparently
without cause. The other day gentle
man came in here on the same erran d,
to inquire concerning exploding chm
neys. He said that few evenings pre-
vious his wife was about lighting s. large
parlor lamp. The chimney, which was
large and heavy, had been removed and
was resting upon the table near by,
when suddenly it exploded, with a sharp
report, covering the table with frag-
ments Of glass.
Il have heard of an instance in which
3 chimney, after being cleaned, was
placed in q saucer upon a pantry shelf.
Not long after strange cracking sound
was heard in the pantry. Investigation
showed that the saucer was filled with
millions of minute particles OF glass,
which were still stirring and cracking.
Evidently the chimney had sponta-
neously crumbled to fragments in this
instance. instead of exploding. as in the
case of the other. Such occurrences are
not at all uncommon, though they can
scarcely be said to be frequent. They
are, perhaps. more common in lamp
chimneys than in other wares. l have
known chimney attached to q lamp
suspended over dinner table to fly into
fragments without apparent cause,
spreading CONSERVATION among the
guests and spelling the dinner. A mil
lion minute particles of glass scattered
over dinner table is not conducive to q
good appetite. But then, I have known
other articles Of glassware to explode,
sometimes with loud report, tumblers,
goblets and wine glasses sometimes i'y-
ing into fragments without the least
warning. Such occurrences hundred
years ago were undoubtedly regarded as
supernatural.
:'What is the cause Of such explo-
sions?''
*:They may be traced to variety of
! causes. A lamp chimney, when heated,
r.
pansion. Carelessly made chimneys
often vary in thickness, and thus the
expansion by heat is unequal in different
places; hence the breakage But CHM
| news when not in use and other articles
! of glassware which explode suddenly,
are improperly or imperfectly annealed.
s.Now, here are these inkstands,"
continued Mr.. Roby, taking from the
table q large square inkstand of solid
crystal, s.they are liable to break direct
ly across the center as even as though
cut by diamond They are so thick
that they are cooled uneyenly in the an
nealing process, and the weakest point
is through the center. One may last q
lifetime and one may break in 8; night,
and the janitor or office boy be blamed
for his carelessness the next day
Mr.. Dougherty, an old, practical
glass-maker, for many years in the en-
ploy Of the New England Glass Works
at Cambridge, said:
'.It is not uncommon for glassware in
various forms to explode without warn
ing and often with u sharp report.
remember that as much as forty years
ago it was not uncommon for people
10 rush to the works, as pale as ghosts,
saying that dozen tumblers upon q
shelf had exploded, and they were
afraid that it foretold death or other
calamity in the family. 1t was the old
superstition, you see. But it was only
imperfect annealing that caused it. The
art was not understood SO well in those
DAYS as now. There is one odd thing,
that q t,,mbler or goblet which is badly
annealed will explode if spoon, fork
or other hard substance is stirred about
in it,
eyes, interrupted a bystander; 81
remember hearing Of a gentleman Who
left a wine glass with spoon in it on
sideboard while he left the room for
o moment When he returned the
spoon was lying on the marble and the
sideboard was covered with fragments
of glass, AS no one had been near 1t
the gentleman was greatly mystitied. y
''That's it, said Mr.. Dougherty
"The weight Of the spoon in the wine
glass caused it to explode: Why it is,
[ don't know, but it is so.''
'.What is the annealing process?"
was asked.
''rhe articles of glass, after they are
finished. are placed in an oven about
seventy-fve feet long, which is heated
to about two hundred degrees at one end
and is cold at the other. The glass is
placed at the hot end, and when thor
oughly heated is moved two feet away
from the Ere. In few moments it is
moved two feet farther away, and SO on
at intervals until itreaches The cold end.
In this way it is gradually and evenly
cooled. This is called annealing, and
when this is properly done the glass is
not so liable to break spontaneously.
eff this is the final process, much OF
your stock must be broken before it
reaches the ovens?''
Fully one-half is broken before it is
ready for the market, and has TO go into
the pot and be melted over We have
to make two tumblers to get one to