It  will  be  readily  understood  that  by
varying  the  shape  and  adjustments  of
the  pipes  fattened  to  the  air-holes  and
by  fitting  to  the  pipes  rubber  hose  of
various  lengths  and  connecting  each
with  a  nozzle,  the  blowing-pipe  can  be
given  any  desired  mobility,  and  the
smallest  as  well  as  the  largest  articles,
for  instance  cylinders  3  feet  in  diam-
eter, can  be  blown  with  the  greatest
ease.
Another  use  of  compressed  air  is  for
the  manufacture  of  pressed  glass.  Ap-
pert's  apparatus  consists  of  a  cylinder,
in  which  moves  a  piston.  Thick  rubber
plates  on  both  enas  of  the  piston-trark
serve  for  breaking  the  shocks.  The
core  is  fastened  to  the  lower  pan  of  the
piston,  whose  motion  c&n  be  accurately
regulated.
The  piston  is  put  in  motion  by  a  slide-
valve  constructed  similar  to  that  of  a
steam-engine.    This  machine  can  exert


be  eipenseB  of  blowing  gliOB  hj
ipreBsed  air  are  not  iDcrf^ased^  but
'    >f  the  ^eat  rapidity  of  the


work  rather  di
the  work  ia  eoaie
the  process  does
of  the  present
elf  -


iiahed;  and,  besides,


th  many
:    of    bio


Without  the  aid  of  il lustrations  it
would  be  difficult  to  g;ive  a  coiii]ilele
description  of  the  process.  From  the
accompany ing  accnral^  illuBtrations
with  explanations  the  practiciil  impor*


.    will


a  preasare  of  1450  pounds,  and  the

fireflsure  ia  carried  out  nith  such  rapid-
ly that  extremely  tliin  articles  can  be
tnade.     The  average  capacity  of  the


the    ,

Figs.  S2  and  63  show  a  section  of  the
air-noiile  into  which  the  workman  in-
troduces hia  blowing-pipe  in  the  mo-
ment of  blowing.
Fig.  64  is  a  longitudinal  section
through  the  working-room  of  the  glass-

a.  Air  reservoir  under  a  preasnte  of
8.8  pounds.
TECHNO-CHEHICAL  RECKtPT  BOOK.
t-


tmJmimi


TECaMO-CHEMICAI.  BECEIPT  BOOK.
