130 
AN  AUTOMATIC  •  VACCUUM  APPARATUS. 
self  for  its  simplicity,  its  comparatively  small  cost,  its  automatic 
action  and  its  inexpensive  operation. 
This  plan  was  devised  by  the  writer  several  years  since,  but  it 
is  proper  to  remark  that  it  has  never  been  put  into  actual  prac- 
tice. 
The  peculiarity  of  the  method  consists  in  the  means  employed 
for  effecting  the  exhaustion ;  it  is  founded  upon  the  well  known 
principle  of  the  Torricellian  vacuum.  Substitute  for  the  baro- 
metric tube  of  thirty-four  inches,  one  of  water  of  as  many  feet, 
SCALE  OF  INCHES 
 1-foot      a  feet 
1 1 1 1 1 1 1 1  hi  1 1 1 1 1 1 1 1  lirff) 
Dimensions  in  inches. 
18X60 
7-5X13 
8X13-75 
18X28 
Diameter  11 
Capacity  in  gallons. 
66-09 
2-48 
2-99 
A — Vacuum  chamber  
7?— Reservoir  
C — Receiver  
D — Condenser  
E— Still,  with  an  eight  inch  opening   Diameter  11  2  82 
F—  Still  head.  G — Water-bath,  a—  Vacuum  guage ;  a  bent  glass  tube  communicating  with  the 
vacuum  chamber.  The  closed  limb  is  completely  filled  with  mercury,  which  also  slightly  ascend* 
into  the  other  limb.  Behind  the  tube  is  a  scale  of  inches,  b — Hydrant  pipe,  c — Stopcock,  actu- 
ated by  the  float,  d — Pipe  allowing  the  egress  of  the  air  from  the  vacuum  chamber,  and  also  the 
escape  of  surplus  water  into  the  reservoir,  e— Stopcock,  closed  by  a  spring  attached  to  the  rod,  g. 
y_gpring,  g — Hod  connected  with  the  float,  h — bloat,  i — Pipe  issuing  from  the  bottom  of  the 
vacuum  chamber.  It  is  provided  with  a  stopcock,  (j)  and  is  thirty-six  feet  long;  its  lower  ex- 
tremity being  turned  upwards  and  surmounted  by  the  funnel,  k.  j — Stopcock,  k — Funnel-shaped 
vessel,  furnished  with  a  spout.  I — Tube  connecting  the  vacuum  chamber  with  the  receiver, 
m— Stopcock,  n — Glass  guage  tube,  showing  the  height  of  liquid  within  the  receiver,  oo — Con- 
densing tube,  p — Stopcock,  q — Gas-burner,  rr- -Connection  couplings. 
