CHEMICAL  AND  PHARMACEUTICAL  MANIPULATIONS.  10 
"A  much  more  convenient  implement  than  the  preceding  is  the  lever  press, 
described  in  Muspratt's  Chemistry,  and  a  perspective  view  of  which  is 
shown  by  Fig.  375.  It  consists  of  two  wrought-iron  pillars  b  b,  supported 
in  sockets  by  the  cast-iron  feet  a  a.  The  bed-piece  c  is  also  secured  to  the 
feet  by  two  perforated  ears,  and  has  two  intersecting  grooves  sunk  into  its 
surface,  as  channels  for  conducting  off  the  expressed  liquid.  The  follower 
~d,  corresponding  in  size  with  the  bed-piece  c,  is  adjusted  to  the  pillars  by 
sliding-ears,  and  has  the  rack-bar  f  fixed  in  the  centre.  The  gearing  is 
sustained  by  framework  e  attached  to  b  b.  Motion  is  effected  as  follows 
The  ratchet-wheel  g  turns  upon  an  axle  having  its  bearings  in  the  top 
frame.    On  the  same  centre  is  a  fixed  pinion  of  eight  teeth,  only  partially 
Fig.  375. 
the  fi; 
pure,  which  works  in  the  wheel  i,  of  twenty-four  cogs ;  and 
upon  the  axis  of  i  is  another  eight-teeth  pinion,  which  acts 
upon  the  rack.  The  lever  k  is  forked  at  the  extremity 
nearest  the  small  winch-handle  l,  and  the  terminations  of 
of  the  furcation  are  received  upon  the  axle  g.  A  pin,  near 
h,  is  adapted  to  a  small  hole  in  the  frame,  by  the  insertion 
of  which  the  descent  of  the  lever  may  be  prevented.  The 
matter  to  be  pressed  is  placed  in  a  shallow,  cylindrical 
box  a,  of  tinned  copper,  Fig.  376,  which  rests  upon  the 
bed  c  of  the  press.  To  prevent  the  contents  from  being 
pressed  against  the  sides  of  the  cylinder,  and  thus  abstruct- 
ing  the  flow  of  the  liquid  thence,  it  is  necessary  to  use  a 
perforated  band  with  perpendicular  ribs  on  the  exterior. 
Being  movable  and  formed  of  two  parts  joined  together  by 
