Report  on  Implements  at  York. 
611 
wires  are  close  together  during  the  operation  of  screening,  which 
of  course  is  only  whilst  they  are  below  the  spindle.  They 
open  sufficiently,  when  performing  that  portion  of  the  revolution 
above  the  spindle,  to  allow  any  grains  that  are  held  between 
the  wires  to  fall  away,  and  thus  this  screen  is  self-cleaning, 
brushes  or  metal  discs  being  done  away  with.  In  two  important 
points,  therefore,  this  screen  is  a decided  advance,  viz.  in  doing 
away  with  the  internal  worm  and  with  the  external  brush. 
The  screen  heads  have  heavy  rims  projecting  considerably 
beyond  the  bosses,  which  fit  loosely  upon  a disc  on  the  shaft. 
the  rate  of  speed  appeared  to  have  no  effect  upon  steadiness. 
And  all  who  witnessed  this  trial  must  have  been  as  much 
impressed  as  the  Judges  with  the  great  superiority  of  Cattley’s 
plough  over  balance  implements.  Working  so  steadily,  it  is 
well  adapted  for  shallow  work,  as  it  made  a good  furrow  when 
only  four  inches  deep.  This  is  the  first  machine  that  has  been 
made,  and  both  price  (150/.)  and  weight  may  eventually  be  con- 
siderably reduced. 
Shield  and  Crockett's  Corn-Screen. — This  is  a circular  corn- 
screen  on  a novel  principle,  and  highly  ingenious,  inasmuch  as 
the  helical  form  of  the  wires  and  the  corrugated  outline  of  the 
screen  secure  the  passage  of  the  grain  with  great  regularity 
without  the  aid  of  a sheet-iron  worm,  so  that  the  whole  of  the 
interior  is  screening-surface.  But  the  most  noticeable  feature 
is,  that  the  screen  is  so  attached  to  the  spindle  that  the  upper 
portion  is  more  extended  than  the  lower,  and  consequently  the 
Fig.  11  . — View  of  Shield  and  Crockett's  Self -cleaning  Corn-screen. 
