4S0 
Report  on  the  Exhibition  of  Implements. 
carrying  20  cogs,  and  keyed  upon  the  shaft  E,  which  shaft  has  a universal 
joint  F ; so  that,  although  the  lower  part  of  this  shaft  is  secured  in  po- 
sition by  the  bearings  a and  b,  the  upper  part,  c,  would  be  free  to  move  in 
any  direction,  were  it  not  controlled  by  means  hereafter  described. 
On  the  lower  part  of  the  shaft  E is  keyed  the  bevil-wheel  G,  carrying 
100  cogs;  into  this  wheel  the  pinion  H works,  carrying  21  cogs,  and 
keyed  upon  the  shaft  I,  which  also  carries  a band-wheel  J,  carrying  a 
strap  in  common  with  a band-wheel  on  a steam-engine  that  gives  motion  to 
the  testing-machine,  and  through  it  to  the  threshing-machine  under  trial. 
By  a careful  inspection  of  the  figure  it  will  be  seen  that  when  power  is 
applied  to  the  band-wheel  J,  and  in  the  direction  of  the  dotted  arrow,  the 
effect  will  be  to  turn  the  main  wheel  C in  the  direction  of  the  arrow  d; 
but  if  resistance  to  motion  is  caused  by  the  short  arms  x,  x,  x,  x of  the 
horse-works  to  the  flanch  A,  the  shaft  B and  the  wheel  C will  be  im- 
movable, and  the  pinion  D and  the  upper  end  of  the  shaft  E will  move  in 
the  direction  cf,  unless  they  were  retained  in  position  by  the  combined 
action  of  the  compound  lever  K and  L (the  radial  bar  M keeping  the  gear- 
work  at  its  proper  depth).  Now,  whatever  stress  may  be  placed  upon 
the  cogs  of  the  wheel  C,  an  equal  stress  is  transmitted  to  the  bearing  C 
of  the  shaft  E : hence  the  levers  K and  L become  a steelyard  for  indi- 
cating the  resistance  of  the  work.  At  the  end  of  Ihe  lever  L is  placed  a 
Salter’s  balance  e,  for  the  purpose  of  keeping  the  power  employed  and 
the  resistance  to  motion  in  equilibrium,  and  for  measuring  the  intensity 
of  these  forces. 
A pencil  is  placed  in  the  end  of  the  lever  L at  h,  and  traces  a diagram 
upon  the  sheet  of  paper  g,  recording  every  variation  of  the  power  em- 
ployed during  the  experiment ; the  sheet  of  paper  passes  from  the  roller  i 
to  the  roller  j ; k is  an  oil  cylinder,  with  a piston  moving  in  it,  and 
attached  to  the  lever  L,  to  check  any  momentary  impulses  either  in  the 
power  of  or  the  resistance  to  the  machinery,  and  l is  a clock  to  record 
the  time  occupied  in  each  experiment.  A counter  is  also  attached  to  the 
6haft  I,  for  the  purpose  of  registering  the  number  of  revolutions  the 
testing-machine  makes  during  that  time. 
The  shaft  I makes  28-571,  a little  more  than  28 J,  revolutions  during 
the  time  that  the  shaft.  B,  the  wheel  C,  and  the  horse-wheel  of  the 
threshing-machine  make  one  revolution.  The  power  of  the  compound 
levers  K and  L is  75  to  1,  and  if  the  shaft  I were  only  to  make  one  revo- 
lution per  minute,  601*42,  or  rather  less  than  601 J lbs.  would  be  required 
on  the  end  of  the  lever  L to  be  equal  to  one  horse-power.  Hence  the 
number  of  revolutions  per  minute  made  by  the  shaft  I,  multiplied  by  the 
weight  on  the  lever  L,  and  the  product  divided  by  60r42,  the  quotient 
will  equal  the  horses’  power  employed  : 
N 
Or  m X W 
TT  p . 
601-42  ’ 
where  N the  number  of  revolutions  made  by  the  shaft  I,  W the  weight 
on  the  lever  L,  T the  time  in  minutes  occupied  in  the  experiment,  and 
H P the  horse-power  employed. 
When  all  is  in  readiness  for  commencing  the  trial  of  the  implement,  the 
machinery  is  put  in  motion  and  a few  sheaves  of  wheat  are  passed  through 
the  threshing-machine,  to  enable  the  exhibitor  to  adjust  his  screen,  con- 
cave, & c.,  in  a proper  manner.  One  hundred  sheaves  of  wheat  are  then 
given  to  him,  and,  upon  a signal  being  given  by  one  of  the  Judges,  the 
feeding  commences.  At  that  instant  an  attendant,  by  a simple  con- 
trivance, instantaneously  puts  in  motion  a counter  (attached  to  the  shaft 
