1 rials  of  Agricultural  Motors. 
187 
because  the  time  occupied  in  the  headlands  varied  considerably 
as  the  plot  ploughed  became  wider;  but  it  may  be  mentioned 
that  the  speed  of  ploughing  in  the  case  of,  for  example,  the 
McLaren  tractor  was  sometimes  considerably  more  than  five  miles 
per  hour,  at  wThich  speed  the  land  in  the  dryer  parts  was  much 
broken  up  and  roughly  laid  over. 
This  ploughing  was  not  so  pretty  to  look  at  immediately 
afterwards,  but  the  disintegrated  condition  would  in  some  lands 
be  advantageous. 
The  measured  area  of  ploughing  having  been  completed, 
and  other  intermediate  trials  made,  the  ploughs  were  taken  to  a 
second  field  at  a distance  of  about  a quarter  of  a mile  where  the 
land  was  of  a heavy  and  very  tough  description,  closely  overlying 
a chalk  bottom.  Here  the  tractors  were  tested  by  ploughing  to 
a depth  varying  from  4^  in.  to  7 in.  and  on  an  average  from  9|  in. 
to  10  in.  in  width  per  furrow.  The  work  in  this  field  was  a heavy 
test,  although  not  so  difficult  as  if  the  land  had  been  in  a wet 
condition.  The  McLaren  engine,  for  example,  ran  over  this  land 
with  fully  as  much  speed  as  the  ploughs  could  withstand. 
The  Mann’s  tractor  was  not  so  fully  the  master  of  the  work  in 
this  field,  but  both  it  and  the  Wallis  and  Steevens’  engine  accom- 
plished the  work  without  apparent  material  damage  to  the  land 
by  pressure  upon  it. 
The  Ivel  tractor  with  two-speed  gear  was  also  taken  into  this 
heavy  land,  but  it  was  found  that  the  three-furrow  plough  was 
more  than  this  rather  high-geared  motor  could  manage,  and  the 
slower-geared  single-speed  tractor  was  therefore  put  in  its  place, 
and  this  succeeded  in  hauling  the  plough ; but  the  draw-bar  pull 
lifted  the  front  wheel  off  the  land  so  much  that  it  was  difficult  to 
steer,  and  the  ploughing  consequently  difficult. 
The  Saunderson  tractor,  entered  as  45-50  b.h.p.,  was  also 
taken  into  this  field,  and  evidently  would  have  been  quite 
capable  of  doing  the  work  if  its  engine  had  been  in  good  working 
order.  Owing,  however,  to  hasty  completion  and  the  in- 
sufficient time  for  shop  and  road  trials,  it  was  really  doing  its 
experimental  tuning  up  and  getting  into  order  in  the  trial  field, 
and,  whatever  its  merits,  this  wras  an  injudiciously  chosen  time 
for  these  experiments. 
On  each  of  the  plots  of  land  ploughed  a sample  of  the  soil 
one  yard  square,  moved  to  the  depth  of  the  pan,  was  taken  and 
weighed.  Table  No.  1 gives  a summary  of  the  weight  of  these 
samples.  From  the  plough  dynamometer  is  obtained  the  mean 
draugh,t  of  each  of  the  ploughs,  so  that  the  amount  of  work  done 
