255 
in  which  the  flow  of  water  would  be  so  slow  that  there  would  be 
little  or  no  erosion.  Theoretically,  this  is  a fine  idea,  to  let  each 
row  carry  off  its  own  proporlion  of  the  excess  of  rainfall  so  gently 
that  there  shall  be  no  erosion,  thus  s acting  as  a miniature  drain. 
Practically,  however,  it  is  often  impossible  to  keep  these  rows  from 
breaking  through,  and  when  the  bed  is  once  broken  and  the  water 
overflows  into  the  next  row  the  accumulation  of  water  is  sufficient 
to  break  down  bed  after  bed  until  the  rows  from  ail  the  held  are 
discharging  into  this  narrow  channel. 
To  overcome  this  difficulty  sidehill  ditches  may  be  used  in  which 
larger  and  more  substantial  ditches  are  provided,  following  very 
nearly  the  contour  of  the  held,  so  that  there  shall  be  a fall  of  from 
I to  6 inches  in  lOO  feet.  The  distance  apart  of  the  ditches  will 
depend  upon  the  slope  of  the  held  ; with  a very  steep  slo,»e  they 
should  be  close  together,  often  not  over  6 to  lo  feet  apart:  with  a 
gentle  slope  they  should  be  at  intervals  of  15  or  20  feet,  or  even 
further  apart,  depending  upon  the  texture  of  the  soil  and  the  con- 
tour of  the  surface. 
These  sidehill  ditches  are  very  easily  constructed,  being  made 
almost  entirely  with  the  plough.  A bank  is  formed  by  running  a 
number  of  furrows,  throwing  the  dirt  toward  the  middle.  The  last 
furrow  on  the  upper  side  is  cleaned  out  with  a spade  to  torm  the 
bottom  of  the  ditch.  If  the  plough  is  well  handled  it  takes  very 
little  work  with  the  spade  to  make  a very  substantial  ditch.  It  is 
well  to  get  the  bank  forming  the  lower  side  of  the  ditch  sodded 
with  grass  to  help  hold  it  and  to  lessen  the  danger  of  its  giving 
way  during  a heavy  rainfall.  When  the  slope  is  thus  protected 
with  a number  of  ditches  at  the  proper  distance  apart,  the  rows  can 
be  given  a rather  steeper  fall  so  that  they  shall  run  out  into  the 
drains  at  frequent  intervals  and  not  have  to  carry  the  water  so  far. 
These  ditches  have  to  be  constructed  with  care  and  have  to  be 
strengthened  where  they  cross  any  depression  or  sudden  curve  by 
building  up  an  embankment.  Unless  these  ditches  are  thoroughly 
constructed  they  are  worse  than  useless,  for  if  they  break  they  con- 
centrate a volume  of  water  upon  one  point  in  the  field  which  would 
otherwise  have  been  distributed  over  the  surface,  and  this  often 
forms  a torrent  which  does  great  damage. 
It  is  essential  that  these  ditches  and  rows  be  run  according  to 
the  contour  of  the  surface  of  the  land,  and  that  there  shall  be  no 
low  places  where  the  water  would  accumulate  and  gather  force. 
They  should  always  be  run  with  a level,  of  which  there  are  several 
forms  on  the  market  suitable  for  this  work. 
more  efficient,  but  at  the  same  time  much  more  expensive, 
method  of  preventing  the  washing  of  lands  where  there  is  consider- 
able slope  is  lo  terrace  the  held  so  that  there  shall  be  level  steps 
uj)on  which  the  water  can  rest  for  a while  and  be  absorbed.  In 
terracing,  the  lines  are  run  with  a spirit  level  following  the  contour 
of  the  surface  so  as  to  give  a perfect  level  line.  .\  furrow  is  run 
along  tins  lim',  and  a similar  furrow  i-^  run  along  a lower  contour, 
