99 
Improvement  of  Land  by  Warping. 
depth  of  the  warping-drain  will  of  course  vary  according  to  the 
situation  of  the  land,  consequently  the  expense  of  cutting,  &c., 
must  also  vary  in  proportion. 
The  thickness  of  the  deposit  usually  left  upon  the  land,  for 
those  districts  in  the  neighbourhood  of  the  Trent,  averages  about 
18  inches;  the  minimum  being  6 inches,  and  the  maximum  2 feet 
6 inches,  or  3 feet.  In  some  few  instances,  it  is  true,  it  has  been 
observed  to  reach  as  high  as  4 or  even  5 feet ; but  these  occur 
only  rarely,  and  in  very  good  seasons.  On  lands  in  the  parishes 
of  Crosby  and  Scunthorpe,  which  stand  upon  a somewhat  higher 
level  than  others  in  the  immediate  vicinity,  the  warp  very  seldom 
exceeds  6 inches  in  depth.  It  is  never  desirable,  however,  to  be 
contented  with  less  than  18  inches,  when  as  much  or  more  can  be 
obtained.  With  regard  to  the  qualities  of  warped  land  for  the 
purposes  of  the  agriculturist,  it  has  been  observed,  that  it  is 
always  best  to  allow  land  so  treated  to  remain  untouched  for  one 
year,  in  order  to  afford  time  for  the  atmospheric  air  to  act  upon 
the  alluvial  matters  and  reduce  them  to  a proper  temper  (if  it 
may  be  so  called)  and  state  of  dryness.  It  is  then  sown  down 
with  four  bushels  of  oats  per  acre  and  a mixture  of  clover  and 
grass  seeds.  The  crops  so  produced  are  then  depastured  by 
sheep  for  two  years  in  succession,  when  the  soil  is  ploughed  up 
and  planted  with  wheat  and  oats. 
Beans  and  rape  also  thrive  well  upon  this  land  ; the  former  have 
even  been  found  to  succeed  as  a first  crop.  Barley  and  turnips, 
however,  do  not  answer  so  well,  on  account  of  its  slimy  nature. 
Warped  land  is  grateful  for  manure,  but  does  not  require  any 
until  it  has  been  cropped  a few  times,  say  for  five  or  six  years. 
Guano  is  then  found  to  be  one  of  the  best  that  answers.  Linseed- 
cake  and  rich  farm-yard  manure  also  furnish  very  good  results. 
Experience  has  proved,  however,  that  the  quality  of  the  warp 
often  makes  considerable  difference  in  this  respect ; so  much  so, 
in  fact,  that  one-half  of  a field  has  done  better  without  additional 
manure  than  the  other  half  has  with. 
Having  thus  in  the  preceding  pages  given  a brief  account  of 
everything  that  is  known  or  has  been  written  upon  the  subject  of 
warping  up  to  the  present  time,  I shall  now  proceed  to  attempt  to 
explain  the  rationale  of  the  process,  based  upon  chemical  prin- 
ciples. Prior  to  doing  so,  however,  it  will  be  necessary  for  me  to 
give  an  account  of  my  analyses,  from  the  consideration  of  which 
my  conclusions  have  been  arrived  at.* 
* Amongst  the  works  to  which  I have  referred  for  the  practical  details  of  the  pro- 
cess, may  be  mentioned  Mr.  Creyke’s  Memoir,  published  in  the  forty-third  volume  of 
the  Society  for  the  Encouragement  of  Art,  &c. ; and  an  article  in  the  ‘ Penny  Magazine  ’ 
for  the  year  1844.  I have  also  derived  several  new  facts  from  the  notes  which  Mr. 
Kirkby,  the  steward  of  R.  Thorold,  Esq.,  of  Great  Grimsby,  kindly  placed  at  my 
disposal. 
n 2 
