in  its  Effect  on  Cultivation. 
43 
tain;  and  it  is  in  these  districts  that  the  culture  of  the  turnip  is 
the  most  successful.  The  Orkney  islands  have  of  late,  under 
improved  culture,  grown  excellent  crops  of  turnips,  and  the  dis- 
tribution of  temperature  at  Sandwich,  given  in  Table  No.  1, 
shows  the  conditions  of  heat  highly  favourable  to  this  root. 
97.  On  the  warm  south-east  plain  of  England  the  turnip  does 
not  succeed  so  well  as  further  north,  though  this  crop  constitutes 
the  main-spring  of  the  improved  husbandry  of  the  eastern  coun- 
ties. The  great  heat  of  summer  will  not  admit  of  so  early  a til- 
lage, and  cold  winters  still  further  limit  the  period  of  growth. 
But  the  success  of  the  turnip-crop  more  especially  depends  on 
the  proper  supply  of  moisture  in  June,  July,  and  August.  It  is 
highly  creditable  to  the  agriculturists  of  the  south-eastern  dis- 
trict, that  with  an  annual  amount  of  rain,  about  half  that  of  their 
more  favoured  neighbours  of  the  north,  such  excellent  crops  are 
raised.  During  the  summer  months,  indeed,  this  district  has  a 
larger  proportion  of  its  own  smaller  annual  amount  than  falls 
on  the  western  lands.  But  it  appears  that  the  country  around 
Chiswick,  for  instance,  is  subject  to  considerable  variations  in  dif- 
ferent years ; occasionally  not  an  inch  of  rain  falls  a month,  and 
the  average  for  each  of  these  months,  for  ten  years,  is  2J  inches. 
At  Manchester  the  average  rises  to  3^  inches ; at  Applegarth 
manse,  Dumfriesshire,  to  3f ; and  at  Orkney  the  quantity  is 
2J  inches.  Thus  the  advantages  of  climate  and  moisture  are 
greatly  in  favour  of  the  northern  and  western  counties. 
98.  In  the  south-west  of  England  turnips  have  been  cultivated 
with  great  success.  The  parish  of  Probus,  Cornwall,  is  one  of 
the  best  farmed  parishes  in  the  county ; and  the  structure  of  the 
soil,  and  the  amount  of  rain,  are  highly  favourable  to  this  crop. 
The  rock  is  a decomposable  clay  slate,  nearly  on  its  edge,  which 
affords  an  excellent  under  drainage,  on  which  lies  a clayey  but 
porous  subsoil,  and  on  this  a deep,  healthy,  friable  loam.  About 
3 inches  of  rain  fall  per  month  during  the  most  rapid  period  of 
the  growth  of  the  turnip,  and  the  nature  of  the  soil  is  such  as 
admirably  to  regulate  the  supply  of  moisture  to  the  root.  The 
plant  seldom  receives  a check  from  drought,  and  consequently  is 
not  subject  to  mildew,  and  heavy  crops  are  yearly  raised. 
In  some  parts  of  the  slate-formation  the  beds  lie  horizontal, 
and  a thin  soil  rests  on  a subsoil  of  clay.  In  such  districts  the 
turnip  is  a most  precarious  crop,  and  seldom  does  well.  The 
soil  is  either  saturated  with  water,  or  very  dry,  and  a few  weeks  of 
hot  weather  bring  on  the  mildew'  in  its  worst  form. 
On  the  elevated  land  of  Dartmoor,  with  a granitic  soil  1100 
feet  above  the  sea,  under  the  excellent  management  of  Mr.  Fowler, 
turnips  answer  remarkably  well.  He  writes  me  under  date  of 
the  27th  of  October,  1849: — “ My  stone  turnips,  with  tops  and 
