in  its  Effect  on  Cultivation. 
G19 
be  raised  to  a very  high  temperature.*  The  absorption  of  latent 
heat  by  the  conversion  of  water  into  steam  considerably  modifies 
this;  bence  the  ancient  division  of  climates  into  insular  and  con- 
tinental, the  former  of  which  are  characterised  as  mild,  and  the 
latter  as  severe.  Where  places  are  situated  remote  from  the 
ocean,  and  at  a considerable  distance  from  the  equator,  the  rays 
of  the  sun  falling  upon  the  land,  and  being  absorbed  thereby, 
and  accumulating  at  its  surface,  tend  to  raise  the  temperature 
very  considerably ; and  there  being  but  a short  time  during  the 
night  for  the  radiation  of  heat,  considerably  more  heat  is  received 
by  the  land  during  the  day  than  can  be  given  off  during  the  night, 
and  a rapid  accumulation  thereof  takes  place ; and  thus  the  heat 
of  summer  at  Moscow  is  found  equal  to  that  of  the  mouth  of  the 
Loire,  though  the  latter  is  10°  degrees  nearer  the  equator; 
whilst  the  average  cold  of  winter  at  Moscow  is  greater  than  that 
of  the  extreme  north  of  the  coast  of  Norway. 
A glance  at  the  map  of  the  world  will  at  once  show  that  the 
whole  of  Europe,  compared  with  Asia,  has  an  insular  or  mild 
climate,  and  that,  compared  with  the  rest  of  Europe,  the  British 
Islands  experience  this  mildness  to  a far  greater  extent  than 
eastern  or  continental  Europe.  Again,  some  parts  of  the  British 
Islands  experience  this  much  more  than  others.  Thus  Ireland, 
the  south-western  parts  of  England  and  Scotland,  experience  this 
much  more  than  the  eastern  parts  of  England,  and  through  their 
whole  extent  the  western  parts  being  nearest  to  the  Atlantic 
Ocean,-]-  their  climate  is  more  equal  than  that  of  their  eastern  or 
central  parts.  But  the  greatest  extent  of  land  in  Britain  being 
on  the  south,  and  decreasing  in  extent,  or  being  intersected  by 
numerous  inlets  towards  its  northern  part,  it  follows  that  though 
the  average  temperature  decreases  towards  the  north,  from  52° 
at  Penzance,  to  50° '36  at  London,  47° '84  at  Edinburgh,  and  to 
42°  in  the  north  of  Scotland,  yet  this  decrease  is  almost  entirely 
owing  to  the  greater  heat  of  summer  in  the  south  and  south- 
eastern parts,  the  winter  temperature  in  the  north  of  Scotland 
being  nearly  equal  to  that  of  London.  Thus,  whilst  the  tem- 
perature of  the  coldest  month  at  London  is  37° ‘76,  that  of  the 
same  month  at  Edinburgh  is  38°  ■ 30 ; the  mean  of  the  three 
winter  months  being  in  the  former  place  39°  *56,  in  the  latter 
38° -66  (‘Encyclopaedia  Metropolitana,’  article  Meteorology, 
page  32)  ; whereas  the  temperature  of  the  summer  months  in 
* This  effect  must  probably  be  reversed  by  the  amount  of  cloud  proceeding  from 
the  sea,  and  other  causes.  It  is  stated  further  on,  that  in  South  Britain  the  land  in 
the  early  summer  months  is  heated  more  than  the  sea. — Ph.  P. 
f It  seems  quite  established  that  the  winter  warmth  of  the  western  side  of  our 
Islands  is  due  to  the  special  warmth  of  the  sea  on  that  side,  proceeding  from  the  set  of 
the  Gulf-stream. — Ph.  P. 
