8 
On  the  Climate  of  the  British  Islands 
succession  the  south  of  Spain,  the  north  of  Africa,  and  the 
Canary  Islands,  for  a climate  more  adapted  to  its  perfect  de- 
velopment in  the  West  Indies ; so  the  vine,  introduced  into 
England  and  carefully  nourished  as  a valuable  exotic,  has  ulti- 
mately deserted  a clime  unsuited  to  the  perfection  of  its  rich 
luscious  juice,  or  only  lingers  as  a good  illustration  of  the  value 
of  meteorological  science  in  determining  the  course  which  the 
husbandman  should  most  successfully  pursue. 
22.  A geological  map  shows  at  a glance  that  the  soil  of  many 
of  the  vale-lands  of  England  is  composed  of  the  new  red-sand- 
stone formation ; and  even  their  general  extent  may  often  be 
traced  on  the  map  by  the  limit  of  the  characteristic  colour.  This 
is  the  case  with  regard  to  the  vales  of  York,  Stockton,  Trent, 
and  of  the  Severn.  Smaller  vales,  like  fertile  gardens  sur- 
rounded by  elevated  lands,  display  the  same  peculiarity,  and 
afford  good  illustrations  of  this  fact.  It  may  be  seen  in  the  vale 
of  Carlisle  in  the  north  of  England,  of  Clwyd  in  North  Wales, 
and  of  Taunton  Dean  in  Devon. 
The  fragmentary  and  siliceous  nature  of  the  soil  on  the  new 
red-sandstone  renders  it  very  susceptible  of  the  influence  of  solar 
heat,  and  when  exposed  to  the  sun’s  rays,  its  temperature  is 
rapidly  raised,  and  the  radiation  of  heat  which  follows  tends 
considerably  to  increase  the  temperature  of  the  superincumbent  air. 
23.  The  observations  necessary  for  forming  a correct  know- 
ledge of  the  temperature  of  Ireland  are  very  scarce,  particularly 
in  respect  to  its  western  coast.  From  the  very  accurately  re- 
corded observations  I have  obtained  from  Cork,  it  appears  that 
the  low  lands  on  the  south  coast  enjoy  the  high  mean  tempera- 
ture of  54°.  At  Dublin  the  mean  temperature  is  49°,  corre- 
sponding with  the  eastern  coast  of  England  in  the  same  latitude ; 
and  the  north  of  Ireland  has  a mean  temperature  of  48°. 
The  summer  heat  around  Cork  is  greater  than  in  any  other 
part  of  the  British  Islands,  being  65°:  at  Dublin  it  amounts  to 
59°,  and  in  the  northern  counties  to  58°.  The  general  elevated 
character  of  the  lands  in  the  interior,  with  the  large  amount  of 
evaporating  surface  presented  by  the  bogs,  tend  to  decrease  the 
summer  temperature  of  the  inland  districts.  A compensating 
effect  is  in  some  measure  produced  from  the  thin,  friable,  and 
easily  heated  soil  of  the  limestone  formations,  which  extend  over 
three-fourths  of  the  island.  But  the  climate  of  Ireland  at  all 
seasons  is  more  tempered  and  modified  by  the  influence  of  the 
Atlantic  Ocean  than  any  other  portion  of  the  British  Isles.  The 
prevailing  warm  westerly  winds,*  loaded  with  moisture,  sweep 
over  the  land,  producing  cool  damp  summers,  and  mild  wet  win- 
* At  Cork  the  wind  blows  between  the  south  and  the  north-west  three-fourths  of  the 
year. 
