in  its  Effect  on  Cultivation.  U 
ters,  and  equalizing  the  temperature  of  the  different  seasons  to  a 
remarkable  degree. 
24.  The  difference  between  the  mean  temperature  of  day  and 
night,  is  given  in  the  following  table  for  the  places  mentioned. 
It  shows  that  on  the  sea  coast  the  change  is  comparatively  little 
in  winter,  and  that  it  is  greatest  in  the  inland  districts  in  April 
and  May.  Store  or  young  cattle  kept  in  warm  houses  through 
the  winter,  are  in  danger  of  suffering  from  this  fluctuation  of  the 
temperature  when  “ turned  out”  early  in  the  spring. 
Table  III. — Showing  the  Mean  Difference  between  Night  and  Day  for 
eacli  Month  in  the  Year. 
Place. 
Jan. 
Feb. 
Mar. 
April. 
May. 
June. 
July. 
Aug- 
Sept. 
Oct. 
Nov. 
Dec. 
o 
o 
o 
o 
o 
o 
o 
o 
o 
c 
Truro  • • 
G-8 
0- 7 
8-8 
12-3 
13-4 
13-6 
11-4 
11-8 
11-3 
10-1 
7-9 
6'9 
Exeter  . • 
8-6 
9-6 
12-3 
13-5 
15‘5 
15-6 
15-1 
14-6 
13-4 
11-4 
9-4 
7*1 
Chiswick  . . 
H-8 
12-9 
17-0 
22*8 
23-6 
22-8 
21-2 
21-1 
19-4 
17-8 
14-2 
12-7 
Norwich  • . 
65 
5-4 
12-2 
16-0 
27-8 
18-5 
17-3 
16-8 
14-9 
10-1 
8-4 
7-9 
Dumfriesshire 
9-1 
9-0 
11*9 
15-6 
1G-8 
15-2 
12-5 
13-8 
14*1 
11-5 
9-6 
8-2 
Whitehaven  . 
8-8 
7-6 
10-1 
12-5 
15-4 
12-9 
11-0 
11-0 
9-6 
7*0 
7*5 
6-4 
25.  The  general  slope  of  various  districts  in  the  United  King- 
dom tends  perceptibly  to  augment  their  temperature.  The  lands 
around  CorK,  the  coast  of  South  Wales,  the  Isle  of  Wight  and 
contiguous  lands,  the  South  Hams  of  Devon,  and  the  far-famed 
neighbourhood  of  Penzance,  are  districts  more  or  less  sheltered 
from  the  chilly  influence  of  northerly  winds,  and  open  to  the  full 
effect  of  the  sun’s  rays,  and  to  the  warmth  communicated  by  the 
higher  temperature  of  the  waters  of  the  adjoining  sea. 
26.  The  low  country  at  the  foot  of  the  Highlands,  extending 
along  the  coast  from  Dundee  to  Aberdeen,  and  even  as  far  as 
Elgin,  has  a very  high  summer  temperature  in  respect  to  latitude, 
and  to  other  parts  of  Scotland,  being  from  58°  to  60°.  This  ac- 
counts for  the  perfection  with  which  wheat  is  raised  in  the  low- 
lands of  this  district,  and  for  the  fine  samples  now  grown  so  far 
north  as  the  Murray  Frith. 
27.  The  geological  structure  of  the  soil  influences  in  a per- 
ceptible manner  the  temperature  of  the  air.  1 have  often  found 
an  oppressive  heat  on  a summer’s  evening  at  nine  o’clock,  when 
walking  over  bare  sands  after  a hot  day  ; and  in  proportion  as 
soils  are  siliceous  and  gritty,  they  receive  and  radiate  heat.  The 
fragmentary  nature  of  the  crag  of  Norfolk  and  Suffolk,  and  the 
sands  of  the  tertiary  strata,  render  the  soil  very  susceptible  of 
the  influence  of  solar  heat,  and  therefore  well  adapted  to  bring 
the  barley  crop  to  its  highest  perfection.  A belt  of  warm 
siliceous  soil  runs  from  Cambridge  in  a south-west  direction 
through  the  counties  of  Bedford,  Buckingham,  Oxford,  and 
Berks.  It  lies  on  portions  of  the  green-sand  formation,  and  is 
