THE ROYAL SOCIETY, AND AT THE ROYAL OBSERVATORY, GREENWICH. 593 
year of 1846 was preceded by a warm winter and was followed by a moderate one. 
The warm year 1848 was both preceded and followed by warm periods. 
The mean temperatures of the years 1771, 1782, 1784, 1786, 1799 and 1814, were 
all below 46°; the coldest was 1784, and its value was 45°'l. 
The mean temperatures of the years 1779, 1818, 1822, 1834 and 1846, were all 
above 50°'5 ; the year of highest temperature was 1846, and its value was 51°’3. 
Thus seventy-nine years, from 1771 to 1849 inclusive, gives a mean temperature 
of 48°’3, with a variation, between one year and another, from 45°T in 1784 to 51°'3 
in 1846 ; the difference is 6°'2. 
Table XXIII. — Showing the mean temperature of the Air in Spring, Summer, 
Autumn, Winter, and for the year from March, and the same for successive groups 
of years. 
Spring. 
Summer. 
Autumn. 
I Winter. 
The year from March. 
Year. 
March, 
April, 
May. 
Group of 
years. 
June, 
July, 
August. 
Group of 
years. 
September, 
October, 
November. 
Group of 
years. 
December, 
January, 
February. 
Group of 
years. 
Whole 
year. 
Group of 
years. 
1771. 
42-6 
57'3 
o 
46*7 
O 
35*9 
... ° 
45*6 
1772. 
43-1 
59*7 
50*3 
37*1 
47*5 
1773. 
44-2 
58*3 
47*1 
35*9 
46*4 
1774. 
46-9 
60*7 
47*6 
39*8 
48*7 
1775. 
48-5 
U6-4 
62*1 
^60*5 
48*9 
J>49*0 
35*4 
>36*9 
48*8 
>48*2 
1776. 
47-2 
60*7 
49*6 
36*6 
48*5 
1777. 
47*0 
59*7 
51*0 
35*4 
48*3 
1778. 
47-3 
63*9 
48*0 
41*0 
50*0 
1779. 
50-8 
62*3 
51*5 
34*7 
49*8 
1780, 
49-6 
62*7 
49-6 
37*7 
49*9 
1781. 
47-3 
63*6 
49*0 
38*1 
49*5 
1782. 
42-5 
57*9 
45*1 
37*4 
45*7 
1783. 
44-6 
61*6 
48*7 
32*0 
46*7 
1784. 
1785. 
45-0 
44-2 
>.45*5 
57*3 
59*8 
>60*0 
47*3 
48*0 
>47*5 
32*5 
35*8 
>36*3 
45*5 
46*9 
>47*3 
1786, 
43-7 
59*2 
44*2 
37*4 
46*1 
1787. 
46-2 
60*1 
47*5 
38*6 
48*1 
1788. 
48-1 
59*7 
48*5 
34*1 
47*6 
1789. 
43-9 
-- 
57*9 
46*7 
40*5 
J 
47*3 
J 
1790. 
45-6 
58*6 
48*5 
-N 
39*2 
48*0 
1791. 
46-8 
59*5 
48*2 
35*7 
47*6 
1792. 
46-9 
58*4 
49*1 
38*3 
48*2 
1793. 
44*1 
59*8 
49*2 
39*7 
48*2 
1794. 
1795. 
48*2 
45-2 
>45*8 
60*8 
57*8 
>591 
48*4 
51*6 
;>48*8 
31*6 
43*2 
>37*0 
47*2 
49*5 
>47*7 
1796. 
45-8 
58*2 
48*6 
33*8 
46*6 
1797. 
44-6 
59*0 
47-7 
39*0 
47*6 
1798. 
47*8 
61*3 
48*8 
34*5 
48*1 
1799. 
42-7 
57*6 
48*2 
34*6 
45*8 
1800. 
46-6 
60*7 
49-3 
38*7 ■ 
48*8 
1801. 
47*7 
60*5 
49*9 
36*0 
48*5 
1802. 
46-6 
59*6 
49-0 
35*8 
47*7 
1803. 
46-7 
60*5 
47*7 
41*1 
49*0 
1804. 
1805. 
47-1 
45-6 
>46*5 
60*5 
58*4 
:>60*3 
51*6 
48*9 
;>49*2 
36*3 
40*5 
>38*3 
48*9 
48*4 
>48*6 
1806. 
46’2 
60*8 
51*9 
41*2 
50*0 
1807. 
45-8 
61*6 
48*3 
36*6 
48*1 
1808. 
45‘6 
62*1 
48*4 
38*5 
48*7 
1809. 
46-5 
- 
58*7 
48*4 
38*0 
47*9 
/ 
4 G 
MDCCCL. 
