THE ROYAL SOCIETY, AND AT THE ROYAL OBSERVATORY, GREENWICH. 597 
Table XXIV. (Continued.) 
Spring. 
Summer. 
Autumn. 
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, 
Februarj’. 
Group of 
years. 
Whole 
year. 
Group of 
years. 
1820. 
O 
+ M 
o 
O 
— 2*0 
o 
O 
-1*6 
>1 
+ 6*2 
'J ° 
-0*6 
o 
182L 
+ 1-1 
— 2'2 
+ 3*3 
+ 4*9 
+ 1*8 
1822. 
4-3*5 
+ 2*1 
+ ^9 
—2*2 
+ 1*6 
1823. 
-0*7 
-2*0 
-0*6 
+ 0*2 
-0*7 
1824. 
1825. 
-2*1 
4-0*5 
> + 0*7 
-0*8 
+ 2*0 
> 0*0 
+ 2*0 
+ 1*3 
>-0*7 
+ 1*8 
+ 0*7 
>+0*4 
+ 0*2 
+ 1*2 
> + 0*5 
1826. 
+ 1*0 
+ 3*9 
+ 0*3 
— 2*0 
+ 0*8 
1827. 
+ 1*1 
0*0 
+ 0*8 
+ 3*8 
+ 1*5 
1828. 
+ 1*7 
+ 0*3 
+ 1*4 
+ 0*6 
+ 1*0 
1829. 
-0*7 
J 
-1*1 
J 
-2*6 
J 
-4*3 
J 
-2*1 
J 
1830. 
+ 3*2 
-1*2 ' 
+ 0*4 ■ 
N 
-0*8 ■ 
+ 0*4 ' 
•N 
1831. 
+ 1*9 
+ 2*3 
+ 2*6 
+ 1*1 
+ 2*0 
1832. 
0*0 
+ 0*5 
+ 1*3 
+ 2*2 
+ 1*0 
1833. 
+ 1*0 
-0*5 
-0*9 
+ 5*5 
+ 1*3 
1834. 
1835. 
+ 2*2 
+ 0*4 
> + 0*1 
+ 2*5 
+ 2*6 
> + 0*5 
+ 1*8 
+ 0*1 
>-0*2 
+ 2*5 
— 1*3 
> + 0*9 
+ 2*2 
+ 0*5 
>+0*4 
1836. 
+ 0*2 
+ 0*3 
— 1*8 
+ 1*4 
0*0 
1837. 
— 5*5 
— 0*2 
-0*4 
-3*3 
—2*3 
1838. 
-1-8 
-0*9 
-0*8 
+ 0*7 
-0*7 
1839. 
— 3*1 
J 
-0*7 
+ 0*4 
/ 
+ 1*3 
' 
-0*5 
1840. 
-0*1 
-0*1 ' 
— 1*1 ~ 
— 3*5 - 
-1*2 ■ 
1841. 
+ 3*7 
— 1*8 
+ 0*6 
+ 0*5 
+ 0*8 
1842. 
+ 1*4 
+ 2*8 
— 1*0 
+ 2*7 
+ 1*5 
1843. 
+ 1*0 
-0*2 
+ 1*1 
+ 1*8 
+ 1*0 
1844. 
1845. 
+ 2*3 
-2*8 
> + 1*3 
-0*1 
-0*7 
> + 0*7 
+ 0*9 
+ 0*6 
> + 0*8 
-2*9 
+ 5*5 
> + 0*9 
+ 0*1 
+ 0*7 
> + 1*0 
1846. 
+ 1*9 
+ 4*3 
+ 3*0 
— 3*1 
+ 1*5 
1847. 
+ 1*2 
+ 1*8 
+ 2*1 
+ 2*7 
+ 1*9 
1848. 
+ 3*9 
-0*5 
+ 1*2 
+ 4*8 
+ 2*4 
1849. 
+ 0*2 
+ 1*0 
+ 2*0 
+ 1*6 
+ 1*2 
The sign — denotes that the temperature of that period was below the average, 
and the sign + denotes that it was above the average. 
By taking the mean of the numbers for each period, without regard to gauge, 
The mean variability in Spring is . 
The mean variability in Summer is . 
The mean variability in Autumn is 
The mean variability in Winter is . 
The mean variability in the Year is . 
1-6 
1*5 
T4 
2*2 
IT 
All the following Tables are based upon the readings of self-registering thermo- 
meters, and exhibit the extreme readings at the Apartments of the Royal Society, 
and at the Royal Observatory, Greenwich. The first process in their formation was 
the copying from the Philosophical Transactions every reading of these thermometers, 
arranging all the minimum readings one under the other, and all the maximum read- 
ings similarly under each other, and then taking their monthly mean readings, or 
otherwise as was necessary to the construction of the Tables. 
