02 
FIFTH REPORT — 1835. 
Table XV. —Showing the relation of the Mean Temperature 
of every similar Pair of Hours to that of the whole day, or 
Mean Annual Temperature. 
Pair of 
Hours. 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
Mean Temp. 
52-97 
52-69 
52-28 
51-80 
51-23 
51-03 
51*17 
51-76 
52-18 
52-57 
52.90 
53-06 
CO 
CO 
rH 
Deviation 
+ 0-84 
+0-56 
+0-15 
-0-33 
- 0-90 
-1-10 
-0-96 
-0-37 
-0-05 
+ 0-44 
+0-77 
+ 0-93 
Mean Temp. 
54-74 
54-35 
53-92 
53-35 
52-80 
52-57 
52*70 
53-00 
53-60 
54-01 
54-40 
54-67 
CO 
CO 
Deviation 
+1-07 
+0-68 
+ 0-25 
-0*32 
-0-87 
-1-20 
-0-97 
-0-67 
-0-07 
+ 0-34 
+073 + 1-00 
a 
Mean Temp. 
53-86 
53-53 
53-10 
52-57 
52-01 
51-79 
51-94 
52-34 
52*88 
53-30 
53-69 
53-89 
s 
Deviation 
+0-96 
+ 0-63 
+0-20 
-0-33 
-0-89 
-I’ll 
-0*96 
-0-66 
-0-02 
■P0-40 
+ 0-79 
+ 0-99 
It appears by this table— 
1 st, That the deviation of any similar pair of hours from the 
temperature of the whole twenty-four or mean annual tempera¬ 
ture does not greatly exceed one degree of Fahrenheit: 
2 ndly, That the mean temperature of the pairs of hours from 
10 h to 3 h inclusive exceeds the mean annual temperature, or mean 
temperature of the whole twenty-four ; and the mean tempera¬ 
ture of the pairs of hours from 3 h to 10 h exclusive is less than 
the mean temperature of the whole twenty-four : 
3rdly, That the mean temperature of 9 h and 9 h does not greatly 
differ from the mean annual temperature or mean temperature 
of the twenty-four hours. 
We may infer from these results that the mean temperature of 
Plymouth may be very nearly determined by two observations 
in the day taken throughout the year at 9 a. m. and at 9p.m; 
or by observations at any other similar pair of hours, provided 
we apply the correction for deviation as given in the preceding 
Table XV. according to its sign. 
It may not be unworthy of remark, that the hours of 9 h and 9 h 
are nearly those which give the mean temperature of the day at 
Paris. At Leith, the mean temperature of 4 h and 4 h approaches 
nearest the mean, being those nearest the hours of the maximun 
and minimum. 
