588 MR. HUDSON’S HOURLY OBSERVATIONS ON THE BAROMETER. 
Eighth set of fifteen days’ Observations. Feb. 6th to Feb. 20th, 1832. 
Times of 
Observation. 
Number 
of Obser¬ 
vations at 
each hour. 
Barometer. 
A ttacbed 
Thermo¬ 
meter. 
External 
Thermo¬ 
meter. 
Barometer 
reduced 
to 32°. 
Difference 
of Baro¬ 
meter from 
mean. 
Difference 
of attached 
Thermometer 
from mean. 
Difference 
of external 
Thermo¬ 
meter from 
mean. 
h 
A.M. 8 
15 
inches. 
30-144 
o 
42-7 
37-6 
inches. 
30-112 
+ •001 
O 
— 1-4 
-2-6 
9 
15 
30-149 
43-0 
38-1 
30-116 
+ •005 
— 1-1 
— 2-1 
10 
15 
30-154 
43-3 
39-2 
30-120 
+ •009 
— 0-8 
-1-0 
11 
15 
30-156 
43-7 
40-3 
30-121 
+ •010 
-0-4 
+ 0-1 
12 
15 
30-149 
44-2 
41-4 
30-112 
+ •001 
+ 0-1 
+ 1-2 
P.M. 1 
15 
30-141 
44-6 
42-1 
30-103 
— •008 
+ 0-5 
+ 1-9 
2 
15 
30-132 
45-0 
41-8 
30-093 
-•018 
+ 0-9 
+ 1-6 
3 
15 
30-131 
45-1 
42-4 
30-092 
-•019 
+ 1-0 
+ 2-2 
4 
15 
30-132 
45-0 
41-8 
30-093 
-•018 
+ 0-9 
+ 1-6 
5 
15 
30-138 
44-8 
41-3 
30-100 
— •011 
+ 0-7 
+ 1-1 
6 
15 
30-147 
44-4 
40-8 
30-110 
— •001 
+ 0-3 
+ 0-6 
7 
15 
30-152 
44-2 
40-3 
30-115 
+ •004 
+ 0-1 
+ 0-1 
8 
15 
30-153 
43-9 
39-9 
30-117 
+ •006 
— 0-2 
— 0-3 
9 
15 
30-154 
43-8 
39-6 
30-119 
+ •008 
— 0-3 
-0-6 
10 
15 
30-155 
43-8 
39-2 
30-120 
+ •009 
— 0-3 
— 1-0 
11 
15 
30-155 
43-7 
38-8 
30-120 
+ •009 
— 0-4 
— 1-4 
12 
15 
30-156 
43-6 
38-4 
30-121 
+ •010 
— 0-5 
— 1-8 
Mean .... 
30-147 
44-1 
40-2 
30-111 
The external thermometer registered during this period was very accurate 
and sensible, and constructed many years ago by Nairne. 
The most striking results which these observations have afforded, are exhi¬ 
bited, by means of linear representations, in the four Plates which accompany 
this paper. The respective variations from each general mean are referred, 
according to a given scale, to the mean line, and their points of distance 
from it, at each successive hour, are connected together by means of straight 
lines. The barometrical changes, and the variations of temperature, are each 
referred to the same scale, ‘001 of an inch in the former case being equal to 
*1 of a degree in the latter. 
Plate XXI. represents the mean hourly variations of the Standard Baro¬ 
meter, and also those of the Attached Thermometer, in the first five sets of 
observations; and displays,— 
1. The general similarity of character, and of amount, in the mean varia¬ 
tions, compared with the irregular changes of the barometer under 
ordinary circumstances. 
