298 
Abstracts of the Makerstoun Observations, 1843. 
After the number of the times which the wind blew, and the sums of the pressures for the observation 
hours, the sums of the times blowing and pressures for all the 9 observations are given, and next the sums of 
the times blowing and pressures for 12 observations, three times the mean of the sums for 18 h and 10 h being 
taken as the sums for the three observations wanting to complete the day. The following quantities have also 
been made use of in forming the sums for 12 observations : — 
Direction. 
NNW. 
NW by N. 
NW. 
W. 
Times. 
I 
6 
5 
12 
Sums of Pressures, 
lb. 
0-2 
2-7 
4-3 
7-7 
Direction. 
Why S. 
SW by W. 
ssw. 
Times. 
2 
18 
5 
Sums of Pressures, 
lb. 
3-0 
14-9 
3-2 
These being estimated for the first week of January, and for the observation at 1 8 h , omitted in the second week. 
Diurnal Variation of the number of the times which the Wind blew in 1843. — The following are the sums 
of the number of times which the wind blew, at each observation hour, with a pressure of one-tenth of a pound 
or upwards on a square foot of surface, as obtained from Table XXXI. : — 
5 h 10 m . 7 h 10". 9 h 10">. ll h IQm AM . lh IQm p.M. 3I1 10m. 
5 k 10 m. 7h 10 m. 
9 h 10 m . 
138 166 205 233 256 242 212 171 126 
Differences, 28 39 28 23 14 30 41 45 
The number of times which the wind blew increased from 5 h 10 m a.m. till l h 30 m p.m., the interpolated 
period of maximum, and diminished from l h 30 m p.m. till 9 h 10 m p.m. The number increases most rapidly 
about 8 h a.m., and diminishes most rapidly about 8 h p.m. The wind, therefore, blew most frequently exactly 
at the time of the maximum temperature of the air. 
Diurnal Variation of the number of Points of the Compass in which the Wind blew. — The numbers of the 
points of the compass in which the wind blew at the observation hours, are — 
51 10m. 7ta IQm. 9I1 l()m. \\h \Qm A . M . 11, \Qm p. M . 31, \Qm m 5I1 10m. 7h IQm. gh 10m 
27 27 30 29 31 30 30 26 25 
The wind, therefore, seems to blow less steadily from 9 a.m. till 5 p.m. than before the former and after 
the latter of these hours. 
Diurnal Variation of the Sums of Pressures of the Wind. — This, of course, is the same as that of the 
means, Table XXVII., or a maximum about 25 m after Noon. The sums are as follow : — 
5>' 10'". 7'' 10'". 9 h 10"'. II 1 ' 10™ a.m. l h 10™ p.m. 3 h 10". 5 h 10 m . 7 h 10">. 9 h 10™. 
lb. lb. lb. lb. lb. lb. lb. lb. lb. 
139-5 133-5 170-4 211-5 224-0 192-1 156-1 118-7 103-8 
Diurnal Variation of the Mean Pressure of the Wind while blowing. — This is obtained by dividing the 
sums of the pressures by the number of times which the wind blew, and is as follows : — 
gh iQin. 711 iom. gh iom. lib i0'" a.m. \ h 10>" p.m. 3 1 ' 10"'. 5 h 10 m . 10™. 9 U 10"'. 
lb. lb. lb. lb. lb. lb. lb. lb. lb. 
1-01 0-80 0-83 0-91 0-88 0-79 0-74 0-69 0-82 
The wind, while blowing, was a minimum about 7 h 40 m a.m. 
maximum at Noon. 
minimum about 7 h 10™ p.m. 
The greatest force occurred at 5 h 10 m a.m. ; the maximum pressure of the wind while blowing probably 
occurs, therefore, at or after midnight. 
The fact that the wind blows with the greatest force at Noon, but the greatest number of times at l h 30 m 
p.m., the time of the maximum temperature, explains why the sums of the pressures attain their maximum be- 
tween these two periods. 
