Pressure of Aqueous Vapour. 
271 
TABLE X. — Pressure of Aqueous Vapour, considered in relation to the Moon's Age and Declination. 
It 1 U \J 11 s 
A ere. 
No. of 
Daily 
Means. 
Pressure. 
Affe. 
o 
No. of 
Daily 
Means. 
Alexin 
Pressure. 
After 
farthest 
North. 
No. of 
Daily 
Means. 
^Me<iu 
Pressure. 
After 
farthest 
North. 
No. of 
Daily 
Means. 
Pressure. 
Day. 
in. 
Dav. 
in. 
Dav. 
in. 
Dav. 
in. 
15 
9 
0-299 
6 
12 
0-278 
6 
11 
0-257 
14 
11 
0-293 
16 
11 
•290 
1 
10 
•284 
1 
12 
■255 
15 
12 
•285 
17 
10 
•292 
2 
11 
•274 
2 
9 
•322 
16 
9 
•333 
18 
11 
•311 
3 
9 
•253 
3 
11 
•276 
17 
11 
■309 
19 
10 
•279 
4 
11 
•280 
4 
12 
•271 
18 
12 
•298 
20 
9 
•315 
5 
10 
•277 
5 
11 
•273 
19 
\l 
•282 
21 
12 
•298 
6 
9 
•305 
6 
12 
•259 
20 
•288 
22 
9 
•324 
7 
12 
•295 
7 
11 
•272 
21 
11 
•262 
23 
11 
•295 
8 
10 
•310 
8 
12 
•267 
22 
12 
•305 
24 
10 
•284 
9 
11 
•277 
9 
9 
•321 
23 
9 
•341 
25 
11 
•285 
10 
9 
•281 
10 
11 
•292 
24 
11 
•317 
26 
10 
•278 
11 
11 
•284 
11 
12 
•303 
25 
12 
•302 
27 
9 
■297 
12 
10 
■293 
12 
11 
•302 
26 
11 
•278 
28 
11 
•301 
13 
9 
•303 
13 
12 
•292 
27 
11 
•262 
29 
9 
•303 
14 
12 
■285 
This Table has been formed from Table IX. in the manner already indicated, Table II. of the Abstracts 
of the Magnetical Observations, excepting that no means for the Sundays were employed. 
Pressure of Aqueous Vapour with reference to the Moon's Age. — From the above, and the following means 
of groups, there seems to be a maximum of pressure about three days after the time of fidl moon, and a mini- 
mum about three davs after the time of new moon. 
12 days till 18 days, Full Moon, 
15 22 ... 
19 26 ... 
23 29 ... 
in. 
0-296 
0-301 
0-295 
0-292 
27 davs till 3 days, New Moon, 0-284 
0 ...... 7 ... 0-281 
4 11 ... 0-289 
8 14 ... 0-290 
Pressure of Aqueous Vapour with reference to the Moon's Declination. — The means in the above Table 
seem very irregular. The projected quantities shew four maximum peaks, which occur at intervals of seven 
days, namely, on the 2d, 9th, 16th, and 23d days after the Moon has its greatest north declination ; but these 
may be at once traced to the less number of observations from which the means are deduced for these days, 
and this due to the want of means for the Sundays. The means of groups are as follow : — 
25 days till 3 days, Moon farthest North, 0-279 
0 6 ... 0-273 
4 ...... 10 ... 0-279 
7 13 ... 0-293 
11 days till 17 days, Moon farthest South, 
14 20 ... 
18 24 ... 
21 27 ... 
in. 
0-302 
0-298 
0-299 
0-295 
These means shew the minimum about three days after the Moon has its greatest north declination, and 
the maximum about three days after it has its greatest south declination. 
Extreme Daily Mean Pressures of Aqueous Vapour and the Ranges. 
Jan. Feb. March. April. May. June. July. -Aug- Sept. Oct. Nov. Dec. 
in. in. in. in. in. in. in. in. in. in. in. in. 
Greatest, 0-342 0-259 0-304 0-322 0-359 0-365 0-489 0-541 0-529 0-417 0-311 0-331 
Least, 0-154 0-107 0-157 0-150 0-217 0-253 0-308 0-320 0-229 0-167 0-174 0-191 
Range, 0-188 0-152 0-147 0-172 0-142 0-112 0-181 0-221 0-300 0-250 0-137 0-140 
The greatest daily mean in the year is that for August 17, being . . 0*541 in. 
The least February 18, being . . 0-107 ... 
The greatest range of the daily means in any month is that for September, being 0-300 ... 
The least June, being 0-112... 
The range of the daily means for the whole year 1843, is ... 0-434 ... 
