278 MR. LUKE HOWARD ON THE INFLUENCE OF THE MOON’S DECLINATION 
Table II. 
Barometrical Averages on successive Cycles of nine Solar Years, classed according 
to the Moon’s place in Declination. 
Periods 
taken. 
1 . 
Moon at or 
near equator, 
and going 
north. 
2. 
Moon at or 
near her 
greatest north 
declination. 
3. 
Moon at or 
near equator, 
and going 
south. 
4. 
Moon at or 
near her 
greatest south 
declination. 
5. 
Averages on 
whole periods 
of nine years. 
6. 
Averages on 
the four re- 
sults prece- 
ding. 
in. 
in. 
in. 
in. 
in. 
in. 
1815-23 
29-8114 
29-8263 
29-8267 
29-8054 
29-8173 
29-8174 
1816-24 
29-8270 
29-8408 
29-8398 
29-7794 
29-8059 
29-8218 
1817-25 
29-8596 
29-8759 
29-8608 
29*8081 
29-8366 
29-8511 
1818-26 
29-8929 
29-8939 
29-8779 
29-8349 
29-8577 
29-8749 
1819-27 
29-9069 
29-8964 
29-8873 
29-8513 
29-8696 
29-8856 
1820-28 
29-9142 
29-8927 
29-8729 
29-8680 
29-8691 
29-8870 
1821-29 
29-9011 
29-8765 
29-8451 
29-8500 
29-8518 
29-8682 
1822-30 
29-8922 
29-8523 
29-8304 
29-8484 
29-8372 
29-8560 
1823-31 
29-8678 
29-8282 
29-8014 
29-8100 
29-8123 
29-8269 
1824-32 
29-8505 
29-8257 
29-8076 
29-8058 
29-8076 
29-8225 
Mean by 
the columns. 
j 29-8724 
i ■* 
29-8608 
29-8450 
29-8261 
29-8365 
29-8511 
The averages presented at the foot of columns 1 to 4, show a decrease in the baro- 
metrical mean, consequent on the moon’s varying positions in declination, which may 
be thus stated : 29‘8724 in. on equator, minus by north place, '0116 in. ; again, minus 
by passage of equator south, '0158 in. ; again, minus by south place, '0189 in. ; lastly, 
plus by return north over equator, '0463 in. 
The averages in columns 5 and 6 exhibit the barometrical mean, increasing and 
decreasing with great regularity, during the course of a lunar cycle of eighteen years. 
The averages which form the two Tables before us were obtained in the following 
manner : — 
1. The year was divided, by an ephemeris, into periods of lunar declination, the 
whole set in each case including not less than 361, nor more than 3/0 days. 
2. These periods of declination were subdivided into weeks (or spaces of from six 
to eight days, generally seven) with the moon’s extreme north, her extreme south, and 
her respective positions on the equator, coming and going, placed as nearly as might 
be in the midst of the space on which the average was taken — to wit, the average of 
the medium heights of the barometer for each twenty-four hours of the space. 
3. These weekly averages, obtained generally from the curves inscribed by the 
barometer, on the face of a clock by Gumming, in my possession, were then placed 
under their respective heads of the four positions of the moon above-mentioned. 
4. They were then laid together for the whole year, or for the number of days 
necessarily so accounted, which numbers make an average of 365^ days to the year. 
5. Averages were, lastly, taken under the respective heads of north, south, &c. on 
successive periods of nine years , as 1815-23, 1816-24, &c., the series beginning 23rd 
December 1814, and ending 19th December 1832. These results occupy the four 
leading columns of the second Table ; the preceding are in Table I. 
