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BI-MONTHLY SUMMARY OF BCIENCH. 247 
the action of the sun; but the earth’s rotation must not be disrecarded, as it is 
very itaportant, and the nioon probably exerts a tidal influence upon the air ag 
well as upon the water of our globe. If no disturbing operations took place, 
we shoud ouly have hot air ring from equatorial regions, and being replaced 
by colder streams from the less heated poles, The real facts are, however, in 
the highest degree complicated, as many distinct forces contribute more or less 
0 excife motion at different heights and in different directions, and a host of 
circumetances, such as the distribution of land and water, mountain ranges, 
piaing, etc., ete., produce modilications over a wider or smaller range. 
Of the influence of the moon, he writes: 
Upon the difficalt question of the action of the moon, Admiral Hitzroy bas an 
interesting chapter, and he does not consider that the probability of an impor- 
tant tidal influence is invalidated by the fact that the barometer does not. give 
proportionate indications, He believes that there is ‘a continuous overflow of 
air, De that Geseribed by Dove aud others, which not only prevents nuch sensi- 
ble increase of statical pressure or tension, but auements the dynamical forces of 
the tropical currenis of air, periodically by lunar periods, and diurnally also.” 
this theory is probable, and the Admiral states that ** recurriig periods of about 
fourteen days (semi-lunar), of seven, and of three or four days, have been traced, 
however masked or irrezular, more or less synchronous wilh the moon’s phases, 
occasionally, and then for a few times rather correspondent, therefore evidencing 
Some kind of connection.” The Admiral also observes that the eonsecutive 
actions of the moon in raising and eausine an overflow of a mass of air must 
Give vise to periouical impulses bearigg a diferent direction to the normal 
currents, 
“ Domine the moon’s pacsage from quadrature to Syzyey ler action on air 
CUITENTS Should increase, aud conversely, When she has ereai north declination, 
if Cught to be greater here than when she is far south, and when in perigee 
greater than ii apocee. ‘Tahulor records show euch are the facts. Abstract 
reasoning tehds to the conclusion that the moon must inflaence our etmospuere, 
aithough forces more powerful than that exerted oy our salellite may counteract 
or conceal her work, but, as we shall gee, distinguished antherities adopt con- 
Hicting views. 
Admiral Fitzroy appears to connect the successive impulses to atmospheric 
Movement given Dy the moon with the daily changes that occur ai intervals of 
about six hours. lunar actions may have something to de with these, but they 
seem more directly referalle to the operation of solar heat and of radiation. 
Quetelet says: “If we compare the variations of the barometer with that of the 
thermometer, we observe that oscillations of pressure as weil as of temperalare 
are much stronger in winter than in summer.’ but he adds that in auiumn there 
is less dilurence in ihe barometer and thermometer than might have been antici- 
take place at intervals of about six hours, exhibit peculiar displacements. so 
Vrolcesor Lamont believes that the sun exerts two infaences upon the diurnal 
Varialioig@e the barometer, one that of beat. and the other of an ‘electrical? 
atiractiy Ce; and Peulestor Piantamour coasiders that the tidal action of 
the moon"@n tie air is sown to be insensivle. by oUservations when he carried 
Ob through iwenty four luuatious. ile says: “1 have taken the mean baromet- 
Pical heights, observed at different hours, ihe day of Lue syayey. the day cefore, 
and ihe day ulicr; ie day of the quad-ature, the cay oclore fod Loe dey aller’ 
le then gives the result of one handred and forty four days at dre syzvey epoch, 
and of one bundred aad forty-four cays ab tue Guadra ure epoca, Which do oot 
Correspoud with wll might be Gospuied Irom (he lunar-tidal tucory. he aise 
Sives the bourse at which the maxuna and minima oeeurred al SyZysies an at 
quadratures, and remarke, “tie eceand terms (iNinima) are nearly identical ia, 
Value, and the time only differs a few minutes ; Wale othe almospberie tle 
Cae fro mGlvcular uliraction, exerled by the moon as well as bY ihe gun, tye 
“pie Of isinimum at the quidratures oncht to have changed by six pours, and its 
vaiue should have been reduced about one-third,” | 
