The Sun.
London, England, 1844-08-15 00:00:00

THE PROPHETIC ALMANACS AND
THE " WEATHER CYCLE."
FROM A CORRESPONDENT.)
The period is approaching for the announcement of
the almanacs for the ensuing year, and presents a fit
opportunity for devoting a few passing observations
on a subject universally canvassed, and on that ac-
count alone entitled to attention—namely, the weather. '
What may be advanced in these observations is in-
tended by way of caution to the public—caution
against those moon-and-star struck impostors, the
weather prophets and astrologers, who still infest the
community, and endeavour, by artfully playing upon
the natural disposition of all men to pry into the
future, to abuse the public mind with absurd specu-
lations as regards the weekly or daily weather, and
with debasing superstition as respects astrological
predictions.
Any explanation, however, on the subject of the
coming seasons, simply yet philosophically treated,
certainly ought to command more serious attention
than seems to be bestowed upon it. It is a matter
highly interesting in itself, and there is little doubt
that when stripped of all mystery, it may, upon
further investigation, be rendered familiar to the
most ordinary capacity. It is worthy of considera-
tion, if on no other account than that it is impossible
for any one, learned or unlearned, to live through the
year, or even through the month or the day, without
feeling the influence which the weather has upon his
own comfort, and upon the state of all things around
him. In this country, where the changes are so fre-
quent, and the contrast so striking, the subject is con-
stantly before everybody; and be it in the city or on
the common—in the palace or in the farm-house—in
the garden or on the wide-extended moor—the weather
of the season or the day forms the sure preliminary
topic of conversation.
No observation is more common, and on no oc •
casion, perhaps, is the almanac so frequently consulted,
than in forming conjectures on the state of the
weather; but the general remark goes no further
than this—that changes from wet to dry, and from
dry to wet, usually happen at the changes of the
moon. A reliance upon such a theory would lead to
the supposition of the moon having some influence
upon the currents in the atmosphere, as well as on the
currents and tides in the ocean ; but to say the least
of it, this subject is involved in great doubt and ob-
scurity, and is one which can only be elucidated—if
ever it can be proved—by long and careful ob-
servation.
_ _

If the moon be supposed to have such influence,
why not the sun ? This point has been started and is
maintained by Lieutenant George Mackenzie, of
Perth, in his System of the Weather," who has
discovered, beyond the shadow of a doubt, that there
is a cycle of the weather—that there always has been
such a cycle,—and that there ever will be correspond-
ing cycles. We require no further evidence of this
fact than the personal knowledge of many living in-
dividuals, of the periodical recurrence of dry summers
and wet summers, and of mild winters and winters of
long-continued storm. Mackenzie affirms that no
conclusion as to the character or the state of the
weather can be arrived at by lunar periods, and
although he seems disposed to admit that the moon
may be the source of a certain quantity of the wind
that blows, yet he insists that the weather of itself is
a solar, or rather a magnetic effect. We are gratified
to find that the discoveries of Lieut. Mackenzie, and
his frequent explications on this very interesting sub-
ject for upwards of twenty-five years, have recently
been adopted and followed up by the British Associa-
tion for the Advancement of Science. Upwards of
forty years ago, when he began to record his obser-
vations—which are highly valuable, and founded es-
sentially on the magnetic principle—that gentleman
fixed upon the Ist of November as the commencing
point of the weather year; and Sir David Brewster,
in a communication to the Secretary of the Associa-
tion, published in the Athenaum, on the 31st of
August, 1839, states, " that at the new stations ap-
pointed for observing the weather, the observations
commenced on the Ist November (preceding), the
beginning (as he then called it) of the meteorological
year." Professor Whewell, while in the chair at the
Plymouth meeting of the Association in 1841, seemed
so strongly impressed with the importance of the new
light thus thrown on the system of the weather, that
be stated in his address "we ought to have me-
teorological observations and observers distributed
over the face of the globe"—a suggestion, by the way,
which has been only partially adopted. Of late years
a magnetic apparatus has been erected near the Royal
Observatory at Greenwich, under the able superin-
tendence of Professor Airy and Mr. Glaisher ; and
besides several other stations throughout Great
Britain, we have similar establishments in North and
South 'imerica, the Cape of Good Hope, &c. Some-
thing ought to he elucidated from the united observa-
tions thus in progress at a vast expense ; but if the
results be not placed before the public in a popular
form—a form adapted to the reasoning faculties and
understandings of the people—then the inevitable
concluson is, that the parties entrusted with this im-
portant duty have not succeeded in discovering the
elements of the subject of inquiry ; and persons are
thus unfortunately compelled, for want of anything
tangible or authentic, to fall back upon the usual
predictory schemes of the weather-almanac-makers,
though there are unquestionable grounds for believing
that these are altogether unfounded and absurd.
With regard to the analogy between the lunar in-
fluence on the tides of the ocean and on the atmos-
pheric currents insisted on by some writers, we are
in possession of one fact worth a hundred disquisi-
tions—namely, that M. Bouvard examined more than
100,000 observations made at the Royal Observatory
of Paris, embracing a period of eleven years, and he
found beyond question that the tides caused in the
atmosphere by the action of the moon were so small,
or rather so imperceptible, that it is utterly impossible
to reckon upon them for any purpose of experimental
or practical application. Thus, our scientific friends
must look elsewhere than in the influence of the
moon for a solution of the phenomena producing the
weather, and account in some other way for the cer-
tain and periodical recurrence of favourable or un-
favourable seasons. On this subject, we have seen a
private communication from Mr. Mackenzie, wherein
he says—
" I am very curious about the keen pursuit upon
the subject of magnetism, because this property of
the earth is the sole foundation of the weather, for,
without it, there would be no weather whatever. Its
first sensible effect is to operate upon the loadstone or
compass needle, which is sensible to the sight; the
next step, or property, is on the winds, which is
sensible to the feeling, but not to the sight; then
come the clouds, rain, and all the phenomena belong-
ing to the weather. Perhaps the professors expect to
discover the laws of the weather from continued ob-
servations upon the mechanical (so to say) variations
of this recondite principle upon certain bodies. In
this, I believe, they will be disappointed, since the
cycles of the winds embrace every moment of time,
and every part of the surface of the globe, and fully
explain the coming changes on all these periods (of
time), and in all places. When I mention that the
magnetic principle is the foundation of the weather,
I should have stated that this property is wholly de-
rivable from the solar action. It may be true that
half the winds are produced by the lunar body ; yet
the weather has no reference to lunar influence. So
far, this is certain ; and as the weather recurs in
cycles by the solar, or calendar months, the influence
of the moon is so ar settled."
That there are cycles of the winds, and that they
have been discovered, as stated by Mr. Mackenzie—as
there are cycles in every other system of nature—we
have every reason to believe to be the case. We
know—indeed for centuries it has been known—that,
at the end of every eighteen years, the new and full
moons happen at very nearly the same times of the
year, with all the recurring phenomena of the
heavenly bodies at their regular times. The great
error in forecasting the weather seems to have origi-
nated in connecting and combining a system which is
purely a property of the earth with the planetary re-
volutions and appearances, which have as little influ-
ence on the weather as they ever had on the destinies
of man—this last being a system of gross astrological
superstitious prediction and imposition, at once de-
structive of the intellect and morals of mankind—by
which the reason and common sense of the people
were rendered completely useless—the good and the
bad depending upon an ideal destiny, no
it_a
effort
on
the part of the man having power 1
to
a
de-
basing and delusive system, which e
is helped to be perpetuated in certain almanacsand
publications,
edited by persons of whom better things
might be expected.
With respect to the winds, it may not be amiss, in
concluding this notice of Mackenzie s discovery, to
advert to the opinion of M. Alphonse Blanc, who ob-
serves that the winds are mostly, if not always, caused
by the expansions on condensation of the air due to
changes of the temperature. Between the tropics
the winds are very regular, the cause being perma-
nent, and the equilibrium constant. From this regu-
larity it may justly be concluded that the north and
south winds which we have originate in the north ;
for we cannot for a moment suppose that a south
wind should come to us from a quarter where the
contrary wind is constant. On this view, the south
wind is caused by a condensation, and the north wind
by an expansion, of the polar atmosphere, and the
barometer ought to fall with south winds, and rise
with north winds—the effect, indeed, usually ob-
served. In other words—and as has been long ago
explained—it may be demonstrated that, owing to the
unequal distribution of heat upon the surface of the
globe, and the gradual decrease of temperature from
the equator to the poles, the elastic fluids of the at-
mosphere must perpetually circulate between the
colder and the hotter points, flowing from the former
Ito the latter on the surface of the earth, and return-
ling from the latter to the former in upper opposite
currents. Owing to various causes, but chiefly to the
unequal distribution of water and land upon the sur-
face of the earth, the course of the winds is by no