greater, for there is always a probability that the storm may be of the
character which is extended south, by a polar wave. The observer must
watch the formation of cirri, and the different forms of cirro-stratus and
stratus, and become familiar with their appearance. It is not a difficult
task. With the aid of a few general directions he will soon be familiar
with them:
1. Get a correct idea of the different characters of the primary clouds.
The true fibrous _cirrus_--the different forms of _cirro-stratus_--the
smooth, uniform _stratus_--the _cirro-cumulus_, which is nothing but a
cirro-stratus, separated into _distinct masses_ by the repulsion of static
electricity--and the _cumulus_, too distinct ever to be mistaken. There is
no difficulty, except with the varied forms of cirro-stratus. It is
useless to attempt to give, or the observer to rely on, names for these
numerous forms, without as numerous illustrations. Those in use are rarely
applied correctly. I have never met with ten persons who applied even the
term "mackerel sky" to the same precise form of cirro-stratus. In relation
to all of them it is to be observed that polar belts of condensation, and
local appearances of considerable extent, are often too feeble in action
to precipitate, even when the mackerel form is present; and all may be the
lateral attendants of passing storms. Therefore,
2. Satisfy yourself whether the cirrus or cirro-stratus increases in
density and tends to the formation, or induction, of stratus; and whether
it is isolated, or an extension of the condensation of a storm, and if the
latter, _where that storm is_. The time will come when an intelligent use
of the telegraph will do this for you.
3. Look also to the character of the wind, if there be any. On this
subject I have perhaps said all that is necessary in the preceding pages.
Next to condensation, the direction and character of the wind is the most
valuable prognostic. Indeed it often tells us that a storm is approaching,
and the quarter from which it will come, and its character, before the
condensation is visible.
4. See if there is any _secondary_ condensation or scud. These are
sometimes seen running toward a storm, when there are not distinct clouds
visible in the western horizon, at nightfall, or in the evening, as in the
instance stated in the introduction, and sometimes from the north-east, as
in cases heretofore so often stated. But the easterly scud do not often
form in winter, until after the cirrus has passed into the form of
cirro-stratus, or has induced the latter forms in the inferior portion of
the trade, or the surface atmosphere.
The inductive effect of the primary condensation, therefore, is not
always, and especially in winter, sufficient to create the easterly
current and scud, and it is often the case that the easterly wind is not
felt, or the scud seen, in snow-storms, until the snow has begun to fall,
and the first snow will fall with a S. W. air, as I have heretofore
stated. But when the condensation has so far advanced toward stratus that
the easterly wind and scud are obvious, there is little or no doubt that
rain or snow will fall speedily. The occasional occurrence of easterly
wind and scud, without rain, however--dry north-easters, as I have termed
them--in connection with storms passing south of us, or condensation too
feeble to precipitate, should be remembered. The long, dry,
north-easterly winds of spring have been attributed to the icebergs, but
they are overlaid by feeble stratus or cirro-stratus condensation, or are
the result of attraction, by a more southern precipitation. The observer
must be careful to distinguish between the various forms of N. W. scud and
cirro-stratus, which they sometimes resemble. This he may do _from the
direction in which they move_. Cirro-stratus always moves from some point
between S. S. W. and W. S. W. to some point between N. N. E. and E. N. E.
The various forms of N. W. scud move to the S. E. The March, foggy scud,
from between W. and N. W., rarely have any cirro-stratus above them, but
rather a peculiar turbid condensation.
The character of the primary condensation, the direction and force of the
wind, and the direction of the secondary condensation or scud, must be the
main reliance of the observer. But I must reiterate that they all differ
in different kinds of storms, in different seasons of the same year, and
the same seasons of different years; and the observer must be careful to
make due allowance for those differences.
There are, however, divers other secondary signs, which, although not
alone to be relied upon, will aid the observer, if carefully studied, when
the character of the clouds, and the pressure of easterly or southerly
wind and scud, are not decisive. Of these, a large class are electrical.
The smoke descends the adjoining chimney-flues, or outside of the chimney,
toward the ground.
Thus, Darwin, as quoted by Hone:
"The smoke from chimneys right ascends,
Then, _spreading_, back to earth it bends."
Smoke is electrified _positively_, by the act of combustion; the earth and
the adjacent atmosphere, when storms are gathering or approaching, is
_negative_. Hence the smoke spreads, and is attracted downward by an
opposite electricity. On the other hand, it is interesting to see, at
other times, and when the difference in temperature is not material, but
the whole atmosphere is positive, with what rapidity and compactness the
smoke will ascend in a _straight and elevated column_ from the chimney,
repelled by a similar electricity. I am aware it is generally supposed the
smoke descends because the _air is lighter_. But it is a mistake. I have
seen it descend when the barometer was at 30 deg..60, or .60 above the mean.
There is, too, a draught downward in chimneys, in such cases when there is
no smoke or fire in any of its flues. Thus Jenner says: "The soot falls
down;" whether he meant by this that there was an actual fall of soot
other than what is occasioned by the rain falling in through the chimney
top, and disturbing the soot, as sometimes happens, I do not know. It
occurs rarely, and is of very little practical importance. But every
housewife knows that chimneys, which have been used in winter, and are
full of soot, _smell_ before storms. The odor results from a downward
draught and the dampness of the air. So the smoke from one flue will
descend another, into some unused room, on such occasions. Another class
of these electrical signs are felt by those who are suffering from chronic
diseases, which have affected the nerves and made them sensitive. Thus
Jenner:
"Old Betty's joints are on the rack."
And Hone adds:
"Her corns with shooting pains torment her,
And to her bed untimely send her."
But Old Betty's rheumatism or corns are not alone in this. Those whose
bones have been broken feel it. All invalids feel it. And, indeed, all
observing healthy persons may, and do, although all are not distinctly
conscious of it. It is common for such to say, I feel sleepy, or I feel
dull, or, It _feels_ like snow, or _feels_ like rain, and thus from their
own feelings to be able to predict, not only falling weather, but its
_character_, whether snow or rain, at a time when either may occur
consistently with appearances.
This change is a change from the positive electricity which is so
congenial to the active--"bracing" is the usual term--to negative and
damp--for this change is accompanied by condensation, as I believe all
changes from positive to negative are. Certain it is, if the atmosphere is
highly charged with negative electricity, condensation takes place; if
with positive, evaporation. Perhaps it is a change of the associated
electricity which accompanies magnetism, and not of the free atmospheric
electricity alone. Hence another phenomenon alluded to by Jenner:
"The walls are damp, the ditches smell."
There are localities where this dampness is very obvious. The celebrated
William Cobbett, many years since, when a farmer on Long Island, observed
and published the fact that the stones grew damp before a storm. I know of
flagging stones that usually grow damp two or three hours before rain,
especially in spring and fall, and every step taken upon them is made
visible by a corresponding increase of condensation.
The reverse of this takes place just before the close of storms. Flagging
stones, and walls under cover, will frequently become dry before the rain
ceases. The negative electricity becomes less as the positive prevails,
although the clouds above are still dropping rain.
In the comparatively moist, showery climate of England, these changes from
positive to negative alternate rapidly between successive showers; but
observations of electric phenomena, or of clouds, in that climate, are
not, without qualification, safe guides for us.
So "the ditches smell," particularly in the evening before a rain, when
the immediate surface-atmosphere is charged with negative electricity, and
the _condensing moisture_ prevents the diffusion of the odors. For the
same reason the candle will not relight, and there is crackling in the
ashes or lamp. Thus, again, Virgil:
"Maidens that nightly toil the tangled fleece
Divine the coming tempest; in the lamp
_Crackles_ the oil, the gathering wick grows dim."
Virgil did not live in our cold climate, and knew nothing of the crackling
in the fire, or in the ashes or coals which remain after the wood is
consumed. The lamp exhibits it on a smaller scale, and perhaps he had
noticed it when in company with the maidens. But it is sometimes
noticeable even in the lamp or candle with us. A small particle of
moisture will produce it, in a marked degree, at any time.
In winter, when the air is highly positive and cold, the candle can be
blown out, and by another puff of the breath relighted, with ease. But
when the electricity before a storm becomes negative, and partial
condensation takes place, this can not be done. This partial condensation
before storms and showers shows itself upon vessels containing cold-water,
in summer. It seems to be the received opinion, that the condensation is
evidence of a greater _quantity_ of moisture in the atmosphere. But this,
too, is a mistake, and hence the little reliance to be placed on
hygrometers.
This partial condensation is sometimes visible. When the sun shines
clearly, at the east or west, through a _small opening_ in the clouds, the
condensing vapor is shown by the streaks of sunlight, just as the fine
particles of dust are seen in a dark room, when a few rays of sunlight are
admitted through a small aperture. This phenomenon is often observed, and
it is said of it--"It's a going to rain; _the sun is drawing water_."
Virgil alludes to this as seen in the east in the morning, thus:
"But when beneath the dawn _red-fingered rays_
Through the dense band of clouds _diverging_ break,
* * * * *
Ill does the leaf defend the mellowing grape;
Leaps on the noisy roof the plenteous hail,
Fearfully crackling."
It is well ascertained that storm-clouds of great intensity have polarity
in the different portions, and that in the less intense magneto-electrical
climate of England isolated showers are often of this character--the
polarity existing in rings. Showers are doubtless thus found with us. Mr.
Wise got into one of them; see his description (Theory and Practice of
Aeronautics page 240).
I have, in another place, alluded to the upward attraction of the dust
beneath the advance condensation of a shower. Jenner alludes to it in the
following lines:
"The whirling winds the _dust_ obeys,
And in the rapid eddy plays."
So Virgil:
"Light chaff and leaflets, _flitting, fill the air_,
And sportive feathers circle on the lake."
All these are electrical.
In England, where the action of such isolated clouds is less intense, the
different electricities in different portions of the cloud, whose opposite
and changing action produce all the phenomena, the condensation, the cold
and congelation, the currents, etc., have been accurately ascertained. We
can not get into the situation occupied by Mr. Wise. But every man may
observe these _intestine motions_ occasionally, in the advance
condensation of an isolated thunder-shower, in front of, but near the
smooth line of falling rain. They are more lateral than upward or
downward, and are often exceedingly rapid in movement.
I have said that hail has often been found to fall from particular and
well-defined portions of a cloud, and rain from the other portions, the
hail being positive, and rain negative. An instance of very striking
character may be found in Espy's Philosophy of Storms (Introduction, page
xx.) Doubtless in all cases thunder-showers, which are isolated and
distinct, have opposite electricity in different portions, to whose active
agency all the phenomena are owing. And the return of electricity to the
earth in the rain explains the greater fertilizing effect of the latter
compared With all artificial watering. He was a true philosopher who
attempted to stimulate vegetation by electricity.
Sounds may sometimes aid the observer in doubtful cases in foretelling the
weather. The roar of the surf, or breaking of the waves on the shore, when
great bodies of water are disturbed by a precedent storm-wind, often heard
before the wind is perceived on the land, I have already alluded to. And
thus Virgil:
"When storms are brooding--in the _leeward gulf_
Dash the swelled waves; the mighty mountains pour
A harsh, dull murmur; far along the beach
Rolls the deep rushing roar."
The moaning or whistling of the wind all have noticed. It is not uncommon
to hear the expression, "The wind sounds like rain." Jenner says:
"The _hollow_ winds begin to blow."
And Virgil:
"The _whispering_ grove
Betrays the gathering elemental strife."
This whispering is the motion of the leaves; and they are often stirred by
a peculiar motion which is not that of wind. Sometimes every leaf upon a
tree may be seen _vibrating_ with an _upward and downward_ motion, when
there is not wind enough to stir a twig. This interesting phenomenon is
electrical. Trees, and all vegetables, confessedly discharge electricity,
and such discharges move the leaves, when very active.
With us, sounds can be heard more distinctly from the east or south,
before storms, according to the character of the coming wind. Howard
mentions an instance when he heard carriages five miles off. Steamboat
paddles, rail-road cars, and other sounds, are often heard a great
distance. The distance at which the now common steam-whistle is heard, and
the direction, is not an unimportant auxiliary indication of the weather.
Howard attributes these peculiar phenomena to the "_sounding board_," made
by the _stratum of cloud_; but sounds may be heard from the north-west,
when there is no condensation, and the wind is from that quarter, and also
from the east when it is not cloudy; and in a level country the village
bells often tell the direction of the current of air just over our heads
when we do not feel it at the surface. The wind is undoubtedly moving in a
rapid, and perhaps invisible current, not far above us. If from the east
or south, it betokens rain; if from the western quarter, fair weather.
The conduct of the different animals furnish a considerable portion of the
signs alluded to by Virgil and Jenner, and are never unimportant auxiliary
evidence of the approaching changes, whether from dry to wet, or wet to
dry.
The observer will find, in the conduct of our birds and animals,
especially those which are not domestic, ample evidence of the truth of
the descriptions of Virgil. He denies the animals and birds foresight, but
he does not seem to have observed that the swallow leaves for the south as
soon as the _autumnal_ change begins to be felt, and in August; nor the
evident sagacity of other _migratory_ birds. They do not act from the
"_varying impulse_" produced by an actual state of things, but a knowledge
or apprehension of those which are to come. This is nothing more or less
than foresight. So foresight tends to prudence and skill, and they
exercise both, and with reference to the future. The goldfinch does not
build her nest in the hole of the tree, or in the crotch of the limb; but
_hangs it_ with _exquisite skill_ on the slender _waving, outward branch_,
where no animal, or larger bird, or any depredator, can be sustained. She
is not more timid than others; why does she invariably thus build? What
makes her "_impulses_" differ from those of other birds, and always in the
_same manner_?
Jenner, too, has grouped, in admirably descriptive language, many of the
peculiarities exhibited by animals and birds before approaching storms,
some of which exhibit foresight, and others not.
Perhaps the rooster, who keeps ceaseless watch over his harem, is the most
reliable weather-watcher we have. In my earlier days, when it was the
practice to keep valuable birds of the kind much longer than it now is,
and they had opportunity to become _experienced_, it was interesting to
observe how closely they watched the weather. I well remember a venerable
chanticleer, who, perched on the tree among his hens, would always
foretell the coming storm of the morrow, by sounding forth _in the
evening_, and _often_, his defiant note. Such note in the evening was
invariable evidence of foul weather. And during the night, their earlier
and more frequent crowing is often indicative of it. It is, however, in
the earlier part of the day, in doubtful cases, that no inconsiderable
reliance may be placed on their sagacity. Often, when a storm is gathering
in the forenoon, they will announce it by an almost incessant crowing. The
habits of an _experienced_, old-fashioned bird, of this kind, will well
repay attention; but I can not answer for the Shanghai and other _fancy
breeds_.
Jenner says:
"The leech disturbed, is newly risen
Quite to the summit of his prison."
Few have had, or will have, opportunities to observe this, but it is
strikingly true. It is difficult to conceive how mere condensation, from
an increase of vapor in the atmosphere, should be foreseen by the leech in
his watery prison. It is obvious, I think, there is an electric change
which reaches him, as it does the whole animal creation, the once broken
bones, and the joints of Aunt Betty. Thus much of the philosophy of signs.
_The barometer_ is a useful instrument, in connection with observations of
the other phenomena. It is especially useful to the sailor, as its
indications relative to the winds are much the most certain. But it is
not, _alone_, to be relied upon. This is well settled, although the
reasons for it have not been understood. Why it should rise sometimes
before storms, in opposition to the general rule--or fall at others
without rain--or rise occasionally during the heaviest gales, has been a
mystery, and impaired the confidence in its accuracy and usefulness even
of the class of philosophers of whom Sir George Harvey spoke, in the
sentence quoted in the introduction. But, as I have already intimated, it
is all very intelligible.
I have said that the barometer has no fair weather standard--the mean of
30 inches at the level of the sea being an _average_ of the _fair weather_
elevations and the _foul weather_ depressions. Its fair weather position,
it would seem, must be above the mean, therefore, and as much above as its
foul weather depressions are below. But this is not precisely true. Its
extreme fair weather range is 31 inches, and it rarely reaches that; while
its lowest storm range is down to 28, and is the most often reached of
the two. My barometer stands about 40 feet above ordinary high-water mark.
It is not a "wheel," but an open, "scale" barometer, and a perfectly good
one. Its most reliable fair weather standard is about 30-30/100 inches. It
is its _most common summer, set fair position_, but that position is often
at other and different elevations, at other periods of the year, during
fair weather. The reader must observe for his own locality, and satisfy
himself what the most common set fair position for the barometer is, at
the different periods of the year, where he resides. When he has
ascertained this, he may apply the following principles to illustrate its
exceptional action, and in judging of the future of the weather:
1st. _As to its rise before storms._--Supposing it to have been
stationary, at or about a set fair position, _for the period_, and for one
or two or more days, a very _gradual_ and _moderate_ rise is an indication
of continued fair weather; and a _sudden_ and _considerable rise_ is
indicative of a storm. If the sudden and considerable rise occurs in the
latter part of spring, summer, or early autumn, it indicates a storm of
the _first_ or _third classes_ described in Chapter X., if in winter, a
storm of the _first class_ only. If the elevation is _very_ sudden and
considerable, the storm will probably be _severe_. The philosophy of this,
according to my present apprehension of it, is, that these storms present
an _extended easterly front_--_settle very near the earth_--and _have a
rapid progress_--thus accumulating the atmosphere somewhat, in advance of
them.
2d. _As to its fall before storms without previous rise._--This is always
very regular before the second class of storms, or polar belts of showers
and storms. It is very fairly exemplified in the table from Reid, on page
329. The barometer, so far as I have opportunity to observe, does not rise
from a stationary position on the approach of this class of storms. At the
commencement of heated, summer, dry terms, my barometer has most
frequently ranged at about 30.30, and gradually, but slowly, fallen below
30 inches before the belt of showers arrived, and the term closed. The
fourth rule of Dalton (Meteorology, page 183) indicates a similar law in
England. It is as follows:
"In summer, after a long continuance of fair weather, with the
barometer high, it generally falls gradually, and for one, two, or
more days, before there is much appearance of rain. If the fall be
sudden and great for the season, it will probably be followed by
thunder."
3d. _It falls frequently and considerably without rain._--This is owing to
the fact that _all_ regular, periodic efforts at condensation do not
result in rain. The second, third, and fourth classes of storms described,
may not (as we have said) _be sufficiently active to precipitate_,
although the _series of phenomena_ (including the fall of the barometer)
may be, in other respects, perfect. Such an instance may be found in
Reid's table, on page 329, and on the 11th of the month. But the fall in
such cases is not as great, unless the wind be violent.
4th. _It rises during considerable gales._--But these are of the kind so
often alluded to--viz., the N. W., in the northern hemisphere, and the S.
W., in the southern; and the _philosophy_ of it has been explained, and is
observable.
With these explanations, the reader will be able to understand, and
practically apply, the barometric changes, in connection with the other
phenomena, in forming an opinion of the weather.
_The thermometer_ is also an auxiliary. It _rises_, during the winter half
of the year, in the _advance portion of the storm_, and falls when it
passes off again; and the reverse is true, as we have seen, when its range
is very high in summer. It is, therefore, to some extent, a useful
auxiliary, although of minor importance.
_The hygrometer_ is of less importance still. It is not in general use as
a practical guide to the changes of the weather, and does not deserve to
be.
A question, which has been much mooted, deserves a passing notice in this
connection--viz., whether our climate has gradually become ameliorated and
milder on the eastern part of our continent, since its settlement. I have
not space left for its discussion. Humboldt (Aspects of Nature, page 103)
is of opinion that there has been no material change. He says:
"The statements so frequently advanced, although unsupported by
measurements, that since the first European settlements in New
England, Pennsylvania, and Virginia, the destruction of many forests
on both sides of the Alleghanys, has rendered the climate more
equable--making the winters milder and the summers cooler--are now
generally discredited. No series of thermometric observations worthy
of confidence extend further back, in the United States, than
seventy-eight years. We find, from the Philadelphia observations,
that from 1771 to 1824, the mean annual heat has hardly risen 2 deg..7
Fahrenheit--an increase that may fairly be ascribed to the extension
of the town, its greater population, and to the numerous
steam-engines. This annual increase of temperature may also be owing
to accident, for in the same period I find that there was an increase
of the mean winter temperature of 2 deg. Fahrenheit; but, with this
exception, the seasons had all become somewhat warmer. Thirty-three
years' observation, at Salem, in Massachusetts, show scarcely any
difference, the mean of each one oscillating within 1 deg. of Fahrenheit,
about the mean of the whole number; and the winters of Salem, instead
of having been rendered more mild, as conjectured, from the
eradication of the forests, have become colder, by 4 deg. Fahrenheit,
during the last thirty-three years."
The facts hereinbefore stated show that there is nothing like a _regular_
amelioration; that the seasons differ during the same decade, and
different decades. The cold decade, from 1811 to 1820, has not been
reproduced. But it may be, and we know not how soon. Since that period
there has certainly been a change--for even the cold period from 1835 to
1840 did not equal that from 1815 to 1820, nor indeed those of 1775 to
1780 or 1795 to 1800. But as these variations, so far as we are enabled to
judge, depend upon the varying influence of the sun's rays, and of
volcanic action, it is impossible to say that equally cold periods will
not return, during the latter half of this century.
If the influence of the sun was constant, and volcanic action regular, two
causes would tend to modify the seasons:
1st. The exposure of the surface to a more effective action of the solar
rays, by a removal of the forests, and by drainage. That such action would
be more effective upon a surface thus uncovered and drained, can not be
doubted.
2d. _The movement of the area of magnetic intensity, and the magnetic
pole, to the west._--There is such a movement, and its progress can be
measured by the increase of declination on the east of it, and its
decrease on the west. And the effect of it on climate is unquestionable.
In all probability it has had an influence upon ours; and a removal of
that area and pole still further west--60 deg. or 80 deg.--would change the
location of the concentrated trade, and the Gulf Stream, and restore to
Greenland the fertility she once had, and which the Faroe Islands now
enjoy. And, on the other hand, its removal as far east of its present
position would again depopulate Greenland, and render it again
inaccessible. But I can not pursue this subject.
Finally, assistance may be derived from the occasional, although
imperfect, accounts of the state of the weather elsewhere, which the
newspapers afford. I have been much indebted to the Associated Press of
New York for intelligence contained in their telegraphic reports.
Occasionally they have been very full and instructive.
On this point, however, there is less of reality in the present than of
hope in the future. The time must come when the collection and
dissemination of meteorological truth, will be deemed an object of
national importance, and national duty. Population is increasing, by
immigration and propagation, in a rapidly progressive ratio. There has
been great danger that it would outrun agricultural production. A short
crop this year would have been disastrous to our prosperity--and the
danger was imminent. Every description of business, and every financial
circle, felt that fever of anxiety it was so well calculated to induce.
The importance of extended agricultural production, and the dependence of
all classes upon its success, are now in a greater measure appreciated;
and none can fail to see the value of a correct understanding of the
weather to the agriculturist, how short-sighted soever they may be, in
relation to its direct influence upon their own prosperity and happiness.
Our country is, physically, a most favored one. The facts disclosed or
alluded to in this volume show that it is without a parallel on the face
of the globe; and our facilities for meteorological observation, and the
ascertainment and practical application of meteorological truth, are
equally pre-eminent. The great extent and unbroken surface of the eastern
portion of the continent; its excessive supply of magnetism and
atmospheric currents, and the consequent marked character of the
phenomena; the existence and prospective increase of telegraph lines over
most of its surface; the homogeneous and energetic character of a
population united, upon so large a surface, under one government; the
freedom of that government from debt, and the excess of its revenue; the
possession of a National Observatory, with a competent philosopher at its
head; and a national institution, liberally endowed, and adapted to the
collection and diffusion of practical and scientific intelligence, give
us an opportunity and a capacity for connected observation and
investigation, and an ability to profit by it, that no other nation can
boast.
We have, too, a just national pride. Our exploring ships have penetrated
and made discoveries in both hemispheres, and our travelers have visited
successfully every clime; and thus our national interests, and
obligations, and pride, demand an organization, practical and permanent,
in relation to this subject, and the time will come when we shall have it.
When that time comes--when the present _limited horizon_ of each of us is
_practically extended over the entire country_--and when the actual state
of the weather over every part of it is known, at the same time, to the
inhabitants of every other, and every where _read in the light of a
correct philosophy_, prognostication will be comparatively simple and
certain; and A PROGRESS will have been made, productive of an amount of
pecuniary, intellectual, and social benefit to the people, which can not
be overestimated. May it come before the shadows of the night of death
have gathered around us, that we may have a more perfect view of that
atmospheric machinery which distinguishes our planet from others, and is,
with such infinite wisdom, adapted to make it a fit habitation for man!
THE END.
APPENDIX.
Since this work was completed I have received a very valuable publication,
entitled, the "Army Meteorological Register." It is a compilation of the
observations made by the officers of the medical department of the army,
at the military Posts of the United States, from 1843 to 1854 inclusive,
prepared under the supervision of the Surgeon-general, and published by
direction of the Secretary of War. To this, there is appended a report or
general review of the prominent features of American climatology, so far
as the basis afforded by the published observation of the army medical
Bureau would warrant positive deduction, by Mr. Lorin Blodget, a
distinguished meteorologist, accompanied by temperature and rain charts,
for each of the four seasons;--exhibiting the various local differences
and peculiarities relative to temperature and precipitation in each.
These local differences and peculiarities and contrasts are deduced and
delineated by Mr. Blodget with much ability. He was fettered, however, by
the prevailing calorific theories, and the unfortunate practice of
grouping the phenomena into means for the seasons, Spring, Summer, Autumn,
and Winter, which grouping is arbitrary, and comparatively uninstructive.
Hence, he failed to discover what the tables and summaries most clearly
disclose--the principles and system unfolded in the foregoing work.
But the summaries of this register contain observations made at posts in
Western and Southwestern Texas, in Kansas and Nebraska, and in New Mexico
and California, where there has been a dearth of such observations
hitherto, and enable me to demonstrate, more conclusively, and I think so
that none can fail to understand it, the truth of the philosophy I have
endeavored to exhibit.
To do this, I will take a _year_,--divide it into two seasons, the periods
of northern and southern transit, the only natural and correct
division--and note the phenomena in each, as each progresses.
And I will take the year 1854, because that is the last year for which the
record of observation is complete; because it had marked peculiarities
which are remembered; and because I have alluded to those peculiarities,
and those allusions should be confirmed or disproved by the record. Unless
I mistake exceedingly, the confirmation will be found signal and
convincing.
I have assumed, pp. 187, 351, that the transits were greater in some
seasons than others; that the drought of 1854 was owing to an extreme
northern transit, or to an extension west of the concentrated
counter-trade, or both, leaving us less supplied with moisture than
usual.
In point of fact, it appears from these observations that it resulted from
_both_ causes, operating _connectedly_; and the annals of Science rarely
furnish a more striking instance of analogical inference proved true by
subsequent investigation.
Commencing then with the commencement of the northern transit about the
1st of February, we are enabled to trace the then location of our
concentrated trade, and its subsequent progress to the north till August,
and its influence upon temperature and precipitation. And we can also
trace the situation during the same period, of the intervening drought,
and the inter-tropical belt of rains, and the extension of the latter
north over Florida and the cotton-planting States.
On the 1st of February, 1854, our counter-trade was somewhat more
concentrated on its extreme winter curve, over the Southern States, than
usual. Its line of excess reached up from Fort Brooke, on the peninsula of
Florida, to the northwest, a little east of Pensacola on the gulf, cutting
Mount Vernon Arsenal north of Pensacola, and extending thence
north-westwardly on to Eastern Louisiana, and curving thence and passing
N. E. or E. N. E., to the Atlantic, about the waters of the Chesapeake
Bay. It thinned out to the west over New Orleans and Baton Rouge,
supplying them moderately, but did not extend to the forts of Texas on the
west, nor the posts in the Indian Territory at the N. W. It was east of
Fort Towson, which is the south-eastern one. It did not reach St. Louis on
the north, nor extend north of the Ohio River, as will appear from the
tables hereinafter given. The following cut shows substantially its
situation on the 1st of February.
[Illustration]
Now, during the month of January, we find the following state of things.
_Under_ this concentrated trade, the temperature was above the mean, even
if Forts Monroe and McHenry on the Atlantic are included; but Mr. Blodget
discredits their returns, and some others which do not conform to general
results. On the west and north of its curving line, both precipitation and
temperature were below the mean.
Under the counter trade, we have the following stations, with their actual
and mean temperature. I have inserted the temperature for several
subsequent months, to show a depression in April.
TABLE I.
-------------------------------------------------------------------------
| LAT. | LON. | JAN. | FEB. | MAR. | APRIL.| MAY. |
------------------------------------------------------------------------|
Fort Moultrie | 32.45 | 79.51 | 50.83 | 53.09 | 62.72 | 62.76 | 73.35 |
Mean of 28 yrs.| | | 50.36 | 52.41 | 58.68 | 65.44 | 73.42 |
Fort Pierce | 27.30 | 80.20 | 67.91 | 67.33 | 73.01 | 71.10 | 78.41 |
Mean of 5 yrs. | | | 62.75 | 64.42 | 69.77 | 73.63 | 76.92 |
Fort Meade | 28.01 | 82.00 | 63.75 | 63.33 | 70.64 | 68.10 | 76.31 |
Mean of 3 yrs. | | | 58.40 | 63.23 | 69.02 | 69.89 | 76.69 |
Fort Brooke | 28.00 | 82.28 | 62.94 | 62.36 | 70.06 | 70.07 | 77.49 |
Mean of 25 yrs.| | | 61.53 | 63.54 | 67.72 | 71.82 | 76.64 |
Fort Myers | 26.38 | 82.00 | 67.56 | 67.39 | 73.74 | 71.07 | 79.13 |
Mean of 4 yrs. | | | 63.39 | 67.98 | 72.19 | 73.86 | 80.13 |
Key West | 24.32 | 81.48 | 71.75 | 71.95 | 76.56 | 73.89 | 80.84 |
Mean of 14 yrs.| | | 66.68 | 68.88 | 72.88 | 75.38 | 79.10 |
Fort Barrancas | 30.18 | 87.27 | 54.71 | 54.56 | 64.98 | 62.93 | 75.40 |
Mean of 17 yrs.| | | 53.61 | 55.58 | 61.80 | 68.51 | 75.45 |
Mt. Vernon Ars'l| 31.12 | 88.02 | 51.52 | 53.18 | 65.24 | 62.30 | 74.64 |
Mean of 14 yrs.| | | 50.44 | 53.69 | 60.26 | 66.87 | 73.92 |
Baton Rouge | 30.26 | 91.18 | 53.43 | 56.48 | 66.24 | 64.63 | 75.10 |
Mean of 24 yrs.| | | 53.47 | 55.02 | 61.93 | 69.30 | 75.60 |
-------------------------------------------------------------------------
-------------
JUNE. | JULY.
-------------
78.55 | 82.06
79.01 | 81.72
82.09 | 84.16
79.02 | 82.50
79.10 | 80.17
78.24 | 79.76
80.51 | 81.08
79.46 | 80.72
82.35 | 81.91
81.25 | 82.87
83.34 | 83.30
81.63 | 83.00
81.00 | 84.55
80.80 | 82.26
79.17 | 78.90
78.03 | 78.62
80.61 | 80.09
80.56 | 81.81
-------------
It will be seen that the temperature was above the mean in January at
every post except Baton Rouge, and there it was at the mean. We shall see
hereafter that Baton Rouge was near its western line.
Under this trade during this month, and at the same posts, the fall of
rain was as follows, compared with the mean:--
TABLE II.
--------------------------------------------------------------
| JANUARY. | FEBR'Y. | MARCH. |
--------------------------------------------------------------
| 1854. | Mean.| 1854. | Mean.| 1854.| Mean.|
--------------------------------------------------------------
Key West. | 1.77 | 2.86 | 2.55 | 1.38 | 0.51 | 4.21 |
Fort Myers. | 1.15 | 3.90 | 4.70 | 2.16 | 0.20 | 4.60 |
" Brooke. | 3.88 | 2.20 | 6.89 | 3.01 | 2.44 | 3.37 |
" Mead. | 1.30 | 1.07 | 2.21 | 1.01 | 1.85 | 1.64 |
" Pierce. | 3.55 | 4.45 | 3.40 | 2.72 | 1.05 | 3.01 |
" Barrancas. | 3.45 | 3.87 | 5.55 | 4.95 | 7.21 | 5.87 |
Mt. Vernon Ars'l | 11.01 | 6.80 | 12.83 | 6.04 | 6.22 | 4.59 |
Baton Rouge. | 2.85 | 5.26 | 5.50 | 4.91 | 6.15 | 4.68 |
Fort Moultrie. | 3.80 | 2.39 | 2.84 | 2.33 | 0.25 | 4.06 |
--------------------------------------------------------------
-------------------------------------------
| APRIL. | MAY. | JUNE.| JULY.
| 1854.| Mean.| 1854. | Mean.| |
-------------------------------------------
| 2.99 | 1.55 | 3.14 | 2.58 | 4.54 | 3.45
| 2.75 | 3.14 | 5.65 | 3.33 | 6.75 | 9.70
| 8.82 | 1.95 | 6.21 | 3.24 | 9.44 | 15.53
| 3.19 | 1.78 | 10.51 | 5.34 | 7.24 | 8.55
| 7.00 | 3.85 | 5.70 | 4.27 | 6.63 | 4.97
| 0.50 | 2.94 | 3.47 | 4.05 | 3.39 | 5.43
| 1.96 | 4.21 | 4.45 | 4.62 | 6.72 | 6.13
| 3.58 | 5.22 | 8.05 | 5.18 | 4.00 | 6.55
| 2.20 | 1.75 | 3.70 | 4.08 | 4.20 | 5.69
-------------------------------------------
It will be observed that in February the counter-trade and extra-tropical
belt had moved up from Key West, and a drought, which sometimes intervenes
between the concentrated counter-trade and the inter-tropical belt,
appeared there in February and March. In April, the inter-tropical belt
appeared at that point, and went on increasing till September. As the
counter-trade commenced moving north in February, an increased
precipitation above the mean commenced at all the more southern stations
under the concentrated-trade--an earnest of that irregularity which
followed, and marked the season as the most excessive of the century.
In March, the intervening drought appeared at the other posts on the
peninsula, and also at Fort Moultrie, followed _much more closely than
usual_, by the inter-tropical belt of rains. In April, the drought
appeared at Fort Barrancas and Mount Vernon Arsenal (the wave of
precipitation having moved to the west), and slightly in comparison at
Baton Rouge.
If now we look at the condition of things, _west_ and _north_ of the
curving line of concentrated trade, from Fort Brown, at the mouth of the
Rio Grande, in South-western Texas, through that State, the Indian
Territory, Arkansas, Missouri, Kentucky, and Northern Pennsylvania, to the
Atlantic, we find the thermometer every where in January below the mean.
The following table will show this, and the precipitation for that month
and February:--
TABLE III.
------------------------------------------------------------------------
| JANUARY. | FEBRUARY. | MARCH. |
|-----------------------------------------------|
| 1854. | Mean. | 1854. | Mean. | 1854. | Mean. |
-----------------------------------------------------------------------|
_Western Texas._ | | | | | | |
Fort Brown | 59.34 | 60.41 | 62.45 | 63.63 | 71.87 | 68.95 |
" Ewell | 50.47 | 52.92 | 58.12 | 57.61 | 70.34 | 67.00 |
" Inge | 47.24 | 49.46 | 56.04 | 55.39 | 67.54 | 62.63 |
| | | | | | |
_Indian Territory._ | | | | | | |
Fort Towson. | 36.32 | 43.14 | 49.29 | 45.97 | 59.55 | 53.40 |
Forts Gibson, Washita, | | | | | | |
and Arbuckle, in much| | | | | | |
the same proportions.| | | | | | |
| | | | | | |
_Arkansas._ | | | | | | |
Fort Smith. | 33.92 | 40.18 | 47.01 | 43.89 | 57.01 | 51.58 |
| | | | | | |
_Missouri._ | | | | | | |
St. Louis Arsenal. | 25.47 | 31.44 | 36.66 | 33.43 | 46.10 | 42.30 |
| | | | | | |
_Kentucky._ | | | | | | |
Newport Barracks. | 31.75 | 34.04 | 39.60 | 36.94 | 46.74 | 45.46 |
| | | | | | |
_Pennsylvania._ | | | | | | |
Allegheny Arsenal. | 29.08 | 29.25 | 33.49 | 31.16 | 40.36 | 39.02 |
| | | | | | |
_Delaware._ | | | | | | |
Fort Delaware | 32.38 | 33.67 | 34.56 | 35.84 | 43.18 | 42.90 |
| | | | | | |
_New York Harbor._ | | | | | | |
Fort Columbus. | 28.71 | 30.18 | 28.17 | 30.44 | 36.17 | 38.28 |
------------------------------------------------------------------------
--------------------------------------
| Rain in January. | Rain in February.
--------------------------------------
| 0.45 | 1.50
| 0.22 | 2.86
| 0.20 | 2.15
| |
| 1.01 | 2.00
| |
| 1.37 | 2.05
| |
| 0.65 | 2.40
| |
| 3.20 | 5.30
| |
| 2.23 | 2.33
| |
| 2.30 | 5.45
| |
| 2.60 | 4.00
--------------------------------------
We find, also, from this and table first, that every where, except at Fort
Brown, and upon the Atlantic coast, the temperature had risen above the
mean in February.
The situation of the belt which supplied the western coast in winter, and
its excess of precipitation, are also represented upon the cut. The
intervening area was not without counter-trade and precipitation--the
latter, of course, greatest over the area of intensity--but they were
_comparatively_ less, as the tables will show.
The following cut and table show the situation of the concentrated
counter-trade in March.
[Illustration]
TABLE IV.
------------------------------------------------------------------------
| JAN.|FEBR.| MAR.| APR.| MAY.|JUNE.|JULY.
------------------------------------------------------------------------
Fort Barrancas, Pensacola Bay| 3.45| 5.55| 7.21| 0.50| 3.47| 3.39| 5.43
Mean. | 3.87| 4.95| 5.87| 2.94| 4.05| 4.66| 6.80
Baton Rouge, Louisiana | 2.85| 5.50| 6.15| 3.58| 8.05| 4.00| 6.55
Mean. | 5.26| 4.91| 4.68| 5.22| 5.18| 5.52| 7.42
Fort Towson, Indian Territory| 1.01| 2.00| 5.10| 2.22|Recr'd stops here.
Mean. | 3.13| 2.97| 4.38| 5.33| | |
Fort Gibson, Indian Territory| 0.30| 1.43| 7.83| 3.16| 7.67| 2.80| 0.21
Mean. | 1.33| 2.26| 2.54| 4.19| 4.65| 4.30| 2.75
Fort Smith, Arkansas | 1.37| 2.05| 7.05| 6.55| 6.25| 2.26| 1.02
Mean. | 1.96| 2.17| 2.92| 5.10| 4.46| 4.74| 3.82
St. Louis Arsenal | 0.65| 2.40| 7.10| 4.30| 4.65| 2.20| 1.70
Mean. | 1.93| 3.37| 3.82| 4.16| 4.88| 6.94| 0.04
Newport Barracks, Kentucky | 3.20| 5.30| 8.10| 2.10| | |
(No Mean given.) | | | | | | |
------------------------------------------------------------------------
We see from this table that its focus had extended west in Florida over
Fort Barrancas, and over Baton Rouge in Louisiana; N. W. to Forts Towson
and Gibson in the Indian Territory, and Smith in Arkansas; north to St.
Louis Arsenal at St. Louis, and to Newport barracks in Kentucky; but it
was spread over a larger surface east of the mountains. Its greatest
progress for the month, was a west and north-west progress.
In April, we find it had progressed rapidly west and north-west, and its
position is shown by the following cut and table.
[Illustration]
TABLE V.
------------------------------------------------------------------------
| JAN.|FEBR.| MAR.| APR.| MAY.|JUNE.|JULY.
------------------------------------------------------------------------
Fort Riley, Kansas. | 0.00| 0.94| 1.86| 4.55| 4.35| 1.10| 0.00
Fort Leavenworth, Kansas. | 0.04| 1.78| 1.33| 3.35| 5.55| 4.50| 0.18
Mean | 0.72| 1.01| 1.61| 2.74| 3.62| 5.80| 3.15
Alleghany Arsenal, Pittsburgh | 2.23| 2.33| 2.82| 4.21| 2.24| 2.06| 1.45
Mean | 2.18| 2.17| 2.70| 3.10| 3.58| 3.56| 2.97
Fort Columbus, New York Harbor| 2.60| 4.00| 0.70| 8.80| 7.70| 2.20| 1.90
Mean | 2.78| 2.92| 3.44| 3.33| 4.78| 3.46| 3.17
Fort Independence, Boston | 2.50| 3.36| 2.55| 5.40| 4.28| 2.00|
West Point. | 3.52| 5.04| 2.81|10.53| 2.00| 1.62|
Mean | 3.50| 3.44| 3.71| 4.55| 6.18| 4.79|
----------------------------------------------------------------------
We see, too, that both east and west of the mountains, its focus of
precipitation was one month in advance of the mean. At all the stations
where the greatest fall was in March, it should have been in April, and
the fall at those points was greatly in excess of the usual quantity. And
the same was true of stations reached in April. The concentrated trade,
instead of spreading out, and precipitating over the whole south-eastern
portion of the continent (its normal condition), was gathered into a wave
of greater volume, resulting in greater precipitation, and was rapidly
hastening its curve to the west over Texas, and to the north-west over the
Indian Territory, and northward on its usual curve to the north and east
of them.
The observations for April disclose another singular and instructive
condition. The temperature, that had every where been above the mean in
March, fell below it in April under the concentrated trade. And snow fell
on three days in some localities, and four in others.
Along the Ohio River, it fell to the depth of 8 to 10 inches on the 17th,
and east of the mountains to a greater depth on the 18th, one day later.
It fell to the depth of 4 inches at Marietta on the 29th also. Dr.
Hilldreth, American Journal of Science for March, 1855, says:--
"It is a singular fact that the deepest snow, 8 inches, fell on the 17th
of April, and at the head waters about Pittsburg over a foot. Also, on the
29th of the month, at Marietta, 4 inches, a very rare occurrence." This
depression of the temperature was quite general, but the fall of snow was
local. The latter was north of a line drawn from Fort Laramie, at the base
of the Rocky Mountains, in an E. S. E. direction--north of Forts Kearney
and Leavenworth, and of St. Louis, but south of Newport barracks in
Kentucky, and from thence to the Atlantic. Snow fell at every station
north of this line, at no station south of it. The depression of
temperature, however, was experienced over the continent, east of the
Rocky Mountains, under, and south of, the belt of precipitation. Now what
occasioned this general depression of temperature, and local fall of snow?
It will not do to say, as perhaps some calorific theorist may be inclined
to say, because the concentrated trade had been carried up where it was
cold, a month too soon; or that the sun had heated the land in advance of
it, and drawn it up.
For, 1st, it might be asked how, if it was warm enough to draw it up,
could it be cold enough to make it snow; or, 2d, how happened it to start,
when, as we have seen, it was warmer than the mean under it, and colder
than the mean to the north and west of it, when it commenced its journey?
But again, it snowed at posts north of the line, while the thermometer
remained above the mean; and the thermometer fell below the mean down to
Fort Brown in south-western Texas, and at Key West in the southern part of
Florida; and what is more remarkable still, at Key West, Fort Barrancas,
and every other south-eastern station, except Forts Brooke and Moultrie,
it not only fell below the _mean_ of the month, but _below the actual
temperature of March_. (See Table I.) At Forts Brooke and Moultrie it did
not rise above that temperature. West of the Rocky Mountains the
depression was not felt; nor at stations north, or north-west of the belt
of precipitation.
It is obvious, the calorific theory can furnish no rational explanation of
this matter; for the reason that, whatever the cause, it operated not
only under, but south, and far south of the belt of precipitation. It
could not have been spots upon the sun, or other general cause, for then
it would have operated in New Mexico and California, and at the
north-western stations. It operated most intensely in Florida and the
South-Eastern States, which approach most nearly the volcanic areas of
South America and the West Indies. I believe it to have been occasioned by
volcanic action affecting the local magnetism of our intense area; but it
is a most important development, and should be thoroughly investigated. We
may find in it the key to the mysterious, but unquestionable, influence of
volcanic upon magnetic action; and I hope the distinguished
surgeon-general will cause the records of that month to be published "in
extenso."
In May and June, the trade became more concentrated, a perfectly developed
belt from the Rio Grande to the Lakes and British possessions, and
doubtless to the Atlantic, with every where a central focus of excessive
precipitation, gathering to itself in one vast wave the current that
should have been spread out over the whole country; and leaving every
where on its eastern and southern borders, down to the northern edge of
the inter-tropical belt of rains--(which extended up to lines drawn from
Baton Rouge to Charleston)--a _perfectly well developed_ and _defined
drought_. That drought will long be remembered. The following cuts show,
approximately, the location of the belt of precipitation and drought for
those months, and the table which follows will show their correctness.
The tables also show that this wave was occasionally a double, or divided
one--evinced by an intervening _partial_ precipitation. Tables IV., V.,
and VI., also show the commencement of the drought at the several
stations, as the wave moved to the west and north.
[Illustration: MAY.]
[Illustration]
TABLE VI.
JAN. FEBR. MAR. APR. MAY. JUNE. JULY. AUG. SEPT.
Fort Brown 0.45 1.50 1.15 0.05 4.10 7.65 4.25 5.00 11.31
Mean 1.61 2.25 1.20 0.56 2.21 4.55 1.95 2.76 6.73
Ringgold Barracks 0.70 1.69 0.22 0.00 2.83 10.98 4.06 1.58 3.02
Mean 1.24 1.18 0.72 1.08 2.09 3.47 3.18 1.50 3.22
Fort Merrill 0.11 1.99 0.05 1.16 7.66 4.70 5.44 3.13 5.01
Mean 0.23 2.09 0.09 1.62 3.43 4.10 6.13 3.40 4.60
Fort Duncan 0.05 0.69 1.50 0.00 2.53 6.83 0.83 0.90 4.81
Mean 0.26 1.27 1.34 0.71 1.50 5.63 3.35 0.93 3.28
Fort Inge 0.20 2.15 3.00 0.75 3.88 2.09 0.97 1.67 4.80
Mean 0.64 2.21 1.79 1.26 3.01 5.38 3.66 2.02 2.21
Fort McKavet 0.01 0.77 2.10 0.28 3.72 0.15 2.91 0.04 3.86
" Belknap 0.11 1.10 1.42 1.75 4.97 8.33 0.00 0.75 1.53
" Massachusetts,
Northern New
Mexico 3.93 0.24 2.14 2.61 1.53
Fort Kearney 0.23 1.33 1.87 2.56 4.15 5.40 3.51 1.18 4.60
Mean 0.50 0.48 1.55 2.68 6.57 4.36 5.07 2.62 1.83
Fort Laramie 0.18 0.40 0.80 3.98 4.46 3.67 3.26 1.27 1.60
Mean 0.27 0.71 1.37 1.93 5.39 2.95 1.83 0.92 1.33
Fort Ridgley 1.20 0.01 1.18 2.83 6.84 2.70 2.49 2.28 2.58
" Snelling 0.72 0.03 1.03 2.51 4.30 3.31 3.92 1.75 6.55
Mean 0.73 0.52 1.30 2.14 3.17 3.63 4.11 3.18 3.32
Fort Ripley 0.67 0.03 0.79 0.97 4.34 3.68 0.62 1.69 4.40
Mean 0.86 0.37 1.80 1.42 3.09 5.15 5.20 2.27 4.92
Fort Mackinac 2.59 1.23 1.56 1.04 2.65 6.35 5.67 4.26 3.22
Mean 1.25 0.82 1.14 1.21 2.32 2.81 3.20 2.87 2.97
Fort Brady 2.49 1.18 1.34 2.14 3.61 1.23 3.21 3.86 3.18
Mean 1.84 1.13 1.37 1.83 2.24 2.83 3.73 3.39 4.33
Fort Niagara 1.63 2.52 1.87 2.25 3.90 1.71 4.08 1.52 2.61
Mean 2.25 1.89 2.12 2.20 2.55 3.28 3.49 3.04 3.95
But the belt of trade continued its progress to the west and north, and
during the months of July and August the drought extended in both
directions, reaching, in August, from Mississippi, Alabama, Georgia, and
South Carolina, to the Lakes, and from the Rocky Mountains to the
Atlantic. Its position is shown by the following cut, and the position of
the belt of precipitation by the following table.
[Illustration]
TABLE VII.
_Situation of the focus of Precipitation in July and August._
-----------------------------------------------------------
| JUNE.| JULY.| AUG. | SEPT.| OCT.
-----------------------------------------------------------
_New Mexico._ | | | | |
| | | | |
Fort Thorne | 0.08 | 2.23 | 6.01 | 3.50 | 0.00
Albuquerque | 0.28 | 2.50 | 1.19 | 2.67 | 1.37
Santa Fe | 0.32 | 4.11 | 3.86 | 4.06 | 2.50
Fort Defiance | 1.24 | 3.94 | 5.24 | 3.47 | 0.62
" Yuma | 0.00 | 0.01 | 2.37 | 0.17 | 0.30
San Diego | 0.02 | 0.07 | 1.35 | 0.13 | 0.01
Fort Snelling, Minnesota | 3.31 | 3.92 | 1.75 | 6.35 | 1.23
" Brady | 1.23 | 3.21 | 3.86 | 3.18 | 3.40
" Mackinac | 6.35 | 5.67 | 4.26 | 3.22 | 2.28
-----------------------------------------------------------
I have not space for all the comment which this exposition is calculated
to induce. The reader will not only find in it an explanation of the
extraordinary character of the summer of 1854, but will see from the
_means_, that it was but an _excessive development_ of an ANNUAL
PHENOMENON,--THE PROGRESS OF A CONCENTRATED COUNTER-TRADE.
It is not necessary to follow with particularity the return transit. It
required no great degree of sagacity to predict, at the time, that the
drought would continue in the vicinity of New York till about the 10th of
September. The return of the belt to that latitude, was not to be expected
before that time, and the drought continued, in fact, until the 9th of
September.
Its return progress was slow, and it was every where behind time. The
autumn was warm, and so, indeed, were December and January, west of the
area of magnetic intensity, although upon, and east of it, there was a
depression in December. The retreating but lingering edge of
counter-trade, with its excess of snow for the season, caught the Iron
Horse, with its train and passengers, upon the prairies of the west, and
laid its embargoing hands upon them. Few, if any, can have forgotten the
thrilling accounts which reached us from that section, of the sufferings
endured by those who were thus embargoed for days and nights, far from the
comfortable habitations of their fellow men.
But the return transit, though slow, was extreme, and February and March
were exceedingly cold for the season. The transit to the north, again, did
not commence as early as usual, and the spring was backward, and the
summer cool. Both were without irregularity, and the season was
productive. The following table exhibits the temperature on a line of
posts, running north and south at the west, during the winter months of
1855, and will illustrate what has been said.
TABLE VIII.
---------------------------------------------------
1855. |JANUARY |FEBRUARY.| MARCH.| APRIL.
---------------------------------------------------
Key West | 67.18 | 65.94 | 70.28 | 75.09
Mean | 66.58 | 68.88 | 72.88 | 75.38
Fort Snelling | 17.09 | 12.62 | 25.30 | 49.86
Mean | 13.76 | 17.57 | 31.41 | 46.34
Fort Kearney | 23.55 | 25.69 | 32.86 | 54.39
Mean | 21.14 | 26.11 | 34.50 | 47.13
Fort Laramie | 35.85 | 29.01 | 36.41 | 52.94
Mean | 31.03 | 32.60 | 36.81 | 47.60
Fort Arbuckle | 41.94 | 39.86 | 49.09 | 67.43
Mean | 39.10 | 43.69 | 53.22 | 61.85
Fort Belknap | 45.92 | 44.49 | 53.09 | 70.00
Mean | 42.80 | 47.47 | 56.90 | 65.79
Fort Chadbourne | 48.89 | 45.87 | 56.68 | 68.51
Mean | 44.29 | 46.75 | 58.01 | 65.52
Fort McKavitt | 46.74 | 44.51 | 53.66 | 67.05
Mean | 44.75 | 46.87 | 57.39 | 66.25
Fort Merrill | 54.51 | 54.65 | 61.82 | 74.50
Mean | 54.82 | 57.20 | 68.66 | 73.27
Fort Brown | 60.23 | 61.60 | 66.24 | 74.98
Mean | 60.41 | 63.63 | 68.95 | 75.05
Fort Inge | 52.21 | 50.63 | 61.22 | 74.48
Mean | 49.46 | 55.39 | 62.63 | 68.02
---------------------------------------------------
The return transit to the south for this winter, 1855-6, has been an
extreme one. It is too early yet (Feb. 18th) to write its history, but the
extreme southern transit is as obvious as the unusual severity of the
cold. The rains which usually fall upon the Southern States are
precipitated further south upon the West Indies, and threaten a
deterioration of their sugar crop. The snow, and cold winds, and ice, of
the middle latitudes, are felt even in Florida. Our sheet of
counter-trade has been exceedingly thin, and the barometer has ranged, in
fair weather, much below the mean. Occasional, and for a part of the time,
_weekly_ periods of an increase of its volume, with a corresponding
elevation of the barometer, and a consequent moderation of the intense
cold, and a storm, have occurred. But those periods have been few and
brief. No regular thaw has yet occurred. From the 26th of December to this
date, at Norwalk, there have been but two periods when the wind has blown
from the south-west with sufficient force to stir the limbs of the trees.
There has been no wind from south of that point, or east of north-east;
and even our storm-winds, with one exception, have been north of
north-east--owing to the situation of the focus of precipitation far to
the south of us--and there is reason to fear that a cold summer like those
of 1816 and 1836 may follow. If this extreme transit is owing to defect in
the influence of the sun, from spots, or other causes, such will probably
be the result. If from volcanic action at the south, the influence of that
action may cease, and a rapid return transit, and an ordinary season, may
follow. Believing in the laws of periodicity in relation to the weather
and disease, I planted an early kind of corn (the Dutton), in 1836, and
had a crop when few around me succeeded. We must watch this return
transit, with hope, indeed, but not without fear, and be wise in time.
There is a mass of other evidence in these summaries which shows the truth
of what I have written. There is not a deduction of Mr. Blodget which it
will not explain. The ascent of the summer lines of temperature to the
west is explained by the diminution of magnetic intensity. Their descent
in winter by the location and attractions of the concentrated trade. The
excess of precipitation in Alabama and Mississippi by the succession of
summer and winter belts. That of the interior of the Atlantic slope in
summer, by the showers which fall upon the elevations; and of the coast,
by the easterly storms and their attraction of the surface atmosphere of
the ocean, at other seasons. But I cannot further particularize. Even the
influence of the spots is clearly demonstrated by the observations at
_interior stations_, which were unaffected by contiguous oceans or
elevations. At Forts Washita, Gibson, Scott, Smith, and others, the years
1847 and 1848 were below the mean. All that evidence, and those
deductions, however, I must pass by for want of space, and take leave of
the subject.
Footnotes:
[1] See the diagram for summer at page 55.
[2] Law of Storms, p. 42.
[3] Kearakakua Bay (called Cavrico above), is on the S. W. side of the
island, and the trade was reversed during the day by the cloud
condensation inland.
[4] Lieutenant Wilkes spent twenty days upon the top of this or an
adjoining mountain, and his observations there will be alluded to in
another connection.
[5] All attempts to produce this result by the sudden exhaustion of air
about the chickens in receivers, or shooting them from cannons, have
failed, and no patent for a chicken-picker has been applied for.
[6] A meter is 1 yard, and .0936 of a yard.
[7] See his map, accompanying the Geography of the Sea.
[8] See Am. Jour. of Science, New Series, Vol. 18. p. 187.
[9] Their estimate was 100 to 120 miles.
[10] Since the text was in type, and, as might have been anticipated, we
have intelligence confirmatory of this, from the Cape De Verde Islands.
The inter-tropical belt of rains has not moved as far north as the
northern islands--they have had no rain--and the people are in a starving
condition.
Transcriber's Notes:
Passages in italics are indicated by _italics_.
Punctuation has been corrected without note.
The following misprints have been corrected:
"appearnces" corrected to "appearances" (page 44)
"Faroday's" corrected to "Faraday's" (page 84)
"gentleman" corrected to "gentlemen" (page 96)
"two" corrected to "too" (page 105)
"surise" corrected to "sunrise" (page 111)
"acion" corrected to "action" (page 164)
"Stanta corrected to "Santa" (page 167)
"Augugst" corrected to "August" (page 167)
"baloon's" corrected to "balloon's" (page 192)
"mannner" corrected to "manner" (page 214)
"1198" corrected to "1798" (page 221)
"sevententh" corrected to "seventeenth" (page 240)
"maner" corrected to "manner" (page 254)
"particulary" corrected to "particularly" (page 256)
"are are" corrected to "are" (page 288)
"iso-theral" corrected to "iso-thermal" (page 299)
"the the" corrected to "the" (page 360)
"phenonema" corrected to "phenomena" (page 403)
"calorifice" corrected to "calorific" (page 409)
Other than the corrections listed above, inconsistencies in spelling and
hyphenation have been retained from the original.
Tables throughout this text version have been adjusted for readability.