Before proceeding to do this, however, it may be well to look at some
theories which have been advanced, and to a greater or less extent
adopted, and at their bearing upon the question.
The calorific theory is at present the prevailing one in Europe and in
this country. Meteorologists there and here refer all atmospheric
conditions and phenomena to the influence of heat. The principal
applications of that theory have been considered. But within the last few
years the elasticity and tension of the aqueous vapor of the atmosphere
have received much attention, as exerting an auxiliary or modifying
influence. Professor Dove, of Berlin, who ranks perhaps as the most
distinguished meteorologist of that continent, attributes barometric
variations to _lateral overflows_, and, in the upper regions, resulting
from the elevation of the atmosphere by expansion; and in this view
meteorologists of Europe seem generally to acquiesce. In an article sent
to Colonel Sabine, and recently republished in the American Journal of
Science, January, 1855, in thus attempting to account for the annual
variation of barometric pressure, which occurs in Europe and Asia, and,
indeed, over the entire hemisphere. He says:
"From the combined action or the variations of aqueous vapor, and of
the dry air, we derive immediately the periodical variations of the
whole atmospheric pressure. As the dry air and the aqueous vapor
mixed with it, press in common on the barometer, so that the up-borne
column of mercury consists of two parts, one borne by the dry air,
the other by the aqueous vapor, we may well understand that as with
increasing temperature the air expands, and by reason of its
augmented volume rises higher, and _its upper portion overflows
laterally_," etc.
And in another place he says:
"From the magnitude of the variations in the northern hemisphere, and
the extent of the region over which it prevails, we must infer that
_at the time of diminished pressure a lateral overflow probably takes
place_," etc.
Doubtless, the mean pressure of the atmosphere, in summer, in the northern
hemisphere, is less than in winter, in some localities, and greater in
others, and it differs in different countries of equal temperature. And
this is all very intelligible. The mean of the pressure for the month is
made up by _averaging_ all the _elevations_ and _depressions_. During a
month, showing a very low mean, the barometer may, at times, attain its
_highest altitude_, if the depressions below the mean are great or more
frequent. The barometer is depressed during storms, and ranges high during
_set fair_ weather. Ordinarily, therefore, the more stormy the season the
more diminished the mean pressure; and it is a mistake to look to an
overflow to account for the fact. The changes in the location of the
atmospheric machinery, and consequent change in the amount and severity of
falling weather, and the periodic frequency and character of storms, and
consequent _periodic_ depressions and elevations of the barometer,
explain the annual mean variations, as they do the other phenomena. But it
is perfectly consistent with the calorific theory to attempt to account
for these differences by another of those ever-necessary modifications,
viz.: the different tension and elasticity of aqueous vapor in different
countries of equal temperature; and then to _suppose_ an expansion of the
whole body of the atmosphere and a lateral overflow from the place where
the air is expanded, on to some other, where it is not; and thus _suppose_
all necessary currents in the upper regions, setting hither and yon, by
the force of gravity alone. And apparently he who is best at supposition
becomes the most distinguished meteorologist. Perhaps I have already said
all that I ought to be pardoned for saying, in relation to the utter
absurdity of attributing all meteorological phenomena to the agency of
heat; but when I find such views as those which that article contains,
emanating from so distinguished a man, sanctioned by the President of the
British Association, and copied into the leading journal of science in
this country, I can not forbear a further and a somewhat critical
examination of them. There is more error of supposition and less truth in
it, than in any other article regarding the science, of equal length,
which has fallen under my notice.
What is the height of this expansion? The moisture of evaporation ascends,
ordinarily, but a few thousand feet. The atmosphere grows regularly
cooler, from the earth to the trade, and _the increased warmth that is
felt at the surface extends but little way_. Currents of warm air do not
ascend. The strata maintain, substantially, their relative positions; and
this is a most beneficent provision. In northern latitudes of the
temperate zone, all the warmth derived from a few hours' sunshine is
needed at the surface; and, deplorable, indeed, would be our condition, if
the atmosphere, as fast as warmed by the rays of the sun, were to hasten
up, and the frigid strata descend in its place. The earth would not be
habitable. All the warm air on its surface would be rising as soon as it
became warmed, and the cold air above be descending, and enveloping us
with the chilling strata which are ever floating within two or three miles
above us. No. Infinite wisdom has ordered it otherwise. The laws of
magnetism and of static-electric induction and attraction keep the strata
in their places, and preserve to us the warmth which the solar rays afford
or produce. The inhabitant of the valley, in a high northern latitude, in
summer, can plant, and sow, and reap, at the base of the mountain whose
summit penetrates the stratum of continual congelation, and up its sides,
almost to the line of perpetual snow; and, as he looks upon the fruits of
his labor, and up to the snow-clad peak that towers above him, can thank
his Maker for placing a warm equatorial current, a perpetual barrier,
between the fertility and warmth which surround him, and the cold
destructive strata above; and thank Him for not creating such a state of
things, as certain meteorologists insist we shall believe He has created.
Again, where are the _upper regions_, from which the lateral overflow
takes place? The atmosphere is differently estimated, at from thirty to
forty-five miles, or more, in height. Whatever its height may be, it is
exceedingly attenuated in its "upper regions."
Gay-Lussac marked the barometer at 12-95/100 inches at the height of
23,040 feet. Two thirds of the atmospheric density, then, is within five
miles of the earth. Air, too, is _compressible_. Allowing for the latter
and the attenuation, how many miles in vertical depth, of its "_upper
regions_," must move from one portion to another, to depress the barometer
two inches--its range sometimes in twenty-four hours--or even half an
inch? Let the computation be made, and see how startling the proposition,
how utterly impossible that the theory can be true.
The distinguished Professor, in the paper referred to, introduces his
theory of the formation of hurricanes, and we quote--
"If we suppose the upper portions of the air ascending over Asia and
Africa to flow off laterally, and if this takes place suddenly, it
will check the course of the upper or counter-current above the
trade-wind, and force it to break into the lower current.
"An east wind coming into a S. W. current must necessarily occasion a
rotatory movement, turning in the opposite direction to the hands of
a watch. A rotatory storm, moving from S. E. to N. W., in the lower
current or trade, would, in this view, be the result of the encounter
of two masses of air, impelled toward each other at many places in
succession, the further cause of the rotation (originating primarily
in this manner) being that described by me in detail in a memoir 'On
the Law of Storms,' translated in the 'Scientific Memoirs,' vol. iii.
art. 7. Thus, it happens that the West India hurricanes, and the
Chinese typhoons occur near the lateral confines on either side of
the great region of atmospheric expansion, the typhoons being
probably occasioned by the direct pressure of the air from the region
of the trade-winds over the Pacific, into the more expanded air of
the monsoon region, and being distinct from the storms appropriately
called by the Portuguese 'temporales,' which accompany the out-burst
of the monsoon when the direction of the wind is reversed."
The analogy between this, and a theory of Mr. Redfield's, will be noticed
further on. But I remark, in passing, that there is not a fact or
inference in this paragraph which will bear examination.
1. There is no such regular S. W. wind over the surface trade, as he
supposes. Doubtless, there are, occasionally, secondary S. W. currents
between the counter-trade and the surface one, with partial condensation,
for much of both becomes depolarized by their reciprocal action and
precipitation, and these induced S. W. currents are sometimes so strong as
to usurp the place of the surface-trade, and become very violent in the
latter part of hurricanes; but such is not the usual course of the upper
currents of the West Indies, as the progress of storms there, and
observation, prove.
2. There can not be any _periods_ of extensive and _sudden_ expansion over
Africa. If there is any place on the earth which has a more uniformly
progressive temperature, either way, and is more free from _sudden_
extremes, or which is more arid and destitute of aqueous vapor, and sudden
aqueous expansions, than another, it is Africa. No such occasional sudden
expansions are there possible.
3. Winds do not, and can not, "_encounter_." They stratify upon each
other. They are produced by the action of opposite electricity, and are
_connected together_ in their origin and action. The atmosphere is never
free from the regular and irregular currents, however invisible for the
want of condensation. Aeronauts find them in the most serene days. They
exist without encounter or tendency to rotation, every where, and at all
times; even over the head of the distinguished Professor, whether he
sleeps or is awake. We can all see them when there is condensation, and it
is rarely the case that there is not some degree of it in some of them.
4. That "Great region of expansion" is a chimera. It does not exist. It is
a region of _lower temperature_, and of _condensation_, instead of
_expansion_ of _aqueous vapor_. The trade does not rise in it, or the S.
W. wind overflow from it. See the table cited page 165.
5. The hurricanes do not originate _in the surface trades_, as he
supposes. They originate in the belt of rains, the supposed "region of
expansion," and issue out of it; or in the counter-trade, where volcanic
elevations rise far into or above the surface trade.
6. This hypothesis can not be sustained upon his own principles. The
distance between Africa and the West India Islands, where most of the
hurricanes originate, is from 2,500 to 3,000 miles. These gales are small
when they commence, not ordinarily over one or two hundred miles in
diameter, and often less. There are trades all the way over from Africa,
and S. W. winds also, if they exist, as he supposes, in the West Indies.
How can it happen that this lateral overflow should pass _without effect_,
over 2,500 miles of S. W. wind and trade, and concentrating the overflow
of a continent over one small and chosen spot of the West Indies, _pitch
down_ there, and there only, and crowd the S. W. wind into the trade
below? This is too much for sensible men to believe.
What does Professor Dove mean by the term _impulsion_, as applied to the
winds? How are they _impelled_? It is the fundamental idea of his
calorific theory, that they are _drawn_ by the _suction_ caused by a
_vacuum_, and the vacuum created by expansion and overflow above, in
obedience to the law of gravity; that the S. E. trade is drawn to the
great region of expansion, and the S. W. runs from it as an overflow. But
if the S. W. is driven down into the plane and place of the
surface-trades, how does it continue to be impelled, and why is it not
then subject to the suction of the vacuum which draws the trade? Does that
vacuum _select its air_, and so attract the trade, in preference to the
depressed portion of the S. W. current, that the former runs around the
latter to get to the vacuum, and the latter around the former to get away
from it? And does the trade, when it has got around the S. W. current,
instead of going to the vacuum, continue to gyrate, and the S. W. current,
instead of pursuing its regular course, gyrate also about the trade, and
both move off together, regardless of the vacuum of the great region of
expansion, in a new direction to the N. W., in an independent,
self-sustaining, cyclonic movement, increasing in power and extent,
involving extended and increasing condensation, producing the most violent
electrical phenomena, and thus continuing up, even to the Arctic circle?
Yes, says Professor Dove. No, say all fact, all analogy, and his own
principles.
7. His theory relative to the typhoons is unintelligible. If they
originate near the lateral confines of the great region of atmospheric
expansion, they originate in the region of the trade-winds, for the two
are identical. How the direct pressure of the air from the trade-wind over
the Pacific, in the more expanded air of the monsoon region, can occasion
a typhoon upon any principles, passes my comprehension. If, as Lieutenant
Maury supposes, the monsoons are reversed trades, then the trade-wind and
monsoon region are identical. If the monsoons are found in the belt of
rains, then, the trades, upon Professor Dove's principles, pass into the
monsoon region by attraction or suction, without pressure. Either way the
theory is undeserving of consideration.
A new theory has recently been started by Mr. Thomas Dobson, and, although
it is (like all other efforts to get the _upper strata down_ to produce
condensation, or those below _up_, that they may be condensed), without
foundation, his collection of facts is brief and interesting. I copy his
article from the London, Edinburgh, and Dublin Phil. Mag., for December,
1853. It adds to the collection of facts in relation to the connection
between volcanic action and storms for the seventeenth century, made by
Dr. Webster:
The following appear to be the main facts which are available as a
basis for a theory which shall comprehend all the meteors in
question:
1st. The eruption of a submarine volcano has produced water-spouts.
"During these bursts the most vivid flashes of lightning continually
issued from the densest part of the volcano, and the volumes of smoke
rolled off in large masses of fleecy clouds, gradually expanding
themselves before the wind in a direction nearly horizontal, and
drawing up _a quantity of water-spouts_."--(Captain Tilland's
description of the upheaval of Sabrina Island in June, 1811, Phil.
Trans.)
With this significant fact may be compared the following analogous
ones:
"In the Aleutian Archipelago a new island was formed in 1795. It was
first observed _after a storm_, at a point in the sea from which a
column of smoke had been seen to rise."--(Lyell, Principles of
Geology.)
"Among the Aleutian Islands a new volcanic island appeared in the
midst of _a storm_, attended with flames and smoke. After the sea was
calm, a boat was sent from Unalaska with twenty Russian hunters, who
landed on this island on June 1st, 1814."--(Journal of Science, vol.
vii.)
"On July 24th, 1848, a submarine eruption broke out between the
mainland of Orkney and the island of Strousa. Amid thunder and
lightning, a very dense jet black cloud was seen to rise from the
sea, at a distance of five or six miles, which _traveled toward the
north-east_. On passing over Strousa, the wind from a slight air
became _a hurricane_, and a thick, well-defined belt of large
hailstones was left on the island. The barometer fell two
inches."--(Transactions Royal Society, Edinburg, vol. ix.)
2d. Hurricanes, whirlwinds, and hailstones accompany the paroxysms of
volcanos.
"1730. A great volcanic eruption at Lancerote Island, and _a storm_,
which was equally new and terrifying to the inhabitants, as they had
never known one in the country before."--(Lyell, Principles of
Geology, vol. ii.)
"1754. In the Philippine Islands a terrible volcanic eruption
destroyed the town of Taal and several villages. Darkness,
hurricanes, thunder, lightning, and earthquakes, alternated in
frightful succession."--(Edinburgh Philosophical Journal.)
"In 1805, 1811, 1813, and 1830, during eruptions of Etna, caravans in
the deserts of Africa perished by violent whirlwinds. In 1807, while
Vesuvius was in eruption, a whirlwind destroyed a caravan."--(Rev. W.
B. Clarke in Tasw. Journal.)
"1815, Java. A tremendous eruption of Tombow Mountain. Between nine
and ten P.M., ashes began to fall, and soon after _a violent
whirlwind_ took up into the air the largest trees, men, horses,
cattle, etc."--(Raffles' History of Java.)
"1817, Dec. Vesuvius in eruption. In the evening _a hail storm_,
accompanied with red sand."--(Journal of Science, vol. v.)
"1820, Banda. A frightful volcanic eruption, and in the evening an
earthquake and a violent hurricane."--(Annales de Chimie.)
"1822, Oct. Eruption of Vesuvius. Toward its close the volcanic
thunder-storm produced an exceedingly violent and abundant fall of
rain."--(Humboldt, Aspects of Nature.)
"1843, Jan. Etna in eruption. Violent hurricanes at Genoa, in the Bay
of Biscay, and in Great Britain.
"1843, Feb. Destructive earthquakes in the West Indies, a volcanic
eruption at Guadaloupe, followed by hurricanes in the Atlantic."
"1846, June 26. Volcano of White Island, New Zealand, in eruption.
Heavy squalls of wind and hail; it blew as hard as in a
typhoon."--(Commodore Hayes, R.N., in Naut. Mag., 1847.)
"1847, March 20. Volcanic eruption and earthquake in Java; and on the
21st of March, and 3d of April, violent hurricanes."--(Java Courant.)
"1851, Aug. 5. A frightful eruption of the long dormant volcano of
the Pelee Mountain, Martinique. Aug. 17. Hurricane at St. Thomas,
etc.; earthquake at Jamaica, etc.
"1852, April 14. Earthquake at Hawaii, and on the 15th a great
volcanic eruption. On the 18th _a gale of unusual violence_ lasted
thirty-six hours, and did great damage."--(The Polynesian, April 22,
1852.)
3d. In volcanic regions, earthquakes and hurricanes often occur
almost simultaneously, but in no certain order, and without any
volcanic eruption being observed.
In 1712, 1722, 1815, and 1851, earthquakes and hurricanes occurred
together at Jamaica; in 1762 at Carthagena; in 1780 at Barbadoes; in
1811 at Charleston; in 1847 at Tobago; in 1837 and 1848 at Antigua;
in 1819, an awful storm at Montreal, rain of a dark inky color, and a
slight earthquake. People conjectured that a volcano had broken out.
In 1766 the great Martinique hurricane, a _waterspout_ burst on Mount
Pelee and overwhelmed the place. Same night, an earthquake.
1843, Oct. 30. Manilla.--Twenty four hours' rain and two heavy
earthquakes. 10 P.M., a severe hurricane.
"1852, Sept. 16. Manilla--An earthquake destroyed a great part of the
city; many vessels wrecked by a great hurricane in the adjacent seas,
between the 18th and 26th of September."--(Singapore Times.)
"1731, Oct. Calcutta.--Furious hurricane and violent earthquake;
300,000 lives lost."
"1618, May 26. Bombay.--Hurricane and earthquakes; 2,000 lives
lost."--(Madras Lit. Tran., 1837.)
"1800. Ongole, India, and in 1815, at Ceylon, a hurricane and
earthquake shocks."--(Piddington.)
"1348. Cyprus.--An earthquake and a frightful hurricane."--(Hecker.)
"1819. Bagdad.--An earthquake and _a storm_--an event quite
unprecedented.
"1820, Dec. Zante.--Great earthquake and hurricane, with
manifestations of a submarine eruption."--(Edinburg Phil. Journal.)
"1831, Dec. Navigator's Islands.--Hurricane and
earthquakes."--(Williams' Missionary Enterprise.)
"1848, Oct., Nov. New Zealand.--Succession of earthquake shocks, and
several tempests.
"1836, Oct. At Valparaiso, a destructive tempest and severe
earthquakes."--(Nautical Magazine, 1848.)
When an earthquake of excessive intensity occurs, as at Lisbon, in
1755, the volcanic craters, which act as the safety-valves of the
regions in which they are placed, are supposed to be sealed up; and
it is a remarkable and highly-suggestive fact, that _no hurricane
follows such an earthquake_. The number of instances of the
concurrence of ordinary earthquakes and hurricanes might easily be
increased, but the preceding suffice to show the _generality_ of
their coincidence, both as _to time_ and place.
4th. The breaking of water-spouts on mountains sometimes accompanies
hurricanes.
In 1766, during the great Martinique hurricane, before cited.
"1826, Nov. At Teneriffe, enormous and most destructive water-spouts
fell on the culminating tops of the mountains, and a furious cyclone
raged around the island. The same occurred in 1812 and in
1837."--(Espy and Grey's Western Australia.)
"1829. Moray.--Floods and earthquakes, preceded by water-spouts and a
tremendous storm."--(Sir T. D. Lander.)
"1826, June. Hurricanes, accompanied by water-spouts and fall of
avalanches, in the White Mountains."--(Silliman's American Journal,
vol. xv.)
5th. The fall of an avalanche sometimes produces a hurricane.
"1819, Dec. A part (360,000,000 cubic feet) of the glacier fell from
the Weisshorn (9,000 feet). At the instant, when the snow and ice
struck the inferior mass of the glacier, the pastor of the village of
Randa, the sacristan, and some other persons, _observed a light_. A
frightful hurricane immediately succeeded."--(Edinburg Philosophical
Journal, 1820.)
6th. Water-spouts occur frequently near active volcanos.
This is well known with regard to the West Indies and the
Mediterranean. The following notices refer to the Malay Archipelago
and the Sandwich Islands:
"Water-spouts are often seen in the seas and straits adjacent to
Singapore. In Oct., 1841, I saw _six_ in action, attached to one
cloud. In August, 1838, one passed over the harbor and town of
Singapore, dismasting one ship, sinking another, and carrying off the
corner of the roof of a house, in its passage landward."--(Journal of
Indian Archipelago.)
"1809. An immense water-spout broke over the harbor of Honolulu. A
few years before, one broke on the north side of the island (Oahu),
washed away a number of houses, and drowned several
inhabitants."--(Jarves' History of Sandwich Islands.)
7th. Cyclones begin in the immediate neighborhood of active volcanos.
The Mauritius cyclones begin near Java; the West Indian, near the
volcanic series of the Caribbean Islands; those of the Bay of Bengal,
near the volcanic islands, on its eastern shores; the typhoons of the
China Sea, near the Philippine Islands, etc.
8th. Within the tropics, cyclones move toward the west; and, in
middle latitudes, cyclones and water-spouts move toward the N. E., in
the northern hemisphere, and toward the S. E. in the southern
hemisphere.
9th. In the northern hemisphere, cyclones rotate in a horizontal
plane, in the order N. W., S. E.; and in the southern hemisphere, in
the order N. E., S. W.
By applying the principles of electro-dynamics to the electricity of
the atmosphere, I shall endeavor to connect and explain the preceding
well-defined facts. The continuous observations of Quetelet, on the
electricity of the atmosphere, from 1844 to 1849 (Literary Journal,
February, 1850), show that it is always positive, and increases as
the temperature diminishes. It therefore increases rapidly with the
height above the earth's surface. We may, consequently, regard the
upper and colder regions of the atmosphere as an immense reservoir of
electric fluid enveloping the earth, which is insulated by the
intermediate spherical shell formed by the lower and denser
atmosphere. Now, whenever a vertical column of this atmosphere is
suddenly displaced, the surrounding aqueous vapor will be immediately
condensed and aggregated, and the cold rarefied air and moisture will
form a vertical conductor for the descent of the electrical fluid.
This descent will take place down a spiral, gyrating in the order N.
W., S. E., in the northern hemisphere, since the electric current is
under the same influence as that of the south pole of a magnet; and
in the order N. E., S. W., in the southern hemisphere. The air
exterior to the conducting cylinder will partake of the violent
revolving motion, and a tornado or cyclone will be produced.
Upon the foregoing facts I shall comment in another place.
Three theories have been advanced by meteorologists of this country, two
of which profess to explain all the phenomena of the weather. Professor
Espy attributed the production of storms and rain to an ascending column
of air, rarefied by heat, and the rarefaction increased by the latent heat
of vapor given out during condensation, and an inward tendency of the air,
from all directions, toward the ascending vortex, constituting the
prevailing winds. Thus, Professor Espy conceived, and to some extent
proved, that the wind blew inward, from all sides, toward the center of a
storm, either as a circle, or having a long central line, and he conceived
that it ascended in the middle, and spread out above; and that clouds,
rain, hail, and snow, were formed by condensation consequent upon the
expansion and cooling of the atmosphere, as it attained an increased
elevation.
_This ascent_ was not, in fact, _proved_ by Professor Espy, _has not been
found by others_, and _is not discoverable, according to my observations_.
The theory was ingenious, founded on the theory of Dalton, that the vapor
was maintained in the atmosphere by reason of a large quantity of latent
heat, which was given out when condensation took place. This theory is
also unsound. No such elevation of temperature is found in clouds or fogs
when they form near the earth, however dense. Thus the two principal
elements of Professor Espy's theory are found to be untrue, and the theory
untenable. But it was sustained with great ability and research, and the
distinguished theorist deserves much for the discovery and record of
important facts in relation to the weather. Aside from its theoretical
views, his book contains a great mass of valuable information, and will
well repay the cost of purchase and perusal.
Another theory, by Mr. Bassnett, is of recent date, founded on the
influence of the moon, and the supposed creation of vortices in the ether
above, whose influence extends to the earth, producing storms and other
phenomena. No one can peruse his book without conceding to him great
ability and scientific attainment; and if his theory was true, the periods
of fair and foul weather could be calculated with great mathematical
certainty. But it contains inherent and insuperable objections. I will
only add that all herein before contained is in direct opposition to it.
Mr. W. C. Redfield, of New York, as early as 1831, first advanced in this
country the theory of gyration in storms, and investigated their lines of
progress on our coast and continent. His theory is limited in its
character, and does not profess, except indirectly, to explain all, or
indeed any, of the other phenomena of the weather. As far as it goes,
however, it is generally received in this country and Europe, and has
been adopted by Reed, Piddington, and others, who have written on the law
of storms. The position of Mr. Redfield is honorable to himself and his
country. Science and navigation are much indebted to him for his industry
in the collection of facts. Nevertheless, his theory is not in accordance
with my observation, and I deem it unsound. Although expressed disbelief
of the theory has been characterized as an "attack" upon its author, I
propose, with that _respect_ which is due to him, but with that _freedom_
and _independence_ which a search for _truth_ warrants, to examine it with
some particularity. It is a part of the subject, and I can not avoid it.
When the theory was first announced, I adopted it as probably true; and
being then engaged in a different profession, which took me much into the
open air by night and day, I watched with renewed care the clouds and
currents for evidence to confirm it. I discovered none; on the contrary, I
found much, very much, absolutely and utterly inconsistent with its truth.
The substance only of these observations will be adduced.
Mr. Redfield admits that the progression of our storms in the vicinity of
New York, is from some point between S. S. W. and W. S. W., to some point
between N. N. E. and E. N. E. According to my observation, except perhaps
in occasional autumnal gales, they are not often, if ever, from S. of S.
W., and the great majority of them, including, I believe, all N. E.
storms, are between S. W. and W. S. W. Now, the card of Mr. Redfield,
moving over any place from any point between S. W. and W. S. W., calls for
a S. E. wind at its axis, an E. wind at its north front, and a S. wind at
its south front, and does not call _for a N. E. wind on its front at all,
except at the north extreme_, where it could _not continue for any
considerable period_.
[Illustration: Fig. 17.]
In relation to this, I observe, 1st. _About one-half of our N. E. storms,
including some of the most severe ones, not only set in N. E., but
continue in that quarter without veering at all, during the entire period
that the storm cloud is over us_; usually for twenty-four hours; not
unfrequently for forty-eight hours, sometimes for seventy-two or more
hours. This every one can observe for himself, and it can not, of course,
be reconciled with his theory.
2d. N. E. storms, whether they set in from that quarter in the
commencement, or veer to it afterward, when they do "change" round, more
frequently veer by the S. to the S. W. in clearing off, than back through
the N. into the N. W. The former, in accordance with his theory, they can
not do, as the reader can see by passing the left side of the card over
his place of residence on the map from S. W. to N. E.
3d. N. E. storms often pass off without hauling by S. or backing by N.,
and with or without a clearing off shower, the _wind shifting and coming
out suddenly at S. W._ This they could not do in accordance with his
theory, as slipping the card will show.
4th. From June to February it is _exceedingly uncommon_ for a N. E. storm
to back into the N. W. They do so more frequently from February to May,
especially about the time of the vernal equinox and after; and then,
because the focus of precipitation and storm intensity of the extra
tropical zone of rains is S. of 42 deg. east of the Alleghanies. His theory
requires them to back by N. into N. W. _in all cases, when they set in N.
E._
5th. When they do back from the N. E. into the N. W., it rarely indeed
continues to storm after the wind leaves the point of N. E. by N., and
generally, if it does continue stormy, _the wind is light_, and not a
gale, how violent soever the gale from the eastward may have been.
Usually, by the time the wind gets N. W., it has cleared off. This, Mr.
Redfield, as we shall see, evades by embracing the N. W. fair wind as a
part of the same gale. According to my observation, therefore, a _very
large proportion_ of the _N. E. storms_, and they are a majority of the
most violent ones of our climate east of the Alleghanies, do not
_commence, continue_, or _veer_ in accordance with his theory, but the
_reverse_; and so long as this is so, I can not receive his theory as
true.
6th. S. E. storms do not always, or indeed often, conform to the
requirements of his card. When they set in violently at S. E., and
continue so for hours without veering, the axis of the storm should be
over us, and the wind should change _suddenly_ to N. W. This did not occur
in the storm of Sept. 3, 1821, nor does it often, if ever, occur in the
summer or early gales of the autumnal months. In the later storms of
autumn, and as often in those which are very gentle as any, and in the
winter months when S. E. gales are rare, it does sometimes so change after
the storm cloud has passed. But in the winter months, as in the storm
investigated by Professor Loomis, the storms are frequently long from S.
E. to N. W., and the S. E. wind blows nearly in coincidence with its long
axis, for a thousand or fifteen hundred miles, till the barometric minimum
is passed, and the inducing and attracting force of this part of the storm
cloud is spent, and then the N. W. wind follows; sometimes blowing in
under the storm cloud, turning the rain to snow; but oftener following the
storm within a few hours, or the next day. The storm of Professor Loomis,
when over Texas, was not probably more than four or five hundred miles in
length. As it curved more, and passed north and east, it extended
laterally, its center traveling with most rapidity, and when it reached
the eastern coast was about fifteen hundred miles long, and not more than
six hundred broad. Along the eastern part of that storm, except when by
its more rapid progress the front projected much further eastward over New
England than its previously existing line, the S. E. winds blew. When it
bulged out, so to speak, by reason of the increased progress of the
center, the wind veered to the N. E. The center of the storm passed near
St. Louis and south of Quebec, as the _fall of rain_, the _bulging_ of the
_rapidly-moving center_, and the _line of subsequent cold_, attest. It is
utterly impossible for any unbiased mind to look at the description of
that storm, and attribute to it a rotary character. With all the data
before him, Mr. Redfield himself has not attempted it directly.[8]
The September storm of 1821 was more violent in character than any which
have since occurred. My recollection of it is as distinct as if it
occurred yesterday. Peculiar circumstances, not important in this
connection, fixed my attention upon the weather during that day and night.
There were cirro-stratus clouds passing all day, from about S. W. to N.
E., thickening toward night with fresh S. S. W. wind and flocculent scud,
such as I have since seen at the setting-in of S. E. autumnal gales. In
the evening the wind (in the immediate neighborhood of Hartford, Ct.),
veered to S. E., the cloud floated low, it became very dark, and the wind
blew a most violent gale. The trees were falling about the house where I
then resided, the windows were burst in, and I was up and observant. When
the cloud passed off to the east, it was suddenly light, and almost calm.
The western edge of the storm cloud was as perpendicular as a steep
mountain side, and was enormously elevated, and very black. I have
sometimes seen the western side of a summer thunder cloud, which had drawn
a violent gust along beneath it, as elevated and perpendicular, but never
a storm cloud. No cloud of that _depth_, or _intensity_ as exhibited by
its peculiar blackness, ever floated or will float so near the earth,
without inducing a devastating current beneath. After it had passed the
ridges east of the Connecticut valley, its top could be seen for a long
and unusual period over the elevated ranges.
Now that storm was but an _intense portion_ of an extensive stratus-rain
cloud. Such portions frequently exist, and Mr. Redfield admits the fact.
Another like portion, in the same storm, passed over Norfolk, Virginia,
and the adjacent section, where the wind was N. E., and veered round by N.
W. to S. W. Baltimore, and some vessels at sea, were between the two
intense portions of the storm, and were not affected by either. Its
northern limit was bounded by a line, drawn from some point not far north
of Trenton, New Jersey, north-eastward, and north of Worcester,
Massachusetts. I was about forty miles south of its northern limit, and
north of its center. During that day, and the next, there was wind from
S. W. to S. E., inclusive, including the gale, and _from no other
quarter_. It did not at any time veer to the W. or N. W. After the passage
of the storm-cloud, the wind was very light. When this intense portion of
the storm passed over the valley of the Connecticut, its longest axis was
from S. S. E. to N. N. W., and the _wind was S. E. the whole length of
it_. In its passage from the longitude of Trenton to Boston, there was N.
W. wind at one point, and but one, and that was in the iron region, at the
N. W. corner of Connecticut, at the northern limit of the intense cloud,
and owing, doubtless, to some local cause. The direction of the wind in
that storm was in accordance with what is generally true of our storms.
The wind on the front of the storm depends upon its shape. If the storm is
long in proportion to its width (and no other _violent_ autumnal or winter
storm has been investigated, to my knowledge), the wind blows axially, or
obliquely, on its front. Thus, if long from S. E. to N. W., the wind on
its front will blow from the S. E. So, if the storm is long from S. W. to
N. E., and has a south-eastern lateral extension, with an easterly
progression, the wind will blow axially in the center, and obliquely at
the edges. Instances might be multiplied, but I refer to one of recent
date and striking character. All of us remember the drought of 1854. It
ended in drenching rain on the 9th of September. This rain fell from a
belt, half showery and half stormy in character, which had a S. E. lateral
extension.
The evening of the previous day there was some lightning visible at the
north, and the usual S. S. W. afternoon wind _continued fresh after
nightfall_. The next day we had a brisk wind from the same quarter, and,
after noon, the clouds appeared to pile up in the far north, seeming very
elevated. They continued to do so, extending southerly during the
afternoon, _with a high wind from S. S. W._, the cumulus clouds moving E.
N. E. At 5 P.M., gentlemen who left New York at 3 P.M., reported that a
dispatch had been received from Albany, dated 1 P.M., stating that it was
raining very heavily there. About 7 P.M., the belt reached us, and it
rained heavily from that time till morning. Not far from 8 P.M., and
during the heaviest rain, the wind shifted from the S. S. W. to N. E., and
blew fresh and cold from that quarter during the night, and till the belt
had passed south, and then from N. E. by N., cool, with heavy scud, during
the forenoon, veering gradually to the N. N. E., and dying away. After the
rain ceased, the northern edge of the belt was distinctly visible in the
S. and S. E., its stratus-cloud moving E. N. E., and its scud to the
westward.
The front of that storm did not pass over us. It was long and narrow. The
wind blew somewhat obliquely inward, along its southern border, to the
eastward, and, in like manner, to the westward, on its northern border,
but from the N. E. axially along its central portions.
In the last instance, the wind changed from S. W. to N. E. This, too, is
impossible, according to Mr. Redfield's theory. Similar instances, in
summer, and early autumn, are not uncommon. But I shall recur to this in
connection with the different _classes_ of storms.
Again, the manner in which these S. E. winds co-exist with the N. E., and
become the prevailing wind, toward the close of the storm, is instructive,
and inconsistent with the theory of Mr. Redfield. In the West Indies, the
first effect of the storm is to increase the N. E. trade; the wind then
becomes baffling, but settles in the N. W. or N. N. W., _in direct
opposition to the admitted progress of the storm_. At this point, or at S.
W., it blows with most force. Sometimes it veers gradually, and sometimes
falls calm, and comes out from the S. W., blowing violently. It ends by
veering to the S. E., following gently the course of the storm. Thus, Mr.
Edwards, in the third volume of his History of Jamaica, as herein before
cited, "_all hurricanes begin from the north, veer back to W. N. W., W.,
and S. S. W., and when they get round to S. E. the foul weather breaks
up_."
A short, sudden gale, resembling those of our summer thunder-showers, is
sometimes met with from the S. E.; but the violent hurricanes of any
considerable continuance are, in almost every case, as just stated.
Now, there is, in our latitudes, an obvious law on the subject, and it is
this:--If the storm is not disproportionately long, northerly and
southerly, there is a general tendency to induce and attract a surface
current, in opposition to the course of the storm on its front, and
especially its north front. At the same time, there is a tendency to
induce a lateral current on its side, particularly the southerly side, and
sometimes its south front: that the latter current is, in the first part
of the storm, above the former; in the middle and latter part, it becomes
the prevailing current at the surface, and the wind changes accordingly,
with or without a calm--that this lateral change sometimes takes place on
either side, but usually occurs on the side where the water is warmest, or
there is, for other and local reasons, a _greater susceptibility in the
atmosphere to inductive and attractive influence_. Thus, our N. E. storms
very frequently have a southerly current also, drawn from the ocean, south
of us, which forms the middle current, and, in the middle and latter part
of it, becomes the prevailing one. _I have seen more than a hundred such
instances, clearly and distinctly marked._ Since I have been writing this
chapter, January 29th, 1855, such an instance has occurred. On Sunday, the
28th, the cirro-stratus were all day passing from the S. W. to N. E., and
gradually thickening with light air from the E. N. E., in the afternoon.
During the evening the wind set in _violently_ from the N. E., with a
deluging rain. During the night, and after a brief calm, it changed
suddenly to the southward, and blew in like manner. This morning the storm
was gone, and with it, six inches of hard, frozen icy snow; the trade was
clear, with the exception of here and there a broken, melting piece of
stratus, but scud were still running from the southward, and the wind has
been from the south, veering to S. W., all day, with sunshine. As I have
before remarked, this middle current is always present, in this locality,
in stratus storms, when there is a heavy fall of rain or snow, although,
when the latter happens, the middle current is sometimes from the
northward; if it be from the southward, it turns the snow first into very
large flakes, and then to rain in our part of the storm.
Doubtless, the same thing occurs every where. In the West Indies, and
especially over the Leeward Islands, the middle current is most commonly
from the stream of warm water which runs off to the westward into the
Caribbean Sea; as the S. W. moonsoon is from the same current below the
Cape de Verdes. The S. W. winds, which come from those south polar waters,
in the West Indies, appear to be the most violent. But it may be on either
or both sides.
The hurricane cloud of the West Indies moves confessedly N. W. in most
instances, and undoubtedly it does in all. There is an immutable law that
requires it. The seeming exceptions are not such; they are but instances
imperfectly investigated. Now, a circular storm moving N. W. can set in N.
W. only on the left front, and _can not change to S. W. on that side of
the axis_. Nor can the wind blow at the axis from N. W. at all. It should
be N. E. in first half, and S. W. in last half. Strange as it may seem,
the axis of a West India hurricane in conformity with Mr. Redfield's
theory, and a N. W. progression, has never been found, with perhaps a
single exception, in any one of which I have seen a description. On the
west coast of Europe, the gale is commonly from the Atlantic, either
following under the storm from the S. W., or blowing in diagonally from
the W. or N. W.; the N. E. wind of western Europe being a cold, dry wind,
which there is reason to believe has been around the Siberian pole and is
returning, as the cold northerly winds of the North Pacific have around
the North American magnetic pole. "If the N. E. winds always prevailed,"
says Kaemtz, speaking of Berlin, "even at a considerable height it would
never rain." This was based on an observation of showers, and not fully
reliable. But the dry and cool character of the N. E. wind of western
Europe is unquestionable. The S. E. wind is also a storm wind, but owing
to the character of the surface from which it is attracted, it is not as
violent as the westerly winds are.
Such, too, is the general course and character of the side wind in the
southern hemisphere. There gales are less frequent, the magnetic intensity
is less, the counter-trades are less; it is not in "the order of
Providence" that as much rain shall fall there. Nevertheless, gales occur,
although rarely, if ever, with equal violence. About New Holland, where
storms are pursuing a S. E. course, they have the wind N. E.,
corresponding to our S. E., veering from thence, _by the north_, to the
westward, clearing off from S. W., with a rising barometer, as ours do
from N. W.
In the Bay of Bengal, the Indian Ocean, and the Arabian Sea, there is more
irregularity.
But the law of progress and lateral winds can be distinctly traced as
_present_ and prevailing, notwithstanding the irregularities. Our limits
do not permit an analysis. In the celebrated case of the Charles Heddle,
there was much evidence to show that she was driven across the front of
the storm by one lateral wind, and back by another. (Diagram of Colonel
Reid, p. 206.)
The waters of the Indian Ocean are hot and confined. Storms there are
often composed of detached masses, move slower--sometimes not more than
three or four miles an hour--and they curve over the ocean, where it is
hotter than in any similar latitude. Yet, notwithstanding all
peculiarities and irregularities, the law we have been considering is
probably the _prevailing_ law there.
No man knows better the existence of these different currents than Mr.
Redfield. Doubtless it has escaped his attention that the upper of two,
after the passage of a considerable proportion of the storm, becomes the
lower, and causes a seeming change of the same wind.
In a series of elaborate articles, substantially reviewing the whole
subject, published in the American Journal of Science, for 1846, he says:
"In nearly all great storms which are accompanied with rain, there
appear two distinct classes of clouds, one of which, comprising the
storm scuds in the active portion of the gale, has already been
noticed. Above this is an extended stratum of stratus cloud, which is
found moving with the general or local current of the lower
atmosphere which overlies the storm. It covers not only the area of
rain, but often extends greatly beyond this limit, over a part of the
dry portion of the storm, partly in a broken or detached state. This
stratus cloud is often concealed from view by the nimbus, and scud
clouds in the rainy portion of the storm, but by careful
observations, may be sufficiently noticed to determine the general
uniformity of its specific course, and, approximately, its general
elevation.
"The more usual course of this extended cloud stratum, in the United
States, is from some point in the horizon between S. S. W. and W. S.
W. Its course and velocity do not appear influenced in any
perceptible degree by the activity or direction of the storm-wind
which prevails beneath it. On the posterior or dry side of the gale,
it often disappears before the arrival of the newly condensed cumuli
and cumulo-stratus which not unfrequently float in the colder winds,
on this side of the gale."
"The general height of the great stratus cloud which covers a storm,
in those parts of the United States which are near the Atlantic, can
not differ greatly from one mile; and perhaps is oftener below than
above this elevation. This estimate, which is founded on much
observation and comparison, appears to comprise, at the least, the
limit or thickness of the proper storm-wind, which constitutes the
revolving gale.
"It is not supposed, however, that this disk-like stratum of
revolving wind is of equal height or thickness throughout its extent,
nor that it always reaches near to the main canopy of stratus cloud.
It is probably higher in the more central portions of the gale than
near its borders, in the low latitudes, than in the higher, and may
thin out entirely at the extremes, except in those directions where
it coincides with an ordinary current. Moreover, in large portions of
its area, there may be, and often is, more than one storm-wind
overlying another, and severally pertaining to contiguous storms. In
the present case, we see, from the observations of Professor Snell
and Mr. Herrick, at Amherst, Massachusetts, and at Hamden, Maine (115
and 135 b.), that the true storm wind, at those places, was
super-imposed on another wind; and various facts and observations may
be adduced to show that brisk winds, of great horizontal extent, are
often limited, vertically to a very thin sheet or stratum."
Much of the foregoing is graphically described, and unquestionably true.
But it may well be asked how he, or others, distinguish which of two or
more currents (for there are frequently three, and sometimes four
visible), are the true currents of the storm, and which interlopers from
another storm? Is the true one always the upper one, and why? If the
upper one, why is the interloper at the surface noted and quoted to prove
what a storm is? How does he know what proportions of the winds he has
recorded to show the revolving motion of gales, were the true storm winds
of the particular storm? or, that every one of them was not an interloping
wind on which the true storm wind was superimposed?
These inquiries are pertinent, for obviously, unless some rule for
distinguishing between the currents is given, and there be evidence of
direct observation to show that the surface wind, whose direction is
noted, is the true wind of the storm, and that the _latter_ is not
_superimposed_, no reliance can be placed upon logs, or newspaper
accounts, or registers. There is another element besides direction, viz.:
superimposition, a determination of which _is_ essential to _truth_. It
will be difficult for Mr. Redfield to say that a determination of that
element has been made, with certainty, in a single storm he has
investigated; and in relation to the convergence of storms, and blending,
and superimposition of their winds, I think he is mistaken.
Mr. Redfield is right in saying (American Journal of Science, vol. ii.,
new series, p. 321) that "too much reliance may be placed upon mere
observations of the surface winds in meteorological inquiries," and yet
_they_ only have thus far been regarded, and he has proved gyration in no
other way. I have frequently, with a vane in sight, asked intelligent men
how the wind was, and been amused and instructed by their inability to
state it correctly. Mr. Redfield, in his inquiries, often found two
reports of the weather at the _same time_, from the _same place_,
materially different; and I have known, from my own observation,
newspapers and meteorological registers to be several points out of the
way; and this, because the vanes are influenced by local elevations, and
change several points, and very often; because few know the exact points
of the compass in their own localities, and because entire accuracy has
not been deemed essential. For these reasons, newspaper and telegraphic
reports are not always reliable; and therefore, and because, also,
storm-winds are easterly and fair winds westerly, and the former veer from
east around to west, on one or both sides in many cases, there are few
storms which can not be represented as whirlwinds, by a proper _selection_
of _reports_, a corresponding _location_ of the _center_, and an
_extension_ of the lines of supposed gyration, so as to include the
_preceding_ winds, the actual winds of the storm, and the _lateral_, and
_succeeding_ fair weather ones.
But, again, Mr. Redfield is right in saying there is, in such cases, "an
extended stratum of stratus cloud," and it is always present. But why does
he say this _covers the storm_? Is it distinct from it, and if so, what is
it doing there? What power placed it there, and for what purpose? Has this
extended stratum of cloud, which forms the canopy of a vast chamber--five
hundred to one thousand miles in diameter, and less than two miles in
vertical depth, while the earth forms the floor--any agency in producing
the whirl that is supposed to be going on within it, and if so, what? Has
the earth any agency, and if so, what? If neither the ceiling nor floor of
the chamber have any agency in producing it, what does? Are we to consider
the _storm-scud_ as possessing the power, and as waltzing around the
aerial chamber, carrying the air with them in a hurricane-dance of
devastation? _What, in short, is the power, and how is it exerted?_
To these questions, Mr. Redfield's essays furnish no comprehensive answer.
There is an intimation that the cause of storms will be, at some future
day, developed. One attempt, and but one, has thus far been made, and that
I quote entire:
"We have seen that the two Cuba storms, as well as the Mexican
northers, have appeared to come from the contiguous border of the
Pacific Ocean.
"Now, are there any peculiarities in the winds and aerial currents of
those regions, which may serve to induce or support a leftwise
rotation in extensive portions of the lower atmosphere, while moving
on, or near the earth's surface? I apprehend there are such
peculiarities, which have an extensive, constant, and powerful
influence. First, we find on the eastern portion of the Pacific, from
upper California to near the Bay of Panama, an almost constant
prevalence of north-westerly winds at the earth's surface. Next, we
have an equally constant wind from the southern and south-western
quarter, which, having swept the western coast of South America,
_extends across the equator to the vicinity of Panama_, thus meeting,
and commonly over-sliding the above-mentioned westerly winds, and
tending to a deflection or rotation of the same, from right to left.
As this influence may thus become extended to the Caribbean or
Honduras Sea, we have, next, the upper or S. E. trade of this sea,
which is here frequently a surface-wind, and must tend to aid and
quicken the gyrative movement, ascribed to the two previous winds;
and lastly we have the N. E. or lower trade, from the tropic, which,
coinciding with the northern front of the gyration, serves still
further to promote the revolving movement which may thus result from
the partial coalescence of these great winds of Central America, and
the contiguous seas.
"Thus, while a great storm is, in part, on the Pacific Ocean, its N.
E. wind may be felt in great force on that side of the continent,
through the great gorges or depressions near the bays of Papagayo or
Tehuantepec, as noticed by Humboldt, Captain Basil Hall, and others,
the elevations which there separate the two seas being but
inconsiderable; and, when the gyration is once perfected, the whole
mass will gradually assume the movement of the predominant current,
which is generally the higher one, and will move off with it,
integrally, as we see in the cases of the vortices, which are
successively found in particular portions of a stream, where subject
to disturbing influences."
The analogy between this and the theory of Professor Dove, cited above,
and prior, in point of time, is obvious. They are substantially alike in
principle, with different locations. They differ also in this, Professor
Dove appears to think something more than over-sliding necessary, and
assigns the duty of crowding the upper current down in to the lower, to
make an _encounter_, to a lateral overflow from Africa. Mr. Redfield seems
to think there may be a tendency to deflection when they "over-slide" each
other. They are both closet hypotheses, the poetry of meteorology, with
something more than poetical license as to facts.
In the first place, _no such concurring winds exist in the same locality
at the same time_. When the inter-tropical belt of rains is over Central
America and Southern Mexico, a S. W. monsoon blows in under it, but it
usurps the place of all other surface winds; and, when the belt is absent,
that portion of the eastern Pacific is most remarkably calm, or is covered
by the N. E. trades. Secondly, the _trade-winds every where pursue their
appointed course without "tendency to deflection" by the meeting, or
"over-sliding," or "breaking in," or "encounter,"_ of other winds. The
great laws of circulation do not admit of any such _confusion_. And,
lastly, _no storm ever came over the eastern United States from that
quarter_. The unchangeable laws of atmospheric circulation forbid it.
Recent observations also have shown that the storms on the west coast of
Central America, and the eastern Pacific, pursue a N. W. course, precisely
as in the West Indies, and every where over the surface-trades of the
northern hemisphere. Indeed _Mr. Redfield himself has recently
investigated several of them, and admits their course to be
north-westerly_. (See American Journal of Science, new series, vol. xviii.
p. 181.)
But, suppose the co-existence of the winds and the course of the storms
admitted as claimed, let us seek for clearer views. What do these
gentlemen mean? Do they intend to have us believe the air has inherent
moving power, and that the "tendency" of which they speak is an attribute
of the winds, and that when they thus meet, and "come into each other,"
"encounter," or "over-slide," and become acquainted, they wheel into a
waltz, and move off northward, "integrally," with unceasing circular
movement, even until they arrive at the Arctic circle? Or is it a mere
mechanical effect of meeting, "coming into each other," or "over-sliding?"
If the latter, why a tendency to rotation from right to left? The
trade-winds, at least, are _continuous, unbroken sheets_, and not
disconnected portions which meet and blow past each other, and there is no
warrant for placing them _side and side_, and attributing to them any
such mechanical effect, and as little respecting the other winds. Outside
of the fanciful hypothesis, there are no facts to show such a tendency one
way rather than the other; and, in accordance with the known facts
regarding stratification of the currents of air, no such "tendency" can
exist.
But what _power_ impels the winds, which thus meet at these points? If
they be impelled, is it consistent with the action of this power that the
_winds_ it has _created_ and _controls_, should thus assume an _opposite
"tendency,"_ and whirl away to the north-eastward, regardless of the power
that originated and controls them? What must this "_tendency_" be, which
thus _occasionally_ not only diverts the winds from the _usually regular
course_ given them by their originating power, but increases their action,
from gentle, ordinary winds, to hurricanes? Nay, which gives them a new,
resistless gyratory and electric energy, increasing as the new,
independent, supposed cyclonic organization moves off, "_integrally_,"
away from "the home of its many fathers," on a devastating journey towards
the north pole?
And, further, if all this were true as to the West Indies and Central
America, what is to be said of the billions of other storms, originating
on a thousand other portions of the earth's surface, and how are they to
be accounted for, inasmuch as such other "meetings," "coming into each
other," and "over-sliding," and "tendency to deflection," is not assumed
to exist?
These questions cannot be satisfactorily answered. The distinguished
theorists are mistaken. The stratus-cloud does not over-lie or cover the
storm. IT IS THE STORM. The winds beneath, whether surface or
superimposed, are but its incidents, due to its static induction and
attraction. Their _direction_ depends on the shape of the storm cloud, and
its course of progression, and the susceptibility of the surface
atmosphere in this direction or that, to its inductive and attractive
influence. Their _force_ to its depth, its contiguity to the earth, and
the intensity of its action; and the scud, are but patches of
condensation, occasioned by the same inductive action which affects and
attracts the surface current in which they form.
Another objection to Mr. Redfield's theory of gyration is based upon the
fact that in order to constitute his _storm_, to get the _gyration_, he
has to include, at least, an equal amount, generally a great deal more, of
_fair weather_. The N. W. wind, the "posterior, or dry side of the gale,"
as he calls it (in the foregoing extract), is a _fair weather wind_. It is
_necessary_, however, to complete the supposed _circle_, and it is
_pressed into the service_. The practical answer given to the question,
"_what are storms?_" is, they are cyclones, part storm, so called, and
_part fair weather_; that is, the stratus-cloud, the scud, the easterly
wind, and rain or snow of day before yesterday, were the _wet side_, or
front part of the storm, and the sunshine, clear sky, and N. W. wind of
yesterday, to-day, and, perhaps, to-morrow, are the posterior or dry side.
When a storm clears off from the N. W. it is not _over_, it is, perhaps,
_just begun_; and, inasmuch as it storms again, very soon after the wind
changes back from the N. W. to the southward, in winter, our weather then
is pretty much all _storms_.
The statement of this claim seems so absurd that it may appear like
injustice to make it. But gyration can not be made out without it, and it
is evident in the extract quoted above; in the claim that the winter
northers of the Mexican Gulf are parts of passing storms; and clearly and
unequivocally advanced as a distinct proposition, as follows:
"1. The body of the gale usually comprises an area of rain or foul
weather, together with another, and, perhaps equal, or greater, area of
fair or bright weather." (Am. Jour. of Science, vol. xlii. p. 114.)
Now, in the first place, we must distinguish between a storm and fair
weather, before we can tell what the former is, and it is difficult to
assent to a theory which explains what a S. E. storm of _twelve hours'_
continuance is, by including _two or three days of succeeding N. W. fair
weather wind_, as a part of it. There is no proportionate relation as to
_time_, nor any relation as to _qualities_, or the attending conditions of
the atmosphere, nor any conceivable _connection_, except the hypothetical
one of _gyration_, between the two winds.
And, in the second place, it is true, and Mr. Redfield is well aware of
the fact, that winds often blow for many days from the N. E., S. W., or N.
W., without any preceding or succeeding winds to which they have any
discoverable relation. If, therefore, truth would justify Mr. Redfield in
including the fair weather wind, a difficulty would remain which his
theory does not cover or explain.
No American, except Mr. Redfield, has been able to discover satisfactory
evidence of the gyration of storms, by actual careful observation, or a
careful unbiased collation of the observation of others. Professor Coffin
is reported to have read to the Scientific Association, at their Buffalo
meeting, a paper, confirmatory, in part, but I have not been able to see
it. The tracks of tornados have been searched as with candles. When they
have been narrow, from forty to eighty rods, their action has been
substantially similar, and, although, as we have herein before stated,
some irregularities have been found which were consistent with
gyration--for irregularities attend the violent action of all forces, and
particularly the motion of electricity through the atmosphere, as every
one who has seen the zig-zag course of a flash of lightning knows--yet the
evidence of two lateral inward currents, or lines of force, has
predominated over all others. In all cases, where the path is narrow,
those lateral currents are the actors; they constitute the tornado; their
_irregularities_ of action produce the exceptions; but the exceptions are
neither numerous nor uniform, and do not prove either the theory of Mr.
Espy or that of Mr. Redfield. The action is not that of moving air,
merely, but of a power exceeding in force that of powder, which nothing
but electricity or magnetism can exert. As the path widens, the wind
becomes more like the straight-line gust which follows beneath the
ordinary severe thunder-showers. His theory finds no substantial
confirmation or support in the path of the tornado.
Several storms were investigated by Professor Espy, some of them the same
which Mr. Redfield had attempted to show were of a rotary character; one
or two by the Franklin Institute of Philadelphia; one by Professor Loomis,
already alluded to; and recently, two by Lieutenant Porter, from logs
returned to the National Observatory. None of these investigations confirm
the theory of Mr. Redfield. Indeed, Mr. Redfield himself has found it
necessary to resort to suppositions of _modifying causes_ to explain the
evident inconsistencies. It is assumed that the axis, or center,
oscillates, and describes a series of circles; and thus, one class of
difficulties is avoided. Again, it is assumed that simultaneous storms
converge and blend upon the same field, and another class of difficulties
are surmounted. And, again, inasmuch as it is notorious that violent gales
are rarely if ever felt with equal violence around the area of a circle,
but from one or two points only, it is assumed, that the storm winds
ascend, superimpose, and descend again, when they return to the place of
their first violent action, etc. The _simple truth_ requires no such
resort to _modifying hypothesis_.
Still, another objection is, that the changes in the barometer, which
occur before, during, and after storms, do not sustain the claims of Mr.
Redfield or the requirements of his theory.
The barometer sometimes rises before storms. It generally commences
falling about the time, or soon after the storm sets in, continues to fall
during its progress, and rises again, sooner or later, afterward. This is
the general rule.
On this subject Mr. Redfield's claim is this:
"EFFECT OF THE GALE'S ROTATION ON THE BAROMETER.--The extraordinary
fall of the mercury in the barometer, which takes place in gales or
tempests, has attracted attention since the earliest use of this
instrument by meteorologists. But I am not aware that the principal
cause of this depression had ever been pointed out, previously to my
first publication in this journal, in April, 1831, when I took the
occasion to notice this result as being obviously due to the
_centrifugal force_ of the revolving motion found in the body of the
storm.
"Since that period, inquiries have been continued by meteorologists
in regard to the periodical and other fluctuations of the barometer,
and the relations of these fluctuations to temperature and aqueous
vapor. But these incidental causes of variation, in the atmospheric
pressure, prove to be of minor influence, and we are left to the
sufficient and only satisfactory solution of this marked phenomenon
which is found in the centrifugal force of rotation."
The average pressure of the atmosphere, at the surface of the ocean, or in
the interior of the country, allowing for elevation, is about equal to the
weight of a column of quicksilver, thirty inches in height; hence the
barometer is said to stand at about thirty inches at the level of the sea.
This is sufficiently accurate for the northern hemisphere, north of the N.
E. trades; but the average is somewhat lower in the trades and in the
southern hemisphere. Thus, the average of sixteen months, during which the
Grinnell expedition was absent, was 30.08/100.
From a large number of logs examined by Lieutenant Maury, the mean
elevation in the N. E. trades of the Atlantic was 29.97/100; the S. E.
trades of the Atlantic, 29.93/100; off Cape Horn, 29.23/100; S. E. trades
of the Pacific, 30.05/100; N. E. trades of the Pacific, 29.96/100. The
height of the barometer off Cape Horn is not a fair index of the general
elevation of the southern hemisphere, inasmuch as it stands lower there
than at the coast of Patagonia and Chili, or at most, if not all, other
stations in that hemisphere.
As the barometer is constantly oscillating up and down (irrespective of
its diurnal oscillation), it has no known fair weather standard. The point
of 30 inches is taken only as it is a mean. I have known it to commence
storming when the barometer was at 30.70, and not to fall before it
cleared off, below 30.30. And I have known it to be below 30 for several
days consecutively, with fair weather. In our climate there is no reliable
fair weather standard for the barometer. It falls below 30 without
storming; it rises far above, and storms without falling below. No
reliance can be placed upon its elevation, except by comparison; but of
that hereafter.
The general rule, nevertheless, is, that it falls more or less during
storms, whatever its height, and rises sooner or later, more or less,
after they clear off.
The difference between its highest and lowest points is called its range.
The greatest range observed, and recorded, is about 3 inches--from about
28 to 31--but this range is rare. The range, in the trade-wind region, is
comparatively small; in this country it is greater than in Europe; and,
generally, the range will be found greatest where the volume of
counter-trade, and magnetic intensity, and the corresponding amount of
precipitation, and extremes of heat and cold are greatest. One of the
greatest ranges during one storm, or two successive portions of a storm,
in this country, which I have seen recorded, occurred at Boston, in
February, 1842. It was as follows--counting the hours as 24, and from
midnight:
Feb. 15..10h..30.36.
" 16..13h..28.47 fall of 1.89 in 27 hours.
" 17..19h..30.39 rise of 1.92 in 30 hours.
" 18.. 2h..30.39 stationary 5 hours.
" 19.. 2h..29.46 fall of 0.93 in 24 hours.
" 20.. 2h..30.43 rise of 0.97 in 24 hours.
Amount of oscillation, 5.71 in 4 days, 11 hours.
These ranges were owing to the alternation of S. E. storms, and N. W.
winds.
Taking the first range as a basis, and allowing the height of the
atmosphere to be 1,100 feet for the first inch, we have nearly 2,000 feet
displaced during one day, if we look for the displacement near the earth,
or some 30 or 35 miles, if we soar aloft in the upper regions to look for
the _lateral overflow_ of Professor Dove, and about the same quantity
restored the next. This brings us to the inquiry, how was it done? It is
perfectly idle to talk about _difference_ of _temperature_ or _tension_ of
_vapor_, the _ascent_ of warm air, or _descent_ of cold in a case like
this; or to say that they were occasioned by a lateral overflow of some
thirty miles of its upper portion, first this way and then that, in such a
brief space of time. The change is equal to nearly 1/15 of the weight of
the whole atmosphere, and the cause, whatever it was, existed within two
or three miles of the earth. Mr. Redfield's explanation I give in his own
words, at length:
"One of the most important deductions which may be drawn from the
facts and explications which are now submitted, is an explanation of
the causes which produce the fall of the barometer on the approach of
a storm. This effect we ascribe to the centrifugal tendency or action
which pertains to all revolving or rotary movements, and which must
operate with great energy and effect upon so extensive a mass of
atmosphere as that which constitutes a storm. Let a cylindrical
vessel, of any considerable magnitude, be partially filled with
water, and let the rotative motion be communicated to the fluid, by
passing a rod repeatedly through its mass, in a circular course. In
conducting this experiment, we shall find that the surface of the
fluid immediately becomes depressed by the centrifugal action, except
on its exterior portions, where, owing merely to the resistance which
is opposed by the sides of the vessel, it will rise above its natural
level, the fluid exhibiting the character of a miniature vortex or
whirlpool. Let this experiment be carefully repeated, by passing the
propelling rod around the exterior of the fluid mass, in continued
contact with the sides of the vessel, thus producing the whole
rotative impulse, by an external force, analagous to that which we
suppose to influence the gyration of storms and hurricanes, and we
shall still find a corresponding result, beautifully modified,
however, by the quiescent properties of the fluid; for, instead of
the deep and rapid vortex before exhibited, we shall have a concave
depression of the surface, of great regularity: and, by the aid of a
few suspended particles, may discover the increased degree of
rotation, which becomes gradually imparted to the more central
portions of the revolving fluid. The last-mentioned result obviates
the objection, which, at the first view, might, perhaps, be
considered as opposed to our main conclusion, grounded on the
supposed equability of rotation, in both the interior and exterior
portions of the revolving body, like that which pertains to a wheel,
or other solid. It is most obvious, however, that all fluid masses
are, in their gyrations, subject to a different law, as is
exemplified in the foregoing experiment; and this difference, or
departure from the law of solids, is doubtless greater in aeriform
fluids than in those of a denser character.
"The whole experiment serves to demonstrate that such an active
gyration as we have ascribed to storms, and have proved, as we deem,
to appertain to some, at least, of the more violent class; must
necessarily expand and spread out, _by its centrifugal action, the
stratum of atmosphere subject to its influence, and which must,
consequently, become flattened or depressed by this lateral movement,
particularly toward the vortex or center of the storm_; lessening
thereby the weight of the incumbent fluid, and producing a consequent
fall of the mercury in the barometrical tube. This effect must
increase, till the gravity of the circumjacent atmosphere, superadded
to that of the storm itself, shall, by its counteracting effect, have
produced an equilibrium in the two forces. Should there be no
overlaying current in the higher regions, moving in a direction
different from that which contains the storm, the rotative effect
may, perhaps, be extended into the region of perpetual congelation,
till the medium becomes too rare to receive its influence. But
whatever may be the limit of this gyration, its effect must be to
_depress_ the _cold stratum_ of the upper atmosphere, particularly
toward the more central portions of the storm; and, by thus bringing
it in contact with the humid stratum of the surface, to produce a
permanent and continuous stratum of clouds, together with a copious
supply of rain, or a deposition of congelated vapor, according to the
state of the temperature prevailing in the lower region."
The italics in the foregoing extract are mine; and, in relation to it, I
observe:
1st. There is no cylindrical vessel around storms, and _air will not thus
resist air_. Confessedly, such resistance is necessary. Let any one watch
his cigar smoke, and see how readily it moves on, with little momentum.
Let any one try the experiment of creating a whirl in the _open air_, or
in a room, or box of paper, or other material, which can be suddenly
removed, with air colored by smoke. I am exceedingly mistaken if he does
not find the presence of a "cylindrical vessel," absolutely essential to
prevent the instantaneous tangential escape of the air.
2d. Turn back to page 3 and look at the fall of the barometer in the polar
regions (recorded in the extract from Dr. Kane), with _scarcely any
wind_, and _as little variation_ in its _direction_, and see how utterly
Mr. Redfield's theory fails to account for the phenomena.
3d. If I understand Mr. Redfield correctly, he has abandoned the claim as
originally made, that the wind moves in circles, expanding, and _spreading
out_ by a "_lateral movement_," and now asserts that it blows spirally
inward, and elevates the air in the center. I quote:
"VORTICAL INCLINATION OF THE STORM WIND.--By this is meant some
degree of involution from a true circular course. In the New England
storm above referred to, this convergence of the surface-winds
appeared equal to an average of about 6 deg. from a circle. In the
present case, such indication seems more or less apparent in the
arrows on the storm figures of the several charts, where the
concentrical circle afford us means for a just comparison of the
general course of wind which is approximately shown by the several
observations.
"Perhaps we may estimate the average of the vorticose convergence, as
observed in the entire storm for three successive days, at from 5 deg. to
10 deg.--out of the 90 deg. which would be requisite for a congeries of
_centripetal_ or center-blowing winds. This rough estimate of the
degree of involution is founded only on a bird's-eye view of the
plotted observations. But, however estimated, this involution seems
to afford a measure of the air and vapor which finds its way to a
_higher elevation_ by means of the vortical movement in the body of
the storm."
If the elevation of the air at the borders of the storm, and depression in
the middle, resulted from the outward tendency and "lateral movement" of
the revolving air, and from the _centrifugal force_, as in the experiment
with the water in a cylindrical vessel, as stated in the first paragraph
quoted, an _involution_ of from 5 deg. to 10 deg. from the action of a
_centripetal force_, must carry the air _inward_, and the _barometer
should stand highest in the middle of the storm_. The change is fatal to
his theory. The two are diametrically opposite in character and effect. In
one, the superior strata would be brought down in the center by the
_lateral pressure outward_; in the other, they would be elevated by the
_involution_, which "affords a measure of the air and vapor which finds
its way to a higher elevation," etc. It is perfectly obvious Mr. Redfield
has refuted his own hypothesis.
In doing this, he is met by the other difficulty alluded to, which he does
not attempt to explain. This gathering of the air inward, spirally, by a
centripetal force, if it took place, not only would not depress, but _must
elevate the barometer in the center, above that of the adjoining
atmosphere_.
When he first attributed the depression of the barometer to a lateral
movement and centrifugal force, he supposed the superior strata descended
into the depression, and their frigidity occasioned the condensation, and
cloud, and rain. How he now proposes to account for the formation of cloud
and rain during storms, while the warm air of the inferior stratum finds
its way to a higher elevation in the center of the storm, he does not
inform us, and we must wait his time.
"I have," he says, "long held the proper inquiry to be, _what are
storms_? and not, _how are storms produced_? as has been well
expressed by another. It is only when the former of these inquiries
has been solved that we can enter advantageously upon the latter."
The former does not seem to be yet solved, or the solution of the latter
commenced. Mr. Redfield tells us (page 259, and onward), that there is an
extended stratum of stratus-cloud, which overlies the storm, and that it
does not differ greatly from one mile in height. We are not told how the
air, which finds its way to a higher elevation during several days
continuance of such a storm, _gets through the stratum_. If he is right it
_must_ do so, and it would not answer to _suppose_ a very small opening or
gentle current through it, to carry off all the air which works inward in
a hurricane, during several days continuance. But he does not seem to
recognize either the necessity or existence of any _vent_ at all; nor is
there any; and this fact is open to the observation of every school-boy in
the country; and it is equally open to his observation that _when and
where the barometer is most depressed, the stratus storm-cloud is nearest
the earth_. Colonel Reid has much to say about the "_storm's eye_," or
"treacherous center" of a storm. A careful analysis of the instances where
the "storm's eye" is noticed will show that the term is applied, in the
northern hemisphere, to that lighting up in the W. or N. W., which is the
commencement of the clearing-off process, and attended with a shift of
wind to the fair-weather quarter: _i. e._, to W. or N. W. Just such an
"eye" as is seen when the last of the storm cloud has passed so far to the
east as to admit the rays of the sun under the western or north-western
edge of it. The same kind of "storm's eye" is described in the southern
hemisphere, except that the wind shifts to S. W. instead of N. W., that
being the clearing-off wind there. No instance of a "_storm's eye_" in
the center of the extended stratum of stratus-cloud, which overlies the
storm, can be found recorded, to my knowledge; and it is obvious that
Colonel Reid adopts the view of Mr. Redfield, that the westerly and N. W.
_fair weather_ winds are a part of the storm. So long as these gentlemen
hold to that opinion they will never solve the question, "_what are
storms?_" or reach the other, "_how are storms produced?_"
Notwithstanding, Mr. Redfield asserts, or adopts the assertion, that the
inquiry should be, "What are storms?" not "How are storms produced?" that
inquiry should be a _rational_ one, and should not violate all analogy, or
call for an explanation which science can not _rationally_ furnish. Mr.
Redfield does not seem to have formed any just conception of the
_immeasurable power_ of a hurricane, _five hundred miles in diameter_; or
of the nature of that _rod_ which the _Almighty must insert in it, to
whirl it with such violent and long-continued force_; nor any just
conception of the tendency of the whirling mass, in the absence of his
"cylindrical vessel," to fly off, tangentially, into the surrounding air;
or of the nature or power of the centripetal force necessary to hold the
gyratory mass in its current, and gather it in involute spirals toward a
center. Nor has any other man who has witnessed, or read of
mountain-tossed waves; of the largest ships blown down and engulfed; of
towns submerged, and vessels carried far inland, and left in cultivated
fields, by the subsidence of the sea; of sturdy forests and strongly-built
edifices prostrated; or listened to the howling of the tempest, and felt
his own house rock beneath him, been able to conceive of any known form of
calorific or mechanical, or other power, acting from a comparatively small
center, which could hold such an immense irresistable mass of whirling air
in a circle, and _gather it_ in toward the center in gradually contracting
spirals. I confess that, to my mind, it seems little less than a mockery
of our intelligence for Mr. Redfield, or Professor Dove, or any other man,
how distinguished soever he may be, to tell us that all this is the result
of a "tendency to left-wise rotation" of ordinary winds, "coming into each
other," or "over-sliding," or "meeting," or "encountering," on this
"front," or that, down in Central America, or in the West Indies, or the
monsoon region; or to talk of "lateral overflows" from mere gravity; of
the ascent of warm air, or the descent of cold strata; of the _resistance
of adjacent passive air_, or other mere _atmospheric resistances_ in
connection with such _awful manifestations of power_. Their explanations
of these phenomena are not rational, nor can they be believed by any
rational man, who will bestow upon them half an hour of _comprehensive,
unbiased reflection_.
Waiving many minor points of great force, for this notice of Mr.
Redfield's theory is already too much extended for my limits, I am
constrained to take issue with him on the fact, and to assert,
unhesitatingly, that in a _majority of instances no such barometric curve
exists_.
Doubtless the depression beneath the storm is found, and exterior lateral
elevations may also be had by _extending the line into the usual fair
weather elevation on each side_, as Mr. Redfield is obliged to do, to get
his supposed circle of winds at all. Doubtless, too, the seamen sailing
out of a storm, on either _side_, and approaching fair weather, will have
a rising barometer. But from _front to rear, on the line of progression_,
in tropical storms, the curve does not exist on shore, in this latitude,
oftener than in two, or possibly three, cases in ten; and then only upon a
single state of facts--that is, when there is an interposition of N. W.
wind; and this, at some seasons, rarely occurs. An elevation usually
occurs before the storm, on its front, if it present an extensive easterly
front, as one of these classes does, and a _depression is left_ after it
has passed off, unless a considerable body of N. W. wind interposes, as
heretofore stated. But when there is not such interposition of N. W. wind
(for W., W. N. W., or even N. W. by W. will not suffice), there is not an
immediate rise of the barometer corresponding in rapidity and extent with
the fall, and frequently none during the first twenty-four hours of
bright, fair weather. Let the reader, if he has access to a barometer,
note this fact, for it is obvious and conclusive.
Finally, there are other atmospheric conditions to which the barometric
changes are obviously due:
1st. The counter-trade is of a different _volume_, at different times,
over the same locality, and hence a difference in the normal elevations of
the barometer.
2d. It is at a different _elevation_, at different times, over the same
locality. It was so found by the investigations of the Kew Observatory
Committee referred to; has been so found by other aeronauts, and may
readily be seen by a careful, practiced observer.
It is highest, with a high barometer, in serene weather, when a storm is
not at hand; and can sometimes be plainly seen to ascend when a
considerable volume of N. W. wind is blowing in beneath, and elevating,
simultaneously, the trade and the barometer.
Opportunities occur every year, when the northern edge of the dissolving
stratus-cloud is attenuated, and the storm is clearing off in the N. W.,
with wind from that quarter, and a rising barometer, when its gradual
elevation may be observed to correspond with the _volume_ of that wind.
3d. During storms, with a low barometer, the _trade_ and the _clouds run
low_. This, too, is clearly observable, especially when the stratus-cloud
passes off abruptly, very soon after the rain ceases. In such cases the
barometer will remain depressed for a considerable time, unless another
storm supervenes speedily, or the wind sets in from the N. W.
4th. The _trade, in a stormy state, moves faster_ than when in a normal
condition. This is observable during the partial breaks which frequently
occur in storms, and at other times. It is also inferable from the more
rapid progress of the more intense center, and other intense portions of
storms, and the consequent greater depression of the barometer, under such
centers or intense portions. (See the storm of Professor Loomis.) It is
obvious, also, from the greater rapidity of progress attending the more
intense and violent storms which all investigations discloses.
These simple facts explain all the phenomena:
1st. The trade stratum is a continuous unbroken sheet, and its descent
must displace a portion of the surface atmosphere. A portion of it is
impelled forward, aiding in the precedent elevation of the barometer, and
a portion is attracted backward, into the space from which a like portion
had been previously attracted by the passing storm cloud, forming the
easterly wind.
2d. The increased progress of the stormy portion of the counter-trade
occasions an accumulation in front of the storm, and an elevation of the
barometer, and tends also to increase the _depression_ under the spot from
which it moves. The latter is, to some extent, counteracted by the thin
sheets of surface wind which are drawn in under the stratus from the
sides. That which is drawn from the front in successive portions, fills
the space from which like portions had been drawn to the westward, and
left behind in a passive state by the passing storm. Thus, the surface
atmosphere of New England may pass under the entire width of a storm, as a
gale; moving now in puffs with great violence, as it passes beneath
irregular and intense portions of the cloud, and now moderately; and be
left, in a passive state, in Kentucky, occupying the space from which the
atmosphere had been previously drawn by the same storm, _in like manner_,
on to northern Texas.
3d. The nearer the stratus-cloud to the earth, the greater the
displacement of surface atmosphere, the lower the barometer, and,
ordinarily, the more violent the wind. First, because the same intensity,
which, by attraction, brings the trade near the earth, acts with greater
force upon the surface atmosphere; and, secondly, the storm winds, which
are often most rapid beneath the clouds and above the earth, are likely to
be felt with more violence at its surface, where the stratus cloud runs
low, especially at sea.
I desire to commend all these facts, in relation to the theory of Mr.
Redfield, to the careful attention and observation of those who, although
believers in the theory, are not wedded to it; and who have a sincere
desire to understand the phenomena which are continually, and thus far,
_mysteriously_, occurring within two or three miles of us, while our
knowledge of the distant worlds around us--the science of astronomy--seems
almost perfect.
I will return to a further and a careful consideration of the nature of
the reciprocal action between the earth and the counter-trade, and the
facts bearing upon the question, in another chapter. It is obvious that
received theories can not aid us materially in the inquiry.