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The important point for the navigator, is to know the time of meridian passage of the vortex, and its latitude at the time of the passage, and then be guided by the indications of the weather and the state of barometer. If it commences storming the day before the passage, he may expect it much worse soon after the passage; and again, if the weather looks bad when no vortex is near, he may have a steady gale setting towards a storm, but no storm until the arrival of a vortex. Again, if the barometer is low the day before the vortex passes, there may be high barometer to the west, and the passage be attended by no great commotion, as it requires time for the storm to mature, and consequently its greatest violence will be to the east. If at the ship the barometer is high, the vortex may still produce a storm on a line of low barometer to the west, and this line may reach the ship at the time of the passage. In tropical climates the trouble must be looked for to the eastward; as a storm, once excited, will travel westward with that stratum of atmosphere in which the great mass of vapor is lodged, and in which, of course, the greatest derangement of electric tension is produced.
It will now be seen that we do not admit, with Col. Reid, that a storm continues in existence for a week together. Suppose a hurricane to originate in the Antilles at the southern limits of a vortex, the hurricane would die away, according to our theory, if the vortex did not come round again and take up the same nucleus of disturbance. On the third day the vortex is found still further north, and the apparent path of the hurricane becomes more curved. In latitude 30d the vortex passes over 3d or 5d of latitude in a day; and here being the latitude where the lower atmospheric current changes its course, the storm passes due north, and afterwards north-east. Now, each day of the series there is a distinct hurricane, (caused by an increase of energy in a particular vortex, as we have before hinted,) each one overlapping on the remains of the preceding; but in each the same changes of the wind are gone through, and the same general features preserved, as if it were truly a progressive whirlwind, except that each vessel has the violent part of it, as if she was in the southern half of the whirl. The apparent regularity of the Atlantic storms in direction, as exhibited by Col. Reid, are owing in a great degree to the course of the Gulf Stream, in which a vortex, in its successive passages in different latitudes, finds more favorable conditions for the development of its power, than in other parts of the same ocean; thus showing the importance of regarding the established character of storms in each locality, as determined by observation. In this connection, also, we may remark, that the meridians of greatest magnetic intensity are, ceteris paribus, also the meridians of greatest atmospheric commotion. The discovery of this fact is due to Capt. Sabine. The cause is explained by the theory.
As it is the author's intention to embody the practical application of this theory to navigation, with the necessary rules and tables, in a separate work, sufficient has been said to familiarize the reader with the general idea of a cause external to the earth, as the active motor in all atmospheric phenomena. We will therefore only allude in a general way to the principal distinguishing feature of the theory. We say, then, that the wind in a storm is not in rotation, and it is a dangerous doctrine to teach the navigator. We also assert as distinctly, that the wind in a storm does not blow from all sides towards the centre, which is just as dangerous to believe. If it were wise to pin our faith to any Procrustean formula, we might endorse the following propositions: That at the beginning of a storm the wind is from the equator towards the poles in every part of the storm; that, at a later date, another current (really a polar current deflected by convection) sets in at right angles to the first one; and that at the end of the storm there is only one wind blowing at right angles to the direction at the beginning. Outside the storm, considered as a hundred, or two or three hundred miles in diameter, there is, under certain limitations, a surface wind setting towards the general focus of motion and condensation, and this surface wind will be strongest from the westward, on account of the motion of the whole atmosphere in which these other motions are performed being to the eastward.[9] The whole phenomenon is electrical or magnetic, or electro-magnetic or ethereal, whichever name pleases best. The vortex, by its action, causes a current of induction below, from the equator, as may be understood by inspecting Fig. 2, which in the northern hemisphere brings in a southerly current by convection: the regular circular current, however, finally penetrates below, as soon as the process of induction has ceased; and thus the polar current of the atmosphere at last overcomes the equatorial current in a furious squall, which ceases by degrees, and the equilibrium is restored.
Every locality will have its peculiar features; in each, the prevailing wind will be at right angles to the magnetic meridian, and the progress of the storm will tend to follow the magnetic parallel, which is one reason why the Atlantic and Indian Ocean storms have been mistaken for progressive whirlwinds. When these views are developed in full, the mariner can pretty certainly decide his position in the storm, the direction of its progress, and its probable duration.
FOOTNOTES:
[3] The specific heat of the ether being a constant factor, it may be divided out.
[4] A term adopted by Prof. Faraday to denote the mode in which bodies are carried along by an electrical current.
[5] Ottawa, Ill.
[6] The principal cause of these waves is, no doubt, due to the vortices, and the eastern progress of the waves due to the rotating ether; but, at present, it will not be necessary to separate these effects.
[7] The inner vortex may reach as high as 83d when the moon's orbit is favorably situated.
[8] The curvature of the earth is more than 10 miles in a distance of 300 miles.
[9] In middle latitudes.
SECTION SECOND.
MECHANICAL ACTION OF THE MOON.
We will now proceed to give the method of determining the latitude of the axis of the vortex, at the time of its passage over any given meridian, and at any given time. And afterwards we will give a brief abstract from the record of the weather, for one sidereal period of the moon, in order to compare the theory with observation.
In the above figure, the circle PER represents the earth, E the equator, PP' the poles, T the centre of the earth, C the mechanical centre of the terral vortex, M the moon, XX' the axis of the vortex, and A the point where the radius vector of the moon pierces the surface of the earth. If we consider the axis of the vortex to be the axis of equilibrium in the system, it is evident that TC will be to CM, as the mass of the moon to the mass of the earth. Now, if we take these masses respectively as 1 to 72.3, and the moon's mean distance at 238,650 miles, the mean value of TC is equal to this number, divided by the sum of these masses,—i.e. the mean radius vector of the little orbit, described by the earth's centre around the centre of gravity of the earth and moon, is equal 238650/(72.3+1) = 3,256 miles; and at any other distance of the moon, is equal to that distance, divided by the same sum. Therefore, by taking CT in the inverse ratio of the mean semi-diameter of the moon to the true semi-diameter, we shall have the value of CT at that time. But TA is to TC as radius to the cosine of the arc AR, and RR' are the points on the earth's surface pierced by the axis of the vortex, supposing this axis coincident with the pole of the lunar orbit. If this were so, the calculation would be very short and simple; and it will, perhaps, facilitate the investigation, by considering, for the present, that the two axes do coincide.
In order, also, to simplify the question, we will consider the earth a perfect sphere, having a diameter of 7,900 miles, equal to the actual polar diameter, and therefore TA is equal to 3,950 miles.
In the spherical triangle given on next page, we have given the point A, being the position of the moon in right ascension and declination in the heavens, and considered as terrestrial latitude and longitude.
Therefore, PA is equal to the complement of the moon's declination, P being the pole of the earth, and L being the pole of the lunar orbit; PL is equal to the obliquity of the lunar orbit, with respect to the earth, and is therefore given by finding the true inclination of the lunar orbit at the time, equal EL, (E being the pole of the ecliptic,) also the true longitude of the ascending node, and the obliquity of the ecliptic PE. Now, as we are supposing the axis of the vortex parallel to the pole of the lunar orbit, and to pierce the earth's surface at R, ARL will evidently all be in the same plane; and, as in the case of A and L, this plane passes through the earth's centre, ARL must all lie in the same great circle. Having, therefore, the right ascension of A, and the right ascension of L, we have the angle P. This gives us two sides, and the included angle, to find the side LA. But we have before found the arc AR; we therefore know LR. But in finding LA, we found both the angles L and A, and therefore can find PR, which is equal to the complement of the latitude sought.
We have thus indicated briefly the simple process by which we could find the latitude of the axis of the central vortex, supposing it to be always coincident with the pole of the lunar orbit. The true problem is more complicated, and the principal modifications, indicated by the theory, are abundantly confirmed by observation. The determination of the inclination of the axis of the vortex, its position in space at a given time, and the law of its motion, was a work of cheerless labor for a long time. He that has been tantalized by hope for years, and ever on the eve of realization, has found the vision vanish, can understand the feeling which proceeds from frequent disappointment in not finding that, whose existence is almost demonstrated; and more especially when the approximation differs but slightly from the actual phenomena.
The chief difficulty at the outset of these investigations, arose from the conflicting authority of astronomers in relation to the mass of the moon. We are too apt to confound the precision of the laws of nature, with the perfection of human theories. Man observes the phenomena of the heavens, and derives his means of predicting what will be, from what has been. Hence the motions of the heavenly bodies are known to within a trifling amount of the truth; but it does not follow that the true explanation is always given by theory. If this were so, the mass of the moon (for instance) ought to be the same, whether deduced from the principle of gravitation or from some other source. This is not so. Newton found it 1/40 of that of the earth. La Place, from a profound theoretical discussion of the tides, gave it as 1/58.6, while from other sources he found a necessity of diminishing it still more, to 1/68, and finally as low as 1/75. Bailly, Herschel, and others, from the nutation of the earth's axis, only found 1/80, and the Baron Lindenau deduced the mass from the same phenomenon 1/88. In a very recent work by Mr. Hind, he uses this last value in certain computations, and remarks, that we shall not be very far wrong in considering it as 1/80 of the mass of the earth. This shows the uncertainty of the matter in 1852. If astronomy is so perfect as to determine the parallax of a fixed star, which is almost always less than one second, why is it that the mass of the moon is not more nearly approximated? Every two weeks the sun's longitude is affected by the position of the moon, alternately increasing and diminishing it, by a quantity depending solely upon the relative mass of the earth and moon, and is a gross quantity compared to the parallax of a star. So, also, the horizontal parallax—the most palpable of all methods—taken by different observers at Berlin, and the Cape of Good Hope, (a very respectable base line, one would suppose,) makes the mass of the moon greater than its value derived from nutation; the first giving about 1/70, the last about 1/74.2. Does not this declare that it is unsafe to depend too absolutely on the strict wording of the Newtonian law of gravitation. Happily our theory furnishes us with the correct value of the moon's mass, written legibly on the surface of the earth; and it comes out nearly what these two phenomena always gave it, viz.: 1/72.3 of that of the earth. In another place we shall inquire into the cause of the discrepancy as given by the nutation of the earth.
MOTION OF THE AXIS OF THE VORTEX.
If the axis of the terral vortex does not coincide with the axis of the lunar orbit, we must derive this position from observation, which can only be done by long and careful attention. This difficulty is increased by the uncertainty about the mass of the moon, already alluded to, and by the fact that there are three vortices in each hemisphere which pass over twice in each month, and it is not always possible to decide by observation, whether a vortex is ascending or descending, or even to discriminate between them, so as to be assured that this is the central descending, and that the outer vortex ascending. A better acquaintance, however, with the phenomenon, at last dissipates this uncertainty, and the vortices are then found to pursue their course with that regularity which varies only according to law. The position of the vortex (the central vortex is the one under consideration) then depends on the inclination of its axis to the axis of the earth, and the right ascension of that axis at the given time. For we shall see that an assumed immobility of the axis of the vortex, would be in direct collision with the principles of the theory.
Let the following figure represent a globe of wood of uniform density throughout. Let this globe be rotated round the axis. It is evident that no change of position of the axis would be produced by the rotation. If we add two equal masses of lead at m and m', on opposite sides of the axis, the globe is still in equilibrium, as far as gravity is concerned, and if perfectly spherical and homogeneous it might be suspended from its centre in any position, or assume indifferently any position in a vessel of water. If, however, the globe is now put into a state of rapid rotation round the axis, and then allowed to float freely in the water, we perceive that it is no longer in a state of equilibrium. The mass m being more dense than its antagonist particle at n, and having equal velocity, its momentum is greater, and it now tends continually to pull the pole from its perpendicular, without affecting the position of the centre. The same effect is produced by m', and consequently the axis describes the surface of a double cone, whose vertices are at the centre of the globe. If these masses of lead had been placed at opposite sides of the axis on the equator of the globe, no such motion would be produced; for we are supposing the globe formed of a hard and unyielding material. In the case of the ethereal vortex of the earth, we must remember there are two different kinds of matter,—one ponderable, the other not ponderable; yet both subject to the same dynamical laws. If we consider the axis of the terral vortex to coincide with the axis of the lunar orbit, the moon and earth are placed in the equatorial plane of the vortex, and consequently there can be no derangement of the equilibrium of the vortex by its own rotation. But even in this case, seeing that the moon's orbit is inclined to the ecliptic, the gravitating power of the sun is exerted on the moon, and of necessity she must quit the equatorial plane of the vortex; for the sun can exert no influence on the matter of the vortex by his attracting power. The moment, however, the moon has left the equatorial plane of the vortex, the principle of momentum comes into play, and a conical motion of the axis of the vortex is produced, by its seeking to follow the moon in her monthly revolution. This case is, however, very different to the illustration we gave. The vortex is a fluid, through which the moon freely wends her way, passing through the equatorial plane of the vortex twice in each revolution. These points constitute the moon's nodes on the plane of the vortex, and, from the principles laid down, the force of the moon to disturb the equilibrium of the axis of the vortex, vanishes at these points, and attains a maximum 90d from them. And the effect produced, in passing from her ascending to her descending node, is equal and contrary to the effect produced in passing from her descending to her ascending node,—reckoning these points on the plane of the vortex.
INCLINATION OF THE AXIS.
By whatever means the two planes first became permanently inclined, we see that it is a necessary consequence of the admission of these principles, not only that the axis of the vortex should be drawn aside by the momentum of the earth and moon, ever striving, as it were, to maintain a dynamical balance in the system, in accordance with the simple laws of motion, and ever disturbed by the action of gravitation exerted on the grosser matter of the system; but also, that this axis should follow, the axis of the lunar orbit, at the same mean inclination, during the complete revolution of the node. The mean inclination of the two axes, determined by observation, is 2d 45', and the monthly equation, at a maximum, is about 15', being a plus correction in the northern hemisphere, where the moon is between her descending and ascending node, reckoned on the plane of the vortex, and a minus correction, when between her ascending and descending node. And the mean longitude of the node will be the same as the true longitude of the moon's orbit node,—the maximum correction for the true longitude being only about 5d +/-.
In the following figure, P is the pole of the earth; E the pole of the ecliptic; L the pole of the lunar orbit; V the mean position of the pole of the vortex at the time; the angle [ARIES]EL the true longitude of the pole of the lunar orbit, equal to the true longitude of the ascending node +/- 90d. VL is therefore the mean inclination +/- 2d 45'; and the little circle, the orbit described by the pole of the vortex twice in each sidereal revolution of the moon. The distance of the pole of the vortex from the mean position V, may be approximately estimated, by multiplying the maximum value 15' by the sine of twice the moon's distance from the node of the vortex, or from its mean position, viz.: the true longitude of the ascending node of the moon on the ecliptic. From this we may calculate the true place of the node, the true obliquity, and the true inclination to the lunar orbit. Having indicated the necessity for this correction, and its numerical coefficient, we shall no longer embarrass the computation by such minutiae, but consider the mean inclination as the true inclination, and the mean place of the node as the true place of the node, and coincident with the ascending node of the moon's orbit on the ecliptic.
POSITION OF THE AXIS OF THE VORTEX.
It is now necessary to prove that the axis of the vortex will still pass through the centre of gravity of the earth and moon.
Let XX now represent the axis of the lunar orbit, and C the centre of gravity of the earth and moon, X'X' the axis of the vortex, and KCR the inclination of this axis. Then from
similarity Ct : Tt :: Cm : Mm but Tt : Mm :: Moon's mass : Earth's mass. That is Tt : Mm :: TC : MC.
Therefore the system is still balanced; and in no other point but the point C, can the intersection of the axes be made without destroying this balance.
It will be observed by inspecting the figure, that the arc R'K' is greater than the arc RK. That the first increases the arc AR, and the second diminishes that arc. The arc R'K' is a plus correction therefore, and the smaller arc RK a minus correction. If the moon is between her descending and ascending node, (taking now the node on the ecliptic,) the correction is negative, and we take the smaller arc. If the moon is between her ascending and descending node, the correction is positive, and we take the larger arc. If the moon is 90d from the node, the correction is a maximum. If the moon is at the node, the correction is null. In all other positions it is as the sine of the moon's distance from the nodes. We must now find the maximum value of these arcs of correction corresponding to the mean inclination of 2d 45'.
To do this we may reduce TC to Tt in the ratio of radius to cosine of the inclination, and taking TS for radius.
{TC x Cos &c. (inclination 2d 45')}/R is equal the cosine of the arc SK' and SK' + AS = AK' and AK' + AR' = R'K'. But from the nature of the circle, arc RK + arc R'K' = angle RCK + angle R'CK', or equal to double the inclination; and therefore, by subtracting either arc from double the inclination, we may get the other arc.
The maximum value of these arcs can, however, be found by a simple proportion, by saying; as the arc AR, plus the inclination, is to the inclination, so is the inclination to the difference between them; and therefore, the inclination, plus half the difference, is equal the greater arc, and the inclination, minus half the difference, is equal the lesser; the greater being positive, and the lesser negative.
Having found the arc AR, and knowing the moon's distance from either node, we must reduce these values of the arcs RK and R'K' just found, in the ratio of radius to the sine of that distance, and apply it to the arc AR or A'R', and we shall get the first correction equal to the arc AK or AK'.
Call the arc AR = a " inclination = n " distance from the node = d " arc AK = k
and supposing the value of AK be wanted for the northern hemisphere when the moon is between her descending and ascending node, we have
n^2 ———- a + n (n - ———- ) sin d. 2 k = a - ——————————— R
If the moon is between her ascending and descending node, then
n^2 ———- a + n (n - ———- ) sin d. 2 k = a + ——————————— R
The computation will be shorter, however, if we merely reduce the inclination to the sine of the distance from the node for the first correction of the arc AR, if we neglect the semi-monthly motion of the axis; for this last correction diminishes the plus corrections, and the first one increases it. If, therefore, one is neglected, it is better to neglect the other also; especially as it might be deemed affectation to notice trifling inequalities in the present state of the elements of the question.
There is one inequality, however, which it will not do to neglect. This arises from the displacement of the axis of the vortex.
DISPLACEMENT OF THE AXIS.
We have represented the axis of the terral vortex as continually passing through the centre of gravity of the earth and moon. Now, by following out the principles of the theory, we shall see that this cannot be the case, except when the moon is in quadrature with the sun. To explain this:
Let the curve passing through C represent a portion of the orbit of the earth, and S the sun. From the principles laid down, the density of the ethereal medium increases outward as the square roots of the distances from the sun. Now, if we consider the circle whose centre is C to represent the whole terral vortex, it must be that the medium composing it varies also in density at different distances from the sun, and at the same time is rotating round the centre. That half of the vortex which is exterior to the orbit of the earth, being most dense, has consequently most inertia, and if we conceive the centre of gravity of the earth and moon to be in the orbit (as it must be) at C, there will not be dynamical balance in the terral system, if the centre of the vortex is also found at C. To preserve the equilibrium the centre of the vortex will necessarily come nearer the sun, and thus be found between T and C, T representing the earth, and [MOON] the moon, and C the centre of gravity of the two bodies. If the moon is in opposition, the centre of the vortex will fall between the centre of gravity and the centre of the earth, and have the apparent effect of diminishing the mass of the moon. If, on the other hand, the moon is in conjunction, the centre of the vortex will fall between the centre of gravity and the moon, and have the apparent effect of increasing the mass of the moon. If the moon is in quadrature, the effect will be null. The coefficient of this inequality is 90', and depends on the sun's distance from the moon. When the moon is more than 90d from the sun, this correction is positive, and when less than 90d from the sun, it is negative. If we call this second correction C, and the moon's distance from her quadratures Q, we have the value of C = +/-(90' x sin Q)/R.
This correction, however, does not affect the inclination of the axis of the vortex, as will be understood by the subjoined figure. If the moon is in opposition, the axis of the vortex will not pass through C, but through C', and QQ' will be parallel to KK'. If the moon is in conjunction, the axis will be still parallel to KK', as represented by the dotted line qq'. The correction, therefore, for displacement, is equal to the arc KQ or Kq, and the correct position of the vortex on the surface of the earth at a given time will be at the points Q or q and Q' or q', considering the earth as a sphere.
In the spherical triangle APV, P is the pole of the earth, V the pole of the vortex, A the point of the earth's surface pierced by the radius vector of the moon, AQ is the corrected arc, and PV is the obliquity of the vortex. Now, as the axis of the vortex is parallel to the pole V, and the earth's centre, and the line MA also passes through the earth's centre, consequently AQV will all lie in the same great circle, and as PV is known, and PA is equal to the complement of the moon's declination at the time, and the right, ascensions of A and V give the angle P, we have two sides and the included angle to find the rest, PQ being the complement of the latitude sought.
We will now give an example of the application of these principles.
Example.[10] Required the latitude of the central vortex at the time of its meridian passage in longitude 88d 50' west, July 2d, 1853.
CENTRAL VORTEX ASCENDING.
Greenwich time of passage 2d. 3h. 1m. Mean longitude of moon's node 78d 29' True " " 79 32 Mean inclination of lunar orbit 5 9 True " " 5 13 Obliquity of ecliptic 23 27 32" Mean inclination of vortex 2 45 0
Then in the spherical triangle PEV,
PE is equal 23d 27' 32" EV " 7 58 0 E " 100 28 0 P " 18 5 7 PV " 26 2 32
Calling P the polar angle and PV the obliquity of vortex.
To find the arc AR.
By combining the two proportions already given, we have by logarithms:
M.R.V. minor = 3256 Log. 3.512683 M.S.D. of moon = 940" " 2.973128 P.S.D. of earth = 3950 A. C. 6.403403 Radius 10.000000 T.S.D. of moon 885".5 A. C. 7.052811 Log. Cosine arc AR = 28d 57' 3" 9.942025 ————-
As the only variable quantity in the above formula is the "True" semi-diameter of the moon at the time, we may add the Constant logarithm 2.889214 to the arithmetical complement of the logarithm of the true semi-diameter, and we have in two lines the log. cosine of the arc AR.
We must now find the arc RK equal at a maximum to 2d 45'. The true longitude of the moon's node being 79d 32', and the moon's longitude, per Nautical Almanac, being 58d 30', the distance from the node is 21d 2', therefore, the correction is
-2d 45' x sin 21d 2' -arc RK = ——————————- = -59' 13" R
To find the correction for displacement.
True longitude of sun at date 100d 30' " of moon " 58 30 Moon's distance from quadrature 48 0
As the moon is less than 90d from the sun this correction is also negative, or
-90' x sin 48d Arc Kq = ———————- = -1d 6' 46". R
Arc AR = 28d 57' 3" RK = - 0d 39' 13" Kq = - 1d 6' 46" Sum = 26d 51' 4" = corrected arc AQ.
We have now the necessary elements in the Nautical Almanac, which we must reduce for the instant of the vortex passing the meridian in Greenwich time.
July 2d. Meridian passage, local time, at 9h. 5m. A.M. " in Greenwich time 2d. 3h. 1m. Right ascension same time 56d 42' 45" Declination north " 18 00 1 Obliquity of the vortex " 26 2 32 Polar angle " 18 5 7 Arc AQ " 26 51 4
PA = 17d 59' 59" } P = 128d 37' 38" PV = 26 2 32 } VA = 89 3 0 V = 47 59 44 VQ = 62 11 56 A = 20 3 42 PQ = 47 14 22 Q = 26 22 55 Latitude of Q on the sphere = 42d 45' 38"
CORRECTION FOR PROTUBERANCE.
We have hitherto considered the earth a perfect sphere with a diameter of 7,900 miles. It is convenient to regard it thus, and afterwards make the correction for protuberance. We will now indicate the process for obtaining this correction by the aid of the following diagram.
Let B bisect the chord ZZ'. Then, by geometry, the angle FQY is equal to the angle BTF, and the protuberance FY is equal the sine of that angle, making QF radius. This angle, made by the axis of the vortex and the surface of the sphere, is commonly between 30d and 40d, according as the moon is near her apogee or perigee; and the correction will be greatest when the angle is least, as at the apogee. At the equator, the whole protuberance of the earth is about 13 miles. Multiply this by the cosine of the angle and divide by the sine, and we shall get the value of the arc QY for the equator. For the smallest angle, when the correction is a maximum, this correction will be about 20' of latitude at the equator; for other latitudes it is diminished as the squares of the cosines of the latitude. Then add this amount to the latitude EQ, equal the latitude EY. This, however, is only correct when the axis of the vortex is in the same plane as the axis of the earth; it is, therefore, subject to a minus correction, which can be found by saying, as radius to cosine of obliquity so is the correction to a fourth—the difference of these corrections is the maximum minus correction, and needs reducing in the ratio of radius to the cosine of the angle of the moon's distance from the node; but as it can only amount to about 2' at a maximum under the most favorable circumstances, it is not necessary to notice it. The correction previously noticed is on the supposition that the earth is like a sphere having TF for radius; as it is a spheroid, we must correct again. From the evolute, draw the line SF, and parallel to it, draw TW; then EW is the latitude of the point F on the surface of the spheroid. This second correction is also a plus correction, subject to the same error as the first on account of the obliquity, its maximum value for an angle of 30d is about 6', and is greatest in latitude 45d; for other latitudes, it is equal {6' x sin(double the lat.)}/R.
The three principal corrections for protuberance may be estimated from the following table, calculated for every 15d of latitude for an angle of 30d, or when the correction is greatest.
Latitude. 1st Corr. 2d Corr. 3d Corr. 0 + 20' + 0 - 2 15 + 19 + 3 - 1.5 30 + 15 + 5 - 1.5 45 + 10 + 6 - 1. 60 + 5 + 5 - 1 70 + 1 + 3 - 0.5
We can now apply this correction to the latitude of the vortex just found:
Latitude on the sphere 42d 45' 38" n. Correction for protuberance + 14 22 ————— Correct latitude 43 00 00
MILWAUKIE STORM, JULY 2.
As this example was calculated about ten days before the actual date, we have appended an extract from the Milwaukie papers, which is in the same longitude as Ottawa, in which place the calculation was made. It is needless to remark that the latitude of Milwaukie corresponds to the calculated latitude of the centre of the vortex. It is not intended, however, to convey the idea that the central line is always the most subject to the greatest violence—a storm may have several centres or nuclei of disturbance, which are frequently waning and reviving as the storm progresses. Generally speaking, however, the greatest action is developed along the line previously passed over by the axis of the vortex.
"SUMMIT, Waukesha Co., Wis., July 4, 1853.
"Our town, on Saturday, the 2d, was visited by a terrible storm, which will long be remembered by those who witnessed its effects and suffered from its fury. It arose in the south-west, and came scowling in blackness, sufficient to indicate its anger, for the space of eighty or a hundred rods in width, covering our usually quiet village; and for nearly half an hour's duration, the rain fell in torrents, the heavens blazed with the lightning's flashes, trees fell and were uprooted by the fury of the blast, fragments of gates and of buildings, shingles, roof-boards, rafters, circled through the air, the playthings of the wind—and buildings themselves were moved entire from their foundations, and deposited at different distances from their original positions. A barn, fifty-five feet square on the ground, owned by Mr. B. R. Hinckley, is moved from its position some ten feet to the eastward; and a house, some fifteen by eighteen feet on the ground, owned by the same person, fronting the east, was driven by the wind to the opposite side of the street, and now fronts nearly west; and what is most strange, is that the grass, in the route the house must have passed over, stands straight as usual, and gives no evidence that the building was pushed along on the ground. A lady running from a house unroofed by the storm, took an aerial flight over two fences, and finally caught against a tree, which arrested her passage for a moment only, when, giving way, she renewed her journey for a few rods, and was set down unhurt in Mr. O. Reed's wheat field, where, clinging to the growing grain, she remained till the gale went by."[11]
The weather at this place is briefly recorded in the accompanying abstract from the journal, as well as in an extract from a note to Professor Henry, of the Smithsonian Institution, from a friend of the authors, who has long occupied a high official station in Illinois. But such coincidences are of no value in deciding on the merits of such a theory, it must be tried before the tribunal of the world, and applied to phenomena in other countries with success, before its merits can be fully appreciated. The accompanying record, therefore, is only given to show how these vortices render themselves apparent, and what ought to be observed, and also to exhibit the order of their recurrence and their positions at a given time.
Extract of a note addressed to the Secretary of the Smithsonian Institution, by Hon. John Dean Caton, on this subject.
"As a striking instance of the remarkable coincidences confirmatory of these calculations, I will state, that on Friday, the first of July last, this gentleman[12] stated that on the next day a storm would pass north of us, being central a little south of Milwaukie, and that he thought, from the state of the atmosphere, the storm would be severe, and that its greatest violence would be felt on the afternoon or night of the next day. At this time the weather was fine, without any indications of a storm, so far as I could judge. At noon on the following day he pointed out the indications of a storm at the north and north-west, consisting of a dark, hazy belt in that direction, extending up a few degrees above the horizon, although so indistinct as to have escaped my observation. At five o'clock a violent storm visited us, which lasted half an hour, although a clear sky was visible at the south the whole time. On Monday morning I learned, from the telegraph office at Chicago, that early on Saturday afternoon communication with Milwaukie had been interrupted by atmospheric electricity, and that the line had been broken by a storm."
NEW YORK STORM.
After this was written, the author discovered that the vortex was equally violent the day before at New York, July 1st, 1853. An account of this storm follows. The calculation has not been made, but it is easy to perceive that the latitude of the vortex, on July 1st, must be very nearly that of New York—being in latitude 43d next day and ascending.
"At a meeting of the American Association, convened at Cleveland, Professor Loomis presented a long notice of the terrible hail storm in New York on the 1st of July. He traced its course, and minutely examined all the phenomena relating to it, from a mile and a half south-east of Paterson, N.J., to the east side of Long Island, where it appeared nearly to have spent its force. It passed over the village of Aqueenac, striking the Island of New York in the vicinity of the Crystal Palace. It was not much more than half a mile wide. The size of the hail-stones was almost incredibly large, many of them being as large as a hen's egg, and the Professor saw several which he thought as large as his fist. Some of them weighed nearly half a pound. The principal facts in relation to this storm were published at the time, and need not be repeated. The discussions arising among the members as to the origin and the size of these hail-stones, and the phenomena of the storm, were exceedingly interesting. They were participated in by Professors Heustus and Hosford, of Cambridge University, Professor Loomis, and Professors Bache and Redfield. The latter two gentlemen differ somewhat, we should suppose radically, in their meteorological theories, and had some very sharp but very pleasant "shooting" between them."[13]
CENTRAL VORTEX DESCENDING.
We will now make the calculation for the central vortex descending, for longitude 88d 50' west, August 7, 1853,—putting down the necessary elements for the time of the meridian passage in order:
Meridian passage in local time at 2h. 25m. P.M. " " in Greenwich time 7d. 8h. 18m. Mass of the moon 1/12.3 M. R. V. minor 3,256 miles. Obliquity of the vortex, same time 26d 5' 0" Polar angle of " " 17 41 47 True longitude of moon's node " 78 42 0 " inclination of orbit " 5 5 0 " longitude of the sun " 135 20 0 Moon's longitude " 169 44 0 " distance from node " 91 2 0 " distance from quadrature " 55 36 0 " true semi-diameter " 943 " right ascension " 172 30 0 " declination north " 8 42 20 Constant logarithm 2.889214 Arith. comp. of log. of 943 7.025488 Log. cos. arc. AR 9.914702 = 34d 44' 48" 1st. correction, + 2 45 0 2d. correction, - 1 14 15 ——————— Corrected arc AQ = 36 15 33 PA = 81d 17' 40" PV = 26 5 0 P = 115 11 47 V = 63 34 26 A = 23 28 24 AV = 92 48 39 Q = 31 32 18 Complement of lat. = PQ = 48d 49' 41" The latitude is therefore for the earth, as a sphere 41 10 18 Correction for protuberance + 0 16 0 —————— True latitude of centre 41 26 18 north. —————— Latitude of Ottowa 41 20 0 " —————— Vortex passed 6 18 north of Ottowa.
As this was nearly a central passage, and as the influence was less extensive than usual, on account of great atmospheric pressure with a low dew point, the central disturbance could the more readily be located, and was certainly to the north, and but a few miles. The following is from the record of the weather:
August 6th. Very fine and clear all day; wind from S.-W.; a light breeze; 8 P.M. frequent flashes of lightning in the northern sky; 10 P.M. a low bank of dense clouds in north, fringed with cirri, visible during the flash of the lightning; 12 P.M. same continues.
7th. Very line and clear morning; wind S.-W. moderate; noon, clouds accumulating in the northern half of the sky; wind fresher S.-W.; 3 P.M. a clap of thunder overhead, and black cumuli in west, north, and east; 4 P.M. much thunder, and scattered showers; six miles west rained very heavily; 6 P.M. the heavy clouds passing over to the south; 10 P.M. clear again in north.
August 8th. Clear all day; wind the same (S.-W.); a hazy bank visible all along on southern horizon.
This was not a storm, in the ordinary acceptation of the term; but the same cause, under other circumstances, would have produced one; and let it be borne in mind, that although the moon is the chief disturbing cause, and the passages of the vortices are the periods of greatest commotion in both settled and unsettled weather, still the sun is powerful in predisposing the circumstances, whether favorable or unfavorable; and as there is no periodic connection between the passage of a vortex and the concurrence of the great atmospheric waves, it will, of course, happen only occasionally that all the circumstances will conspire to make a storm. There are also other modifying causes, to which we have not yet alluded, which influence the storms at different seasons of the year,—exaggerating their activity in some latitudes, and diminishing it in other latitudes. In this latitude, the months of May, June, and July are marked by more energetic action than August, September, and October. The activity of one vortex also, in one place, seems to modify the activity of another vortex in another place. But the great question to decide is: Do these vortices really exist? Do they follow each other in the order indicated by the theory? Do they pass from south to north, and from north to south, at the times indicated by the theory? Do they obey, in their monthly revolutions, a mathematical law connecting them with the motions of the moon? We answer emphatically, Yes! And the non-discovery of these facts, is one of the most humiliating features of the present age.
OTTOWA STORM, DECEMBER 22, 1852.
To show that the same calculations are applicable for other times, we will make the calculation for the centre ascending, for the 22d December, 1852, taking the following elements:
Moon's mer. passage, Dec. 22d 15h. 16m. G. time. " right ascension, same time 51d 57' " declination north 15 42 " true S. Diameter 886.6" " distance from node 37 " " " quadrature 52 ———— Which gives the arc AR 29 5 1st correction -1 51 2d +1 11 ———— Corrected arc AQ 28 25 ————
And the latitude at the time of the meridian passage = 42d north, or about forty miles north of Ottawa.
Abstract from the record:—
[14]Dec. 21st, 1852. Wind N.-E., fine weather.
Dec. 22d. Thick, hazy morning, wind east, much lighter in S.-E. than in N.-W.; 8 A.M., a clear arch in S.-E. getting more to south; noon, very black in W. N.-W.; above, a broken layer of cir. cumulus, the sun visible sometimes through the waves; wind round to S.-E., and fresher; getting thicker all day; 10 P.M., wind south, strong; thunder, lightning, and heavy rain all night, with strong squalls from south.
Dec. 23d. Wind S.-W., moderate, drizzly day; 10 P.M., wind west, and getting clearer.
The next day the vortex passed the latitude of Montreal (the moon being on the meridian about 10 P.M.)
MAGNETIC STORM, DECEMBER 23, 1852.
In the July number of Vol. XVI. of Silliman's Journal, we find certain notices of the weather in 1852, by Charles Smallwood, of St. Martins, nine miles east of Montreal. He mentions "two remarkable electrical storms (which) occurred on the 23d and 31st of December, (in which) sparks 5/40 of an inch were constantly passing from the conductor to the discharger for several hours each day." At 10 P.M. (23d) the vortex passed over Montreal, and again descending on the 31st North, and was visible at Ottowa on the morning of the 1st of January, with southerly wind setting towards it. On the 29th of December, Mr. Smallwood records "a low auroral arch, sky clear." On the 20th, the vortex was 5d to the northward of Montreal, and the aurora was consequently low—the brightest auroras being when the vortex is immediately north without storm, or one day to the northward, although we have seen it very low when the vortex was three days to the north, and no other vortex near.
LIVERPOOL STORM.
On the night of the 24th of December, the same central vortex ascending passed between Cape Clear and Liverpool.
On the 25th, at midnight, the vortex passed to the north of Liverpool: its northerly progress being very slow, being confined for three days between the parallel of Liverpool and its extreme northern limit in latitude about 57d. The accompanying account of the weather will show the result of a long-continued disturbance near the same latitude:
The Baltic, three days out from Liverpool, encountered the vortex on the night of the 23d. On the morning of the 25th, very early, the gale commenced at Liverpool, and did much damage. On the 26th, the vortex attained its northern limit; but we have not been able to procure any account of its effects to the northward of Liverpool, although there can be but little doubt that it was violent on the coast of Scotland on the 26th; for the next day (27th) the vortex having made the turn, was near the latitude of Liverpool, and caused a tremendous storm, thus showing a continued state of activity for several days, or a peculiarly favorable local atmosphere in those parts. It is very probable, also, that there was a conjunction of the central and inner vortex on the 27th. The inner vortex precedes the central in passing latitude 41d; but as the mean radius of its orbit is less than that of the central, it attains to a higher latitude, and has, consequently, to cross the path of the central, in order again to precede it descending in latitude 41d. As a very trifling change in the elements of the problem will cause great changes in the positions of the vortices on the surface of the earth, it cannot now be asserted that such a conjunction did positively occur at that time; but, it maybe suspected, that a double disturbance would produce a greater commotion, or, in other words, a more violent, storm.
It is on this account, combined with other auxiliary causes, that the vicinity of Cape Horn is so proverbially stormy, as well as for the low standard of the barometer in that latitude, it is the stationary point of the vortices in ordinary positions of the nodes and perigee of the moon. We have already alluded to the fact, that none of the vortices scarcely ever pass much beyond latitude 80d, and then only under favorable circumstances, so that we ought to infer, that gales in high latitudes should set from the poles towards the storms in lower latitudes. This is, no doubt, the fact, but, nevertheless, a hard southerly blow may possibly occur in high northern latitudes, if a storm should be raging very violently in a lower latitude on the opposite side of the pole, the distance across the circle of 80d being only about 1,400 miles. As the different vortices have a different limit in latitude every year, the determination of this turning point is obviously of great practical utility, as the fact may yet be connected with other phenomena, so as to give us the probable character of the polar ice at any assigned time. On this point we have more to say.
PASSAGES OF ALL THE VORTICES.
Our remarks have hitherto been confined to the central vortex. We shall now show from the record, that the other vortices are as effective in deranging the equilibrium of our atmosphere. In the following table we have given the passages of the different vortices, which will serve as their true positions within moderate limits, to calculate from, for all future time.
PASSAGES OF THE CENTRAL AND LATERAL VORTICES, OBSERVED IN JUNE AND JULY, 1853, IN LATITUDE 41d 20' NORTH.
I signifying Inner; O, outer; C, central; A, ascending; D, descending.
Order. Vortex. Date. Meridian Passage. Calculated latitude Passage. and Remarks. 1st I. A. June 22 7 A.M. south Centre. About 40d. 23 8 A.M. north Warsaw. Storm. 2d O. D. 27 0 noon north 28 1 A.M. south See record. 3d C. A. July 1 9 A.M. south 2 10 A.M. north Lat. 43d. Storm. 4th I. D. 7 5 P.M. north 8 6 P.M. south Lat. New York. Storm. 5th C. D. 12 5 P.M. north Aurora. 13 6 P.M. south Stormy, very. 6th O. A. 14 10 A.M. south 15 11 A.M. north See Record.
The intervals between the ascending and descending passages of the different vortices, are
Between I. A. and I. D. from 11 to 14 days. " O. A. " O. D. " 10 " 12 " " C. A. " C. D. " 9 " 11 "
and the effect is greatest when the vortex comes to the meridian before the sun, and least when after the sun; in which case the full effect is not developed, sometimes until the following day.
A brief abstract from a journal of the weather for one sidereal period of the moon, in 1853.
June 21st. Fine clear morning (S. fresh)[15]: noon very warm 88d; 4 P.M. plumous cirri in south; ends clear.
22d. Hazy morning (S. very fresh) arch of cirrus in west; 2 P.M., black in W.-N.-W.; 3 P.M., overcast and rainy; 4 P.M., a heavy gust from south; 4.30 P.M., blowing furiously (S. by W.); 5 P.M., tremendous squall, uprooting trees and scattering chimneys; 6 P.M., more moderate (W.)
23d. Clearing up (N.-W.); 8 A.M., quite clear; 11 A.M., bands of mottled cirri pointing N.-E. and S.-W.; ends cold (W. N.-W.); the cirri seem to rotate from left to right, or with the sun.
24th. Fine clear cool day, begins and ends (N.-W.)
25th. Clear morning (N.-W, light); 2 P.M. (E.) calm; tufts of tangled cirri in north intermixed with radiating streaks, all passing eastward; ends clear.
26th. Hazy morning (S.-E) cloudy; noon, a heavy windy looking bank in north (S. fresh), with dense cirrus fringe above on its upper edge; clear in S.
27th. Clear, warm, (W.); bank in north; noon bank covered all the northern sky, and fresh breeze; 10 P.M., a few flashes to the northward.
28th. Uniform dense cirro-stratus, (S. fresh); noon showers all round; 2 P.M., a heavy squall of wind, with thunder and rain (S.-W. to N.-W.); 8 P.M., a line of heavy cumuli in south; 8.30 P.M., a very bright and high cumulus in S.-W., protruding through a layer of dark stratus; 8.50 P.M., the cloud bearing E. by S., with three rays of electric light.[16]
June 29th. A stationary stratus over all, (S.-W. light); clear at night, but distant lightning in S.
30th. Stratus clouds (N.-E. almost calm); 8 A.M., raining gently; 3 P.M., stratus passing off to S; 8 P.M., clear, pleasant.
July 1st. Fine and clear; 8 A.M., cirrus in sheets, curls, wisps, and gauzy wreathes, with patches beneath of darker shade, all nearly motionless; close and warm (N.-E.); a long, low bank of haze in S., with one large cumulus in S.-W., but very distant.
July 2d. At 5 A.M., overcast generally with hazy clouds and fog of prismatic shades, chiefly greenish-yellow; 7 A.M., (S.-S.-E. freshening,) thick in W; 8 A.M., (S. fresh) much cirrus, thick and gloomy; 9 A.M., a clap of thunder, and clouds hurrying to N.; a reddish haze all around; at noon the margin of a line of yellowish-red cumuli just visible above a gloomy-looking bank of haze in N.-N.-W., (S. very fresh;) warm, 86d; more cumuli in N.-W.—the whole line of cumuli N. are separated from the clouds south by a clear space. These clouds are borne rapidly past the zenith, but never get into the clear space—they seem to melt or to be turned off N.-E. The cumuli in N. and N.-W., slowly spreading E. and S.; 3 P.M., the bank hidden by small cumuli; 4 P.M., very thick in north, magnificent cumuli visible sometimes through the breaks, and beyond them a dark, watery back-ground, (S. strong); 4.30 P.M., wind round to N.-W. in a severe squall; 5 P.M., heavy rain, with thunder, &c.—all this time there is a bright sky in the south visible through the rain 15d high; 7 P.M., clearing, (S.-W. mod.)
July 3d. Very fine and clear, (N.-W.); noon, a line of large cumuli in N., and dark lines of stratus below, the cumuli moving eastward; 6 P.M., their altitude 2d 40'. Velocity 1d per minute; 9 P.M., much lightning in the bank north.[17]
July 4th. 6 A.M., a line of small cumulo-stratus, extending east and west, with a clear horizon north and south 10d high. This band[18] seems to have been thrown off by the central yesterday, as it moves slowly south, preserving its parallelism, although the clouds composing it move eastward. Fine and cool all day—(N.-W. mod.)—Lightning in N.
July 5th. Cloudy (N. almost calm), thick in E., clear in W.; same all day.
6th. Fine and clear (E. light); small cumuli at noon; clear night.
7th. Warm (S. E. light); cirrus bank N. W.; noon (S.) thickening in N.; 6 P.M., hazy but fine; 8 P.M., lightning in N.; 10 P.M., the lightning shows a heavy line of cumuli along the northern horizon; calm and very dark and incessant lightning in N.
8th. Last night after midnight commencing raining, slowly and steadily, but leaving a line of lighter sky south; much lightning all night, but little thunder.
8th. 6 A.M. Very low scud (500 feet high) driving south, still calm below, (N. light); 10 A.M., clearing a little; a bank north with cirrus spreading south; same all day; 9 P.M., wind freshening (N. stormy); heavy cumuli visible in S.; 10.30 P.M., quite clear, but a dense watery haze obscuring the stars; 12 P.M., again overcast: much lightning in S. and N.-W.
9th. Last night (2 A.M. of 9th) squall from N.-W. very black; 4 A.M., still raining and blowing hard, the sky a perfect blaze, but very few flashes reach the ground; 7 A.M., raining hard; 8 A.M. (N.-W. strong); a constant roll of thunder; noon (N.-E.); 2 P.M. (N.); 4 P.M. clearing; 8 P.M., a line of heavy cumuli in S., but clear in N-W., N., and N.-E.[19]
NEW YORK STORM, JULY 8, 1853.
"At 5 o'clock Friday afternoon, a terrible storm of rain, hail, and lightning, rose suddenly from the north-west, and passed over the upper part of the city and neighborhood. It was quite moderate in the lower part of the town, and probably scarcely felt on Staten Island. The whole affair lasted not more than a quarter of an hour, yet the results were most disastrous, as will be seen by the following accounts from our reporters:
"Happening to be in the neighborhood of the Palace about 5 o'clock Friday evening, we sought shelter under its ample roof from an impending thunder storm, of very threatening appearance, rapidly approaching from the west. We had scarcely passed the northern entrance, and reached the gallery by the nearest flight of steps, when the torrent—it was not rain, but an avalanche of water—struck the building; the gutters were filled on the windward side in a moment, and poured over an almost unbroken sheet of water, which was driven through the Venetian blind ventilators, into and half way across the north-west gallery, and also through the upper ventilators, falling upon the main floor of the north transept. Workmen hastened to close the blinds, but that did not prevent the deluge. The tinning of the dome being unfinished, the water, of course, came down in showers all over the centre. Many workmen were engaged on the dome when the shower struck it; several of them, in their haste to escape such dangerous proximity to the terrific lightning, came down single ropes, hand over hand. Large number of workmen were engaged all over the exterior, and such a scampering will rarely be witnessed but once in a lifetime. It was found impossible to close a north window, used for ingress and egress of workmen upon the rod, and the water came in, in almost solid columns. For a time the water was nearly two inches deep on the gallery floor, and poured down the stairs in miniature cascades.
"A great number of boxes, bales, and packages of goods lay upon the main floor, among which the water poured down from the edge of the gallery floor in destructive quantities; Fortunately but few goods were opened, and were upon the tables, or the damage would have been irreparable. As it is, we fear some of the goods are injured. In the height of the storm, the centre portion of the fanlight over the western entrance burst in, and several single lights were broken, by staging or otherwise.
"About ten minutes after the storm burst, the most terrific hailstorm we ever saw began to rattle, like discharges of musketry, upon the tin roof and glass sides. Some of the masses of ice were as large as hen's eggs. There were probably a thousand excited workmen in the building, and a good many exhibitors and visitors, among whom there were some twenty ladies, some of whom appeared a good deal alarmed at the awful din. A portion of the frame-work of the addition next to 42d street, went down with a terrible crash, and a part of the brick wall of the engine-house on the opposite side of the street, was blown over, crushing two or three shanties, fortunately without any other injury than driving the occupants out into the storm. But an awful scene occurred on the north side of 43d street, directly opposite the Latting Tower. Here two large unfinished frame buildings were blown, or rather, we should judge from appearances, were crushed down into a mass of ruins, such as may be imagined by supposing a great weight had fallen, with a circular, grinding motion, upon the first fine fabrics. One of them was partly sided, and had the rafters up, but no roof; the other was sided and rooted with tin, and was being plastered. We were told it was three stories high, 50 by 98 feet.
"We reached the ruins among the first, after the burst of the storm subsided a little. The scene was such as we pray God we may never witness again. A small portion of the roof and upper part of the front of the building stood or rather partly hung over the side-walk. The chamber and lower floor of the front rooms lay flat together. The sides were standing. In the rear all were down. In this building, besides the workmen, there were numerous laborers who had taken shelter under its roof when the storm drove them hurriedly from their work. How so many persons escaped death is truly wonderful. It can only be accounted for by supposing that they had a moment's warning, and rushed into the street. The first alarm was from the tearing off a portion of the tin roof, which was carried high over another building, and fell in the street. A horse and cart barely escaped being buried under this. It seems the frame of the other building came down with a deafening crash at the same time, confusing instead of warning those in danger. At any rate, before they could escape, they were buried in a mass of timber, and three of them instantly killed, and four or five dangerously wounded; and others slightly bruised and badly frightened. Several would have perished but for timely assistance to extricate them. In this they were greatly assisted by Jacob Steinant, boss carpenter of the Tower, who with his men rushed to the rescue, notwithstanding the pouring down torrents.
"In Williamsburgh, the storm lasted about fifteen minutes, doing an incalculable amount of damage to dwellings, foliage, &c. Hailstones came down in sizes from that of a hickory-nut to a large apple, some with such force as to drive them through the cloth awnings.
"The storm passed over Brooklyn lightly, in comparison with the effects across the Williamsburgh line. On Flushing avenue, beyond the Naval Hospital, a number of trees were uprooted, and the window-panes of the houses shattered. On the corner of Fulton and Portland avenues, three buildings were unroofed, and the walls of the houses were sprung to the foundation.
"On Spencer street, a new frame building was levelled with the ground. Along Myrtle, Classon, and other streets and avenues of East Brooklyn, many of the shade trees were uprooted, and the windows smashed. In Jay street, two trees were struck by lightning, but no other damage ensued.
"Several schooners at the foot of Jay street were forced from their moorings, but were soon after secured. A small frame house in Spencer street, just put under roof, was prostrated to the ground.
"We understand that a large barn filled with hay, situated on the road between Bushwick and Flushing, was struck by lightning and destroyed with its contents, embracing several head of live stock."[20]
July 10th, 3 A.M. Overcast and much lightning in south (N. mod.); 7 A.M., clear except in south; 6 P.M. (E.); 10 P.M., lightning south; 11 P.M., auroral rays long but faint, converging to a point between Epsilon Virginis and Denebola, in west; low down in west thick with haze; on the north the rays converged to a point still lower; lightning still visible in south. This is an aurora in the west.
11th. Fine clear morning (N.-E.); same all day; no lightning visible to-night, but a bank of clouds low down in south, 2d high, and streaks of dark stratus below the upper margin.
12th. Fine and clear (N.-E.); noon, a well defined arch in S.-W., rising slowly; the bank yellowish, with prismatic shades of greenish yellow on its borders. This is the O. A. At 6 P.M., the bank spreading to the northward. At 9 P.M., thick bank of haze in north, with bright auroral margin; one heavy pyramid of light passed through Cassiopaea, travelling westward 1 1/2d per minute. This moves to the other side of the pole, but not more inclined towards it than is due to prospective, if the shaft is very long; 11.10 P.M., saw a mass of light more diffuse due east, reaching to Markab, then on the prime vertical. It appears evident this is seen in profile, as it inclines downwards at an angle of 10d or 12d from the perpendicular. It does not seem very distant. 12 P.M., the aurora still bright, but the brightest part is now west of the pole, before it was east.
13th, 6 A.M. Clear, east and north; bank of cirrus in N.-W., i.e., from N.-N.-E. to W. by S.; irregular branches of cirrus clouds, reaching almost to south-eastern horizon; wind changed (S.-E. fresh); 8 A.M., the sky a perfect picture; heavy regular shafts of dense cirrus radiating all around, and diverging from a thick nucleus in north-west, the spaces between being of clear blue sky. The shafts are rotating from north to south, the nucleus advancing eastward.
Appearance of the central vortex descending at 8 A.M., July 13th, 1853:
In Fig. 18, the circle represents the whole sky from the zenith to the horizon, yet it can convey but a very faint idea of the regularity and vividness of this display. The reflected image of the sky was received from a vessel of turbid water, which will be found better than a mirror, when the wind will permit.
At noon (same day) getting thicker (S.-E. very fresh); 6 P.M., moon on meridian, a prismatic gloom in south, and very thick stratus of all shades; 9 P.M., very gloomy; wind stronger (S.-E.): 10 P.M., very black in south, and overcast generally.
14th. Last night about 12 P.M. commenced raining; 3 A.M., rained steadily; 7 A.M., same weather; 8.20 A.M., a line of low storm-cloud, or seud, showing very sharp and white on the dark back ground all along the southern sky. This line continues until noon about 10d at the highest, showing the northern boundary of the storm to the southward; 8 P.M., same bank visible, although in rapid motion eastward; same time clear overhead, with cirrus fringe pointing north from the bank; much lightning in south (W. fresh); so ends.
15th. Last night a black squall from N.-W. passed south without rain; at 3 A.M. clear above, but very black in south (calm below all the time); 9 A.M., the bank in south again throwing off rays of cirri in a well-defined arch, whose vortex is south: these pass east, but continue to form and preserve their linear direction to the north; no lightning in south to-night.
16th. Clear all day, without a stain, and calm.
17th. Fine and clear (N.-E. light); 6 P.M., calm.
18th. Fair and cloudy (N.-E. light); 6 P.M., calm.
19th. Fine and clear (N. fresh); I. V. visible in S.-W.
20th. 8 A.M., bank in N.-W. with beautiful cirrus radiations; 10 A.M., getting thick with dense plates of cream-colored cirrus visible through the breaks; gloomy looking all day (N.-E. light).[21]
Appearance of the Inner Vortex at 8 A.M., July 20th, 1853, including the whole sky. (See Fig. 19.)
This was a different passage of the Inner Vortex ascending as compared with the same 28 days before. At that date (June 22) it did great damage in the central parts of Illinois. Still this last passage was very palpable—the clouds were very irregularly assorted—plates of cirrus above and beneath cumulus—various kinds of cirrus clouds, and that peculiar prismatic haze which is a common sign of the passage of a vortex. The appearance depicted above is a very common, although a very evanescent appearance. When the sky appears of a clear blue through the cirri, there will be generally fresh gales without any great electrical derangement; but if the clear spaces are hazy, gradually thickening towards the nucleus, a storm may be expected. Any one who wishes to understand the indications of the clouds, must watch them closely for many years, before he can place much reliance upon them. But we shall again advert to this point.
We have now passed through one sidereal period of the moon. We might continue the record, but it would be tedious. The passages of these vortices vary in violence at different times, as we might expect; but they never cease to circulate, and never will as long as the moon remains a satellite to the earth; and if we take the passage of any of these vortices, and add thereto the time of one sidereal period of the moon, we get approximately the time of the next passage. When the elements of the lunar orbit tend to accelerate the passages, they may come in 26 days; and when to retard, in 28 days; and these are about the limits of the theory.
Having begun and ended this record of the weather with the passage of the Inner vortex ascending, it may not be amiss to notice one more, (the August passage,) as it offers a peculiarity not often so distinctly marked. We have alluded to the greater force of the storms when the passage of the vortex corresponds to the passage of the line of low barometer or the depression point of a great atmospheric wave, which is also due to the action of the ether. In consequence of these waves passing from west to east, the storm will only be violent when formed a little to the westward. If the storm forms to the eastward, we neither see it nor feel it, as it requires time to develop its strength, and always in this latitude travels eastward; so that storms may generally be said to come from the west, although the exciting cause travels from east to west. In the case now alluded to, the weather indicated a high barometer, and the storm formed immediately to the eastward, even showing a distinct circular outline. We subjoin a description.
August 15th. Clear morning (N.-E.), a bank of cumuli in south: noon quite cloudy in S. and clear in north. (N.-E.)
16th. Clear morning (N.-E.); 3 P.M., getting very black in E. and S.-E., very clear to the westward; 4 P.M., much thunder and lightning in east, and evidently raining hard; 5 P.M., a violent squall from east for 10 minutes; tore up several trees; 6 P.M., the storm passing eastward, clear in west all this time; 6.30 P.M., the storm forming a regular arch, the vertex being in S.-E.; the arch of hazy cirrus and heavy cumulus much lower in S.-E., wind still moderate from east; 10 P.M., clear all around, but lightning in S.-E. and E.
17th. Fine clear morning (W.); noon, scattered cumuli in north; 6 P.M., a beautifully regular arch of dense cumuli and cirrus margin in N.-E., with a constant glimmer of lightning; 7 P.M., very clear to the west, and north-west, and south; along the northern horizon a line of high peaked cumuli terminating in N.-N.-W.; a continued roll of distant thunder in the circular bank in N.-E., and not a moment's cessation to the lightning; the electric excitement advancing westward along the lines of cumuli; the cirrus haze also rising and passing towards S.-W.; 8 P.M., the sky alive with lightning, the cirrus now reaches the zenith; no streaks of lightning coming to the earth; they seem to radiate from the heaviest mass of cumuli, and spread slowly (sufficiently so to follow them) in innumerable fibres over the cloudy cirrus portion of the sky; every flash seems to originate in the same cloud; 8.30 P.M., one branching flash covered the whole north-eastern half of the sky, no leafless tree of the forest could show so many branches; 9.30 P.M., all passed to S.-W. without rain, leaving behind a large cumulus, as if it lagged behind. From this cumulus a straight line of lightning shot up 10d above the cloud into a perfectly clear sky, and terminated abruptly without branching.
We have been thus particular in giving these details, as this was a clear case confirming the principles advanced, that the vortices do not form a continuous line of disturbance, in their daily passage around the earth. It shows also that the barometer, in connection with these principles, will be a far more useful instrument than it has yet proved itself, for practical service as an indicator of the weather.
FOOTNOTES:
[10] For convenience to those wishing to verify the calculation of these triangles, we have put down each side and angle as found. Also, as an aid to the navigator.
[11] Daily Wisconsin, July 7.
[12] The author.
[13] Chicago Democrat.
[14] This was also calculated before the event.
[15] The letters in a parenthesis signify the direction of the wind.
[16] Giving this cloud the average velocity of thirty miles per hour, its altitude was determined by the sextant at twelve miles, and we think under-estimated. While measuring, the author's attention was drawn to the fact, that although it appeared equally dense above and below, yet its middle part was the brightest, and as there was only a faint glimmer of twilight in the N.-W., he concluded that the cloud was self-luminous; for when the smallest stars were visible, it glowed about as bright as the milky-way in Sagittarius. Occasionally the whole cloud was lit up internally by the lightning, and about this time it sent off three rays: one horizontally, westward, which was the faintest; one about N.-W., towards Jupiter, and the brightest of the three; and another towards the north. These were not cirrus streaks, but veritable streams of electric matter, and had a very decided rotation from left to right, and continued visible about twenty minutes, as represented above.
[17] This day the central vortex passed in about latitude 47d N.—the southern margin cannot be nearer than 250 miles, throwing off the 40' for the horizontal refraction, would give eight miles of altitude above a tangential plane. Then another seven miles, for curvature, will give an altitude of fifteen miles for the cumuli. The height of these thunder-clouds has been much under-estimated. They seem to rise in unbroken folds to a height of ten and twelve miles frequently; from the data afforded by the theory, we believe they will be found much higher sometimes—even as much as sixteen miles.
[18] These parallel bands, and bands lying east and west, are frequent in fine weather between two vortices. Sailors consider them a sign of settled weather. After dark there was frequently seen along the northern horizon flashes of lightning in a perfectly clear sky. But they were both faint and low, not reaching more than 4d or 5d above the horizon. After sunset there were very distinct rays proceeding from the sun, but they were shorter than on the evening of the 3d. These are caused by the tops of the great cumuli of the storm, when sunk below the horizon, intercepting the sun's rays, which still shine on the upper atmosphere. The gradation was very marked, and accorded with the different distances of the central vortex on the 3d and 4th—although, on the 4th, the nearest distance must have been over four hundred miles to the southern boundary of the storm.
[19] It is worthy of notice here, that New York, which only differs by about 40 miles of latitude and 800 in longitude, had the storm earlier, near the time of the passage, as appears by the appended account of it. This proves, that a storm affects a particular latitude simultaneously, or approximately so. If this had to travel eastward to reach New York, it would have been the 10th instead of the 8th. The principal trouble was, however, in the early part of the evening of the 8th, to the south of Ottawa, where the strong wind was drawn in from the northward. If a vortex passes from north to south, leaving the observer between the passages, there must, nearly always, be a winding up squall from the north to clear away the vapory atmosphere.
[20] From the New York Tribune, July 9, 1853.
[21] These pages are now in the compositors' hands, (Nov. 21st,) and up to the last moment the Author has observed carefully in New York the passages of these vortices. October 24th, in the inner vortex descending produced a violent storm on the coast, and much damage ensued. November 7th, the same vortex ascending was also severe. And on November 13th, early, the passage of the central vortex ascending, caused a flood in Connecticut of a very disastrous nature. Would it not pay the insurance offices to patronize such investigations in view of such palpable facts as these?
SECTION THIRD.
OBJECTIONS TO LUNAR INFLUENCE.
We have now presented a theory of the weather, which accounts for many prominent phenomena, a few of which we shall enumerate. It is an observed fact, that in all great storms electrical action is more or less violent, and that without this element it seems impossible to explain the velocity of the wind in the tornado, its limited track, and the formation of large masses of ice or hail in the upper regions of the atmosphere. It is also an observed fact, that the barometer is in continued motion, which can only be legitimately referred to a change in the weight of the atmospheric column. This we have explained as due to atmospheric waves, caused by the greater velocity of rotation of the external ether, as well as to the action of the three great vortices. These causes, however, only partially produce the effect—the greater portion of the daily oscillations is produced by the action of the great radial stream of the solar vortex, as we shall presently explain. It is an observed fact, that, although the storm is frequently violent, according to the depression of the barometer, it is not always so. According to the theory, the storm will be violent, ceteris paribus, on a line of low barometer, but may still be violent, when the contrary obtains. Another fact is the disturbance of the magnetic needle during a storm. Storms are also preceded generally by a rise in the thermometer, and succeeded by a fall; also by a fall in the barometer, and succeded by a rise. It is also well known, that hurricanes are unknown at the equator, and probably at the poles also. At all events, they are rare in lat. 80d, and, according to Capt. Scoresby, storms are there frequently raging to the south, while above, there is clear sky and fine weather, with a stiff breeze from the northward. The greater violence of storms in those regions where the magnetic intensity is greater in the same latitude, the probable connection of peculiarities in the electric state of the atmosphere with earthquakes, and the indications of the latter afforded by the magnet; the preponderance of westerly winds at a great elevation in every latitude on the globe visited by man; and the frequent superposition of warm layers of air above cold ones at those elevations, are all facts worthy of note. And the connection of cirrus clouds with storms, as well as with the aurora, indicates that the producing cause is external to the atmosphere, and gradually penetrates below. The theory fully explains this, and is confirmed by the fantastic wreathings and rapid formation of these clouds in straight lines of a hundred miles and upwards. But time would fail us in pointing out a tithe of the phenomena, traceable to the same cause, which keeps our atmosphere in a perpetual state of change, and we shall only advert to one more peculiarity of the theory. It places meteorology on a mathematical basis, and explains why it is that a storm may be raging at one place, while in another, not very remote, the weather may be fine, and yet be dependent on the position of the moon.
That the moon has exerted an influence on the weather has been the popular creed from time immemorial; but, ignorant of the mode in which this influence was exerted, men have often been found who have fostered the popular belief for their own vanity or advantage; and, on the other hand, philosophers have assailed it more by ridicule than by argument, as a relic of a barbarian age. Not so with all; for we believe we are not wrong in stating, that the celebrated Olbers compared the moon's positions with the weather for fifty years, before he gave his verdict against it. He found the average amount of rain at the perigee about equal to the amount at the apogee, as much at the full as at the change, and no difference at the quadratures. But this fact does not throw a feather in the scale by which this theory is weighed. Popular opinions, of remote origin, have almost always some foundation in fact, and it is not much more wise to reject them, than to receive them. The Baron Von Humboldt—a man possessing that rare ingredient of learning, a practical common sense—observes: "That arrogant spirit of incredulity which rejects facts, without attempting to investigate them, is, in some cases, more injurious than an unquestioning credulity."[22] If a popular belief or prejudice be absurd, its traditional preservation for a thousand years or more may very well account for the absurdity.
The present system of astronomy still retains the motley garniture of the celestial sphere, as handed down from the most remote antiquity; and granting that ages of ignorance and superstition have involved the history of the different constellations in a chaos of contradictory traditions, there is no doubt at the foundation some seeds of truth which may even yet emerge from the rubbish of fable, and bear fruit most precious. That the zodial[23] signs are significant records of something worthy of being preserved, is prejudice to deny; and we must be allowed to regard the Gorgons and Hydras of the skies as interesting problems yet unsolved, as well as to consider that the belief in lunar influence is a fragment of a true system of natural philosophy which has become more and more debased in postdiluvian times. Amongst those who have not summarily ignored the influence of the moon, is Toaldo, a Spanish physicist, who endeavored to show the connection between the recurrence of warm and cold seasons, and the semi-revolution of the lunar nodes and apogee, and proposed six of those periods, or about fifty-four years, as the cycle in which the changes of the weather would run through their course. According to the present theory, it is not likely such a cycle will ever be discovered. There are too many secular, as well as periodic influences combining, to produce the effect; and the times are too incommensurable. Lately, Mr. Glaisher has presented a paper to the Royal Society, giving about fourteen years from observation. Others have lately attempted to connect the changes of the seasons with the solar spots, as well as with the variations of the magnetism of the earth, but without any marked result.
It may, however, be urged, that if the sidereal period of the moon be approximately a cycle of change, it would have been detected long ago. One reason why this has been so long concealed, is the high latitude of the observers. Spain, Italy, and Turkey, are better situated than other European countries; but the scientific nations lie further north; and from these the law has gone forth to regulate more southern lands. In the United States, particularly in the great plains of the west, the weather can be better compared; not only on account of the latitude being more favorable, but also on account of the greater magnetic intensity of the western hemisphere.
It must also be remembered that there are in latitude 40d, five or six distinct passages of the disturbing cause in one sidereal period of the moon. If two of these periods are drawn closer together by the change of the elements, the interval between two others must necessarily be increased. Besides, the effect produced is not always the same, for reasons already adverted to. One vortex may be more violent one month, or for a few days in one month, while another may be more active the next. It may also happen that for several successive passages, the passage shall be central in one latitude, while two or three degrees north or south, another place shall be passed by. In different months and in different years, as well as in different seasons of the year, the energy of the ether may be augmented or diminished. But it may be said, that, supposing the theory true, if its indications are so uncertain, it is of little value. By no means. It is true there are many things to be inquired into; but it is a great thing in this science to be able to take the first step in the right direction,—to find even the key of the portal. It is a great stride to be able to say, a storm may happen at such a time, but cannot happen at another; that a storm, when raging, will go in this direction, rather than in that; that it will be central here, and less violent yonder; and when we consider its bearing on astronomical and other science, it is difficult to exaggerate its value to the world at large.
Again, it may be said that rain, and cloudy days, and fresh breezes, and even strong winds, sometimes occur, when the vortices do not pass centrally. This is true; yet only indicating that where the vortices are central, an unusual disturbance is taking place. But there is another cause, which was purposely omitted in considering the prominent features of the theory, in order not to encumber the question with secondary influences. By referring to Fig. 3, section 1, we see that the lateral vortices of the globe are continually passing off to the southward, in the northern hemisphere, in a succession of dimples, and continually reforming. We will now represent this mode of action in profile, as it actually occurs in the illustration we have used.
The vortex passing off from O, (Fig. 20,) although it does not actually reach the surface of the atmosphere, affects the equilibrium of the ether, and, for a short distance from the parent vortex, may cause an ascensional movement of the air. If to this is conjoined a northerly wind from the vortex, a band of clouds will be produced, and perhaps rain; but violent storms never occur in the intervals, except as a steady gale, caused by the violence of a distant storm. Thus, it will frequently be noticed that these vortices are flanked by bands of clouds, which pass southward, although the individual clouds may be moving eastward. Hence, instead of disproving the theory, they offer strong evidence of its truth; and could we view the earth from the moon with a telescope, we should no doubt see her beautifully belted.
But it may be again asked, why should not the weather be the same generally, in the same latitude, if this theory be true? If the earth were a globe of level land, or altogether of water, no doubt it would be similar; but it must be remembered, that both land and water are very unequally distributed: that the land is of varying extent and elevation—here a vast plain, far removed from the ocean, and there a mountain chain, interposing a barrier to the free course of the atmospheric currents; sometimes penetrating in full width into the frigid zone, and again dwindling to a few miles under the equator. One very important distinction is also to be remarked, in the superficial area of the different zones, reckoning from the equator, and taking the hemisphere as 100 parts:
Frigid zone 8 parts. Temperate " 52 " Torrid " 40 "
For as the time of rotation in every latitude is the same, the area to be disturbed in the same time, is less in high latitudes, and there a greater similarity will obtain, ceteris paribus. In lower latitudes, where both land and water stretch away for thousands of miles, it is not wonderful that great differences should exist in the electrical and hygrometric state of the air.
The summer of many countries is always dry—California for instance. In winter, in the same country, the rains are apparently incessant. This of course depends on the power of the sun, in diverting the great annual currents of the atmosphere. As long as the dry north-west trade sets down the coast of California, the circumstances are not favorable for giving full development to the action of the vortices. When the trade wind ceases, and the prevailing winds come from the south, loaded with vapor, the vortices produce storms of any magnitude; but (and we speak from two years' observation) the passages of the vortices are as distinctly marked there in winter time, as they are in the eastern States; and in summer time, also, they are very perceptible. The same remark applies to Mediterranean countries, particularly to Syria and Asia Minor; although the author's opportunity for observing lasted only from April to December, during one season. If we are told it never rains on the coast of Peru, or in Upper Egypt, it does not seriously militate against the theory. The cause is local, and the Samiel and the sand storm of the desert, is but another phase of the question, explicable on the same general principles. From the preceding remarks it will be seen, that in order to foretell the character of particular days, a previous knowledge of the weather at that particular place, and for some considerable time, is requisite; and hence the difficulty of laying down general rules, until the theory is more fully understood.
MODIFYING CAUSES.
We now come to the causes which are auxiliary and interfering. It is natural that we should regard the sun as the first and most influential of these causes, as being the source of that variation in the temperature of the globe, which alternately clothes the colder regions in snow and verdure. The heat of the sun undoubtedly causes the ether of the lower atmosphere to ascend, not by diminution of its specific gravity; for it has no ponderosity; but precisely by increase of tension, due to increase of motion. This aids the ascensional movement of the air, and therefore, when a vortex is in conjunction with the sun, its action is increased—the greatest effect being produced when the vortex comes to the meridian a little before the sun. This has a tendency to make the period of action to appear dependent on the phases of the moon, which being the most palpable of all the moon's variations, has been naturally regarded by mankind as the true cause of the changes of the weather. Thus Virgil in his Georgics, speaking of the moon's influence and its signs:
"Sin ortu in quarto (Namque is certissimus auctor) Pura, nec obtusis per coelum cornibus ibit; Totus et ille dies, et qui nascentur ab illo, Exactum ad mensem, pluvia ventisque carebunt."
Hence, also, in the present day we hear sailors speak of the full and change, or the quartering of the moon, in connection with a gale at sea; thus showing, at least, their faith in the influence of the phenomenon. Yet it is actually the case, at certain times, that in about latitude 40d and 41d, the storms appear about a week apart.
There is some reason, also, to suspect, that there is a difference of temperature on opposite sides of the sun. As the synodical rotation is nearly identical with the siderent period of the moon, this would require about forty-four years to run its course, so as to bring the phenomena to exact coincidence again. Since these observations were made, it is understood that Sig. Secchi has determined that the equatorial regions of the sun are hotter than his polar regions. It may be owing to this fact, that we have inferred a necessity for a change, whose period is a multiple of the sun's synodical rotation, but it is worthy of examination by those who possess the necessary conveniences.
Another period which must influence the character of different years, depends on the conjunction of the perigee of the lunar orbit with the node. Taking the mean direct motion of the moon's perigee, and the mean retrograde motion of the node, we find that it takes six years and one day nearly from conjunction to conjunction. Now, from the principles laid down, it follows, that when the perigee of the orbit is due north, and the ascending node in Aries, that the vortices of the earth will attain their greatest north latitude; and when these conditions are reversed, the vortices will reach their highest limit in the lowest latitude. This will materially affect the temperature of the polar regions. In the following table, we have calculated the times of the conjunctions of the apogee and pole of the orbit, taking the mean motions. It may be convenient to refer to by-and-bye, remembering that when the conjunction takes place due south, the vortices reach the highest, but when due north, the vortices in the northern hemisphere have their lowest upper limit:
CONJUNCTION OF APOGEE AND POLE OF ORBIT.[24]
Year. Month and Day. Longitude. 1804, April 18th, 220d 1810, " 17th, 104 1816, " 16th, 348d 1822, " 15th, 232 1828, " 14th, 116 1834, " 12th, 360 1840, " 11th, 244 1846, " 10th, 128 1852, " 9th, 12 1858, " 8th, 255 1864, " 7th, 139 1870, " 6th, 23 1876, " 5th, 267
By this we see that the vortices have never attained their highest limit during the present century, but that in 1858 their range will be in a tolerable high latitude, and still higher in 1876—neglecting the eccentricity of the orbit.
A very potent influence is also due to the heliocentric longitude of the sun, in determining the character of any given year. Let us explain:
The moon's inertia forces the earth from the mechanical centre of the terral system, but is never able to force her clear from the central axis. With the sun it is different. He possesses many satellites (planets). Jupiter alone, from his great mass and distance, is able to displace the whole body of the sun. If other planets conspire at the same side, the centre of the sun may be displaced a million of miles from the mechanical centre of the solar system. Considering this centre, therefore, as the centre of an imaginary sun, from which heliocentric longitudes are reckoned, the longitude of the real sun will vary with the positions of the great planets of the system. Now, although this systematic longitude will not be exactly similar to the heliocentric longitude reckoned from the sun's centre, yet, for the purposes intended, it will correspond sufficiently, and we shall speak of the longitude of the sun as if we reckoned heliocentric longitudes from the mechanical centre of the system. When we come to consider the solar spots, we shall enter into this more fully. In the following diagram we shall be able to perceive a cause for variation of seasons in a given year, as well as for the general character of that year.
Let S represent the centre of the sun, and the circle a vertical section of the sun, cutting; through the centre,—SJ being in the equatorial plane of the vortex, of which ZZ' represents the axis. As the ether descends the poles or axis at Z, it is met by the current down the opposite pole, and is thence deflected in radii along the equatorial plane to J. But on the side S, the ether is opposed by the body of the sun; its direction is consequently changed, and cross currents are produced, assuming it as a principle, that the ethereal fluid is permeable by other currents of similar matter, and that it tends always to move in right lines. This granted, it is evident that, in passing the sun, the quick moving ether forms a conical shell, (the sun being at the apex,) so that the strongest current of ether is in this conical shell, or at the surface of this conical space. As the plane of the ecliptic is not much inclined to the sun's equator, and this last probably not much inclined to the plane of the vortex, should the earth have the same heliocentric longitude at the time, (or nearly the same,) she would be in an eddy, as respects the radial stream, and be protected from its full force by the body of the sun.
Now, the ether comes down the axis with the temperature of space, and may possibly derive a little additional temperature in passing over the body of the sun; so that in this position the earth is protected from the chilling influence of the radial stream, by being protected by the body of the sun. And although, from the immense velocity of the ether, it cannot derive much additional temperature, there may still be an appreciable difference, due to this cause.
It is the chilling influence of the ethereal stream which originated the idea among philosophers, of frigorific impressions, darted from a clear sky. In some years the sun will be nearly in the centre of the system; in other years the axis of the vortex will not come near the sun. And as the sun's longitude may vary through the entire circle, it may happen that the earth's longitude shall coincide in winter or summer, or spring or autumn. When, however, the earth emerges from the protection of the sun, and enters the conical shell, considered as a space of considerable depth, she will again be exposed to the full force of the radial stream, rendered more active by the previous deflection, and by the numerous cross currents pervading it; so that a mild and calm winter may be succeeded by a cold and stormy spring. The present season, (1853) the earth's longitude coincided with the sun's longitude in about 135d, and consequently was in the conical space spoken of, during February and March; but the radius vector of the sun's centre, being then less than 300,000 miles, the protection was not as complete as it is sometimes. Still, the general fineness of these months was remarkable; yet in April and May, when the earth became again exposed to the action of the solar stream, the effect was to retard the spring, and disappoint the prognostications of the weather-wise. In applying these principles, we must consider the effect in those latitudes which are more readily affected,—that is, in the temperate zone, midway between the two extreme zones of heat and cold.
In 1837 and 1838, the longitude of the sun's centre corresponded with the earth's, in August and September, when there was neither rain nor electrical excitement; and consequently those seasons were sickly over the whole country. Now, there is another cause which renders the months of August, September, and October, deficient in electrical energy, and consequently more prone to be sickly. If, therefore, the two causes unite their influence, the autumnal months will be more sickly at those times. This last cause, however, only affects the northern latitudes in autumn, and consequently, ceteris paribus, the autumnal months should not be so proverbially sickly in the southern hemisphere. This is, however, only suggestive.
Again, in 1843, the winter was very mild in January and February; but in March it turned cold and stormy, and continued through April. In this year the longitude of the sun was nearly the same as in 1853,—the two longitudes of the earth and sun corresponding about the last of January; but in March, the earth forsook the comparative calm produced by the sun's position, and hence the greater cold.[25]
Thus it appears at every step we take, that the different members of the solar system do indeed belong to the same family, whose least motions have their influence on the rest. Who could have anticipated that the position of Jupiter in his orbit had anything to do with the health of this remote planet, or with the mildness of its seasons? In this we have a clue to the origin of that astrological jargon about planetary aspects being propitious or malign. Philosophers are even yet too prone to wrap themselves in their mantle of academic lore, and despise the knowledge of the ancients, while there is reason to believe that the world once possessed a true insight into the structure of the solar system. As war became the occupation of mankind, under the despotic rule of ambition, so truth retired, and ignorance seizing upon her treasures, has so mutilated and defaced them, that their original beauty no longer appears. Let us hope that the dawn of a better day is approaching.
There is yet another cause (just alluded to) which modifies the action of the vortices.
We have shown that, if the periodic times of the planets are approximately equal to the periodic times of the contiguous parts of the solar vortex, the density of the ether is directly as the square roots of the distances from the centre. As the earth is at her perihelion about the first of January, the density of the surrounding ether is then less than in other parts of the orbit; consequently, if we suppose that there is a continual tendency to equilibrium, the ether of space must press inwards, during the time between the perihelion and aphelion, (i.e. from January to July,) lowering the temperature and increasing the electrical action of those months. As the distance from the sun is most rapidly augmenting about the first of April, and the effective power of the sun's radiation is most rapidly increasing in May; by combining the two we shall find, that about the first of May we shall have considerable electrical action, and cold weather. This explains also, in part, the prevalent tradition of certain days in May being very cold.[26] When the earth leaves the aphelion, a reaction takes place, being most rapid in September. There is then an escape of ether from the earth, which keeps up the temperature, and causes these months to be sickly, from the negative electrical state of the atmosphere. In the southern hemisphere, the effects in the same season will be reversed, which may partly account for the greater degree of cold in that hemisphere, and for accelerating the approach of both summer and winter, while in the north they were both retarded. |
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