Outlines of a Mechanical Theory of Storms Part 7

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 c.u.muli 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 pa.s.sed 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 pa.s.sed 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 quant.i.ties; 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 gla.s.s sides. Some of the ma.s.ses 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, crus.h.i.+ng 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 ma.s.s 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 G.o.d 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 ma.s.s 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 a.s.sistance to extricate them. In this they were greatly a.s.sisted 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 pa.s.sed over Brooklyn lightly, in comparison with the effects across the Williamsburgh line. On Flus.h.i.+ng 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, Cla.s.son, 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 Flus.h.i.+ng, 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, 2 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 pa.s.sed through Ca.s.siopaea, travelling _westward_ 1 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 ma.s.s 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 10 or 12 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 s.p.a.ces 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.

[Ill.u.s.tration: Fig. 18]

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 10 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. pa.s.sed 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 pa.s.s 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.)

[Ill.u.s.tration: Fig. 19]

This was a different pa.s.sage 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 pa.s.sage was very palpable--the clouds were very irregularly a.s.sorted--plates of cirrus above and beneath c.u.mulus--various kinds of cirrus clouds, and that peculiar prismatic haze which is a common sign of the pa.s.sage 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 s.p.a.ces 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 pa.s.sed through one sidereal period of the moon. We might continue the record, but it would be tedious. The pa.s.sages 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 pa.s.sage 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 pa.s.sage. When the elements of the lunar orbit tend to accelerate the pa.s.sages, they may come in 26 days; and when to r.e.t.a.r.d, in 28 days; and these are about the limits of the theory.

Having begun and ended this record of the weather with the pa.s.sage of the Inner vortex ascending, it may not be amiss to notice one more, (the August pa.s.sage,) as it offers a peculiarity not often so distinctly marked. We have alluded to the greater force of the storms when the pa.s.sage of the vortex corresponds to the pa.s.sage 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 pa.s.sing 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 lat.i.tude 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 c.u.muli 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 pa.s.sing 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 c.u.mulus 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 c.u.muli in north; 6 P.M., a beautifully regular arch of dense c.u.muli 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 c.u.muli 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 c.u.muli; the cirrus haze also rising and pa.s.sing 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 ma.s.s of c.u.muli, 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 pa.s.sed to S.-W. without rain, leaving behind a large c.u.mulus, as if it lagged behind. From this c.u.mulus a straight line of lightning shot up 10 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 pa.s.sage 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 wis.h.i.+ng 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 alt.i.tude was determined by the s.e.xtant 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 pa.s.sed in about lat.i.tude 47 N.--the southern margin cannot be nearer than 250 miles, throwing off the 40'

for the horizontal refraction, would give eight miles of alt.i.tude above a tangential plane. Then another seven miles, for curvature, will give an alt.i.tude of fifteen miles for the c.u.muli. 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 4 or 5 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 c.u.muli of the storm, when sunk below the horizon, intercepting the sun's rays, which still s.h.i.+ne 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.