“This cold air covered the whole country, from Michigan to the eastern coast of the United States, till the beginning of the great storm of the 26th January; and, what is worthy of particular notice is, thatthe temperature began to increase first in the north and north-west. On the morning of the 25th, in the north-western parts of Pennsylvania, and northern parts of New York, thethermometerhad alreadyrisen in some places 30°, and, in others,above 40°. While in the S. E. corner of Pennsylvania, and in the S. E. corner of New York it had notbegun to rise. Thewindalso began to change from thenorth-westtosouthandsouth-east,firstin the north-west parts of Pennsylvania and New York, some time before it commenced in the south-east of those States; and, during the whole of the 25th, the thermometer, in the north of New York, continued to rise, though the wind was blowing from the southward, where the thermometer was many degrees lower.”
“This cold air covered the whole country, from Michigan to the eastern coast of the United States, till the beginning of the great storm of the 26th January; and, what is worthy of particular notice is, thatthe temperature began to increase first in the north and north-west. On the morning of the 25th, in the north-western parts of Pennsylvania, and northern parts of New York, thethermometerhad alreadyrisen in some places 30°, and, in others,above 40°. While in the S. E. corner of Pennsylvania, and in the S. E. corner of New York it had notbegun to rise. Thewindalso began to change from thenorth-westtosouthandsouth-east,firstin the north-west parts of Pennsylvania and New York, some time before it commenced in the south-east of those States; and, during the whole of the 25th, the thermometer, in the north of New York, continued to rise, though the wind was blowing from the southward, where the thermometer was many degrees lower.”
Thus, too, Mr. Redfield (American Journal of Science, November, 1846, p. 329):
“On the contrary, in times of the greatest depression of the thermometer, in numerous instances, the cold period has been found to have first taken effect in, or near, the tropical latitudes, and the Gulf of Mexico, and has thence been propagated toward the eastern portions of the United States, in amannercorresponding to the observed progression of storms.”
“On the contrary, in times of the greatest depression of the thermometer, in numerous instances, the cold period has been found to have first taken effect in, or near, the tropical latitudes, and the Gulf of Mexico, and has thence been propagated toward the eastern portions of the United States, in amannercorresponding to the observed progression of storms.”
This was because the cold N. W. wind whichfollowedstorms began to follow them as the storms curved and passed to the N. E.
They occur in Europe also. Says Kämtz:
“Such contrasts are not uncommon in Europe, and, in this respect, the Alps form a remarkable limit; for they separate the climates of the north of Europe from the Mediterranean climates, where the distribution of rain is not the same as in the center of Europe. Hence the differences between the climates of the north and south of France.If the winter is mild in the north, the newspapers are filled with the lamentations of theItaliansandProvençalsat theseverity of the cold.”
“Such contrasts are not uncommon in Europe, and, in this respect, the Alps form a remarkable limit; for they separate the climates of the north of Europe from the Mediterranean climates, where the distribution of rain is not the same as in the center of Europe. Hence the differences between the climates of the north and south of France.If the winter is mild in the north, the newspapers are filled with the lamentations of theItaliansandProvençalsat theseverity of the cold.”
These facts seem to indicate a primary action in the counter-trade. Probably in connection with oneclass of storms they do, and with another do not. I shall endeavor to show the distinction when I come to the classification of storms.
The difference of seasons in this country, and over the entire northern hemisphere, is often very great. In a remarkable work of a remarkable man—“A Brief History of Epidemic and Pestilential Diseases,” by Noah Webster, published in 1799, 2 vols.—a history of the weather for about two centuries—1600 to 1799 inclusive, is given generally, and then in a tabular form. Those who think that every considerable extreme which occurs exceeds any thing before known, will do well to consult that work. Droughts are described, where “there was not a drop of rain for three or four months, and cattle were fed upon the leaves of the trees.” Winters, so intensely cold that the thermometer fell to 20° below zero, at Brandywine; or so mild that there was little frost, and people upon Connecticut River plowed their fields, and thepeach trees blossomed in Pennsylvania in February. These extremes generally existed in Europe and America at the same time, but occasionally they were opposite and alternate. Says Mr. Webster, in summing up the facts (vol. ii. p. 12): “It is to be observed that in some cases a severe winter extends to both hemispheres, sometimes to one only, and in a few cases to a part of a hemisphere only. Thus in 1607-8, 1683-4, 1762-3, 1766-7, 1779-80, 1783-4, the severity extended to both hemispheres. In 1640-41, 1739-40, and in other instances, the severe winter in Europe preceded, by one year, asimilar winter in America. In a few instances, severe frost takes place in one hemisphere during a series of mild winters in the others; but this is less common. In general, the severity happens in both hemispheres at once, or in two winters, in immediate succession; and, as far as this evidence has yet appeared, this severity is closely attendant on volcanic discharges, with very few exceptions.”
It will be seen that Dr. Webster (LL.D. and not M.D., and therefore the remarkable character of the work) attributes great influence to earthquakes and volcanic action. Probably he is correct in this. The present active volcanic action of the western hemisphere is nearly all within the trade-wind region, from Mexico to Peru inclusive. The West India islands are of volcanic origin, and the influence of volcanic action is not confined to a concussion of the earth, or the eruption of mud and lava. Its connection with magnetic action, and disturbance, is unquestionable. But whether they operate to increase or diminish the trades, and the extent to which they induce violent electric action and storms within and without the tropics, is a question which further observation must determine. The ripples of the ocean, compared by Lieutenant Banvard to that of a “boiling cauldron, or such as is formed by water being forced from under the gate of a mill-pond,” are met with in the vicinity of volcanic islands, where hurricanes and water-spouts originate, and have been observed to precede storms, and be connected with a falling barometer. But whether they are volcanic ormagneto-electric, it is difficult to determine. Dr. Webster remarks, as the result of observation, during the 17th century, that earthquakes had a N. W. and S. E. progression in the United States, and especially in New England. In a recent article, Professor Dana has examined, with great ability, the general and remarkable trending of coast lines, groups of islands, and ranges of mountains, from N. E. to S. W. and from N. W. to S. E. (American Journal of Science, May, 1847.)
The line of magnetic intensity, which connects our magnetic pole with its opposite, is now upon this continent nearly a N. W. and S. E. line, and the pole is fast traveling to the west. It may, and probably will yet, be established, that there is an intimate connection between the cause of volcanic action within the earth, to which the upheaval of the N. W. and S. E., and N. E. and S. W. ranges were due, and of magnetic action without, and between both, and the cause ofthe S. E. extensionof our summer storms and belts of showers and barometricwaves, and thepeculiar N. W. wind. Our limits do not permit us to pursue the subject.
Much influence upon the weather has been attributed to the spots upon the sun. These spots are supposed to be breaks or openings in the luminous atmosphere or photosphere of the sun, through which its dark nucleus body is seen. Counselor Schwabe, of Dessau, has made them his study since 1826, and has arrived at some singular results. They seem to be numerous—in groups—and to appear periodicallywith minima and maxima of ten years. As the result of his observations, from 1826 to 1850, he gives us the following table and remarks:
“I observed large spots, visible to the naked eye, in almost all the years not characterized by the minimum; the largest appeared in 1828, 1829, 1831, 1836, 1837, 1838, 1839, 1847, 1848. I regard all spots, whose diameter exceeds 50”, as large, and it is only when of such a size that they begin to be visible to even the keenest unaided sight.“The spots are, undoubtedly, closely connected with the formation of faculæ, for I have often observed faculæ, or narben, formed at the same points from whence the spots had disappeared, while new solar spots were also developed within the faculæ. Every spot is surrounded by a more or less bright, luminous cloud. I do not think that the spots exert any influence on the annual temperature. I register the height of the barometer and thermometer three times in the course of each day, but the annual mean numbers deduced from their observations have not hitherto indicated any appreciable connection between the temperature and the number of the spots. Nor, indeed, would any importance be due to the apparent indication of such a connection in individual cases, unless the results were foundto correspond with others derived from many different parts of the earth. If the solar spots exert any slight influence on our atmosphere, my tables would, perhaps, rather tend to show that the years which exhibita larger number of spotshad asmaller number of fine daysthan those exhibiting few spots.”
“I observed large spots, visible to the naked eye, in almost all the years not characterized by the minimum; the largest appeared in 1828, 1829, 1831, 1836, 1837, 1838, 1839, 1847, 1848. I regard all spots, whose diameter exceeds 50”, as large, and it is only when of such a size that they begin to be visible to even the keenest unaided sight.
“The spots are, undoubtedly, closely connected with the formation of faculæ, for I have often observed faculæ, or narben, formed at the same points from whence the spots had disappeared, while new solar spots were also developed within the faculæ. Every spot is surrounded by a more or less bright, luminous cloud. I do not think that the spots exert any influence on the annual temperature. I register the height of the barometer and thermometer three times in the course of each day, but the annual mean numbers deduced from their observations have not hitherto indicated any appreciable connection between the temperature and the number of the spots. Nor, indeed, would any importance be due to the apparent indication of such a connection in individual cases, unless the results were foundto correspond with others derived from many different parts of the earth. If the solar spots exert any slight influence on our atmosphere, my tables would, perhaps, rather tend to show that the years which exhibita larger number of spotshad asmaller number of fine daysthan those exhibiting few spots.”
These observationsseemto show that the spots exert no influence upon the weather, and to be satisfactory. But, perhaps, they are not entirely so. No effect would, of course, be expected from day to day, and perhaps the annual mean may not be seriously disturbed, and yet the spots may seriously affect the seasons. Popular tradition has fixed upon certain periods, of 10, 20, and 40 years, for the return of winters of unusual severity; and the tables of Mr. Webster, and other facts, show that it is not wholly without foundation. If we, and those we have cited, are not mistaken in most of the views expressed, the natural effect of a partial interception or failure of the sun’s rays, by or from the existence of the spots, would be to decrease the exciting power of the solar rays upon terrestrial magnetism, and, as a consequence, the volume of the trades and their amount of moisture. This would increase themeanheat of the summer in the temperate zone—for thelessthe volume of trade, the less precipitation and variable wind, and succeeding polar waves of cooler air, and the greater mean heat. On the other hand, the same cause, and the feebler heating power of the sun’s rays, would make the winters more severe, both from an absence of a portion of heat, derived directly from the sun’s rays, and a less mitigating influence, from the action of the trade, by reason of its decreased volume. So, too, the absence of spots, and a more powerful influencefrom the solar rays, may gradually carry the machinery further north in summer, and further south in winter, and thus make theseasons extremewithout seriously disturbing the mean of the year. And both these may occur in a more marked degree over our intense magnetic area than in Europe. I am satisfied that they do so occur. That the partial failure of the sun’s rays limits the transit of the machinery, and the volume of the trades during the latter half of the decade, and extends the transit and increases the volume during the first half, producing an occasional severe summer drought and severe winter, in the warmest portion of the decade. And that the variations correspond with the difference in the character and number of the spots in different decades, and hence the longer and shorter periods.
Turning to the tables of Dr. Webster, we find that a general tendency to extreme seasons does seem to exist from the 6th to the 10th year of every decade, and especially of every alternate decade. The periods of 1707-8, 1728, 1737 and 1739, 1749-50, 1758-9, 1779-80, 1798-9, are those in which the tendency was seen most decided. These tables are very general. The thermometer was not perfected till about 1700, and did not get into general use before 1750. There were very few meteorological registers kept, or accessible to Dr. Webster. Hence he was obliged to resort to such other sources of information as were open to him, and such statements as he found are not always entirely reliable. The oldest inhabitant is apt to express himself very strongly respecting present extremes, and failsomewhat in his recollection of those which have past. Still his tables afford general and obvious evidence of the regularity of those periodic conditions.
Still more definite evidence is found in the meteorological tables of Dr. Holyoke and Dr. Hildreth, andan account, by Dr. Hildreth, of the seasons when the Ohio River was closed or obstructed by ice, found in Silliman’s Journal, new series, vol. xiii. p. 238.
Thus, we have, from the tables of Dr. Holyoke, the following annual means, from 1786 to 1825, inclusive. I have arranged them in periods of five years. It will be seen that there are three peculiarities observable. First, a marked difference between the first and second periods of the decade, corresponding, generally, with the presence or absence of the spots. Second, a difference in the mean of the decades which may well be supposed to correspond with the difference in the number or size of the spots since a like difference is observable in number and size, and the time when they reached their maxima and minima, in the table of Schwabe. And, third, there are occasional single cold years during the warm period, and these correspond with what the tables of Dr. Webster show for both the sixteenth and seventeenth centuries. In relation to this, it should be remembered that volcanic action is a frequent and powerful disturber of the regular action of terrestrial magnetism, and that the extremes, for that reason, are frequently meridional or local and alternating; and to that cause very great extremes, and marked exceptions, may be due, notwithstanding the spots upon the sun may exert an influence in producing hot summers and cold winters toward the close of each decade. Thus, to select an instance to illustrate this and explain an anomaly: The coldest season during the whole period, embraced in the following tables, is that of 1812. This occurs during the decrease ofspots, and the warm half of the decade. Turning to the table of volcanic action, and of earthquakes, found in the Report of the British Association for 1854, we find that year was remarkable for earthquakes in the United States and South America. In December, 1811, earthquakes commenced in the valley of the Mississippi, Ohio, and Arkansas, felt also at places in Tennessee, Kentucky, Missouri, Indiana, Virginia, North and South Carolina, Georgia, and Florida, though not so severely east of the Alleghanies,which continued until 1813. About the same time they commenced in Caraccas, and, in March, 1812, became severe over the greater portion of the northern section of South America, and in the Atlantic. No such general and continued succession of earthquakes occurred during the other periods embraced in the tables, and the mean of the following five years was very low, embracing the memorable cold summer of 1816.
The tables of Dr. Hildreth, from 1826 to 1854, inclusive, furnish, generally, evidence of a like character. There are, however, an anomaly or two whichwill be observed. From 1826 to 1830, the mean is high during the period when spots were at a maximum. But that maximum embraced a much less number of spots than the two succeeding ones. A contrast appears in the tables of Dr. Hildreth, during the early period, for Dr. Holyoke’s register, for 1827, puts itbelow the mean, but Dr. Hildreth’s one of thehighest of the half century. In 1835 commenced a period when the spots were much more numerous, and from 1835 to 1838, inclusive, the seasons were correspondingly below the mean. From that period to 1844 a gradual and slightly irregular rise took place, excepting the year 1843, when another cold year intervened. The table of earthquakes, published by the British Association, closes with 1842, and I have not access to any others. The occurrence of such cold years, in the warm period, at intervals during the two centuries previous, and in 1812, and onward, and evidently owing to increased volcanic action beneath the western portion of the northern hemisphere, justifies the belief that the low temperature of 1843 was owing to the same cause. The following are the means from the tables of Dr. Hildreth:
The observations of Dr. Holyoke were made at Salem, Massachusetts; those of Dr. Hildreth at Marietta, Ohio.
The following, in relation to the freezing of theOhio River, is evidence of a different kind, but shows the same general correspondence, and particularlythe mildness of the winters when there were few spots, and their severity from 1836 to 1838, inclusive, when the spots were most numerous:
1829.—River open all winter—some floating ice.1830.—River closed 27th January.1831.—Floating ice—closed 23d January—opened 20th February.1832.—Closed in December, which was a very cold month—opened January 8, and remained open all winter.1833.—Open all winter.1834.—Open all winter.1835.—Closed January 6—opened the last of the month—cold.1836.—Closed 28th January—opened 25th February.1837.—Closed from 8th December to 8th February. Cold year.1838.—Closed from 13th January to 13th March. Cold year.1839.—Closed from 6th December to 13th January.1840.—Closed 29th December—opened 15th January.1841.—Closed 3d January—opened 8th do.1842.—Open all winter.1843.—Closed 28th November—opened 5th December—open all the rest of the winter.1844.—Open all winter.1845.—Open all winter.1846.—Closed 5th December—opened again a few days—closed again on the 26th. It is not stated how long it remained closed.1847.—Open all winter.1848.—Much floating ice, but not closed—heavy rains and floods.1849.—Floating ice in January, but not closed.1850.—Floating ice, but not closed.1851.—Open all winter—a little ice.(December in the above table, means December previous).
This is more reliable as to the winter season than the tables of annual means—although the evidence they afford, making due allowance for the exceptions, is very striking.
I shall return to this part of the subject again.
But there is other evidence of the influence of these spots. Their connection with the irregularmagnetic disturbance of the earth has been distinctly traced. Colonel Sabine, President of the British Association, in his opening address, September, 1852, after reviewing the recent discoveries in magnetism, says:—
“It is not a little remarkable that this periodical magnetic variation is found to be identical in period, and in epochs of maxima and minima, with the periodical variation in the frequency and magnitude of thesolar spots, which M. Schwabe has established by twenty-six years of unremitting labor. From a cosmical connection of this nature, supposing it to be finally established, it would follow that the decennial period, which we measure by our magnetic instrument, is, in fact, a solar period, manifested to us, also, by the alternately increasing and decreasing frequency and magnitude of observations on the surface of the solar disc. May we not have in these phenomena the indication of a cycle, or period ofsecular change in the magnetism of the sun, affecting visibly his gaseous atmosphere or photosphere, and sensibly modifying the magnetic influence which he exercises on the surface of our earth?”—American Journal of Science, new series, vol. xiv. p. 438.
“It is not a little remarkable that this periodical magnetic variation is found to be identical in period, and in epochs of maxima and minima, with the periodical variation in the frequency and magnitude of thesolar spots, which M. Schwabe has established by twenty-six years of unremitting labor. From a cosmical connection of this nature, supposing it to be finally established, it would follow that the decennial period, which we measure by our magnetic instrument, is, in fact, a solar period, manifested to us, also, by the alternately increasing and decreasing frequency and magnitude of observations on the surface of the solar disc. May we not have in these phenomena the indication of a cycle, or period ofsecular change in the magnetism of the sun, affecting visibly his gaseous atmosphere or photosphere, and sensibly modifying the magnetic influence which he exercises on the surface of our earth?”—American Journal of Science, new series, vol. xiv. p. 438.
I think it may fairly be inferred, that although these spots do not occasion the “cold spells” and “hot spells,” and other transient peculiarities, they do materially affect themeantemperature of the year, and exert an obvious influence when at their maxima; and there is a tendency to an increase of the heat and dryness of summer, and the severity of winter, at the periods named, in our excessive climate, and a well-established connection between the spots and magnetic disturbances and variations.
Popular opinion has ever attributed to the moon a controlling effect upon the changes of the weather. If it be dry, a storm is expectedwhen the moon changes; or if it be wet, dry weather. Such popularopinions are usually entitled to respect, and founded in truth. But every attempt to verifythis opinion, by careful observation and registration, has failed. Weather-tables and lunar phases, compared for nearly one hundred years, show four hundred and ninety-one new or full moons attended by a change of the weather, and five hundred and nine without. The celebrated Olbers, afterfifty years of careful observationand comparison, decided against it. So did the more celebrated Arago, at a more recent date—summing up the result of his observations by saying—“Whatever the progress of the sciences, never will observers, who are trustworthy and careful of their reputation, venture to foretell the state of the weather.” Still, the moon may influence the weather, though she may not effect changes at her syzygies or quadratures, and this subject should not be too summarily dismissed. That the moon can not effect changes at the periods named seems philosophically obvious. She changes, for thewhole earth, within the period of twenty-four hours; yet, how varied the state of things on different portions of its surface. The equatorial belts of trades, and drought, and rains, cover from fifty to sixty degrees of its surface, and know nothing of lunar disturbance. The extra-tropical belt of rains and variable weather moves up in its season, uncovering 10°, or more, of latitude, and admitting the trades and a six months’ drought over it, as in California, regardless of the moon. Under the zone of extra-tropical rains, even upon the eastern part of the continent of North America, “dry spells”and “wet spells” exist side by side; the focus of precipitation is now in one parallel, and now in another—stormsexisthereandfair weather there, on the same continent at the same time; and as the moon’s rays in her northing pass round the northern hemisphere during the twenty-four hours, they, doubtless, pass from ten to thirty or more storms, of all characters and intensities, moving in opposition to her orbit—and as many larger intervening areas of fair weather, not one of which are indebted to her for their existence, or “take thought of her coming.”
The storm, which originates in the tropics, pursues its curving way now N. W., then N. E., and again north, to the Arctic circle, and, perhaps, around the magnetic pole, over gulf, and continent, and ocean,occupying one third the time of a lunation, and two changes, perhaps, in its progress, without any perceptible or conceivable influence from her. Yet every inhabitant of mother-earth, influenced bycoincidences remembered, and uninfluenced byexceptions forgotten, looks up within his limited horizon, and devoutly expects from the agency of some phase of the moon, a change for the special benefit of hisdotupon the earth’s surface. Upon how many of these countless dots is the moon at a particular phase, or relative distance from the sun, to change fair weather to foul, or foul to fair? Upon none. The storms keep on their way;—the wet spells, and the dry spells, the cold and the hot spells alternate in their time, and though the moon turns toward them in passing, her dark face, her half face, or her full orb (thegifts of the sun, which confer no power), they do not heed her. They are originated, and are continued, by a more potent agent. They are the work of an atmospheric mechanism, asceaselessin its operation astime, asregularas theseasons,as extensive as the globe.
Indeed, it seems as if it was expressly designed by the Creator that the moon should not interfere materially with this atmospheric machinery. She is the nearest orb; her influence would be controlling and continuous; would follow her monthly path from south to north, and with changes too violent, and intervals too long; and would interfere with the regular fundamental operation in the trade-wind region, where she isvertical. Aside from the attraction of gravitation, therefore, she seems to have been so created as to be incapable of exerting any influence. She is without an atmosphere; the rays which she reflects are polarized, and without chemical or magnetic power; and, if it be true that Melloni has recently detected heat in them, by the use of a lens three feet in diameter, which could not previously be effected, its quantity is exceedingly small, and incapable of influence. Doubtless, the attraction of her mass is felt upon the earth, as the tides attest; and upon the atmosphere as well as the ocean. But the atmosphere is comparativelyattenuated, and exceedingly so at its upper surface. Her attraction, therefore, although felt, is not influential. She seemed, to Dr. Howard, to produce in her northing and southing, a lateral tide which the barometer disclosed,but owing to the attenuated character of the atmosphere, neither the sun nor moon create an easterly and westerly tide, that is observable, except with the most delicate instruments. Sabine is believed to have detected such a tide by the barometer, at St. Helena, of one four thousandth of an inch. But even thisinfinitesimal influencemay prove an error upon further investigation. There is a diurnal variation of the barometer, but it is not the result of her attraction, for it is not later each day as are the tides, exists in the deepest mines as well as upon the surface, and is demonstrably connected with thegroupofdiurnalchanges produced by the action of the sun-light and heat upon the earth’s magnetism.
Can the lateral tide, if there be one, affect the weather? for in the present state of science it seems entirely certain that the moon can exert an influence in no other way.
If the received idea of many, perhaps most, meteorologists, on which all wheel barometers are constructed, that ahigh barometernecessarily producesfair weather, and alow one foul, were true, she certainly might do so. But that idea can not be sustained, and there is no known certain influence exerted by the moon upon the weather, in relation to which we have any reliable practical data.
Humboldt appears to have adopted the impression of Sir W. Herschell, that the moon aids in the dispersion of the clouds. (Cosmos, vol. iv. p. 502.) But the tendency to such dispersion is always rapid during the latter part of the day and evening, whenthere is no storm approaching, and the full moon renders their dissolution visible, and attracts attention to them. The Greenwich observations, also, carefully examined by Professor Loomis, fail to confirm the impression of Herschell and Humboldt, and those eminent philosophers are doubtless in this mistaken.
From this general and somewhat desultory view of the general facts, which bear analogically upon the question, no decisive inference can be drawn in relation to the seat of the primary influence which produces the atmospheric changes. The preponderance is in favor of the magnetic, or magneto-electric, action of the earth. We must come back to our own country and grapple with the question at home.
Before proceeding to do this, however, it may be well to look at some theories which have been advanced, and to a greater or less extent adopted, and at their bearing upon the question.
The calorific theory is at present the prevailing one in Europe and in this country. Meteorologists there and here refer all atmospheric conditions and phenomena to the influence of heat. The principal applications of that theory have been considered. But within the last few years the elasticity and tension of the aqueous vapor of the atmosphere have received much attention, as exerting an auxiliary or modifying influence. Professor Dove, of Berlin, who ranks perhaps as the most distinguished meteorologist of that continent, attributes barometric variations tolateral overflows, and, in the upper regions, resulting from the elevation of the atmosphere by expansion; and in this view meteorologists of Europe seem generally to acquiesce. In an article sent to Colonel Sabine, and recently republished in the American Journal of Science, January, 1855, in thus attempting to account for the annual variation of barometric pressure, which occurs in Europe and Asia, and, indeed, over the entire hemisphere. He says: