The Philosophy of the Weather Part 30

------------------------------------------- APRIL. MAY. JUNE. JULY.

1854. Mean. 1854. Mean. ------------------------------------------- 2.99 1.55 3.14 2.58 4.54 3.45 2.75 3.14 5.65 3.33 6.75 9.70 8.82 1.95 6.21 3.24 9.44 15.53 3.19 1.78 10.51 5.34 7.24 8.55 7.00 3.85 5.70 4.27 6.63 4.97 0.50 2.94 3.47 4.05 3.39 5.43 1.96 4.21 4.45 4.62 6.72 6.13 3.58 5.22 8.05 5.18 4.00 6.55 2.20 1.75 3.70 4.08 4.20 5.69 -------------------------------------------

It will be observed that in February the counter-trade and extra-tropical belt had moved up from Key West, and a drought, which sometimes intervenes between the concentrated counter-trade and the inter-tropical belt, appeared there in February and March. In April, the inter-tropical belt appeared at that point, and went on increasing till September. As the counter-trade commenced moving north in February, an increased precipitation above the mean commenced at all the more southern stations under the concentrated-trade--an earnest of that irregularity which followed, and marked the season as the most excessive of the century.

In March, the intervening drought appeared at the other posts on the peninsula, and also at Fort Moultrie, followed _much more closely than usual_, by the inter-tropical belt of rains. In April, the drought appeared at Fort Barrancas and Mount Vernon a.r.s.enal (the wave of precipitation having moved to the west), and slightly in comparison at Baton Rouge.

If now we look at the condition of things, _west_ and _north_ of the curving line of concentrated trade, from Fort Brown, at the mouth of the Rio Grande, in South-western Texas, through that State, the Indian Territory, Arkansas, Missouri, Kentucky, and Northern Pennsylvania, to the Atlantic, we find the thermometer every where in January below the mean.

The following table will show this, and the precipitation for that month and February:--

TABLE III.

------------------------------------------------------------------------ JANUARY. FEBRUARY. MARCH. ----------------------------------------------- 1854. Mean. 1854. Mean. 1854. Mean. ----------------------------------------------------------------------- _Western Texas._ Fort Brown 59.34 60.41 62.45 63.63 71.87 68.95 " Ewell 50.47 52.92 58.12 57.61 70.34 67.00 " Inge 47.24 49.46 56.04 55.39 67.54 62.63 _Indian Territory._ Fort Towson. 36.32 43.14 49.29 45.97 59.55 53.40 Forts Gibson, Was.h.i.+ta, and Arbuckle, in much the same proportions. _Arkansas._ Fort Smith. 33.92 40.18 47.01 43.89 57.01 51.58 _Missouri._ St. Louis a.r.s.enal. 25.47 31.44 36.66 33.43 46.10 42.30 _Kentucky._ Newport Barracks. 31.75 34.04 39.60 36.94 46.74 45.46 _Pennsylvania._ Allegheny a.r.s.enal. 29.08 29.25 33.49 31.16 40.36 39.02 _Delaware._ Fort Delaware 32.38 33.67 34.56 35.84 43.18 42.90 _New York Harbor._ Fort Columbus. 28.71 30.18 28.17 30.44 36.17 38.28 ------------------------------------------------------------------------

-------------------------------------- Rain in January. Rain in February.

-------------------------------------- 0.45 1.50 0.22 2.86 0.20 2.15 1.01 2.00 1.37 2.05 0.65 2.40 3.20 5.30 2.23 2.33 2.30 5.45 2.60 4.00 --------------------------------------

We find, also, from this and table first, that every where, except at Fort Brown, and upon the Atlantic coast, the temperature had risen above the mean in February.

The situation of the belt which supplied the western coast in winter, and its excess of precipitation, are also represented upon the cut. The intervening area was not without counter-trade and precipitation--the latter, of course, greatest over the area of intensity--but they were _comparatively_ less, as the tables will show.

The following cut and table show the situation of the concentrated counter-trade in March.

[Ill.u.s.tration]

TABLE IV.

------------------------------------------------------------------------ JAN. FEBR. MAR. APR. MAY. JUNE. JULY.

------------------------------------------------------------------------ Fort Barrancas, Pensacola Bay 3.45 5.55 7.21 0.50 3.47 3.39 5.43 Mean. 3.87 4.95 5.87 2.94 4.05 4.66 6.80 Baton Rouge, Louisiana 2.85 5.50 6.15 3.58 8.05 4.00 6.55 Mean. 5.26 4.91 4.68 5.22 5.18 5.52 7.42 Fort Towson, Indian Territory 1.01 2.00 5.10 2.22 Recr'd stops here.

Mean. 3.13 2.97 4.38 5.33 Fort Gibson, Indian Territory 0.30 1.43 7.83 3.16 7.67 2.80 0.21 Mean. 1.33 2.26 2.54 4.19 4.65 4.30 2.75 Fort Smith, Arkansas 1.37 2.05 7.05 6.55 6.25 2.26 1.02 Mean. 1.96 2.17 2.92 5.10 4.46 4.74 3.82 St. Louis a.r.s.enal 0.65 2.40 7.10 4.30 4.65 2.20 1.70 Mean. 1.93 3.37 3.82 4.16 4.88 6.94 0.04 Newport Barracks, Kentucky 3.20 5.30 8.10 2.10 (No Mean given.) ------------------------------------------------------------------------

We see from this table that its focus had extended west in Florida over Fort Barrancas, and over Baton Rouge in Louisiana; N. W. to Forts Towson and Gibson in the Indian Territory, and Smith in Arkansas; north to St.

Louis a.r.s.enal at St. Louis, and to Newport barracks in Kentucky; but it was spread over a larger surface east of the mountains. Its greatest progress for the month, was a west and north-west progress.

In April, we find it had progressed rapidly west and north-west, and its position is shown by the following cut and table.

[Ill.u.s.tration]

TABLE V.

------------------------------------------------------------------------ JAN. FEBR. MAR. APR. MAY. JUNE. JULY.

------------------------------------------------------------------------ Fort Riley, Kansas. 0.00 0.94 1.86 4.55 4.35 1.10 0.00 Fort Leavenworth, Kansas. 0.04 1.78 1.33 3.35 5.55 4.50 0.18 Mean 0.72 1.01 1.61 2.74 3.62 5.80 3.15 Alleghany a.r.s.enal, Pittsburgh 2.23 2.33 2.82 4.21 2.24 2.06 1.45 Mean 2.18 2.17 2.70 3.10 3.58 3.56 2.97 Fort Columbus, New York Harbor 2.60 4.00 0.70 8.80 7.70 2.20 1.90 Mean 2.78 2.92 3.44 3.33 4.78 3.46 3.17 Fort Independence, Boston 2.50 3.36 2.55 5.40 4.28 2.00 West Point. 3.52 5.04 2.81 10.53 2.00 1.62 Mean 3.50 3.44 3.71 4.55 6.18 4.79 ----------------------------------------------------------------------

We see, too, that both east and west of the mountains, its focus of precipitation was one month in advance of the mean. At all the stations where the greatest fall was in March, it should have been in April, and the fall at those points was greatly in excess of the usual quant.i.ty. And the same was true of stations reached in April. The concentrated trade, instead of spreading out, and precipitating over the whole south-eastern portion of the continent (its normal condition), was gathered into a wave of greater volume, resulting in greater precipitation, and was rapidly hastening its curve to the west over Texas, and to the north-west over the Indian Territory, and northward on its usual curve to the north and east of them.

The observations for April disclose another singular and instructive condition. The temperature, that had every where been above the mean in March, fell below it in April under the concentrated trade. And snow fell on three days in some localities, and four in others.

Along the Ohio River, it fell to the depth of 8 to 10 inches on the 17th, and east of the mountains to a greater depth on the 18th, one day later.

It fell to the depth of 4 inches at Marietta on the 29th also. Dr.

Hilldreth, American Journal of Science for March, 1855, says:--

"It is a singular fact that the deepest snow, 8 inches, fell on the 17th of April, and at the head waters about Pittsburg over a foot. Also, on the 29th of the month, at Marietta, 4 inches, a very rare occurrence." This depression of the temperature was quite general, but the fall of snow was local. The latter was north of a line drawn from Fort Laramie, at the base of the Rocky Mountains, in an E. S. E. direction--north of Forts Kearney and Leavenworth, and of St. Louis, but south of Newport barracks in Kentucky, and from thence to the Atlantic. Snow fell at every station north of this line, at no station south of it. The depression of temperature, however, was experienced over the continent, east of the Rocky Mountains, under, and south of, the belt of precipitation. Now what occasioned this general depression of temperature, and local fall of snow?

It will not do to say, as perhaps some calorific theorist may be inclined to say, because the concentrated trade had been carried up where it was cold, a month too soon; or that the sun had heated the land in advance of it, and drawn it up.

For, 1st, it might be asked how, if it was warm enough to draw it up, could it be cold enough to make it snow; or, 2d, how happened it to start, when, as we have seen, it was warmer than the mean under it, and colder than the mean to the north and west of it, when it commenced its journey?

But again, it snowed at posts north of the line, while the thermometer remained above the mean; and the thermometer fell below the mean down to Fort Brown in south-western Texas, and at Key West in the southern part of Florida; and what is more remarkable still, at Key West, Fort Barrancas, and every other south-eastern station, except Forts Brooke and Moultrie, it not only fell below the _mean_ of the month, but _below the actual temperature of March_. (See Table I.) At Forts Brooke and Moultrie it did not rise above that temperature. West of the Rocky Mountains the depression was not felt; nor at stations north, or north-west of the belt of precipitation.

It is obvious, the calorific theory can furnish no rational explanation of this matter; for the reason that, whatever the cause, it operated not only under, but south, and far south of the belt of precipitation. It could not have been spots upon the sun, or other general cause, for then it would have operated in New Mexico and California, and at the north-western stations. It operated most intensely in Florida and the South-Eastern States, which approach most nearly the volcanic areas of South America and the West Indies. I believe it to have been occasioned by volcanic action affecting the local magnetism of our intense area; but it is a most important development, and should be thoroughly investigated. We may find in it the key to the mysterious, but unquestionable, influence of volcanic upon magnetic action; and I hope the distinguished surgeon-general will cause the records of that month to be published "in extenso."

In May and June, the trade became more concentrated, a perfectly developed belt from the Rio Grande to the Lakes and British possessions, and doubtless to the Atlantic, with every where a central focus of excessive precipitation, gathering to itself in one vast wave the current that should have been spread out over the whole country; and leaving every where on its eastern and southern borders, down to the northern edge of the inter-tropical belt of rains--(which extended up to lines drawn from Baton Rouge to Charleston)--a _perfectly well developed_ and _defined drought_. That drought will long be remembered. The following cuts show, approximately, the location of the belt of precipitation and drought for those months, and the table which follows will show their correctness.

The tables also show that this wave was occasionally a double, or divided one--evinced by an intervening _partial_ precipitation. Tables IV., V., and VI., also show the commencement of the drought at the several stations, as the wave moved to the west and north.

[Ill.u.s.tration: MAY.]

[Ill.u.s.tration]

TABLE VI.

JAN. FEBR. MAR. APR. MAY. JUNE. JULY. AUG. SEPT.

Fort Brown 0.45 1.50 1.15 0.05 4.10 7.65 4.25 5.00 11.31 Mean 1.61 2.25 1.20 0.56 2.21 4.55 1.95 2.76 6.73 Ringgold Barracks 0.70 1.69 0.22 0.00 2.83 10.98 4.06 1.58 3.02 Mean 1.24 1.18 0.72 1.08 2.09 3.47 3.18 1.50 3.22 Fort Merrill 0.11 1.99 0.05 1.16 7.66 4.70 5.44 3.13 5.01 Mean 0.23 2.09 0.09 1.62 3.43 4.10 6.13 3.40 4.60 Fort Duncan 0.05 0.69 1.50 0.00 2.53 6.83 0.83 0.90 4.81 Mean 0.26 1.27 1.34 0.71 1.50 5.63 3.35 0.93 3.28 Fort Inge 0.20 2.15 3.00 0.75 3.88 2.09 0.97 1.67 4.80 Mean 0.64 2.21 1.79 1.26 3.01 5.38 3.66 2.02 2.21 Fort McKavet 0.01 0.77 2.10 0.28 3.72 0.15 2.91 0.04 3.86 " Belknap 0.11 1.10 1.42 1.75 4.97 8.33 0.00 0.75 1.53 " Ma.s.sachusetts, Northern New Mexico 3.93 0.24 2.14 2.61 1.53 Fort Kearney 0.23 1.33 1.87 2.56 4.15 5.40 3.51 1.18 4.60 Mean 0.50 0.48 1.55 2.68 6.57 4.36 5.07 2.62 1.83 Fort Laramie 0.18 0.40 0.80 3.98 4.46 3.67 3.26 1.27 1.60 Mean 0.27 0.71 1.37 1.93 5.39 2.95 1.83 0.92 1.33 Fort Ridgley 1.20 0.01 1.18 2.83 6.84 2.70 2.49 2.28 2.58 " Snelling 0.72 0.03 1.03 2.51 4.30 3.31 3.92 1.75 6.55 Mean 0.73 0.52 1.30 2.14 3.17 3.63 4.11 3.18 3.32 Fort Ripley 0.67 0.03 0.79 0.97 4.34 3.68 0.62 1.69 4.40 Mean 0.86 0.37 1.80 1.42 3.09 5.15 5.20 2.27 4.92 Fort Mackinac 2.59 1.23 1.56 1.04 2.65 6.35 5.67 4.26 3.22 Mean 1.25 0.82 1.14 1.21 2.32 2.81 3.20 2.87 2.97 Fort Brady 2.49 1.18 1.34 2.14 3.61 1.23 3.21 3.86 3.18 Mean 1.84 1.13 1.37 1.83 2.24 2.83 3.73 3.39 4.33 Fort Niagara 1.63 2.52 1.87 2.25 3.90 1.71 4.08 1.52 2.61 Mean 2.25 1.89 2.12 2.20 2.55 3.28 3.49 3.04 3.95

But the belt of trade continued its progress to the west and north, and during the months of July and August the drought extended in both directions, reaching, in August, from Mississippi, Alabama, Georgia, and South Carolina, to the Lakes, and from the Rocky Mountains to the Atlantic. Its position is shown by the following cut, and the position of the belt of precipitation by the following table.

[Ill.u.s.tration]

TABLE VII.

_Situation of the focus of Precipitation in July and August._

----------------------------------------------------------- JUNE. JULY. AUG. SEPT. OCT.

----------------------------------------------------------- _New Mexico._ Fort Thorne 0.08 2.23 6.01 3.50 0.00 Albuquerque 0.28 2.50 1.19 2.67 1.37 Santa Fe 0.32 4.11 3.86 4.06 2.50 Fort Defiance 1.24 3.94 5.24 3.47 0.62 " Yuma 0.00 0.01 2.37 0.17 0.30 San Diego 0.02 0.07 1.35 0.13 0.01 Fort Snelling, Minnesota 3.31 3.92 1.75 6.35 1.23 " Brady 1.23 3.21 3.86 3.18 3.40 " Mackinac 6.35 5.67 4.26 3.22 2.28 -----------------------------------------------------------

I have not s.p.a.ce for all the comment which this exposition is calculated to induce. The reader will not only find in it an explanation of the extraordinary character of the summer of 1854, but will see from the _means_, that it was but an _excessive development_ of an ANNUAL PHENOMENON,--THE PROGRESS OF A CONCENTRATED COUNTER-TRADE.

It is not necessary to follow with particularity the return transit. It required no great degree of sagacity to predict, at the time, that the drought would continue in the vicinity of New York till about the 10th of September. The return of the belt to that lat.i.tude, was not to be expected before that time, and the drought continued, in fact, until the 9th of September.

Its return progress was slow, and it was every where behind time. The autumn was warm, and so, indeed, were December and January, west of the area of magnetic intensity, although upon, and east of it, there was a depression in December. The retreating but lingering edge of counter-trade, with its excess of snow for the season, caught the Iron Horse, with its train and pa.s.sengers, upon the prairies of the west, and laid its embargoing hands upon them. Few, if any, can have forgotten the thrilling accounts which reached us from that section, of the sufferings endured by those who were thus embargoed for days and nights, far from the comfortable habitations of their fellow men.

But the return transit, though slow, was extreme, and February and March were exceedingly cold for the season. The transit to the north, again, did not commence as early as usual, and the spring was backward, and the summer cool. Both were without irregularity, and the season was productive. The following table exhibits the temperature on a line of posts, running north and south at the west, during the winter months of 1855, and will ill.u.s.trate what has been said.