Art. XII. Observations upon the prevailing Currents of Air in the State of Ohio and the Regions of the West.
Art. XII. Observations upon the prevailing Currents of Air in the State of Ohio and the Regions of the West, by Caleb Atwater, Esq. of Circleville, Ohio; in Letters addressed to His Excellency De Witt Clinton, LL. D. Governor of the State of New-York, and President of the Literary and Philosophical Society.
(Communicated for the American Journal of Science, &c.)
Circleville, Ohio, July 23, 1818.
Dear Sir,
With pleasure, I acknowledge the receipt of the circular letter bearing date the 5th instant, which you addressed to me, for which you will be pleased to accept my warmest acknowledgments for yourself personally, and the Philosophical Society of which you are the president. To answer all the questions which are put to me in that letter, is not at present within my limited means, either as it respects the leisure or the ability. I shall therefore, at this time, confine myself to "observations upon the prevailing currents of air in the state of Ohio."[41] These observations will be wholly founded on personal experience, during the four years in which I have traversed this state, from Lake Erie to the Ohio river, whilst attending on the several courts, in all seasons and in all the changes of weather.
The prevailing currents of air, one of which generally obtains in Ohio, are three.
The first comes from the Mexican Gulf, ascending the Mississippi and its larger tributary branches quite to their very sources.
The second proceeds from the back of mountains to the west, descends the Missouri to its mouth, and then spreads over a vast extent of country.
The third comes down the great northern and northwestern lakes to the south end of Lake Michigan and the southern shore of Lake Erie, where it spreads over the region of country lying to the south of them.
That current of air which comes from the Mexican Gulf, is warmer, and perhaps more moist, than any other which prevails here. After a few days prevalence, it uniformly brings rain along with it. That this current of air should be very warm may be readily conceived, when we reflect that it comes from a hot tropical region; and that it should be very moist, excites no surprise, when it is considered, that in its passage upwards it passes wholly over water, and through the warm mists and fogs constantly ascending from the Mississippi and its tributaries. This current prevails much more along the Ohio river than it does at any considerable distance from it. One consequence is, that the climate in the immediate vicinity of the Ohio river is warmer, than it is either north or south of it, unless you go to the southward a considerable distance. Other causes may, and probably do, in a greater or less degree, contribute to produce this result, and I will here state them:
First, The Ohio runs on a surface less elevated above the sea than the country, either north or south of it, but this difference is trifling through the whole of the sandstone formation. This formation prevails from the head of the Ohio to Aberdeen, which is opposite to Marysville in Kentucky, at least two-thirds of the distance which that river washes the southern shore of this state. The reason is obvious, because there are no falls in a sandstone formation.
Another cause which contributes to produce a warmer climate, especially in the winter season, in the valley of the Ohio, is, that several considerable streams which empty themselves into the Ohio, have their sources on the highlands, a great distance to the south of it; for instance, the Great and Little Sandy, and the Great and Little Kenhawa, which descending from a warm region of country, their waters contribute to keep the Ohio open in winter.
But these causes are by no means sufficient to produce the one half of the comparative warmth of climate observable in the immediate vicinity of this invaluable river. To prove that the climate is much milder in the southern than in the northern part of this state, I will proceed to mention several facts, which have fallen under my own observation.
In the latter part of last February I was at the town of Delaware, on the Whetstone Branch of the Scioto river, between eighty and ninety miles south of Lake Erie, and twenty-five miles north of Columbus, the seat of government, which is near the centre of the state, where I saw a number of gentlemen direct from Detroit, by the way of Lower Sandusky, who informed me that the snow at that time was eighteen inches in depth and upwards all along the lake shore, but gradually decreased as they came south until they arrived at Delaware. At that place it was then about twelve inches deep in the open fields, and somewhat deeper in the woods. I descended the road along the Whetstone to Columbus, the snow decreasing in depth all the way as I proceeded. At Columbus it wholly disappeared in the fields, and only ice was found in the road, which also decreased until I came to the Big Walnut Creek, thirteen miles south of Columbus, where it disappeared, and the road began to be muddy. As I still proceeded south, the mud increased in depth until I came to Chillicothe, about thirty-two miles south of Big Walnut, where the frost was entirely out of the ground, and the roads were almost impassable. As I still descended southward, along the Scioto, I found that at Piketon, on the Scioto, nineteen miles south of Chillicothe, the road had considerably improved. I proceeded onwards to Portsmouth on the Ohio river, at the mouth of the Scioto, about twenty-six miles south of Piketon, where the ground was entirely settled, and the innkeeper, where I lodged, was making his garden, sowing his sallad seed, and planting his peas. This journey was performed in three days, and in travelling only one hundred and fifteen miles from north to south, this extraordinary difference of climate was observed.
A traveller may leave Portsmouth when the farmer is beginning to hoe his corn the first time, and travel with good speed to Delaware, and find the husbandman just beginning to plant.
Instances which have fallen within my own personal observation might be multiplied to a great extent, but a few may suffice.
Generally speaking, there is a difference in the beginning and ending of the warm season of about two weeks between Portsmouth and Delaware, or of three weeks between the former place and Lower Sandusky.
In relation to the warmth of the climate, I will state two other facts, originating, as I believe, in the prevalence of the southern current of air from the Mexican Gulf along the Ohio river.
First, In the summer months the paroquet ascends the Scioto more than one hundred miles from its mouth, and until within a few years past, wintered at Miller's Bottom, and at other places along the banks of the Ohio, near its great southern bend in latitude 38° north, in Gallia and Lawrence counties, in the state of Ohio. I have seen them there in all the winter months in considerable numbers, but few however now winter there; and probably if the cold northwestern current of air from the great lakes becomes more and more prevalent in the winter months, these birds will migrate altogether to a more southern clime.
Are these birds found as far to the north on the east side of the Alleghany by at least three degrees? Monsieur Volney, Mr. Jefferson, and others, say not. It has been denied that this fact proves any thing more than that this bird frequented these parts in quest of its favourite food. This food is grass and other vegetable matter in summer, and the cockle bur, and the balls of button-wood, or, as by a perversion of language, it is called in this country sycamore.[42] But this bird may find its favourite food as well east as west of the Alleghanies. The grasses and trees alluded to, flourish as I have observed in forty-five degrees of north latitude, and I am credibly informed that they are abundant as far north as Quebec, and even around Hudson's Bay. Wherever waters run and trees grow on their banks, (if low and wet,) on the American continent, even as high as eighty degrees of north latitude, there the paroquet may find its food in abundance.
Another fact tending to establish the same point is, that the reed cane, before this country was much settled, grew in a higher latitude by several degrees on this than it did on the other side of the Alleghany mountains. It has indeed been said, that this cane was never found north of the Ohio, nor above the mouth of the Big Sandy River, which empties into the Ohio, on the line which separates Virginia and Kentucky. This however is incorrect; for within a few years it was growing in abundance at Miller's Bottom, twenty-six miles above the mouth of Big Sandy. It grew at Lancaster, on the Hockhocking, northward of the mouth of the Big Sandy, in a direct line, at least one hundred and fifty miles, and it now grows on the Whetstone branch of the Scioto, more than two degrees of latitude above the lowest bend of the Ohio, which is at the mouth of the Big Sandy. Before the white people settled there, I have every reason to believe, that the cane grew in great plenty at Delaware, where there are more signs of buffaloes than at any other place within my knowledge. It has been conjectured, that the seed of the cane was brought down and scattered by the Big Sandy; but granting this, in what way could that stream carry this seed up the Hockhocking and Scioto to their sources? to places several hundred feet above the highest freshes ever known in this country? With a knowledge of these facts, cast your eye at the map of Ohio. Proofs within my reach might be multiplied to a much greater extent, but they are probably unnecessary.
But another current of air prevails here, especially in the cold months, coming from the mouth of the Missouri, which is a little to the south of west of this place. This current is colder than the preceding one, and though moist, yet not as much so as the one already described. It prevails generally in October and November, before our warm weather is over, and produces frosts and a chilly dampness, and what I have observed nowhere else, especially on the east side of the Alleghanies, it produces a kind of faintness at the breast.
People of delicate habits, coming here from the northern and eastern states, uniformly complain of this faintness. It is not perhaps extraordinary that this current of air should be cold, proceeding as it does from a high northern latitude, along the great chain of rocky mountains in the northwest; that it should be moist, and perhaps also that it should affect the animal economy unpleasantly, may possibly be attributed to its passing such a length of way over the waters of the Missouri, and the wet prairies and barrens lying so extensively between us and the head waters of that stream. The luxuriant vegetation which covers these prairies and barrens at that season of the year, begins to putrefy, and fills with unhealthy exhalations every gale of wind which passes over them.
At the mouth of this river (Missouri,) which is in about latitude 38° north, this current of air is extremely cold in the winter months. It diverges from this point, and produces extreme cold at a considerable distance to the south of it on the Mississippi river. General Rector, the present surveyor general of the United States, who keeps his office at St. Louis, informs, that he has known the Mississippi at St. Genevieve, in latitude about 37°, so firmly covered with ice in one night, as to be able to bear horses and cattle the ensuing day. This circumstance must have been owing to the sudden change of the current of air from south to the northwest, descending the Missouri river from the cold regions at its sources.
From several gentlemen, residents for many years in Illinois and Missouri Territories, I have been informed, that changes of weather in that region of country are, especially in winter, very frequent and great; that one day the moist south wind from the Mexican gulf will prevail, and produce quite warm and mild weather for the season; on the very next, or frequently in the latter part of the same, the current of air from the sources of the Missouri will prevail, and block up the streams with ice.
There is a third current of air which prevails during our winter months, more and more, annually, as the country becomes cleared of its forests in the direction alluded to; it proceeds from the great lakes to the northwest of us, and even beyond them. Proceeding as it does from the north and northwest of lake Superior, and crossing the great expanse of water in this direction, it rushes down these great lakes to the south end of lake Michigan in latitude about 41° north, diverges from that point, and spreads over the immense regions lying to the south, where the air is more rarefied by reason of its warmer climate. This current of air brings along with it intense cold, and extended last winter even to New-Orleans, where the snow fell to such a depth, that sleighs were seen passing in every part of the city. The more the forests are cleared away between any place in this country and the northern lakes, the more this cold current of air will prevail. This current also diverges from the southern shore of Lake Erie, but is not so strong as that part of it which diverges from the south end of Michigan, and of course does not extend as far to the south. When this part of this state was first settled, this current of air was hardly felt at this place, and then only for a short time in the winter months, and hardly ever reached the Ohio river; but last winter it continued three weeks at one time, and produced good sleighing; and also caused rheumatisms, pleurisies, peripneumonies, &c. which proved mortal to some. In this place, which is in latitude about 39° 20′ north, the thermometer of Fahrenheit, hanging in an entry of a dwelling-house with closed doors, sunk to 24 degrees below zero. This extreme cold may be attributed to general, rather than to local causes, and it may be said that the winters all over the world have been colder of late years than formerly. But on the very day, when it was thus cold, (if newspapers can be believed) a great number of vessels put to sea from Reedy Island in the Delaware below Philadelphia, and about thirty sail of vessels went to sea from New-York harbour.
All our streams were at the same time bridged with ice of great firmness as well as thickness, and continued to be so for a considerable time afterward, until the warmer current of air from the south prevailed over the current from the lakes. It will be proper, and may be necessary, here to state, that the latitudes of several places in this country are very different from what you would be led to believe from examining any map or chart now or ever in existence. For instance, Lake Michigan extends farther south than Fort Wayne, which place by actual survey is in this state; St. Louis is not 38°, and the most southern point or bend of the Ohio river, is not more than latitude 38° north. I state merely what I am informed of by those who have ascertained these facts by actual observation and survey. The place opposite the mouth of the Big Sandy, is nearly as for south as Lexington in Kentucky. The south end of Michigan lake ought to be laid down on the map 41° north. Prevailing currents of air (not every breath of air which moves over the surface) I have attempted to describe. It may be well enough, however, to mention some other currents which sometimes prevail for a few days. And here I will mention what our oldest settlers along the Ohio have observed, that is, that whenever in a dry time, there is a current of air proceeding down the river for three or four days in succession, the current from the Gulf of Mexico is sure to drive it back with redoubled force, and after blowing a day or two, it is equally sure to bring rain with it. It is easy to assign a cause for it; for meeting the trade winds in the Gulf, it is driven back with redoubled violence to the sources of the larger streams which empty themselves into the Gulf.
When a thunder storm, proceeding in either a western or eastern direction, as the case may be, happens to strike a large water-course running either north or south, and when also there happens to be a large branch emptying into the stream, within a few miles either above or below the point where the storm approaches it, I have uniformly observed the storm to cross the large stream at the point where the large branch unites with it, and ascend the branch. Where there are two large tributaries about equi-distant from the point of approach, the storm frequently divides and follows each of them. The reason why it should be so, this is not the place to discuss; but the Wisdom and Goodness which so ordered it, are too apparent to every rational mind to be overlooked. It may be asked if the difference in latitude and elevation between the Ohio and lake regions of country, does not produce a great difference in the climates of those respective regions? These causes certainly produce some difference, but not all. It is my object to establish facts, rather than any favourite theory. The difference of latitude between the Ohio river at the mouth of the Scioto, and lake Erie at the mouth of the Maume or Sandusky, is nearly three degrees, and the difference of elevation above the sea is trifling, if any. From the mouth of the Scioto to Columbus, about 90 miles in a direct line, the water, where there is what is commonly called a ripple, runs briskly, and these ripples happen, perhaps, one to a mile; but they are in a sandstone region, and the fall of course is trifling.
Let us suppose then, that the river Scioto descends one hundred feet from the mouth of the Whetstone, which empties into that river at Columbus, to the Ohio, and that the Whetstone which runs through a limestone formation, descends another hundred feet, which would make Upper Sandusky two hundred feet higher than the Ohio river. From this highest ground between the Ohio and the lake, it is a well-known fact, that the land descends towards the north much more in a given distance, than it does towards the south, and the distance is not half as far. The Maume and other streams putting into the lake, are full of rapids. Admitting for argument's sake, that the Sandusky or Maume descend only 100 feet, then the surface of the lake is 100 feet higher than the Ohio river. Would three degrees of latitude, and 100 feet greater elevation produce three weeks difference in the seasons? Is there that difference between Baltimore in Maryland, and Wilkesbarre in Pennsylvania? Is there that difference between New-York and Fort Edward on the Hudson? It is believed that there is not one half that difference.
I have referred but little to thermometers, because they are kept in so many different situations by their owners, that I have known no less than 8 degrees of difference between several of them kept in one town, within almost a stone's throw of each other, at one and the same moment of time.
Every allowance being made for other causes, I am still of the opinion that the difference in the climates of the Ohio and lake regions of country, is to be attributed chiefly to the prevalence of different currents of air. The southern current rarely, if ever, reaches the northern lakes, and the northern, until lately, never reached the Gulf of Mexico. But as the country is cleared of its native forests, we may reasonably conclude this cold current of air will prevail more and more, until we shall have snow enough for sleighs, at least two months in every winter; the summers will be shorter, the extremes of heat and cold will be greater than at present, and those clouds which formerly obscured the sun almost continually during the summer months, will be chased away, and with them the pale cheek, the sallow hue, the oppression at the breast, and the difficulty of respiration, the headache, and the thousand ills which many of the first emigrants have experienced in our climate. We shall probably then have fewer diseases, and more acute ones. The storms will probably be fewer, more severe, and not continue as long as at present. There are still further views which might be taken of this subject, but they are left to abler pens and future observations.
Thus I have endeavoured to give my opinion on a subject of some interest to the present, as well as future generations; in doing which, I have not sought for flowers which might have been gathered by stepping out of my path, but the fruit rather of my own observation and experience: I have not wandered through the fields of imagination, invoking the poetic muse, but addressed myself chiefly
"To him who soars on golden wing,
Guiding his fiery-wheeled throne,
The cherub contemplation."