Chapter XI: Front Matter (11)

_Coluber heterodon._ This viperine species, of which Latreille has formed a genus under the name of _Heterodon_, varies considerably in its markings, and like most of our serpents, is not constant in the number of its plates and scales, (126, 48-138, 42-141, 42, &c.) perhaps too much reliance has been placed upon colour, and upon the number of the plates and scales beneath the body, of the Ophidiæ generally. In the form of the anterior termination of the head, the _heterodon_ is remarkable, and a good specific character may be obtained from the orbital scales, which are eleven or twelve in number; the parabolic curve which passes through the eyes, and terminates at the maxillary angles, is also generally present. This same serpent was figured in Deterville's ed. of Buffon, under the name of _Coleuvre cannelee_. The _heterodon_ abounds in many sandy situations, and near the sea-shore. Several persons pursuing a pathway, passed within a few inches of one of them without his betraying any emotion, but the moment he perceived me advancing with my eye fixed upon him, he with a sudden exertion assumed a defensive attitude, by elevating the anterior portion of his body, flattening his head, and 3 or 4 inches length of his neck; these he waved with a steady and oblique motion from side to side, uttering at the same time an audible sibilation, he made no attempt to escape, and seemed absolutely fearless until taken. They have the habit of the vipera, but not the fangs. It seems to be synonymous with _Coluber simus_. This species is often called _mockeson_. Dr. Shaw's description of _Boa contortrix_ seems to indicate this species. Was he deceived by an erroneous reference to Catesby's figure of this Hog-nose? or by Forster's catalogue?

_Coluber punctatus._ A good diagnostic character of this species, in addition to the cervical cestus, rests in the triple series of abdominal dots; but these are often wanting or obsolete in the young specimen, in which state it is probably the _torquatus_ of Shaw. Sometimes the dots are wanting on the neck and near the cloaca; and in one aged individual, the intermediate line occurred double, and confluent on the throat.

_Coluber fulvius_, this species is said by Daudin to be closely allied to his _C. coccineus_, notwithstanding the difference in plates and scales. But it is certainly very distinct by other characters, and strikingly so in its perfectly annular black and red bands; the latter are margined with yellowish and spotted with black. A specimen has 224 plates and 32 scales, total length 21 inches, length of the tail 1-9/10 inch. The _coccineus_ has the under part of the body whitish, immaculate. The _fulvius_ seems to belong to the genus _vipera_; it has the fangs, but not the orifice behind the nostril, which communicates with the reservoir of venom, so conspicuous in the _crotali_, &c.

_Ophisaurus ventralis._ The tail of this snake not only breaks in pieces when struck with a weapon, but portions of it are thrown off at the will of the serpent. This singular fact I witnessed in Georgia. This is one of the many which are called horn-snakes. A tip of the tail of one of them was once brought to me as having been taken from a recently withered tree, which the bearer assured me was destroyed by the insertion of this formidable instrument, and it was not without considerable difficulty he was convinced of the innocence of the tail, and of having been the dupe of a knave. There seems to be a peculiar character in the mode of imbrication of the scales of this species, each one of these at the lateral edges, passes beneath the lateral scale on one side, and over the edge of the opposite one. It has been described under five different generic names, and four different specific ones.

The _Crotali_ do not gain a single joint only to the rattle annually, as is generally supposed. They gain more than one each year, the exact number being probably regulated in a great measure by the quantity of nourishment the animal has received. Rattle-snakes in Peale's Museum have been observed to produce 3 or 4 in a year, and to lose as many from the extremity during the same time. Hence it is obvious, that the growth of these curious appendages is irregular, and that the age of an individual cannot be determined from their number. Mr. Rubens Peale informed me, that a female of _Crotalus horridus_, Beauv. _durissus_, Daud. which lived in his Museum more than fourteen years, had eleven joints to her rattle when first in his possession; that several joints were acquired and lost annually, and that at her death, which occurred last year, she had the same number as when brought to the Museum; she had, however, during that time received an accession of four inches to her length. Her death was occasioned by an abortion.

The _C. adamanteus_, Beauvois. _Rhombifer_, Daud. is by much the largest of our North American serpents, and doubtless is the species which Catesby saw a specimen of, eight feet long.

_Crotalus miliarius_ varies in some characters from those laid down by authors. A specimen within my view has five dorsal series, of alternate, irregularly orbicular black spots, those of the intermediate series are obsolete, and slightly connected across the back, those of the vertebral series have not red centres, and are edged with a white line; the ventral spots are disposed adventitiously, so as not to be traced into longitudinal series; they are large, black, irregularly orbicular, and occupy about one half of the surface, which is white. Ventral plates 140; subcaudal, 33, of which the six terminal ones are bifid. Joints of the rattle with but one transverse contraction on the middle of each, besides the terminal contraction. Total length 1 foot 4¼ inches, tail two inches. It appears to be more vindictive than the two species before mentioned. The individual here noticed we encountered in East Florida; he struck at Mr. W. Maclure and myself successively as we passed by him, without any previous intimation of his presence, owing to the inaudible smallness of his rattle, and its having but three joints; he was killed by Mr. T. Peale, (whom we preceded) while preparing for another assault. This incident is noted as a contrast to the anecdote of the _Coluber heterodon_.

_Salamandra alleganiensis_, Daud. appears to be synonymous with _S. gigantea_ of Dr. Barton. It was first described by Mr. Latreille in Deterv. Ed. of Buffon, tom. 11. The name _alleganiensis_, although defective, as it indicates no character, has however the unalienable right of priority.

_Salamandra subviolacea_, Barton. This name has been rejected by Mr. Daudin, and substituted by that of _venenosa_, I do not know for what reason, as none is assigned.

_Salamandra punctata_, Gmel. This appellation was originally given and restricted to the _stelio_ of Catesby. tab. 10. (represented in the bill of Ardea Herodias) and was adopted by many subsequent authors, but was finally rejected by Daudin, who considered the species the same as Barton's _subviolacea_. He concurred with Mr. Latreille in appropriating the name thus rejected to _var. β_ of _Lacerta_, _aquatica_ of Gmel. Notwithstanding this high authority I cannot but coincide with Professor Barton in this instance, in believing it altogether distinct. The single character of the subocellate spots, though not remarked by this author, is a sufficiently discriminative one; these ocellæ are always present, and in no one of the varieties I have seen has the approximation to the _subviolacea_ been so considerable as to render a specific discrepance equivocal. Catesby's variety with the ocellæ on the tail seems to be the least common; in general these spots, or epupillate ocellæ, are exclusively confined to a line on each side of the back, about six in each, extending from the base of the head to the origin of the tail, though there are sometimes scattered smaller ones on each side of the body, and upon the vertex of the head, they are of a beautiful reddish colour, enclosed by a definite black areola; the upper part of the body is brownish, with numerous, distant black points, and a slight vertebral, obtuse carina, the inferior surface of the body of a fine yellow or orange, with distant black points, the tail[37] is compressed, ancipital, attenuated to an obtuse tip, longer than the body, and punctured with black in like manner. The younger specimens vary considerably, in being, on many parts of the body, destitute of black punctures, and in having the dorsal and ventral colour, of the same pale orange. It is decidedly aquatic. Several specimens are preserved in the collection of the Academy of Natural Sciences, and from these it is evident that the reddish colour of the subocellate spots is destroyed by the action of the antiseptic liquid; to this circumstance it is probably owing that these spots have been hitherto described as white.

After stating these differential traits, it may be proper to observe, that the _S. maculata_ of Shaw is synonymous with the above. But I think it most proper to restore Gmelin's name _punctata_, which will afford an opportunity to do justice to the memory of Laurenti, by reviving the original name by which he distinguished the _Var. β. of Lacerta_, _aquatica_, Gmel., that of _parisinus_.

_Bufo cornuta._ This animal, which has been stigmatized as the most prodigiously deformed _creature_ known to exist!! is generally supposed to inhabit North America as well as Surinam. I do not think it has ever been found in North America. Shaw, in Nodder's Nat. Misc. says it is principally found in Virginia, but in his General Zoology, I think he says that Seba was in error when he represented its native country to be North America. Two other species of _Bufo_ have been correctly stated to inhabit this country, viz. _B. musicus_, and _Crapaud rougeâtre_, Daud. (B. rubidus) first noticed as distinct by Mr. William Bartram. I discovered a third species on the banks of St. John's river, East Florida, which, as I am not at present prepared to describe, I shall not surreptitiously name.

It is, I conceive, an incumbent duty on the describer of a natural object, to deposit his specimen, or a duplicate, when practicable, in some cabinet or museum, to which he should refer, in order that subsequent writers may be satisfied with the accuracy of his observations, by examining for themselves. By such reference, and by the re-examination of the same objects by others, the plethoric redundance of synonyma, that prolific source of accumulating error, will be banished or elucidated, and naturalists will most readily arrive at the knowledge of truth, which is, or ought to be, the grand leading object of their labours.

PHYSICS AND CHEMISTRY.

ART. XI. _Outline of a Theory of Meteors._

_By_ WM. G. REYNOLDS, M.D. _Middletown Point, New-Jersey_.

Should the progress of science, for a century to come, keep pace with its rapid advancement for the last fifty years, many appearances in the physical world, now enveloped in obscurity, will then admit of as easy solution as the combustion of inflammable substances, or any familiar process in chemistry does at this day. Among the many subjects from which the veil of mystery would thus be raised, we may include those luminous appearances, in the aerial regions, called meteors, which I am about to consider in the following essay; and which seem to constitute a distinct class of bodies of considerable variety.

Meteors were regarded by the ancients as the sure prognostics of great and awful events in the moral and physical world; and were divided by them into several species, receiving names characteristic of the various forms and appearances they assumed; but of their opinions, as to the physical cause of these phenomena, the ancients have left us nothing solid or instructive. The moderns, more enlightened, have ceased to regard these bodies with the superstitious awe of former ages; but in respect to the cause thereof, are perhaps but little in advance of their predecessors, having, I believe, produced nothing yet that will bear the test of philosophical investigation.

Doctor Blagden (Philosophical Transactions, 1784,) considers electricity as the general cause of these phenomena; Doctor Gregory, and others, think they depend upon collections of highly inflammable matter, as phosphorus, phosphorated hydrogen, &c. being volatilized and congregated in the upper regions of the air. Doctor Halley ascribes them to a fortuitous concourse of atoms, which the earth meets in her annual track through the ecliptic; and Sir John Pringle seems to regard them as bodies of a celestial character, revolving round centres, and intended by the Creator for wise and beneficent purposes, perhaps to our atmosphere, to free it of noxious qualities, or supply such as are salutary. Many other theories, as ingenious as fanciful, might be enumerated; but without commenting on their comparative merit, I must acknowledge that none of them have yet impressed my mind with a conviction of their truth. A series of observations, however, have enabled the moderns to ascertain, with apparent accuracy, several particulars relative to these stupendous bodies, which add much to our knowledge of their general character:--their velocity, equal to 30, and even 40 miles in a second of time; their altitude, from 20 to 100 miles; and their diameter, in some instances, more than a mile, are facts we derive from respectable authority, and may aid us, essentially, in forming just conceptions of their nature and properties.

I believe meteoric stones to result from all meteoric explosions; limiting, however, the term meteor to those phenomena, in the higher regions of the air, denominated fire-balls, shooting-stars, &c. That these bodies move in a resisting medium, must be evident to every attentive observer; and that this medium is our atmosphere, is pretty certain, 1st. Because we know of no other resisting medium round the earth; 2dly. Because the same kind of resistance is apparent at every intermediate altitude, from their greatest to their least, which last we know to be far within our atmospheric bounds; and, 3dly. Calculation has, in no instance, assigned them an elevation beyond the probable height of the atmosphere.

That meteors proceed from the earth, that they arise from certain combinations of its elements with heat, and that meteoric stones are the necessary result of the decompositions of these combinations, are opinions I will endeavour to support, by the following considerations.

1st. The properties and habitudes of matter, under certain conditions and combinations.

2dly. The situation of the earth's surface in respect to the sun, the influence of his rays thereon, and the nature of the elements or compounds on which these rays act:

And 3dly. The identity that exists between the component parts of meteoric stones, and the elements that enter abundantly into the composition of our globe; and, by several other facts and arguments.

Under my first general specification, I will select such principles from the established doctrines of philosophy, as have an immediate bearing on the subject; without engaging in any of those subtle speculations in which certain recondite properties of matter, or the identities of quality and body are affirmed or denied.

Thus, 1st. Heat is the universal cause of fluidity and volatility in bodies; hence no solid can assume the state of gas, until it absorbs, or unites with, a certain portion of caloric; and the subtilty and volatility of compounds thus formed, will be in a due ratio to the quantity of caloric they employ.

2dly. The heat employed to maintain a body in the gaseous state, is said to be latent or fixed, and may be regarded as an ocean or atmosphere of fire, holding the ultimate particles of the body in a state of extreme division, and wide separation, from which they can be driven only by some change in the affinities or condition of the compound.

3dly. If the latent heat in a gaseous compound be suddenly abstracted, as in explosion, its escape is attended with the emission of light and sensible heat, when the volatilized particles held in solution being no longer able to maintain the state of gas, suffer approximation in a due proportion to the quantity of caloric they have lost.

4thly. Caloric, in reducing solids to the state of gas, lessens, but cannot in any case, as far as we know, totally destroy their gravitating force; the diminution of this force, however, being in a direct proportion to the quantity of heat employed.--Hence the following inferences may be fairly drawn, as they seem to be in unison with the relative dependence and harmony existing between the material elements of this globe, and, I believe, are contradicted by no direct experiments; viz. that the expansion of volume, specific levity, and subtilty of artificial gases, are in a direct proportion to the absolute quantity of caloric they employ; and the caloric is in the same proportion to the insolubility of the substance with which it unites.

5thly. When the specific gravity of bodies on the surface of the earth, is reduced below that of the superincumbent atmosphere, they ascend to media of their own density, in obedience to the laws of Aerostatics; thus we raise balloons by filling them with light air, and the carbon of pit coal and common wood exposed to combustion, and water to the sun's rays, will rise until they reach a medium of like specific gravity with themselves.

6thly. Mechanical agitation and division assist the solution of solids, by bringing fresh portions of the menstruum into successive contact with their fragments, and thus exposing a larger surface.

Under the second head I proceed to notice the situation of the earth's surface in respect to the sun, &c. The atmosphere is a thin, elastic, gravitating fluid, that completely envelopes the earth, to which it may be considered a kind of appendage or external covering; its base resting on the earth's surface, is of an uniform density, growing rare as it recedes therefrom, in a due ratio to the diminution of its gravitating force, until it is lost in empty space. The atmosphere is estimated on certain data to be about 44 or 45 miles high, but we have good reasons to believe it fills a much wider circle, though too thin to reflect the rays of light above its reputed height.

The earth presents one whole hemisphere to the sun in unerring daily succession; and those parts of it which have the least protection against his rays, will, cæteris paribus, suffer the greatest intensity of their action. Within the tropics, the atmosphere opposes less resistance to the sun's rays than in the temperate zones; and in both large tracts of cultivated land, the summits and sides of great ranges of mountains, margin of oceans, rivers, &c. present an almost naked surface to their influence.[38] The exterior strata of the earth, and especially the more exposed parts thereof, envelope in their compounds, elements of an identity of character with those composing meteoric stones.

The atmosphere is the great recipient of all volatilized bodies; it possesses but feebly the powers of a solvent, unaided by heat or moisture, but when these are adjuvants, no body in nature can totally resist their action for a long time.

Now if the above principles are admitted, we have in their application a reasonable solution of most meteoric phenomena. Thus, the rays of the sun darting through the atmosphere reach the surface of the earth, where, by accumulation, they produce sensible heat, which though not intense, is steady and uniform, for many hours every day; minute portions of the earthy and metallic compounds exposed to the sun's influence, will be volatilized by the absorption of heat, and thereby assuming the state of elastic fluids, will ascend until they arrive at media of their own density. The atmosphere in contact, will have some of its particles blended in these compounds, will ascend with them, and to supply the vacuum, new portions of air will rush in and ascend, and the process will continue until the sun's rays are withdrawn, or interrupted by some of the common occurrences of nature.

The utmost height to which these elastic fluids ascend, may be estimated at something more than one hundred miles; and they float at every intermediate distance between their greatest elevation and the clouds, but rarely below the latter, except their course is directed towards the earth in their explosions. They probably ascend at first in small daily detached portions of gaseous clouds, and are diffused over wide regions; but having no sensible resistance opposed to their mutual attraction, they will by the laws of their affinities congregate into immense volumes of highly concentrated elastic fluids, which on exploding will exhibit all the phenomena of bursting meteors in the following manner, viz. the latent heat on escaping will manifest itself in the form of fire and light, the force with which it strikes the atmosphere, or the rebound of the latter to fill the vacuum, or both, will occasion sound more or less detonating or hissing, as the escape is more sudden, or the atmosphere more dense; the earthy and metallic particles on the escape of caloric, will obey the laws of cohesive attraction, clash together, recover their gravity, and descend to the earth in masses, or shattered fragments.

Meteoric stones frequently bear the marks of violence, which is doubtless owing to the conflict sustained at the moment of explosion; their difference in size depends on the difference of magnitude in the disploding volumes; something like regular arrangement is frequently perceived in the structure of these stones, because in all productions of solid from fluid matter, the consolidating particles possess a tendency to arrange themselves in the order of their affinities. It is thus the various arrangements in saline crystallization, the freezing of water, and cooling of melted metals, may be accounted for. There is a real, as well as an apparent difference in the velocity of meteoric bodies; the first arising from their difference of magnitude and the violence of the explosion, as well as from the resistance they meet; the latter, from the different distances at which they are seen. The gradation of colour, from a bright silvery hue to a dusky red, is owing, in a certain degree, to the state of the atmosphere refracting different coloured rays, and also to the materials in the compound, similar to the different hues in artificial fireworks. Reddish and white nebicula are sometimes left in the tracks of meteors, which are nothing but ignited vapours, or the particles brushed off the burning body by the resisting atmosphere. The velocity or motion and direction of meteors, depend upon principles well known and daily practised by engineers, and the constructors of fireworks.

The immediate cause of these explosions is a little obscure, and merits a fuller detail than is compatible with my present limits; their analogy to the electric phenomena in the clouds, leaves room to suppose they are effected by certain modifications of electricity. Clouds of opposite electricities will approach each other and explode, by the positive imparting as much electrical fire to the negative cloud as will make them equal, when just as much water as the imparted fire held in solution, will be set at liberty and descend to the earth. If, however, this solution be deemed inapplicable, perhaps the following may be admitted. Thus, when heat is urged upon incombustible[39] bodies with a force that overcomes the cohesive property by which their particles are tied together, it unites with them in large quantities, and becomes latent, by which union they are reduced to the state of elastic fluids; and as it is a universal property of heat to counteract the gravitating force of bodies, these compounds must necessarily become volant, and ascend as above stated. It is only thermometrical or sensible heat, that destroys the attraction of cohesion existing between the particles of bodies, the repulsive power of latent heat being barely able to counteract this property, when the elements under its dominion are removed beyond a certain distance from each other; now the very reduced temperature in the high regions to which these gaseous clouds will ascend, may admit their earthy and metallic particles within the sphere of cohesive or aggregative attraction, when the caloric will be expelled like water from a sponge, accompanied by all the phenomena above stated.

The third general head of my subject leads me to inquire into the constituent principles of meteoric stones: sundry papers on the analysis of these productions, have been furnished us by chemists of acknowledged reputation and ability, and in none of these that I have seen, was there any element described that had not been previously known. But should it hereafter be found that air stones contain matters not found on our globe, the fact will afford no absolute proof of the foreign origin of these stones, as we are successively discovering earthy and metallic principles of distinct characters from those already known.

A portion of one of these stones that fell in the town of Weston, (Connecticut) examined by the late Dr. Woodhouse, gave the following results in a hundred parts, viz.

Silex 50
Iron 27
Sulphur 7
Magnesia 10
Nickel 1 inferred from chemical tests.
Loss 5
----
100

"The sulphur was seen by the naked eye distributed through the silex in round globules the size of a pin's head, after dissolving the powdered stone in diluted nitric acid."

All specimens of these stones do not afford precisely similar results, but differ in their constituent elements and relative proportions; their component parts, however, are to be found abundantly in schist, schorl, pyrites, pebble, granite, &c. on which the sun must daily act.

The following facts go to strengthen the above theory, viz. Meteors are most frequent and stupendous in tropical countries, where the heat of the sun is most intense; and less frequent in our climate in the winter and spring, while, and after the earth has been covered with snow for many weeks in succession; and they are most frequent in the higher latitudes towards autumn, after a continuation of hot dry weather: out of the whole number (179) of shooting stars I have noted during the last twelve years, 149 appeared between June and December, inclusive.

If it be said that the specific gravity of meteoric stones being several times that of water, it is absurd to suppose they can rise, (if even reduced to the state of gas) to the elevated stations here assigned them, seeing the vapours of water can ascend only one or two miles above the earth. To this I reply, that the doctrine of heat is not yet so thoroughly understood, as to acquaint us with all its habitudes with natural bodies, but we infer from analogy, that the more refractory a body is in the fire, the greater in a due ratio is the absolute quantity of heat required to reduce it to, and retain it in, the state of gas, and the greater, in a corresponding degree, will be the dilatation of its particles and decrease of its specific gravity. Hence, if water reduced to vapour by heat, be capable of assuming an altitude of two miles, it follows that more refractory substances reduced to a similar state, will suffer expansion and fugacity in a due proportion to the quantity of caloric they employ, and will assume a corresponding elevation, as already inferred under my first head.

Another objection may be, that though high degrees of heat affect certain solids as above stated, yet these cannot be sensibly acted on by such feeble agents as atmospheric air and the rays of the sun. I answer, if it be admitted that sensible heat acts on solids in an increasing ratio to its intensity, it follows that lower degrees, though acting in an inverse ratio to higher, must affect the same bodies in a conceivable degree at any temperature above their natural zero:[40] and though the heat of the sun beating on a plane surface for several hours is feeble, compared with that produced by a burning lens, or air furnace, yet if it be sufficient to detach from one square foot of the earth's surface the 104023 part of a grain in twenty-four hours, the quantity taken from 100 square miles, in the same time and proportion, would amount to ten pounds, which is abundantly sufficient for all meteoric phenomena; and the loss to each square foot, supposing the process to be uninterrupted, would be no more than one grain in 284 years. When we advert to the intense heat produced by concentrating a few of the sun's rays in a burning lens, the whole quantity daily sent to the earth must strike us forcibly. If collected in a lens of sufficient magnitude, they might volatilize a space equal to the state of New-York in a moment of time! As all bodies possess a limited capacity for heat, does it not follow that there must be some outlet to its perpetual accession to our globe, or the earth would soon become so highly ignited as to glow with the fulgour of a meteor? And may not this outlet be found in the above described compounds? which serve as conductors of the surplus of heat from the earth to the higher regions of the air, where on being freed by displosion, from the grosser matters incumbering it, it finds a rapid passage to its great archetype and parent, the SUN. Thus his daily waste may be restored, and an equilibrium, by the return of his own emanated particles, preserved, between the sun and the earth, and probably all the planets of our system.

The last consideration I shall offer in favour of the domestic or earthly origin of meteoric phenomena, is the difficulties that present to our granting them a foreign one. Though I am well aware of the respectability of the names which the theory of moonstones can summon to its support, yet I have always regarded it as unfounded and unphilosophical for the following reasons, viz. 1st. Whether the moon has an atmosphere or not, we will all admit that she has attraction, which must extend to many thousands of miles from her surface. No projectile force that we are acquainted with can throw a heavy body 100 miles, even though no atmospheric, or other resistance than its own gravity, were present; hence the idea of that force extending to thousands of miles from the moon's surface, is gratuitous and nugatory. 2dly. The products of volcanoes bear no similarity of origin, or kindred resemblance to meteoric stones; those are lavas of different kinds, pumicestone, scoria, ashes, &c. these solid masses of matter, with some degree of regularity in the arrangement of their constituent particles. 3dly. The descent of these stones has no coincidence in point of time with the position of the moon. She is as often in their nadir as their zenith. We also witness in all cases, explosion and light in our own atmosphere, at the time of the descent of these stones. This could not be the case if they proceeded from the moon, for obvious reasons. 4thly. The heat adequate to such projectile force as would carry a body from the moon's surface beyond the sphere of her attraction, would volatilize the matter of meteoric stones in a moment; hence they would not be projected from the Lunarian crater in solid masses, but in elastic vapour.

In conclusion, although the theory which I have endeavoured to elucidate and establish, be subject to some difficulties and objections which science may hereafter remove, it appears to me perfectly consonant with the relative dependence and harmony of our system, and by no means at variance with the infinite wisdom and power by which it was originated.

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