many miles along the shore, the width of the deposit being some four or five inches. An examination of a considerable quantity of this substance, in several places, failed to show anything of a sulphurous nature, either in its taste, color, or smell. Prof. Williams states that, being apprehensive as to whether there was not some uncommon ingredient in the air that day, he put out several sheets of clean paper in the air and rain. When they had been out four or five hours, he dried them by the fire. They were much sullied, and became dark in their color, and felt as if they had been rubbed with oil or grease; but, upon burning them, there could not be detected any sulphurous or nitrous particles.

The motion and situation of the currents or bodies of vapor in the atmosphere likewise exhibited some striking peculiarities. In most places, it was very evident that the vapors were descending from the higher parts of the atmosphere towards the surface of the earth. A gentleman who made some special observations bearing upon this point, mentions a very curious circumstance, as to their ascent and situation, namely, that at about nine o'clock in the morning, after a shower, the vapors rose from the springs in the low lands, in great abundance. Notice was taken of one large column that ascended, with great rapidity, to a considerable height above the highest hills, and soon spread into a large cloud, then moved off a little to the westward. A second cloud was formed in the same manner, from the same springs, but did not ascend so high as the first; and a third was formed from the same places, in less than a quarter of an hour after the second. About three-quarters of an hour after nine o'clock, these clouds exhibited a very striking appearance. The upper cloud wore a peculiar reddish hue; the second showed in some places or parts a green, in others a blue, and in others an indigo color; while the surface of the third cloud was almost white.

Of a somewhat singular nature, also, is the fact, as related by another, that, while

the darkness continued, the clouds were in quick motion, interrupted, skirted one over another, so as to form—at least to the eye of the beholder-a considerable number of strata, the lower stratum being of an uniform height as far as visible; but this height was conceived to be very slight, from the small extent of the horizon that could be seen, and from this circumstance observed in the evening. A lighted torch, held by a person passing along the street, occasioned a reflection of a faint red or coppertinged light-similar to a faint aurora borealis, the apparent height at which the reflection was made, being some twenty to thirty feet. And it was generally remarked, that the hills might be seen at a distance in some directions, while the intermediate spaces were greatly obscured or darkened.

It would thus appear, from the statements now cited, as if the vapors, in some places, were ascending; in most, descending; and, in all, very near to the surface of the earth. To this it may be added, that, during the darkness, objects seemingly cast a shade in every direction, and, in many instances, there were various appearances or corruscations in the atmosphere, not unlike the aurora borealis, though it is not stated that any uncommon exhibitions of the electric fire were witnessed during the day. In some accounts, however, it is mentioned that a number of small birds were found suffocated by the vapor; some were found dead, and some flew affrighted, or stupefied, into the houses.

In New Haven, Conn., there was a shower of rain, with some lightning and thunder, about daybreak in the morning, the rain continuing, with intervals, until after sunrise. The morning was cloudy and darkish; and the sun, rising towards the zenith, gave no increase of light, as usual, but, on the contrary, the darkness continued to increase until between eleven and twelve o'clock, at which time there was the greatest obscurity in that place. What little motion of the air there was just at this period, was nearly from the

south; though the atmosphere was as calm as the blandest summer morning. There was something more of a luminous appearance in the horizon, than in the hemisphere in general; also, a most marked liveliness of tint to the grass and other green vegetation; and a very noticeable yellowness in the atmosphere, which made clean silver nearly resemble the color of brass. At about twelve o'clock, noon, the singular obscuration ceased; the greatest darkness, at any particular time, was at least as dense as what is commonly called 'candlelighting,' in the evening. In the town of Hartford, and the neighboring villages, the phenomenon was observed with all its distinctive peculiarities; and, by some persons, the disc of the sun was seen, at the time of the greatest deficiency of light.

such buildings. At twelve, the darkness was greatest, and a little rain fell; in the street, the aspect was like that at the beginning of evening, as lights were seen burning in all the houses. The clouds were thinnest at the north; at the northeast, the clouds were very thick, and so low that hills could not be seen at the distance of half a mile; south-westerly, hills might be clearly seen at the distance of twenty miles, though the intermediate space was so shaded that it was impossible to distinguish woodland from pasture. At half-past twelve, the clouds, having been hitherto detached, began to concentrate at such an height, that all the hills became visible, and the country around exhibited a most beautiful tinted verdure; at one, at one, the clouds became uniformly spread, and the darkness was not greater

In Middlesex county, Mass., the peals of thunder were loud and frequent at six o'clock in the morning, attended with heavy rain; at seven o'clock, the rain and thunder had ceased, but the sky continued cloudy. Between nine and ten o'clock, the clouds were observed to thicken, and to receive continual accessions from the low lands. Before ten, the darkness had sensibly increased, till it became difficult to read an almanac in a room having two windows; at eleven o'clock, candles were lighted, and at half-past eleven the darkness was so great in the meeting-house, where a court was then sitting, that it was difficult to distinguish countenances at the smallest distance, notwithstanding the large number of windows usual in

than is usual on a cloudy day. The same weather continued through the whole afternoon, except that the sun was seen for a few minutes, in some places, about three o'clock. At eight in the evening, the darkness was so impenetrably thick, as to render traveling positively impracticable; and, although the moon rose nearly full about nine o'clock, yet it did not give light enough to enable a person to distinguish between the heavens and the earth.

In the account of this phenomenon given by Dr. Tenney, of New Hampshire, an intelligent observer and writer, are some interesting details, gathered by him while on a journey to Pennsylvania, from the He repeats and confirms the state

east.

ment made by others, that, previously to the commencement of the darkness, the sky was overcast with the common kind of clouds, from which there was, in some places, a moderate fall of rain. Between these and the earth, there intervened another stratum, apparently of great thickness; as this stratum advanced, the darkness commenced, and increased with its progress till it came to its height, which did not take place till the hemisphere was a second time overspread-the uncommon thickness of this second stratum being probably occasioned by two strong currents of wind from the southward and westward, condensing the vapors and drawing them to the north-east.

The result of Dr. Tenney's journey,during which he made the best use of his opportunities for information,-was, that the darkness appeared to be most gross in Essex county, Massachusetts, the lower part of the state of New Hampshire, and in portions of what was then the province of Maine. In Rhode Island and Connecticut it was not so great, and still less in New York; in New Jersey, the second stratum of clouds was observed, but it was not of any great thickness, nor was the darkness very uncommon; in the lower parts of Pennsylvania, no extraordinary scene was noticed.

Through the whole extent of country referred to, the lower cloud-stratum had an uncommon brassy hue, while the earth and trees were adorned with so enchanting a verdure as could not escape notice, even amidst the unusual atmospheric gloom that accompanied it. The darkness of the following evening was probably as deep and dense as ever had been ob. served since the Almighty fiat gave birth to light; it wanted only palpability to render it as extraordinary as that which overspread the land of Egypt, in the days of Moses. If every luminous body in the universe had been shrouded in impenetrable shades, or struck out of existence, it was thought the darkness could not have been more complete. A sheet of white paper, held within a few inches of the

eyes, was equally invisible with the blackest velvet. And, considering the small quantity of light that was transmitted by the clouds, during the day, it is not surprising that, at night, a sufficient quantity of rays should not be able to penetrate the same strata, brought back by the shifting of the winds, to afford the most obscure prospect even of the best reflecting bodies. The denseness of this evening darkness was a fact universally observed and recorded.

In view of all the information contained in the various accounts of this day, it appears very certain that the atmosphere was charged with an unprecedented quantity of vapor,-from what primary cause has never been satisfactorily determined; and as the weather had been clear, the air heavy, and the winds small and variable for many days, the vapors, instead of dispersing, must have been constantly rising and collecting in the air, until the atmosphere became highly charged with them.

A large quantity of the vapors, thus collected in the atmosphere, on the day in question, was floating near the surface of the earth. Wheresoever the specific gravity of any vapor is less than the specific gravity of the air, such a vapor will, by the law of fluids, ascend in the air; where the specific gravity of a vapor, in the atmosphere, is greater than that of the air, such a vapor will descend; and where the specific gravity of the vapor and air are the same, the vapor will then be at rest,— floating or swimming in the atmosphere, without ascending or descending. From the barometrical observations, it appears that the weight or gravity of the atmosphere was gradually growing less, from the morning of the nineteenth of May, until the evening; and hence the vapors, in most places, were descending from the higher parts of the atmosphere, towards the surface of the earth. According to one of the observations cited, the vapors were noticed to ascend, until they rose to a height where the air was of the same specific gravity—a height not much above the adjacent hills, and here they in

stantly spread, and floated in the atmosphere. From these data, the conclusion. is drawn, that the place where the vapors were balanced must have been very near the surface of the earth.

Reasoning from the premises thus set forth, Prof. Williams was of the opinion that such a large quantity of vapor, floating in the atmosphere, near the earth's surface, might be sufficient to produce all the phenomena that made the nineteenth of May, 1780, so memorable. Thus, the direction in which the darkness came on would be determined by the direction of the wind, and this was known to be from the south-west; the degree of the darkness would depend on the density, color, and situation of the clouds and vapor, and the manner in which they would transmit, reflect, refract, or absorb the rays of light; the extent of the darkness would be as great as the extent of the vapor; and the duration of it would continue until the gravity of the air became so altered that the vapors would change their situation, by an ascent or descent; -all of which particulars, it is claimed, agree with the observations that have been mentioned. Nor does the effect of the vapors, in darkening terrestrial objects, when they lay near the surface of the earth, appear to have been greater than it was in darkening the sun and moon, when their situation was higher in the atmosphere.

It being thus evident that the atmosphere was, from some peculiar cause (perhaps great fires in distant woods) charged, in a high degree, with vapors, and that these vapors were of different densities and occupied different heights, the deduction is, that by this means the rays of light falling on them must have suffered a variety of refractions and reflections, and thereby become weakened, absorbed, or so reflected, as not to fall upon objects on the earth in the usual manner; and as the different vapors were adapted by their nature, situation, or density, to absorb or transmit the different kind of rays, so the colors of objects would appear to be affected by the mixture or prevalency of

those rays which were transmitted through so uncommon a medium. This was the explanation suggested by Prof. Williams, though not to the exclusion of other theories.

But there were not wanting those-and a large number they were too-who gave play, in their minds, to the most strange opinions concerning the cause of so marvelous an appearance. It was imagined by some persons, that an eclipse of the sun, produced of course by an interposition of the moon, was the cause of the darkness -others attributed it to a transit of Venus or Mercury upon the disc of the sunothers imputed it to a blazing star, which they thought came between the earth and the sun. So whimsical, indeed, were some of the opinions which possessed men's minds at this time, that even so bare a vagary as that a great mountain obstructed the rays of the 'sun's light during that day, obtained advocates! Whether they thought that a new mountain was created and placed between the earth and the sun, or that a mountain from this globe had taken flight and perched upon that great luminary, does not appear.

That this darkness was not caused by an eclipse, is manifest by the various positions of the planetary bodies at that time, for the moon was more than one hundred and fifty degrees from the sun all that day, and, according to the accurate calculations made by the most celebrated astronomers, there could not, in the order of nature, be any transit of the planet Venus or Mercury upon the disc of the sun that year; nor could it be a blazing star-much less a mountain,-that darkened the atmosphere, for this would still leave unexplained the deep darkness of the following night. Nor would such excessive nocturnal darkness follow an eclipse of the sun; and as to the moon, she was at that time more than forty hours' motion past her opposition.

One of the theories, looking to a solution of the mysterious occurrence, which found defenders, was as follows: The heat of the sun causes an ascent of numerous particles