and drove me into the house: the only precaution I took on quitting my place with so much regret, was to cover the tub with a cloth, to prevent them from flying entirely away in my absence. The violence of the rain was not of long duration; in half an hour, that is to say, before nine o'clock, it permitted me to return once more to the garden. When the covering was taken off from the tub, the number of ephemera had considerably augmented, and they continued still to multiply under my eyes: many flew off, but I found many more which had been drowned.

"The Ephemera which were already transformed, and continued still in the act of transformation, would have afsuredly been enow to fill it sufficiently; but the number was prodigiously augmented by the continual accefsion of strangers, who, attracted by the light, came thither from all quarters, the most part of them to be drowned. To prevent these from thus perishing, and to enable me to examine them in a perfect state, I caused the cloth to be spread over the tub, above which the light was held; immediately the cloth was almost concealed by the vast multitudes which fell upon it; and they could be gathered almost in handfuls upon the bottom of the candlestick. Those which fell were not, however, in the pitiful plight of those common moths which singe their wings by flying into the flame of a candle; they fell only because they were tired with flying; they seemed to alight because they were under the necefsity of doing so.

"But what I observed about the tub was nothing in comparison with that which I was about to see at the side of the river. I had been ignorant till this

of my gardener, who had descended to the bottom of the stair, called me thither. I stopped on the lowest step of the stair but one, it was then that I beheld a spectacle which far surpassed what I could have expected or desired. The quantity of ephemera which filled the air above the whole of the surface of that branch of the river, especially at that side of it where I stood, can neither be exprefsed nor conceived; but it was chiefly about me, and those who accompanied me, that it was the most prodigious. When snow falls thickest and in the largest flakes, the air is never so completely filled with them as that which surrounded us was with ephemera. Scarcely had I remained a few minutes in one place, when the step on which I stood was covered in every part with their bodies to the depth of two or three, and in some places it even exceeded four inches. The whole surface of the water for six feet at least in breadth beyond the steps was entirely covered with a coat of ephemera; those which the current, there slower than elsewhere, carried away, were more than replaced by those which fell continually in that place. I was several times obliged to abandon my station, by retreating to the top' of the stair, not being able to sustain the shower of ephemera, which, not falling so perpendicularly as an ordinary shower, or with an obliquity equally constant, struck me uninterruptedly, and in a very troublesome manner, on all parts of the face. My eyes, mouth, nose, were filled with ephemera. Let not those who may have sometimes been disturbed in the fine evenings of summer by nocturnal butterflies, or moths, imagine that the inconvenience they may have then felt is to be compared with that of which I now speak;

for no comparison can be made between the numbers of these butterflies and that of the ephemera which now afsailed us.

"If it appears to be singular, that those butterflies which fly only in the night-time, and who seem to shun the day, should be precisely those which come in search of the light even into our apartments; it ought to seem still more extraordinary that the ephemera, which are destined to be born after the sun is set and the day closed in, and which are not permitted to see even the first blush of Aurora, should have such a marked attraction towards the light. It was a bad post to have charge of a candle on this occasion; he who held it in his hand had his whole body covered with these flies in an instant; they rushed to him from all parts in such quantities as to opprefs him. The light of that candle occasioned, and put it in our power to see a spectacle altogether different from any thing that can be observed in any kind of meteorological shower; it was enchanting when once observed. All those who were with me, even to the grofsest of the people, my domestics, never would have tired of admiring it. No astronomic sphere was ever formed so complicated as it was, nor furnished with so many circular zones in all manner of directions, having the flame of the candle for their common centre. Their number appeared to be infinite, having all possible degrees of obliquity with respect to each other, and which were more or lefs eccentric. Each zone was formed by an uninterrupted string of ephemera, which, as if tied together, followed each other close in the same line; they seemed to form a ribbon of silver bent into

ribbon formed of equal triangles put end to end, so that the angles of those that followed were supported by the base of that which preceded it, the whole moving round with great quicknefs. Ephemera, whose wings only were then distinguishable, and which circulated around the light, formed this appearance. Each of these flies, after having described one or two orbits, fell to the earth, or into the water, but without having been burnt by the candle.

"At the end of half an hour, and even sooner, the great shower of ephemera began to abate, the clouds of these flies were lefs dense, and became every moment lefs and lefs so: in short, after ten o'clock scarcely could any be seen above the river, and no more came near the candle.”

典

Mr. Reaumur was at some pains to inform himself whether this phenomenon occurred with the same regularity and at the same hour in other evenings; and he soon became satisfied that the metamorphosis of this insect into the fly state never does take place during the day, but that it commences usually about the same time in the evening, and that this kind of animal shower is nearly of the same duration from the beginning to the end of it each night as long as it continues: nor does this seem to be either accelerated or retarded by the heat or the cold of the atmosphere at the time. When the hour of transformation arrives, no circumstances, it would appear, can pofsibly retard it. It must go forward at all events, and they must submit to the lot which their destinies decree.

But though the numbers be immense that are thus brought forth in one evening, yet they are not all called into this state of existence at one time. Those

which are not ready to come forth at the appointed hour continue in reserve till the same hour the succeeding evening, when they make their appearance nearly in equal numbers as before, and so with a third; and though a few are found for some succeeding evenings, as well as those that precede the great fall, so that the harvest extends to six or seven evenings in all, yet they are so few in number towards the beginning and the end of that period, as scarcely to deserve notice.

Nor are these flies lefs regular in respect to the season of the year at which they make their appearance, than they are in regard to the time of the day. The phenomena above described took place at Paris upon the 19th of August; and by succeeding observations Mr. Reaumur discovered, that the same phenomenon takes place each year nearly about the same period, there being only a week, or a few days of variation; so that, like swallows and other birds of pafsage, they keep their appointed times with surprising regularity and exactness. In contemplating the hour of their appearance, our author remarks, "Whatever has been the temperature of the air during the day, whether it has been cold or hot for the season; whether the sun has shone forth with his utmost splendour, or has been obscured by clouds or rain, the hour at which our ephemera begin to put off their former robes is the same, and another hour appears to be marked out beyond which it is not permitted to them to do so. In lefs than two hours the number of these flies is so immense as to form clouds in the air, and to occasion a continued and heavy shower of these insects already