depending on the figure and elevation of coasts, on straits, and currents of the sea. The north-west and south-west monsoons are weaker and more variable in the bay of Bengal, more steady and violent in the gulf of Arabia. Both those monsoons grow broader to the west, ranging in this direction over the whole tract of sea that lies between Africa and Madagascar. In the seas extending between China, the kingdom of Siam, Sumatra, and the equator, those monsoons are felt likewise; but here, exceptand south. They extend as far as the Philippine islands, and though with much inconstancy, even to Japan. Between the equator, the islands of Java, and New Guinea, the monsoons are nearly similar to those of the Chinese sea, in regard to their direction, which merely varies a little to the north-west in the north monsoon, and a little to the south-west in the south monsoon. But they do not begin till six weeks after those of the Chinese seas. earth to the east, first comes into contact with the quick moving or tropical belt of the globe, the difference of their velocities is great compared with the other motion of the air above described, or that directly towards the equator; and consequently the wind blows at the extreme edge of the trades nearly from the east point. As this cool air, however, is drawn nearer to the equator, and comes successively in contact with parallels of latitude moving faster and faster, this constant action of the earth's rapid easterly motion gradually imparts to the superincum-ing local variations, they are almost entirely north bent air the rotatory velocity due to the equatorial regions which it has now reached; that is to say, there will be less and less difference at every moment between the easterly motion of the earth and the easterly motion of the air in question; while, at the same time, the other motion of the same air, or that which has a tendency to carry it straight towards the equator, having been exposed merely to the friction along the surface without meeting any such powerful counteracting influence as the earth's rotation, will remain nearly unchecked in its velocity. Thus, as I conceive, the trade-wind must gradually lose the eastern character which it had on first quitting the temperate for the tropical region, in consequence of its acquiring more and more that of the rotatory motion of the earth due to the equatorial regions it has now reached. While this cause operates, therefore, to destroy the easterly direction of the trades, their meridional motion, as it may be called, or that towards the equator, by remaining constant or nearly so, will become more and more apparent, till at length, when the friction of the earth in its rotatory motion has reduced the velocity of the cool air to the tropical rate, there will be left only this motion towards the equator, which is found invariably to characterize the equatorial limits of both trade-winds. This velocity, also, is at length checked, first, by its friction on the surface of the earth: secondly, by the air becoming heated, which causes it rather to rise than to flow along the surface: and thirdly, by the meeting of the two opposite currents-one from the north, the other from the south." NOTE B.-Monsoons. " The term Monsoon is otherwise derived from moussin, a Malay word, signifying "season." It is in the Indian ocean alone that the famous monsoons, or half-yearly winds, seem to destroy the uniformity of the general atmospheric movement. No doubt, however, they might be made to accord with it, provided we knew all the circumstances which influence them. We exhibit the facts in the first place. From the 10th degree of south latitude to the tropic of Capricorn, and beyond it, the general east or southeast trade-wind prevails over all the Indian ocean, sometimes in summer extending as far as the 2d and 3d degrees of south latitude. On this side the 10th degree, we first meet with the monsoons or periodical half-yearly winds. North of the equator, from April to October, a violent south-west wind prevails, accompanied with tempests, storms, and rain; while a soft and pleasant north-east wind blows during the other six months. Between the second and twelfth parallels of south latitude, the winds blow generally from north-west during the winter six months, from south-west in summer. Some other striking circumstances still remain to be noticed. The monsoons do not change, or, as sailors express it, do not break, of a sudden. Their change, which usually takes place fifteen days or four weeks after the equinoxes, is announced by the decay of the existing monsoon, by calms and squalls in rapid succession, by storms, water-spouts, tornadoes, and by Indian hurricanes, called taifouns, or typhons, particularly terrible from the explosions of electric matter accumulated by the monsoon. The beginnings of the subsequent monsoon are, at first, liable to variations, till finally it establishes an absolute dominion. Navigators assert, that on quitting the region where a monsoon prevails, one is sure, in ordinary circumstances, to fall in with a very strong and impetuous wind, blowing from a quarter directly opposite. They must naturally have observed this phenomenon with much care, since the calms and whirlwinds it occasions are productive of great danger. It can hardly be explained, except by admitting, with Halley, the existence of two currents,-one above, composed of warm and rarefied air; another below, composed of the column of cold and condensed air. This hypothesis will become almost a settled truth, if we observe how small is the elevation to which the monsoon extends a fact clearly exhibited in the peninsula on this side the Ganges, where the monsoons are arrested for several months by the mountain chain of the Gauts (not certainly of extraordinary height); so that the coast of Coromandel, and that of Malabar, have always their dry and their rainy seasons, at opposite periods of the year. According to the preceding description, it is the south-west monsoon alone which presents any phenomena directly contrary to the general movement of the atmosphere; for the north-east monsoon is in conformity with it, and the north-west wind south of the line seems not to be altogether constant, and may perhaps arise from nothing more than a compound movement, or a higher current of air. What, then, is the origin of this half-yearly wind, which in summer blows from south and south-west, over all the Indian ocean? The sagacity of physical geographers has long been exercised by this question. We give the explanation of which Halley laid the ground-work, and which appears to us the most plausible. The monsoons always change some time after the equinoxes; they constantly blow towards that hemiDuring winter, then, the constitution of the atmosphere in which the sun is found. The action of sphere exhibits the following principal circumstances: north-east winds north of the line; north-west winds south of it, to the 10th parallel; and finally, the east and south-east trade-winds. In summer, the phenomena are less contradictory: south-west winds from the 10th parallel to the northern lim.ts; trade-winds south of the 10th parallel. These general tendencies are subject to variations, this luminary on the atmosphere, is, therefore, plainly one of their causes. When its rays, reflected from the mountains of Thibet, scorching the plains of Bengal, and the valleys of the kingdom of Siam, rarefy and dissipate the atmosphere, the cold air becomes violently attracted from the regions about the south pole. The sun's action is seconded by the marine current, which proceeds from the south polar seas to those of India. This current must bring with it a column of vapours, continually disengaging themselves from its surface. The absence of a northern marine current must farther be added; we can even imagine, that the mountains of Thibet, and the whole central platform of Asia, may arrest and preserve the cold air, which would otherwise proceed from Siberia towards India. But why does not this polar wind prevail south of the equator also? For the same reason which renders the aquatic polar current inconsiderable there. The general movement of the ocean being opposed by no obstacle, has too much force to be modified by the polar current. A similar result happens in the atmosphere, at all times intimately connected with the ocean, which feeds and modifies it. But on leaving New Holland between us and the Pacific ocean, the general movement of the Indian sea must evidently be more and more abandoned to its individual force, and that force must soon be overcome by the polar current, which, after being long deflected or concealed by the general movement of the ocean, now re-appears in all its energy. The polar column of water now fills the atmosphere with cold particles, which, by their gravity, determine the whole atmospheric mass to flow towards the equator, more strongly and more directly than it would have flowed otherwise. It is possible, moreover, that higher currents may exist in the atmosphere, and descend towards the earth at the time when the monsoons commence. NOTE C.-Sand-storm in the Desert. In his travels to discover the source of the Nile, Mr. Bruce observed the astonishing phenomenon of moving pillars of sand, which are probably the effects of a number of whirlwinds in those torrid regions. In relating the particulars of his journey across a part of the deserts of Africa, he observes, "We were here at once surprised and terrified with a sight surely one of the most magnificent in the world. In that vast expanse of desert, from west and to the northwest of us, we saw a number of prodigious pillars of sand at different distances, at times moving with great celerity, and at others stalking on with a majestic slowness; at intervals we thought they were coming in a very few minutes to overwhelm us: and small quantities of sand did actually more than once reach us. Again they would retreat so as to be almost out of sight, their tops reaching to the very clouds. There the tops often separated from the bodies, and these once disjoined, dispersed in the air, and did not appear more. Sometimes they were broken near the middle, as if struck with a large cannon shot: about noon they began to advance with considerable swiftness upon us, the wind being very strong at north. Eleven of them ranged alongside of us, about the distance of three miles. The greatest diameter of the largest appeared to me at that distance as if it would measure ten feet. They retired from us with a wind at south-east, leaving an impression upon my mind to which I can give no name, though surely one ingredient in it was fear, with a considerable deal of wonder and astonishment. It was in vain to think of flying; the swiftest horse, or fastest sailing ship could be of no use to carry us out of this danger; and the full persuasion of this rivetted me as if to the spot where I stood, and let the camels gain on me so much in my state of lameness, that it was with some difficulty I could overtake them. The same phenomenon occurred again in the course of a few days. The same appearance of moving pillars of sand presented themselves to us this day, in form and disposition like those we had seen at Waadi Halboub, only they seemed to be more in number and less in size. They came several times in a direction close upon us: that is, I believe within less than two miles. They began immediately | after sun-rise like a thick wood, and almost darkened the sun; his rays shining through them for near an hour, gave them an appearance of pillars of fire. Our people now became desperate, the Greeks shrieked out, and said it was the day of judgment. Ismael pronounced it to be hell, and the Tucorories that the world was on fire. I asked Idris if ever he had before seen such a sight? He said he had often seen them as terrible, though never worse; but what he feared most was the extreme redness of the air, which was a sure presage of the coming of the simoom. I begged and entreated Idris that he would not say one word of that in the hearing of the people, for they had already felt it at Imhansara, on their way from Ras el Feel to Teawa, and again at the Acaba of Gerri, before we came to Chendi, and they were already nearly distracted at the apprehension of finding it here. On the 16th, at half-past ten in the forenoon, we left El Mout, standing in the direction close upon Syene. At eleven o'clock, while we contemplated with pleasure the rugged top of Chiggne, to which we were fast approaching, and where we were to solace ourselves with plenty of good water, Idris cried out with a loud voice, Fall upon your faces, for here is the simoom.' I saw from the south-east a haze come, in colour like the purple part of the rainbow, but not so compressed or thick. It did not occupy twenty yards in breadth, and was about twelve feet high from the ground. It was a kind of blush upon the air, and it moved very rapidly, for I scarce could turn to fall upon the ground with my head to the northward, when I felt the heat of its current plainly upon my face. We all lay flat upon the ground, till Idris told us it was blown over. The meteor or purple haze which I saw, was indeed past, but the light air that still blew was of heat to threaten suffocation. For my part, I found distinctly in my breast that I had imbibed a part of it; nor was I free of an asthmatic sensation till I had been some months in Italy, at the baths of Poretta, near two years afterwards.' CHAP. XXI. OF METEORS AND SUCH APPEARANCES AS RESULT FROM A COMBINATION OF THE ELEMENTS. IN proportion as the substances of nature are more compounded and combined, their appearances become more inexplicable and amazing. The properties of water have been very nearly ascertained. Many of the qualities of air, earth, and fire, have been discovered and estimated; but when these come to be united by nature, they often produce a result which no artificial combinations can imitate; and we stand surprised, that although we are possessed of all those substances which nature makes use of, she shows herself a much more various operator than the most skilful chemist ever appeared to be. Every cloud that moves, and every shower that falls, show him hidden qualities in air and water, that serves to mortify the philosopher's pride, and to he finds it difficult to explain. Dews, hail, snow, and thunder, are not less difficult for being more common. Indeed, when we reflect on the manner in which nature performs any one of these operations, our wonder increases. To see water, which is heavier than air, rising in air, and then variety of opinion and uncertainty of conjecture, I cannot help thinking that a theory of evaporation may be formed upon very simple and obvious principles, and embarrassed, as far as I can conceive, with very few objections. falling in a form so very different from that in which it rose; to see the same fluid at one time descending in the form of hail, at another in that of snow; to see two clouds, by dashing against each other, producing an electrical fire, which no watery composition that we know of can effect; these, I say, serve sufficiently to excite our wonder; and still the more in proportion as the objects are ever pressing on our curiosity. Much, however, has been written concerning the man-red-hot bar of iron into a vessel of water, the ner in which nature operates in these productions; as nothing is so ungrateful to mankind as hopeless ignorance. We know that a repelling power prevails in nature, not less than an attractive one. This repulsion prevails strongly between the body of fire and that of water. If I plunge the end of a fluid rises, and large drops of it fly up in all manner of directions, every part bubbling and steaming until the iron be cold. Why may we not for a moment compare the rays of the sun, darted directly upon the surface of the water, to so many bars of red-hot iron, each bar indeed infinitely small, but not the less powerful? In this case, wherever a ray of fire darts, the water, from its and, of consequence, as in the case of the bar of iron, a part of it will rise. The parts thus rising, however, will be extremely small; as the ray that darts is extremely so. The assemblage of the rays darting upon the water in this manner, will cause it to rise in a light thin steam above the surface; and as the parts of the steam are extremely minute, they will be lighter than air, and consequently float upon it. There is no need for supposing them bubbles of water filled with fire; for any substance, even gold itself, will float on air, if its parts be made small enough; or, in other words, if its surface be sufficiently increased. This water, thus disengaged from the general mass, will be still farther attenuated and broken by the reflected rays, and consequently, more adapted for ascending. And first, with regard to the manner in which water evaporates, and rises to form clouds, much has been advanced, and many theories devised.' All water, say some, has a quantity of air mixed with it; and the heat of the sun, darting down, disengages the particles of this air from the gross-repulsive quality, will be driven on all sides; er fluid; the sun's rays being reflected back from the water, carry back with them those bubbles of air and water, which, being lighter than the condensed air, will ascend till they meet with a more rarefied air; and they will then stand suspended. Experience, however, proves nothing of all this. Particles of air or fire are not thus known to ascend with a thin coat of water; and, in fact, we know that the little particles of steam are solid drops of water. But, besides this, water is known to evaporate more powerfully in the severest frost, than when the air is moderately warm.3 Dr. Hamilton, therefore, of the university of Dublin, rejecting this theory, has endeavoured to establish another. According to him, as aqua fortis is a menstruum that dissolves iron, and keeps it mixed in the fluid; as aqua regia is a menstruum that dissolves gold; or as water dissolves salts to a certain quantity, so air is a menstruum that corrodes and dissolves a certain quantity of water, and keeps it suspended above. But however ingenious this may be, it can hardly be admitted; as we know by Mariotte's experiment, that if water and air be enclosed together, instead of the air's acting as a menstruum upon the water, the water will act as a menstruum upon the air, and take it all up. We know also, that of two bodies, that which is most fluid and penetrating is most likely to be the menstruum of the other; but water is more fluid and penetrating than air, and therefore the most likely of the two to be the menstruum. We know that all bodies are more speedily acted upon, the more their parts are brought into contact with the menstruum that dissolves them; but water enclosed with compressed air, is not the more diminished thereby. In short, we know, that cold, which diminishes the force of other menstruums, is often found to promote evaporation. In this 1 See Note upon Evaporation, at page 126. 3 Memoires de l'Academie des Sciences, an. 1705. From this plain account, every appearance in evaporation may be easily deduced. The quantity of heat increases evaporation, because it raises a greater quantity of steam. The quantity of wind increases evaporation; for, by waving the surface of the water, it thus exposes a greater surface to the evaporating rays. A dry frost, in some measure, assists the quantity of evaporation; as the quantity of rays are found to be no way diminished thereby. Moist weather alone prevents evaporation; for the rays being absorbed, refracted, and broken, by the intervening moisture, before they arrive at the surface, cannot produce the effect; and the vapour will rise in a small proportion. Thus far we have accounted for the ascent of vapours; but to account for their falling again is attended with rather more difficulty. We have already observed, that the particles of vapour, disengaged from the surface of the water, will be broken and attenuated in their ascent, by the reflected, and even the direct rays, that happen to strike upon their minute surfaces. They will, therefore, continue to ascend, till they rise above but to a certain height above the surface of the the operation of the reflected rays, which reaches earth. Being arrived at this region, which is cold for want of reflected heat, they will be condensed, and suspended in the form of clouds. Some vapours that ascend to great heights, will be frozen into snow; others, that are condensed lower down, will put on the appearance of a mist, which we find the clouds to be, when we ascend among them, as they hang along the sides of a mountain. These clouds of snow and rain, being blown about by winds, are either entirely scattered and dispersed above, or they are still more condensed by motion, like a snow-ball, that grows more large and solid as it continues to roll. At last, therefore, they will become too weighty for the air which first raised them to sustain; and they will descend with their excesses of weight, either in snow or rain. But as they will fall precipitately, when they begin to descend, the air, in some measure, will resist the falling; for as the descending fluid gathers velocity in its precipitation, the air will increase its resistance to it, and the water will, therefore, be thus broken into rain; as we see, that water which falls from the tops of houses, though it begins in a spout, separates into drops before it has got to the bottom. Were it not for this happy interposition of the air, between us and the water falling from a considerable height above us, a drop of rain might fall with dangerous force, and a hailstone might strike us with fatal rapidity. 6 In this manner evaporation is produced by day; but when the sun goes down, a part of that vapour which his rays had excited, being no longer broken and attenuated by the reflecting rays, it will become heavier than the air, even before it has reached the clouds; and it will, therefore, fall back in dews, which differ only from rain in descending before they have had time to condense into a visible form. Hail, the Cartesians say, is a frozen cloud, half melted, and frozen again in its descent. A hoar-frost is but a frozen dew. Lightning we know to be an electrical flash, produced by the opposition of two clouds; and thunder to be the sound proceeding from the same, continued by an echo reverberated among them. It would be to very little purpose to attempt explaining exactly how these wonders are effected; we have as yet little insight into the manner in which these meteors are found to operate upon each other; and, therefore, we must be contented with a detail rather of their effects than their causes. the mildest and kindest aspect, every meteor seems to befriend us. With us, rains fall in refreshing showers, to enliven our fields, and to paint the landscape with a more vivid beauty. Snows cover the earth, to preserve its tender vegetables from the inclemency of the departing winter. The dews descend with such an imperceptible fall as no way injures the constitution. Even thunder is seldom injurious; and it is often wished-for by the husbandman to clear the air, and to kill the numberless insects that are noxious to vegetation. Hail is the most injurious meteor that is known in our climate; but it seldom visits us with violence, and then its fury is but transient. One of the most dreadful storms we hear of,7 was that of Hertfordshire, in the year 1697. It began by thunder and lightning, which continued for some hours, when suddenly a black cloud came forward, against the wind, and marked its passage with devastation. The hailstones which it poured down, being measured, were found to be many of them fourteen inches round, and consequently as large as a bowling-green ball. Wherever it came, every plantation fell before it; it tore up the ground, split great oaks, and other trees, without number; the fields of rye were cut down, as if levelled with a scythe; wheat, oats, and barley, suffered the same damage. The inhabitants found but a precarious shelter, even in their houses, their tiles and windows being broke by the violence of the hailstones, which, by the force with which they came, seemed to have descended from a great height. The birds, in this universal wreck, vainly tried to escape by flight; pigeons, crows, rooks, and many more of the smaller and feebler kinds were brought down. An unhappy young man, who had not time to take shelter, was killed; one of his eyes was struck out of his head, and his body was all over black with bruises; another had just time to escape, but not without the most imminent danger, his body being bruised all over. But what is most extraordinary, all this fell within the compass of a mile. Mezeray, in his History of France, tells us of a shower of hail much more terrible, which happened in the year 1510, when the French monarch invaded Italy. There was, for a time, a horrid darkness, thicker than that of midnight, which continued till the terrors of mankind were In our own gentle climate, where nature wears changed to still more terrible objects, by thun 6 It has been observed with surprise, that when a number of bodies are exposed together to dew, some are quite wetted with it, while others remain dry. This circumstance probably depends upon the goodness of the body as a conductor of heat. Good conductors will part with their heat more readily, and will therefore evaporate the dew again, whereas it will remain upon bad conductors, which will not so easily part with their heat. If this explanation be the true one, it follows that bodies exposed to the dew, and dry, must have a lower temperature than those which remain moist.-ED. der and lightning breaking the gloom, and bringing on such a shower of hail, as no history of human calamities could equal. These hailstones were of a bluish colour; and some of them weighed not less than a hundred pounds. A noisome vapour of sulphur attended the storm. All the birds and beasts of the country were entirely destroyed. Numbers of the human race suffered the same fate. But what is still more extraordi 7 Phil. Trans. vol. ii. p. 148. nary, the fishes found no protection from their native element; but were equal sufferers in the general calamity. These, however, are terrors that are seldom exerted in our mild climates. They only serve to mark the page of history with wonder; and stand as admonitions to mankind, of the various stores of punishment, in the hands of the Deity, which his power can treasure up, and his mercy can suspend. The thunder which attends the fall of these rains is much more terrible than that we are generally acquainted with. With us, the flash is seen at some distance, and the noise shortly after ensues: our thunder generally rolls in one quarter of the sky, and one stroke pursues another. But here it is otherwise; the whole sky seems illuminated with unremitted flashes of lightning; every part of the air seems productive of its own thunders; and every cloud produces its own In the temperate zones, therefore, meteors are shock. The strokes come so thick, that the inrarely found thus terrible; but between the tro-habitants can scarcely mark the intervals; but pics, and near the poles, they assume very dread-all is one unremitted roar of elementary confuful and various appearances. In those inclement sion. It should seem, however, that the lightregions, where cold and heat exert their chief ning of those countries is not so fatal or so danpower, meteors seem peculiarly to have fixed gerous as with us; since in this case the torrid their residence. They are seen there in a thou-zone would be uninhabitable. sand terrifying forms, astonishing to Europeans, yet disregarded by the natives, from their frequency. The wonders of air, fire, and water, are there combined, to produce the most tremendous effects; and to sport with the labours and apprehensions of mankind. Lightnings, that flash without noise; hurricanes, that tear up the earth; clouds, that all at once pour down their contents, and produce an instant deluge; mock suns; northern lights, that illuminate half the hemisphere; circular rainbows; halos; fleeting balls of fire; clouds reflecting back the images of things on earth, like mirrors; and water-spouts, that burst from the sea, to join with the mists that hang immediately above them. These are but a part of the phenomena that are common in those countries; and from many of which our own climate is, in a great measure, exempted. The meteors of the torrid zone are different from those that are found near the polar circles; and it may readily be supposed, that in those countries where the sun exerts the greatest force in raising vapours of all kinds, there should be the greatest quantity of meteors. Upon the approach of the winter months, as they are called under the Line, which usually begin about May, the sky, from a fiery brightness, begins to be overcast, and the whole horizon seems wrapt in a muddy cloud. Mists and vapours still continue to rise; and the air, which so lately before was clear and elastic, now becomes humid, obscure, and stifling; the fogs become so thick, that the light of the sun seems in a manner excluded; nor would its presence be known but for the intense and suffocating heat of its beams, which dart through the gloom, and instead of dissipating only serve to increase the mist. After this preparation, there follows an almost continual succession of thunder, rain, and tempests. During this dreadful season, the streets of cities flow like rivers; and the whole country wears the appearance of an ocean. The inhabitants often make use of this opportunity to lay in a stock of fresh water for the rest of the year; as the same cause, which pours down the deluge at one season, denies the kindly shower at another. When these terrors have ceased, with which, however, the natives are familiar, meteors of another kind begin to make their appearance. The intense beams of the sun darting upon stagnant waters, that generally cover the surface of the country, raise vapours of various kinds. Floating bodies of fire, which assume different names, rather from their accidental forms than from any real difference between them, are seen without surprise. The draco volans, or flying dragon, as it is called; the ignis fatuus, or wandering 8 The ignis fatuus, or will-o'-the-wisp, most philosophers are agreed, is caused by some volatile vapour of the phosphoric kind, probably the phosphoric hydrogen gas. The light from putrescent substances, particularly putrid fish, and those sparks emitted from the sea, or sea-water when agitated in the dark, correspond in appearance with this meteor. vapour shining without heat;" and it is usually Sir Isaac Newton defines the ignis fatuus to be “a visible in damp places, about dunghills, buryinggrounds, and other situations which are likely to abound in phosphoric matter. A remarkable ignis fatuus was observed by Mr. Derham, in some boggy ground between two rocky hills. He was so fortunate as to be able to approach it within two or three yards. It moved with a brisk and desultory motion about a dead thistle, till a slight agitation of the air occasioned, as he supposed, by his near apand as he approached, it kept flying before him. He proach to it, caused it to jump to another place; was near enough to satisfy himself that it could not be the shining of glow-worms or other insects-it was one uniform body of light. M. Beccaria menfrequently observed in the neighbourhood of Bologna, tions two of these luminous appearances, which were and which emitted a light equal to that of an ordinary faggot. Their motions were unequal, sometimes rising, and sometimes sinking towards the earth; they continued hovering about six feet from the sometimes totally disappearing, though in general ground. They differed in size and figure; and indeed the form of each was fluctuating, sometimes floating like waves and dropping sparks of fire. He was assured that there was not a dark night in the their appearance at all affected by the weather, whole year in which they did not appear; nor was whether cold or hot, snow or rain. They have been known to change their colour from red to yellow; vanishing entirely when the observer came very near and generally grew fainter as any person approached, to them, and appearing again at some distance. Dr. Shaw also describes a singular ignis fatuus, which |