under ground? May they not proceed from a sufficient collection of inflammable exhalations in the regions of the air? presters being a kind of continu'd lightning.

Sometimes there appears first, like a flaming cloud in the horison, from whence proceeds the fiery tempest, in a most astonishing manner; and some of these hurricanes and whirlewinds have seem'd so very terrible, as if there had happen'd one entire conflagration of the air and seas. I was inform'd by Captain Prowd of Stepny, a person of great experience and integrity, that in one of his voyages to the East Indies, about the 17th degree of south latitude he met with a tempest of this nature, towards the coast of India; of which I had some particulars extracted from his journal: First, contrary to the course of the winds, which they expected to be at south-east, or between the south and east, they found them between the east and north, the sea extremely troubl'd; and, which was most remarkable and dreadfull, in the N.N.W., north, and N.N.E. parts of the horison, the skye became wonderfully red and inflam'd, the sun being then upon the meridian. These were thought omens of stormy weather, which afterwards happen'd according to their suspicions; and as the darkness of the night encreas'd, so did the violence of the wind, till it ended in an extreme hurricane; which an houre after midnight, came to such an height, that no canvas or sayles would hold; and seven men could scarce govern the helme. But that which I mention as most considerable to our purpose, was, that the whole hemisphere, both the heavens and raging seas, appear'd but as one entire flame of fire; and those who are unacquainted with the reputation of this grave person, will find no just reason to distrust the truth of the relation.

Although these fiery whirlewinds are to be reckon❜d as the most wonderfull events in Nature, yet we have frequent examples of them in historians and philosophers: one of the most memorable which ever I read of, was known, some years since, here in England; and describ'd at large in the Public Gazet: it run in a long tract, as a dreadfull torrent of fire, destroying all places wherever it came; and, if I mistake not, did much damage in Lincolnshire; but I cannot now recollect the particulars, though, as I remember, it happen'd since the last Dutch war.

They have a strange kind of ecnephias towards the Arabian Gulf, which rises from the north; where also they have oftentimes sandy tempests; and that not only in Africk, near the temple of Jupiter Hammon, (as seems to have been noted by Herodotus,) but especially in Arabia; where the floating sands are driven by the winds, and sometimes have overwhelm'd no lesse then six thousand persons at once, travelling in caravans from Aleppo on their way to Babylon.

I shall conclude with a description of hurricanes, which have the greatest affinity in their nature to the tornados, but farre more lasting and violent by some, they are call'd hurracanos, and by others, orancan Yet I rather think the word was borrowed of the natives, and deduc'd from a barbarous origine.

We seldome hear of any hurricanes, but between the tropiques, and within the jurisdiction of the generall, or trade-wind, which blowing perpetually from the eastern points, if it chance to be repell'd by a land brise, or any contrary motion from the west; this must needs occa

sion strange conflicts and seditions in the air: and, were our senses fine enough to discerne the invisible commotions of the atmosphere, we should see it oftentimes disturb'd and fluctuating, no lesse then the most tempestuous seas.

They are not alike terrible in all places between the tropiques, but raign more especially near high shoars and islands that lye to the eastward from the Continent; so that they infest the Phillippine and Caribbe Isles, more then any other parts of the habitable world.

Nearer the Line its most inclin'd to calmes; and though in the torrid zone, there is but one set wind all the year round, yet they are also extremely subject to tempests, whenever the Levants encounter any opposition from the west. For although (as I before noted) the progresse of wind is naturally direct, yet meeting with any impediment, it whirles about in a circular and vortiginous motion. This cause was assign'd by Dorisi of the dangerons storms that happen near the equinoctiall, and (not to instance in severall others, who have declar'd for the same hypothesis) Ricciolus, and more expresly Varenius, in his geography, gives the like account of these typhons, or hurricanes:

"Causa typhonis procul dubio est, quòd ventus ex aliqua plaga erumpens, versus aliam, in hac reperit impedimentum, &c. Potest etiam esse ab oppositis ventis simul spirantibus, &c."

We see these kind of eddys in rivers, when the course is stopt by a dam or bank, at least when two contrary currents meet. And I believe the phenomenon of hurricanes might be sufficiently illustrated from hydrostatique experiments, were it not my intention rather to prosecute their natural history, then to determine their cause. Though I shall endeavour to collect such observations, as may not obscurely hint to us the fittest materials, on which to superstruct an hypothesis. But we cannot safely adventure upon this arduous attempt, without more exact discoveries of many particular circumstances, and accidents, which are of greatest importance to these nice speculations.

I should enquire what anniversary winds blow either in Guiana, or the neighbouring continent, especially from the west, in those months which are most suspected for hurricanes.

Then, what judgment can be made of their causes, from their prognostiques, since I am assur'd from very good hands, that they have oftentimes been foretold by the Indians. Moreover the influences of the sun, the nature of the currents and shoars, the phasis of the moon, &c., ought not to be neglected by the inquisitive naturallist.

Lastly, whether they are not frequently accompany'd by earthquakes, as I have been inform'd by some who were planters in the West Indies, which was likewise taken notice of in that excellent history of the Caribbes, of an hurricane which happen'd in the year 1563, together with an earthquake. For the included spirit, which caus'd that palpitation in the bosome of the earth, being afterwards releast from its imprisonment, might occasion these dreadfull tempests and winds. Fournier (who is generally reputed an author of good credit, and skilfull in what relates to hydrography) mentions an innundation on the coasts of America, an eruption of a burning mountain, and an earthquake neer the same time; which for the memorableness of the event, I shall set down in a few lines.

Thirty-five leagues on the south of Lima, is situate a famous port call'd Hisco; and a town in which most of noblesse and persons of qualitie doe reside; who perceiving one day, that the sea retir'd all at once from their shoars, and left the river dry, great numbers of people flock't together on the shoare, to behold so extraordinary a sight; little uspecting the ill destiny which was to attend them: for presently after hey saw a great and suddain tumour of the sea, and perceiv'd the water to boyl, and the waves to swell, and rowle one upon another; not like waves, but mountains of water, so high, that there remain'd no hope of saving their lives by flight; expecting every moment when they should be swallow'd up by the sea: So that, the ocean quitting its ordinary bounds, made an excursion for three hundred leagues; overturn'd the houses and trees, and left the country desolate; the ships saly'd over the highest walls, during this wonderfull innundation. Canama, a noted village distant two hundred and thirty leagues from Lima, was destroy'd with its port, and many other places; more especially the town of Arica, which lost in the harbour many ships richly laden, to the value of a million in gold. The mountain Onerate, which, some years since, had vomited out a great quantity of ashes, began a very terrible conflagration, and was followed by a suddain trembling of the earth, which in less than a quarter of an houre, swallow'd up severall villages; that there was scarce ever a more dreadfull earthquake.

It is not unusuall to have innundation of the seas, eruptions of burning mountains, earthquakes, and then violent tempests, like hurricanes, to happen about the same time, and probably from the same cause: For the nitro-sulphureous spirit which causes the trembling of the earth, and that stupenduous commotion of the seas, may afterward break loose into the most horrid conflagrations and winds; especially in such places that abound with these thundring minerals; which, if we consider their active nature, are the fittest materials for hurricanes. I know not how farre it may be thought a confirmation of this, that Braybrook in Northamptonshire, where (as was at large describ'd in the last of the Philosophical Transactions,) there happen'd that dangerous whirlewind the last year, has been a place much subject to earthquakes. But I return from this digression to the hurricanes of the West Indies, where it seems to me very odd, that they should be so dreadfull in some places of the Caribbe Islands, insomuch that Mevis and St. Christophers have severall times been almost depopulated by them, when they never reach to Jamaica, on the one side, (hapily as lying without the vortex of the whirlewind,) nor on the other, beyond Barbados, where they have seldome more then the tail of an hurricane, though it is not farre situate from St. Christophers, Porto Rico, Gardaloupe, and other islands, where they rage with the greatest violence.

They are no strangers to the Moluccas and Philippines, and we have most incredible relations of the stormes in the way to Japan, which have carry'd ships a considerable distance from the sea, up the dry land: some have been miserably wreck't, and bury'd in the waves, others split in a thousand pieces against the rocks, that scarce one ship in five escapes these disasters in the tempestuous months about autumn, or at the change of the monsoons. From hence we may collect this considerable remarque. That they never happen but on the eastern shoars,

*

where they are fatal to the Chinese and Caribbe seas, and so farre as the River of Plate; likewise to that part of Africk from the Cape to St. Lawrence, and the adjacent isles: when they are altogether unknown to the African Ocean, from the Canaries to Cape Bon Esperance, are never heard of at New Spain, or the coasts of Peru, nor towards any other western parts of America; because there the winds, which blow off from land, make no opposition against the generall brise, but comply with the constant motion of the air between the tropiques, from east to west: For the shifting of the trade wind from the easterly points, is usually the first onset of an approaching hurricane.

Yet, however these suspicions of mine be receiv'd, I think it cannot be rationally disputed, but that those direfull tempests have their first from the western continent, for we seldome encounter them very remote from land, and the experienc'd masters of ships are never jealous of hurricanes in the spacious ocean; or, if they perceive them coming, immediately make out to sea, where their fury is much lesse, then neer the shoars.

They are the most to be dreaded about the end of summer, in the months of July and August; for both winds and seas, imitate the motions of the sun, and being dilated by the Celestial heat, annually revert from north to south; and from south to north again; so that the sun hasting from one tropique to another, causes the like suddain conversions in the currents and winds; and being the most universall efficient, must needs be principally concern'd in all vicissitudes of the sublunary world.

(To be concluded in our next.)

AUSTRALIAN NAVIGATION.-Mordaunts Shoal, at the entrance of Bloomfields Rivulet.-Australia, Eastern coast.

THIS shoal is not laid down in any of the charts, and is very dangerous for ships running into Weary Bay, particularly during the night, or any other time after sunset. It is of small extent, not more than half a ship's length over, and nearly dries at low water, at which time it slighty breaks; it is composed of hard sand, and the vessel struck heavily on it, and had it not been for the assistance of the other ships she must have sustained much greater damage. I made the position of the shoal to be in latitude 15° 54' south, and longitude 145° 22′ east, by chronometer corrected at Fitzroy Island. The channel between the sand and the shore is quite clear, and a ship may run in within threequarters of a mile of the shore, carrying four and a half, and four fathoms. The shoal bears from the entrance of Bloomfields Rivulet N.E.b.E. off shore about two, or two and a half miles. Should a ship be steering for the bay from the southward, by paying strict attention to the lead, will receive notice of the approach towards it, having passed Cape Tribulation at the distance of two, or two and a half miles. If the sounding decrease to nine fathoms, and then quickly to seven, and six and a half, she should haul in for the shore, and run along it at the distance of about one mile in four or four and a half fathoms, rr if dark, it would be prudent to anchor immediately. I observed this

Now called Madagascar.

shoal last voyage, when weighing from the northern part of the bay, in company with her Majesty's brig Britomart, but as Captain Stanley and officers contended that it was not a shoal, I concluded that I was mistaken.

N.B.-But it is now evident that this is the same that I saw before, and being a new discovery, I have named it Mordaunts Shoal.

Two shoals bearing east from north 8°, showing brown, and not very plain until very close :—we were forced to haul very quick to the eastward to clear them.

J. MORDAUNT.

An extract from Captain Mordaunt's log, of the ship Canton. "At 4h, 30m. abreast of Cape Tribulation: at 5h. 30m. shortened sail and ran for Weary Bay: at 6 suddenly shoaled our water to nine fathoms, eight, seven, and six and a half, decreasing rapidly; rounded to and brought up with the bower in six fathoms,-the Robert Henderson immediately rounded to and brought up likewise, about half a cable's length to the southward and westward of us. The Bencoolen, in giving us a berth of about a cable's length, grounded on a sandbank to the eastward of us, and remained fast,-immediately lowered the cutter, and went with eight hands to assist in getting her off: got a hawser from the Robert Henderson, and also run out a stream anchor, and hove a heavy strain, the Robert Henderson having taken her hawser to their windlass. After letting go their second anchor, for fear of their first coming home, at nine sent the remainder of the crew to assist in heaving her off; about 10h. 20m. got her afloat, and anchored her in six fathoms ahead of us, but not before she had knocked her rudder off, having broke four of the pintles."

NEW REEFS AND ISLANDS.—Australia.

9, Upper Park Street, Greenwich, Oct. 5th, 1840. Sept. 21st, 1836.-AT 6 A.м. weighed with a moderate breeze from N.E. by eastward, and stood for the eastern side of the large Palm Island. Mount Hinchinbrook, (which has a rugged summit and several peaks,) visible from the deck. At 8 A.M. this mountain bore N.W.b.W.-Palm Island No. 2, W.S.W. Ran to the northward along the group of the Palms,at the distance of four or five miles, and at 11h. 30m. A.M., discoloured water was seen about one-third of a mile on the starboard bow, -altered course to clear it, and passed one-third of a mile from an (apparently) shoal patch of coral. When its extremes bore E.N.E. and N.b.E., and the vessel was one-third of a mile from the body of the shoal; the following bearings were taken with an azimuth compass :South-east point of the large Palm Island S.S.E. E. easterly, (magnetic.) North-west point of ditto SW. Northward peak of Mt. Hinchinbrook N.W.b. W. W. westerly

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From the masthead it appeared to be three-quarters of a mile in length, north-west and south-east, and one and a half cable's in breadth at its centre, narrowing towards each end. One cable's length to the eastward of it are two small round patches, with deep water between them and the large shoal!