The information contained in this notice will be carefully considered, be noted in the Sailing Directions, and compared with the chart when the ship is navigating the waters to which the notice refers. HYDROGRAPHIC NOTICE. [ No. 1.] (The last number for 1867 was 19.) THE GULF OF CADIZ AND WESTERN SHORE OF THE SPANISH PENINSULA. The folbwming Observations on the Winds, Currents, and Tides of the Gulf of Cadiz and Western Shore of the Spanish Peninsula, are taken from the London Nautical Magazine for October, November, and December, 1867, and January, 1868: [There are few parts of the ocean more frequented by ships and seamen than the Strait of Gibraltar and its adjacent sea; and a general view of this subject, bearing on the requirements of the navigator, could not perhaps be looked for from a more worthy source than the chief of the Royal Hydrographic Office at Madrid. From the current volume of the Anuario lHidrografico, our usual copy of which has been so considerately presented by Don Salvador Morena, we lose no time in preparing a translation of the paper on the subject that it contains, and which will be completed in future numbers of this work. The reader will remember the papers on the Ladrones in our, last year's volume obtained from the same source.] As that part of the Iberian Peninsula under present consideration varies much in its contour-one line of its coast being nearly at right angles to another-and as this difference of direction produces an effect on the winds and currents that prevail in its neighboring seas, it will be as well to classify them, describing first their prevailing characters between the Strait of Gibraltar and Cape St. Vincent, and then those between this Cape and Cape Prior. Before we proceed with them, however, let us state what we mean byThe Gulf of Cadiz. —The portion of coast included under this name is the great bay which the south coast of Portugal and the seacoast of Spain form with the coast of Morocco. The limits of this gulf, which might be permanently named the Gulf of Cadiz, are the Cape St. Vincent to the North and that of Mazigan to the South, those capes lying N.N.W. and S.S.E. of each other, two hundred and thirty miles distant. This great- gulf, which, as we have observed, is entirely open to winds from West to South, would be no doubt very dangerous to vessels if it had not at its interior the Strait of Gibraltar, and a little to the northward of it the excellent shelter of the Bay of Cadiz. Coast of the Gulf of Cadiz.-The coasts of this gulf are generally low and uniform, excepting those in the vicinity of the strait and about Cape St. Vincent. Besides, much of the coast about Cadiz is fringed with outlying and dangerous reefs, from which it would not be easy for vessels to extricate themselves if they had not that port to run for. Fortunately, the whole shore of the gulf is lined with a bank of soundings, which, on the coast of Spain and Portugal, taking the onehundred-fathom line, extends out from fifteen to twenty miles, and from the African shore to nearly the same distance; thus giving ample warning to the navigator, by the lighter color of the water, of his proximity to the shore, should he not be able to distinguish this on account of its distance and the state of the weather. Winds in the Gulf of Cadiz.-It is admitted that winds are merely currents of our atmosphere, occasioned by diversity of temperature; and that such currents are affected by the configurations of continents over which they pass, the presence of seas near them, lakes, river overflows, etc. We also know that while, in a certain extent of sea, a certain wind prevails, in another not far from it another wind is blowing, if not directly opposed to it, at least from a very different quarter. Thus we find that in the limited space of the ocean under consideration, off the western part of the peninsula, fresh northerly winds may prevail; while in the southern portion of it, S.E. winds are blowing of more or less duration. This contrast of direction is very remarkable, and owes its origin not only to the configuration of the coast, but also to the proximity of the Mediterranean. Within the Gulf of Cadiz, and especially near the Strait of Gibraltar, easterly and westerly winds are the most prevalent, while on the coast of Portugal and Galicia, northerly and southerly winds are the most common. Let us here observe that what we mean by the term "Easterly" (a term used by the generality of navigators on the south coast of the Peninsula) refers to those winds from the "Eastward" which blow from E.N.E. to E.S.E.; and by the name of "Westerly," those which blow from the opposite points, or from W.N.W. to W.S.W. Easterly Winds. —Within the Mediterranean easterly winds are generally moist and attended with foul weather, heaping dense clouds on the mountains on the eastern side of the Strait of Gibraltar; but are very dry and clear on the coast of Cadiz, Huelva, and Algarve, as if in traversing the heights of Algeciras they dispose of all their moisture and mist on the cordilleras which separate the high land from the low. Force of the EasterlyWind.-The strength with which the easterly wind blows increases until it passes the meridian of Tarifa; but it then soon loses its strength as it approaches Cape Trafalgar, and frequently does not even reach Cadiz. It must be observed, however, that this same strong Levanter which scarcely reaches Cadiz continues established in the parallel of the strait to a much greater distance from its western entrance. It is also to be noted that while the fresh Levanter prevails within the strait at Cadiz and in the Gulf of Huelva, land and sea breezes are blowing at Cadiz and in the Gulf Huelva, Cape Trafalgar being almost always the dividing limit of these contending winds. Thus it is common, particularly in summer-time, for a vessel to be running through the strait with a strong Levanter and then into Cadiz with a fresh sea breeze. In such cases the Levanter accompanies the vessel to the meridian of Tarifa, and sometimes to that of Trafalgar, losing in strength and hauling gradually to S.E. and South until it arrives at S.W. or W.S.W. If the navigator bound to Cadiz foresees this change, he does not keep along the coast, but runs on a parallel to the southward of Tarifa, so as to be well clear of' Cape Trafalgar, and in a good position when he catches the sea breeze to make Cadiz with it. Slackness of the Levanter.-Sometimes the easterly wind is two or even three days in reaching Cadiz, and sometimes even although it may be strong in the Strait. Sometimes also it will reach Chiclana and Carracca without touching the mouth of the bay, where only the sea breeze prevails. But in this latter case it soon becomes general, extending over the whole coast as far as Cape St. Mary or even West of this cape. Sometimes also it does not pass the Broa de Sanluicar. Yet when the Levanter is spreading as just observed it also becomes intermittent. It comes in gusts of brief duration as if it would overcome its opponent, the western breeze. In these cases vessels from the strait making for Cape St. Vincent have it partially or in gusts until it becomes general. Sometimes it does not pass the meridian of Cape St. Mary, where it generally meets the westerly wind. On the coast of Cadiz, or between Cape Trafalgar and the mouth of the Guadalquivir, the Levanter also comes in gusts; but when once established it maintains its place, and above all in summer-time, lasting sometimes as long as fifteen days together. Perhaps the only intermission of it is about sunset, and slackening throughout the night, but recovering itself about daylight and regaining its former strength as the sun gets at its height. It will thus set in with some gusts soon after sunrise, becoming stronger as the sun gets at its height, and blowing hardest about noon. In recompense for this there are some years in which this most pernicious wind will not blow for even a couple of months. Ill effects of the Levanter.-The greatest scourge of the Bay of Cadiz is undoubtedly the Levanter or East wind. When this wind has been continuing for a week, perhaps for a fortnight, especially in those places which are heated by it, all mercantile transactions are suspended, and the most powerful boats can scarcely be trusted, except in the night or early mornings, when it is slack. On these latter occasions, the Levanter will sometimes become so light that it will even asssume the benign influence of the land wind and will draw to the northeast; but as soon as the sun is up it again makes itself felt with severe gusts, and at nine or ten o'clock no boat can cross the bay. This mostly happens in the hot season, and at times when it is scarcely felt in the eastern entrance of the Strait of Gibraltar. Principal character of the Levanter.-From the meridian of Tarifa to the westward the Levanters are very dry and clear, especially in summer. When, in this season, they blow with the intensity above mentioned, they are attended with a suffocating heat, which obliges the people of Cadiz and its vicinity, as a protection from it, to close their houses hermetically if they can, and prevent the dust which it brings from entering their dwellings. In its course it destroys the crops and produces much ill effect on health. Within the bay it blows from E.S.E. and S.E., excepting about daylight, when it is E., or even E.N.E. Aspect of the Levanter.-While the Levaidter lasts, the sky keeps clear; but the horizon is somewhat heavy, and the land misty. If a cloud be seen it is very light and high, of the cirrus order. The sun rises and sets very dull and hazy, so much so that the eye can look at it without flinching. Dryness is its distinctive character on the western coast of' the province of Cadiz; one totally different to that which it presents on its eastern shore, where it is remarkable for its humidity. The most lasting Levanters are those which establish themselves by slow and gradual progress, or which do not reach Cadiz until they have prevailed for two or three days in the Strait; those which come suddenly and perhaps with much strength are the soonest over. In wvinter-time the Levanters do not last so long, and at their commencement are clear, but lose this quality when they become S.E.; then they also bring heavy clouds and showers, sure signs that they will haul to the southward, and change to the Vendaval, or S.W. wind. Indications of the Levanter.-The warnings of the Levacnter are the entire absence of dewv, and the peculiar dryness of everything about the decks. In calm weather, or when the wind is very light from the westward, this dryness is very evident, and at the same time light threads of gossamer will be seen clinging to the rigging; they are sure indications of the approaching Levanter. Some persons believe that these filaments of gossamer are really threads of spiders. But such is scarcely credible. If we consider the enormous quantity that the Levanter brings with it while it lasts, some fine, some coarse, it is impossible to imagine that there can be such a multitude of spiders to produce them in the small tract of country between the heights of Algeciras and the plains of Chiclana. We suspect that they are a watery meteor which is imperceptible from its minuteness. The same phenomenon is found at Vera Cruz with northers, and at the river Plata with pamperos, as well as in the interior of the continents when dry winds prevail. It is frequently observed in the country about Madrid, especially in autumn. There are others who consider that these filaments are produced by microscopic spiders which emit them in dry winds. It is sufficient to see the secretions of the insects which are the property of the microscope. Masses of these filaments are found on the vessels anchored at Cadiz clinging to all parts of the rigging, some very fine and others coarser, and there are also some which are clotted and tolerably long, transparent, and also opaque, white, and generally elastic. Some are found coagulated together in the water, and all separate when taken by the hand. With close attention they may be seen to cover the surface, carried along by the wind like skeins of thread. With this same wind, the Levanter, none of these are found in the rigging of vessels anchored at Algeciras. What does it consist of? This phenomenon must have some relation to the hygrometric condition of the atmosphere. On the shores of the Gulf of Mexico in the dry season it is also observed; there these gossamers are generally called the threads of the Virgin, and considered an infallible proof of an approaching norther. The same phenomena are observed in the river Plata, where they are found in the midst of fine weather with a light northerly wind and a clear sky, and are the same precursor of a pampero. The same is observed on the shore of the Spanish Peninsula. In all these cases the atmosphere is very dry and transparent, and the threads adhere to all parts of the vessel from the trucks to the sides, not even excepting the persons on board.* Signs of the Levanter in Gibraltar Strait -The experien ced mariner who may be at Cadiz knows very well when the Levantcr prevails in the strait. If he sees on the heights of Ubrique, and the more elevated mountains of Algeciras, little white clouds like bunches of raw cotton adhering to their summits, he knows they are proofs of the easterly wvind blowing in f he eastern entrance of the strait. And if, with these proofs, he finds the suffocating heat which accompanies this wind, and the dryness which belongs to it, he concludes that the Levanter will soon be with him, although at the time the westerly wind may be blowing in the bay. The seamen also in the * In reference to this subject, it may contribute towards settling the question of whence do these numerous filaments come, by quoting the following extract from the Commercial Advertiser, published at Honolulu, Sandwich Islands, (weekly;) or, as they are improperly called, Hawaii, the French pronunciation forCook's "Owhyhee." It appears to be addressed to the "curious," and certainly in the subject of these filaments, or " threads of the Virgin," there is enough to excite the attention of curiosity. It reads thus: *'FOR THE CuRnous.-An old resident on Hawaii, whose letters are always welcome, sends us some incidents relating to spiders:' Will some of the scientific gentlemen of Honolulu explain the following facts: Many years ago, perhaps forty-five, while residing in the United States, I one day saw, in the latter part of summer, a spider start from a bush and go up at an angle of about 450 without any web to go on. In after years I often thought of the above incident, and came to the conclusion that I was mistaken. About eight years ago, I observed a green spider, being of a different color from any I recollected to have seen before. I broke off the bush on which I found it, and was examining it rather closely, when he started off as the first had done. Two years ago last July, on the mountain side of Hualalai, I saw one of the common large spiders of Hawaii up some forty feet in the air with considerable web floating above it. It was nearly calm, and no tree within a quarter of a mile. A gentleman was with me, whose attention I called to the spider, but no explanation of the phenomenon could be given by either of us. One week ago I saw the same thing again in an open plain. As I have not heard of any other person seeing spiders in such a position, I have come to'the conclusion that it was not a common thing. Now, I wish to know how so large a thing as a full-grown Hawaiian spider can float in the air; or if suspended, to what can it be attached? "' It is not essential to our question that the spider should float in the atmosphere, although his own filaments might prevent his too rapid descent; enough for us that those filaments produced by it do so. Therefore, we shall not endeavor to answer the gentleman's question; but it would occur to any one that a spider may be blown off a neighboring tree, or he may be lifted in the air by a breeze of wind seconding his own exertions in the way of soaring. But in the violence of the West India "norther," or the South American " pampero," the searching strength of the wind would dislodge those filaments from every recess, even in the ground to which it would penetrate, and the extraordinary masses of the spider's thread collected by the wind would be accounted for by the encouraging effects of the warm climate, so favorable as it is to insect life. But the strength of those winds is not essential to the presence of the phenomenon, for we read here that they are also swept from the plains of Andalusia by the east wind. The ordinary N. E. Trade would carry them westward away from the Gulf of Mexico, where they are met and considered as a sign of the norther, the atmosphere then having a tendency to flow southward to the gulf. Thus, then, to complete the phenomenon, we first have the abundance which will be favored by the climate, then the soaring propensity of the insects themselves here supplied, and the irresistible violence of the wind to snatch the filaments of these insects from every possible hold they may have to leaf, flower, or weed, from which to carry them and to leave them on the resisting obstacles of yards, masts, and riggings of vessels to which the gale has brought them. Doubtless they are floating in the air, and may have been left there by the insects themselves as we have seen above, or caught up in passing over their haunts. In conclusion, we may also remark that the accidental observation in the Anuario that they are never seen in the rigging of vessels at Algeciras, confirms our opinion that they come from the ground and its belongings, being the produce of innumerable minute as well as large spiders, for the vessels there are to windward of them, while those at Cadiz are to leeward with the Levanter.-ED. N. M. Gulf of Huelva, or off the Broa of Sanlufcar, know that the Levanter is blowing at Cadiz and in the Strait when the sun at rising presents a white appearance, and the land is misty. The light virazon is also a precursor of the Levanter. When it is found that this daily breeze begins to decrease in strength, and when at night hauling to the land it inclines more to N.E. than N.W., accompanied by some light broken clouds, it may be expected shortly. It may also be expected sooner when the heights of the distant mountains are distinctly seen. These same heights will remain clear while the wind continues to the N.E. or E. But as soon as their summits become clouded the wind may be expected to draw to S.E., which is the wind that soonest overcasts the sky. The winds which preserve the clearest atmosphere are those from N.E. to East. The barometer will also announce the easterly wind. A small depression of the.mercury in the barometer, and a simultaneous rise of the thermometer, are indications of the quick approach of that wind; but as soon as it has set in, the mercury of the barometer again rises. After the Levanter has been blowing for some days, especially in summer, if the barometer is found to rise, it may be expected soon to cease, even if it be blowing in heavy squalls. And, in fact, it vill be gone the next day, and succeeded by the wind from the opposite quarter, and this is only violent when it sets in against it. Westerly Winds.-These winds alternate with the Levanter, and consequently blow in all seasons. They are distinguished by their healthy influence on the animal system. their freshness mitigating that heat and dryness which are the effects of the Levanter. These westerly winds have an entirely opposite character to the Levanters. They are moist, and generally accompanied by clouds. They never blow so hard as the Levanters, nor are they so persevering, and generally slacken or go down with the sun. In winter-time, when these winds draw to S.W., they bring heavy clouds and showers, which expend themselves in wind as well as in rain, in a manner so as to obscure the whole coast; still between the showers there are in general sufficiently clear intervals that enable the navigator to make his easting for the coast. If they draw to the N.W. they are clearer and generally last for intervals of eight or ten days. Signs of the Westerly Winds.-The approach of the westerly wind is marked by dews. If in the interval of the easterly wind, at night or early in the morning, moisture is seen on the different parts of the ship proceeding from the dew, it will soon terminate, to be followed by the westerly wind. Veering of the Easterly Wind by the South to West. —In general, before the west wind is set in it will gradually lessen in force and veer by S.E. and South to S.W., accompanied at the same time by a fall in the barometer. If this should happen in winter, the sky begins to become overcast as soon as the wind gets to S.E.; it blows from this point for one or two days, the barometer continuing to fall, and it finally becomes South. As soon as it gains this quarter the sky is entirely overcast; then the wind freshens up and changes to S.W., accompanied by heavy clouds and constant rain. In this state of the weather it is that the barometer is lowest, and the wind may be soon expected to veer to West if the barometer has a tendency to rise and the rain becomes less frequent. On the coasts of Huelva and Cadiz the east and west winds divide the year between them. It should not be supposed, however, that the easterly are more persisting than the westerly winds. The last prevails perhaps more than the former; but as the east wind is the scourge of Cadiz Bay and its vicinty, while the westerly wind mitigates and cools the atmosphere which it brings, a single day of the easterly wind is more notable, and, in fact, more feared, than a week of the westerly wind. The annexed table will afford conclusions which will corroborate what we have stated. Number of Days of each Wind. Total Clas of Wind. _ - Days of 1856 1857 1858 1859 1860 each Wind. Calms....................... 0 1 2 1 1 5 Light Variable.......... 19 16 4 28 20 87 North....................... 2 6 13 5 8 34 N. N. E..................... 14 11 11 13 12 61 N. E........................ 14 16 15 22 12 79 E.N.E...................... 4 9 10 9 2 34 E........................... 76 72 50 46 53 297 E. S. E................ 6 11 17 3 5 42 S. E........................ 12 13 9 16 16 66 S.S.E....................... 3 3 5 2 13 S........................... 14 16 18 6 9 63 S.S. W...................... 12 14 6 6 6 44 S. W........................ 28 27 35 27 30 147 W. S. W..................... 35 29 38 46 40 186 W.......................... 27 31 22 27 26 133 W. N. W.................... 26 27 18 23 40 134 N. W....................... 70 55 84 79 81 369 N.N.W..................... 4 8 8 6 5 31 RESULTS. Number of Days N. 34 Number of Days of 1st quarter 471 t" S. 63 e.. 2d " 184 t" E. 297.. 3d C" 512 IC'W. 133 e" 4th " 568 Days of East Wind during the five years...... 373 Days of West Wind "".. 455 This table has been formed from the daily official journal kept in the tower of Tavira, and the wind has been taken at noon of every day and considered definitely established. It will be seen from the above table that westerly winds, or those between W.N.W and W.S.W., much exceed those from the eastward or between E.N.E. and E.S.E., although the days of easterly wind surpass considerably those of westerly wind. This must be attributed to the fact that the winds from the third quarter (or S.W.) are always more lasting than those of the second (S.E.,) as those of the fourth (N.W.) are more so than those of the first (N.E.) Consequently, the west, which participate with S.W. and N.W., have a great predominance over the easterly winds, which participate with opposite points N.E. and S.E. N. W. Winds.-The winds which also prevail much at Cadiz and its vicinity are those of the fourth quarter, and of these, those from N.W., which circumstance rises, in our opinion, from that bay being situated at the eastern limit of the Gulf of Huelva, in which those largish rivers, the Guadalquivir and Guadiana, fall, besides the Odiel and the Tinto. S. W. Winds.-Next to winds of the fourth quarter, those of the third may be considered to predominate, which are those that bring the storms and rains of winter, and are the same in summer that constitute the Virazon. Northers.-Northerly winds blow but little, and when they do, generally in the winter. They must be considered as land winds, and always incline to the N. E. in the Mediteranean if the easterly winds prevail, or to the N. W. if in the ocean with a westerly wind. The winds of the first quarter (between North and East) are the least violent and mostly attended with clear weather. Southerly Winds.-Nor do southerly winds blow much, for in wintertime they soon haul to S. W.; and if in summer, they form part of the virazon and are transitory. Although the Levanters will prevail at all times of the year, they do so more in the months of March and April and in the hot months. In July, 1856, there was a whole fortnight of continuous easterly winds, and also in August of that year. The N. E. winds, as we have seen, were the most persisting, and prevailed from March to September, blowing hardest in April and May. From November to March, or in the winter months, the S. W. winds were the most prevalent; and they certainly are the winds most to be'feared in the Gulf of Cadiz; for besides blowing strong, they bring heavy and constant showers, which conceal the land and throw in so much sea, that all the bars even become impassable. These winds, called Vendavales, vary between W. S. W. and S. S. W. Fortunately, they give notice of their approach, and the navigator who may either be cruizing off Cadiz or to the westward, sees its approaching signs and can get clear of the shore to the parallel of the strait, and if necessary he can always be sure of the strait. Signs of the Vendaval.-The Vendaval gives unequivocal signs of its approach. If the easterly wind be blowing it will veer to the S.E., the sky will become obscured and the coast concealed, especially the Broa of Sanlucar, and the wind may be expected from the southward with rain, and soon the Vendaval will follow. This change is always preceded by a considerable fall of the barometer. A calm and a dense fog are always signs of the Vendaval. In winter, after the Levanter has been blowing, if it draws from S. E. to South, and it continues so with light misty winds,, a gale may be expected from the offing. Vessels should be careful not to encounter the Vendaval, not only on the dangerous coast between Point San Sebastian and Cape Trafalgar, but also within the Gulf of Huelva. On the first of these parts, beset with reefs, the sea breaks at a great distance from the shore, and it often happens that breakers are seen before the coast is visible. In the second portion of coast, a vessel runs great risks, for in the breaking sea which is raised by the gale, in addition to this there is a set towards the shore; and if the navigator should not have sufficiently foreseen this so as to provide for getting away from it, and becomes hampered with it, he may reckon himself fortunate if he be not wrecked on the Arenas Gordas. On that portion of coast between Cape St. Mary and Cape St. Vincent the risks are not so great; for with the wind at S. W., a vessel can escape by standing off S. E., unless the wind be so strong that with with it and the sea she cannot weather Cape St. Mary. In respect of the coast of Africa included between Cape Mazigan and the Strait, there is not so much risk there with the Vendavat, because the land trends much in its direction, and it has no great sinuosity. The worst winds on it are from West to Northwest, and with these a vessel should take care not to risk her safety in Jeremias Bay. What is most to be apprehended in this part is the sea which gets up always, which in a gale on shore will very soon lose a ship and her crew, should she unfortunately, in the thick weather of the Vendaval, mistake this bay for the entrance of the Strait-a mistake indeed which has been fatal to many vessels. Veering of the Vendaval. —Although usually the Vendaval does not 11 last above three days, sometimes it is stubborn and will continue for nine or even twelve days with but slight interruptions. If, after blowing strong, it veers to West, fine weather may be looked for, because it does not remain long at this point, but hauls to N. W., which is generally the concluding quarter of the gales in our hemisphere, and is that which clears up the atmosphere. But if from West it returns again to Southwest, the bad weather will begin afresh, and the wind will blow harder than before, although it may not last so long. But when it becomes steady at N. W. it very seldom backs to S. W. The wind once established at N. W., for some days it may blow hard, but then'vill become more moderate, and is almost always attended with clear weather, although blowing harder by day than by night. If it change to North afterwards, it seldom remains so long, for it will pass to N. N. E. and then to N. E., where it will remain foi some days more. This wind is always the precursor of the Levanter, northeast (ind easterly winds in the Gulf of Iluelva. In wintertime in the Gulf of Huelva N. E. winds are the almost certain sign of the Levanter blowing at Cadiz and in the Strait of Gibraltar, as the N. W. winds are of there being a westerly wind on the south coast of Portugal. In this Gulf of Huelva, far enough from the strait, the Levanters are not so fresh nor yet so lasting; they sometimes take two or three days to reach Huelva, and die away here before they cease at Cadiz. Baffling Winds.-When the Levanters enter the gulf they do so by fits and starts, and are preceded by light baffling winds from all parts of the horizon that are called Alacareos by the Spanish sailors. If these baffling winds are attended by a suffocating heat in summer-time, the Levanter may be expected, which generally lasts some days when once it sets in, blowing hard, as if it was from S. E., while the sun is high and drawing to N. E. at night with fine weather. But in summer in the Seville river their heat is intolerable. In winter-time in the Gulf of Huelva the continuance of the northeasterly wind is generally considered a sign of the Vendaval, and as soon as it passes to the eastward this terrible wind may be expected, for then it soon becomes S. E. and shifts to South and S. W. As soon as the wind begins to veer thus, and the barometer falls, a vessel should get out of the Gulf as soon as possible into deep water, and avoid compromising her safety by getting hampered with the Arenas Gordas. It frequently happens that while these changes are going forward in the Gulf, at Cadiz and in the Strait the Levanter may be blowing, and on the coast of Algarve the westerly wind. When mist is ob served over the entrance of the Strait the Levanter may be known to be outside, and the westerly wind prevails at Cape St. Vincent when the Portugese land is clear, or if the mist be seen at the mouth of the Guadiana. Old sailors who know the Bay of Cadiz and its neighborhood have an idea that the climate of those parts has undergone a change of late, an alteration which they consider extends even to winds and storms. They consider that of late storms are scarce in comparison with those of former times, when bad weather commenced in September and lasted until spring; storms following each other with scarcely any intermission. It seems that the general tendency of storms now. almost as soon as they are established, is to slacken, and not to last any time. But at any rate, both in summer and winter the wind is more variable, and it is seldom observed that the same wind will last for fifteen days together, as, in their opinion, it used to do formerly. Storms scarcely ever get up on the coast of Cadiz, but come from other parts more or less distant. A storm at Cadiz, where it is remarkable for the force of the wind, is soon over, and in general bad weather comes from the S. E., a quarter from which the wind is much stronger than from the East. Land and Sea Breezes.-These partial winds proceeding from the same causes as those which give rise to the Trade winds, are common during summer in the Bay of Cadiz. The sea breeze, as in tropical countries, is found on the coast at Cadiz in summer when the east wind does not prevail, and are strong and lasting in the Gulf of iuelva. Sea Breeze on the Coast of Cadiz.-From nine to ten o' clock in the morning the sea breeze sets in gradually, and veers to S. S. W. and S. W. as the sun gains height, attaining its greatest strength when the sun has passed the meridian, or at the hottest time of the day, and gradually subsides as the sun loses height, veering westerly until eight or nine o'clock in the evening, when it falls calm. After two or three hours of calm the land wind gets up, acquiring more strength in proportion as the coolness of the night increases. At daylight it has attained its utmost strength, and fails gradually as soon as the sun appears and begins to warm up the ground again to receive in its turn the cool sea breeze. In the Gulf of Huelva this land breeze is from N. E. and E. N. E. in the Bay of Cadiz; while on the African coast it becomes E. S. E. When the land breeze blows from the East in Cadiz Bay it shows that the Levanter is blowing in the Strait of Gibraltar. Sea Breezes in the Gulf of Huelva.-These sea breezes in the Gulf of Huelva begin at S.E. and leave off at N. W. In summer-time they are almost constant, and while they last a vessel will be safe off the coast, even to anchoring to obtain water, or to rest from a cruize. Off the Cadiz coast the sea breeze is not so strong, for it is subject to interruptions from the easterly wind, which is not so frequent in the gulf, inasmuch as that noxious wind does not reach so far. Although the sea and land breezes belong to summer, they also come in winter, attended with long intervals of fine weather. Let us now turn our attention to the winds of the coast of Portugal and Galicia. Winds on the Western Coast of the Peninsula.-The prevalence of polar and tropical winds on the western shore of the Iberian Peninsula may be considered as constant, since those from N. W. and S. W. are but inflections from them, and those from N. E. and S. E. may be considered as land winds, or from the opposite quarter. The south coast of Portugal, which forms a portion of the Gulf of Cadiz, is thoroughly persecuted by winds from the S. E. and S. W. quarters, and the dividing limit between the winds from these two quarters may be considered as Cape St. Vincent; so that a vessel doubling this Cape from one side or the other finds shelter from S. W. or S. E. In like manner, for a third part of the year, northerly winds are found to prevail, the wind varying between N. E. and N. W. fresh, with clear weather during the summer, and cloudy or showery during the winter. From April to October the northerly winds mostly prevail, southerly winds blowing during the other months; that is, S. W. winds prevail from November to March, and which generally leave off at N. W. When in the fine season the Vendcval prevails, it is moderate and seldom lasting. Southerly and S. S. E. winds frequent from December to March, scarcely blow for twenty-four hours, for they will be light, with rain about a day, and then jump to S. W., where they remain longer, and leave off at West or W. N. W., which serve for either tack. Winds of Winter.-The bad weather season begins on this coast in November and ends in February. During these winter months those heavy rains take place which come with S. W. and N. W. gales. The Vendaval, which is the byword among the seamen of these shores to distinguish the severe weather from S. S. W. to W. S W., brings up heavy clouds from the southward, preceded by a light mist, which flies with more or less swiftness according to the strength of the wind which may be expected. Signs of the Vendaval.-When the sky is clear, and small clouds appear which are very high and scattered, and embellish the firmament, (cirro-cumulus,) to which navigators give the name of cielo aborrigado, (mottled sky,) the Vendaval may be expected, especially in winter, as a day cannot pass without the sky being completely overcast, and the wind is settled at South. If the Vendaval is strong, it will bring abundance of rain in the first twenty-four hours, and will next change to the S. W., where it will continue for two or three days, then veering to West, and perhaps to N. W., always blowing hard, perhaps with less rain. The appearance in the rigging of those threads called telaranas, to which we have alluded, is also a sign of the Vendaval. These, however, are mostly limited to very fine clear weather when all is calm and quiet. When this sign appears in winter a southerly wind may be expected, which will soon freshen to a gale with rain. In summer this sign is preceded by cloudy weather and winds from the S. W. and N. W. quarters, which are those that supply rain. Some years there are when, during the whole of the winter, the S. W. and N. W. winds set in more or less strong, but always accompanied by showers, the interval of clear weather between them being brief, and in which intervals the wind will shift from N. W. to North and N. E.; at these points it will remain, and bring fine weather until it returns'to S. W. Backing of the Vendaval.-When the Vendaval drops to a calm, and showers cease without any wind from the N. E., tile S. W. wind may again be expected, with a return of bad weather far worse than the former. But in order to have any confidence in the weather, the Vendaval must take its normal course, that is, should terminate at N. W., and fiom thence the wind should change to N. N. E. or N. E., when it would be settled for several days. The northeasters in winter are also attended with an overcast sky and occasionally showers accompanied with snow or hail, but in general they bring clear weather. In summer, when they blow hard, they are accompanied by a mist, so that the coast cannot be seen from twelve to fifteen miles off. When about the end of winter the ground is saturated with wet, this will prevent the Vendaval from reacliing the coast, and vessels which may be running from bad weather at sea to some inlet, find the wind will change to the South and S. E. on nearing the coast, and thus retarding their approach to it. S. E. winds, however, are rare, and when they blow in winter they are attended by heavy snow showers and are very strong. The easterly wind is always the coldest. The northerly winds, properly so called, vary between N. N. E. and N. N. W., and mostly are found on the west shore of the peninsula; they prevail from May to September, interrupted with light Vendavals, and almost always are attended with clear skies. The Vendavals of this season, which are almost always of brief duration, generally bring cloudy weather, which does not clear away until the wind veers to N. W. on its way to North. In proportion to the density of the clouds which the Vendaval brings, the less most probably will be the duration of the wind. Notwithstanding the prevalence mostly of northerly winds in summer on this coast, it is also very liable, and especially that of Galicia, to waterspouts and showers, the effects of opposing winds. Waterspouts.-These phenomena will form with an easterly wind, or perhaps some off-shore wind, at the time when the wind at sea is from S. W., and as the clouds which this wind accumulates over the coast are driven back by the off-shore wind a waterspout is formed. Sometimes the waterspout is formed instantaneously, accompanied by heavy thunder and rain, for which it is necessary to be prepared by shortening all sail, for they usually are attended with much wind. These opposing winds occur in August and September; principally in summer when there is much heat. As there are years with hot seasons on the coast of Cadiz and the Strait of Gibraltar from the Levanters, so also are there others of cold seasons from northers on the coast of Portugal. Nevertheless, in these same years there are many marked changes, which prove how difficult it is to determine the limits of the changeable wind on any particular coast. The following table, formed from meteorological observations made at Lisbon, will give a good idea of the winds which have prevailed there for two consecutive years: Statement of the prevailing winds at the mouth of the river Tagus, from the first of October, 1863, to the end of September, 1865, with the heights of the barometer and thermometer corresponding to the wind. No. of Barometer. Thermometer. Observations and Winds. days it Remarks. lasted. Max. Min. Max. Min. Calm.... 10. North 128 774.2 753.6 6 6 2.2 They are generally clear N. N. E... 96 773.8 753.3 27.5 4.2 and fresh during all the N. E.... 110 775.0 751.7 29.1 2.3 year, especially from May E. N. E. 28 768.2 759.5 29.9 2.0 to September. East.. 38 772.1 750.4 27.1 4.4 J E. S. E. 18 768.5 756.3 23.3 10.2 They are fresh and atS. E... 9 765.6 745.7 19.8 10.1 tended with rain or snow S. S. E. 2 768.6 764.6 19.2 8.2 from October to April, esSouth... 28 764.4 752.2 24.8 9.5 pecially with winds from S. S. W... 45 768.4 745-2 21.6 9.1 S. S. E. to W. S. W. S. W..... 50 773.2 741.1 20.0 8.9 Fogs are frequent from W. S. W.. 25 767.7 744.2 22.6 8.9 Oct. to Feb., and generally West.... 26 768.6 755.3 25.7 6.2 with S.E. to S. W. winds. W. N. W.. 13 763.5 744.0 21.7 10.2 ) They are fresh, with snow N. W.... 49 773.6 756.3 26.3 5.5 showers and often rain in N. N. W.. 56 770.4 755.9 25.0 8.4 summer. In winter fresh and showery. The foregoing may be resolved into the following table: Winds of Winds of Winds of Winds of Months of observation. N. E. S. E. S. W. N. W. quarter. quarter. quarter. quarter. Days. Days. Days. Days. 1863, October.. 12 5 8 5 November........ 24 5 0 1 December.............. 26 0 2 2 1864, January............... 19 7 2 3 February.............. 12 0 11 5 March................. 13 3 11 2 April.................. 12 3 6 6 May................... 14 5 8 6 June.................. 15 4 3 8 July................... 14 5 3 9 August........... 18 2 5 6 September.......19 6 2 3 October................ 8 3 17 4 November.............. 13 3 6 8 December.............. 5 2 4 10 1865, January............... 6 2 15 8 February. 15 2 3 8 March................ 20 0 4 7 April.................. 9 4 10 7 May................... 15 2 9 5 June.14 4 5 6 July................... 20 0 1 10 August.14 0 6 11 September............. 17 0 7 5 In the two years............. 363 67 148 144 From the foregoing we may conclude that winds from the northward, or those from between N. W. and N. E., both inclusive, have prevailed for.................................. 439 days From South, or between S,E. and S. W....... 134 From East, or between E. N. E. and E. S. E.... 84 " From West, or between W. N. W. and W. S. W. 64 " So that the prevailing winds for the period of two years were from the north, with a remarkable preponderance over the rest, and they were the most lasting in the months from May to September. It must be noted that the observations were made at nine a. m., a time when perhaps the wind for the day is not established according to that outside, especially in winter; and that the place of observation was the observatory, which, besides being well up the river Tagus, (or, rather, the Lisbon estuary,) is subject to the prevalence of the land wind which commences at the lower part of the Tagus. Observations carefully made at the light-house on the Berlings will give us hereafter a better idea of' the winds which prevail on the western coast of the peninsula. Nevertheless, we may be satisfied from the above results that the prevailing winds on the coast of Portugal are northerly, those of the opposite quarter prevailing from October to April, and which alternate with those from west and N. W. CURRENTS. Currents are the maifestations of that great system of circulation in the waters of the ocean, arising from the same causes which produce those of the atmosphere, viz., heat and cold; and it may be said that there is a complete similarity between the movements of each, differing only in velocity, in consequence of the great difference in the densities of the two fluids. Besides this cause, there are others perhaps as powerful, not only in promoting them, but in contributing to their strength; also proceeding from the same origin of heat and cold. Such are the various degrees of pressure of the atmosphere on the surface of the sea and the impulsive power of the winds. All these agents combined keep the waters of the ocean perpetually moving, forcing them to pass to and fro between the equatorial and Polar regions. So that from whatever part of the ocean a current may run, another of the same extent and force is set in motion in an opposite direction, thus always preserving a due equilibrium. Diversity in Currents. —The great masses of water in its motion from South to North and North to South, (setting aside the disturbing effect Hydro. No. 1. 2 of the diurnal motion of the earth,) rush along the coasts of the great continents, islands, and gulfs in their irregular distribution on the surface of our planet, and in encountering these obstacles alter their course, become divided, run counter to each other, taking different directions, and forming the eddies and ripples which we so often meet with. Such perturbations are also common to the currents of the atmosphere, the effect of which we find sometimes on our coast. At sea, by means of our reckonings and accurate observations, we can detect the set and velocity of the currents, which on the coasts are still more readily detected, being familiar to coasting vessels, and even to fishermen of the deep sea, who experience them with the nets which they use from their boats as they watch over their stone moorings. Doubtless the current is one of the most formidable enemies which the sailor has to deal with; for besides being imperceptible, it is also variable, and as yet no means have been invented of immediately knowing its strength and direction with that facility which we have of seeing the progress and course of the ship. Hence the necessity of collecting all the information we possess of the currents on every coast, bay, or channel, and describing them for the mariner, in order that he may provide against his insidious and dangerous enemy. Yet the subject is one of difficulty, and it is only with time and observation we can arrive at general conclusions as to their force and direction in any particular locality; for they never are the subjects of continual observation, as is the case with meteors, for which a multitude of instruments have been invented, and observatories specially established for them, while collecting the secondary notes of navigators and fishermen is the imperfect mode of obtaining an approximate idea of these. Currents of the Bay of Cadiz.-Confining ourselves here to Cadiz Bay, we might observe that there is a general current running from South to North and from North to South, inclining to either quarter according to the direction of the wind that is blowing, or that which is about to blow; for sometimes the current runs in anticipation of the wind which will afterwards add to its strength, and the navigator satisfies himself of the quarter from whence the wind will come by the direction of the current. It is only in the immediate neighborhood of the mouth of the Strait of Gibraltar, and within it, that a constant current is observed setting to the eastward, occasioned by a small difference of level supposed to exist between the ocean and the Mediterranean in consequence of the expenditure of water in that inland sea from an excess of evaporation beyond precipitation; a loss which the Atlantic re-supplies. Rennell's Current.-An English officer, Major Rennell, in reference to the above current, considers that, in the space between the parallels of 30~ and 450 N., and to the East of the meridian of 14~ W. longitude, there is a tendency of the waters of the Atlantic to set towards the Mediterranean at a rate varying between twelve and twenty miles in the twenty-four hdurs. We think this is a bold decision and somewhat of an exaggeration. If, with the above data, we reduce to figures the surface of the ocean in question, we shall find it represents forty-two thousand square leagues, and however superficial we may allow the stream of this extensive surface to be as it runs towards the strait on reaching its mouth, so large a volume would be collected that it would not be sufficiently large to receive it, and the result would be that the neighboring shores would be inundated, and the strength of' the strait current would be more than we could calculate. Current of the Strait of Gibraltar.-That there is a perpetual current in the Strait of Gibraltar is no doubt a fact proved by every day's experience; but sometimes even this current is quite insignificant, it is only felt at its edges, and a few leagues to the West of the entrance it is scarcely perceptible. Every day's experience, and history itself, informs us that this current is of no great dimensions. The ships which suffered by loss of masts and sails after the battle of Trafalgar, far from being swept into the Mediterranean by this supposed current, drifted to the coast of Cadiz and the Gulf of Huelva, and the pilot of the faluca Real Carlos, burnt within the strait in the year 1801, reports his being thrown on Tangier Beach, instead of having been carried away by that current.* Nor do we remember of any bottles, thrown overboard for the purpose of detecting currents, having been found on its shores. The difference of level between the two seas is not so much as would occasion any extraordinary current; and it might altogether have escaped observation if the constantly easterly set had not suggested it. Vessels that have been perpetually cruising off Cadiz and its vicinity on many occasions have never troubled themselves about the easterly current, for it has never affected them, and they have been concerned only about being set into the strait when becalmed in the mouth of it. * This accident occurred within the Strait in the night of the 12th of July. The Real Carlos, supposing that she Was engaging one of the enemy's vessels that were hovering about the rear of the French and Spanish squadron on its way from Algeciras to Cadiz, attacked her companion, the Real Hermenegildo. Unfortunately the mistake was not discovered until they mutually closed to decide the action, and both were burnt, nearly all the crew of both being lost. Forty men were saved by a boat, and six or seven in the fishing boat belonging to the crew of the Carlos, picking up also the second in command of the Hermenegildo from the water. The pilot above mentioned was also saved. —a Marina por Travieso, vol. 3, Madrid. 20 Counter Currents in the Strait of Gibraltar. —There is, however a periodical difference of level which passes unperceived, although of importance, sometimes between the waters to the westward of the strait and those not very far off to the eastward. This difference of level, about 3.3 m. ten feet occasionally, and which is the effect of the tides, nevertheless does not contribute in any way to increase the easterly current into the Mediterranean. It is very well known that in this sea there are scarcely any tides, excepting in some places, one of which is at the strait itself communicating with the two seas. From Malaga to the eastward, where the tides go on decreasing, and become so imperceptible that on the meridian of Cape de Gata all trait of this great phenomenon is gone, while on that of Cadiz, which passes not very far from the mouth of the strait, spring tides rise 3.3 m. ten feet. And notwithstanding this difference of level of ten feet in a distance of two hundred miles, far from increasing the easterly current, this is diminished by it during the flood tide. When the tidal wave of flood passes in its course from South to North along the African coast, the Gulf of Cadiz and coast of Portugal, it does not penetrate (as one would at first suppose) into the Mediterranean, increasing the strength of the general current; but draws along with it its waters, which, in obedience to lunar action, rise in the strait and mingle with the great tidal wave to pursue with it its ocean course. Consequently, during the flood the waters of the Mediterranean, as far as a certain limit which is known as not beyond the limit of Almeria, commence moving to the westward on the coasts. This movement is the more perceptible as the mouth of the strait is approached, so that at the points of Europa and Almeria the tidal current to the westward interferes with the eastern current of the strait, in the middle of the strait reducing its strength and narrowing its limits. When the ebb is established the waters of the strait return to join those of the Mediterranean, and yet a large amount of them joins the ocean tidal wave on its way to the South; the rest running through the strait to the eastward, and even, perhaps, with more strength than they had on the flood. It is when these currents are running within the strait that the most considerable deviations and counter currrents are produced, of which a good idea is given in the general directions for the Mediterranean, and it is by availing themselves of them that the coasting vessels pass through the strait against westerly winds; and when once clear of its western entrance they need no longer trouble themselves about any current which may take the direction of the strait, for they get to windward without any difficulty. The wrecks of vessels on the coasts of Cadiz and Huelva, as well as those on the African coast, quoted by Major Rennell, are occasioned by the current from S.W. to N.W. principally. These may be considered as inflections of the general current from South to North and North to South, in the same way as we may recognize the S.W. and N.W. winds as inflections from the South and North. Polar and Equatorial Currents.-When the ocean waters run from South to North, by this movement they most likely reduce the atmospheric pressure experienced then in the polar regions, originated by the intertropical winds. The S.W. wind with its impulsive force would naturally affect the direction of the current setting northward and compel it to run to the N.E., and drift vessels over to the African and European shores. Then an atmospheric reaction takes place that acquires a very low temperature in the nortern latitudes and exerts a considerable pressure on the surface of the sea, compelling its waters to flow towards temperate regions, where there is also going forward a constant displacement arising from evaporation. By this new change of place the current from North to South is formed, impelled by the N.W. wind, which is an inflection of that from the North, and it consequently assumes a S.E. direction, which also throws vessels on the coasts above mentioned. In the perpetual transfer of the waters as thus stated, the different currents take place as we find them on the coasts, assuming that direction which their bays, islets, and channels impart to them. In the open sea doubtless the winds play a random game in directing the currents. When after a calm any particular wind sets in, the surface waters make a slight wave carrying them gradually to leeward, their magnitude being proportioned to its strength, until waves of a considerable size are formed, which agitate the ocean to great depths; and seamen know pretty well the force of these huge masses of water, which sometimes may be a hundred feet in depth. Perpetual Currents.-Certain it is that there are currents following constantly the same direction, that will be running against the prevailing wind, like those of the Bosphorus, the Strait of Gibraltar, bhe Florida Channel, etc. But these are but the results of physical causes and peculiarities affected by the form of the seas or gulf adjacent to the Atlantic. The ocean current sdarcely ever changes its direction so readily as that of the atmosphere, as one should expect from the difference in 22 density of the two fluids; but the equilibrium of the waters being once re-established, they obey the impulse of any agitating cause. It is often observed that before a wind comes home upon a coast, the waters are moving in the same direction as if they were driven by it, and the navigator finds this out before the wind has come.* It is then that the current is the prelude to the wind which is coming in the same way as the swell indicates the wind which produces it; and should this not have arrived at the place of observation, it is no reason that it should not be found in another locality perhaps not very far away. Currents from the Southward.-When the S.W. wind prevails in the Atlantic in the vicinity of the strait, which wind expands the atmosphere, the level of its surface is raised, and that of the Mediterranean not being raised by the same cause, the difference of level becomes greater and the easterly current stronger. But both levels obeying e'qual pressures from their contiguity, it may be said the difference of level is constant. However, a stronger easterly current is always found when the wind is blowing hard from the westward, and this has its explanation. Always when these winds are general in the Mediterranean the waters accumulate in its interior, and in some places attain an extraordinary elevation.t This accumulation towards the interior naturally occasions a deficiency at its western end, which the Atlantic has to make up. But the wind ceases and takes the opposite direction, and also the waters, causing a lower level in both seas, and even a temporary paralysing of the easterly current. It is well known that occasionally the current through the strait from the Atlantic is N.E., and that this will occur when a strong Levanter is blowing in the Mediterranean that produces a transfer of the waters contrary to that which we have pointed out. During the hard Vendavals a strong current runs from South to North in the Gulf of Cadiz, that assumes the direction of the coast off which it runs. On the African coast it takes a N.E. direction, North and N.N.W. on the coast of Cadiz, a small portion penetrating the strait, and the rest running N. W. and West by the Gulf of Huelva and the Algarve coast; passing Cape St. Vincent it joins the general current. In the middle of the gulf its direction is N.E.' There was a remarkable instance of this in the China Sea in the loss of H. M. S. Reynard, in 1851, Commander P. Cracroft. A current had been setting this ship for a whole day in a calm towards the Paracels in the China Sea, a heavy gale following it the day after, which was the occasion of her loss.-ED. t Vice-Admiral W. H. Smyth quotes elevations of twelve English feet on the coast of Tuscany with strong labeches. 23 After this mass of water which comes from the intertropical regions has made this passage within the Gulf of Cadiz, it mingles with t J larger mass passing outside, and both run along the coast of Portugal and Galicia, following its sinuosities; then passing Capes Finisterre and Prior, run along the Bay of Biscay and enter the English and St. George's Channels, to expend in the northern seas. It is certain that with the above-mentioned winds, strong currents are experienced in those channels, and in the estuaries and ports of their coasts there are astonishing accumulations of water. The current of which we are speaking affords us good evidence of its efforts by the great rise above the ordinary level of the sea in the Gulf of Cadiz; for in its bays, ports, and estuaries it exceeds by two and three feet the usual rise, and makes the establishment, or hour of high water, later. This extraordinary rise of itself reveals a current. Still this accumulation in the gulf has its limit, and the waters which it cannot contain, repelled by the coast of Cadiz, escape to the westward to mingle with the current running northward. Losses occasioned by this Current.-To the effects of this current may be attributed the wrecks, above mentioned, of the dismasted ships after the battle of Trafalgar, which was followed by a Vendaval; and also of many ships which considered themselves to be running safely along the Spanish coast for the Strait of Gibraltar, terminating their career on the reefs of Conil and Santipetri, and others, especially before the lighting of the coast was general. We may also cite the case of a Spanish merchant ship, which, considering herself certain of making Cape Spartel at daylight, and confident of her reckoning, found herself nearly in the midst of the breakers of Santipetri, and owed her safety to the weather enabling her to double Cape Trafalgar and to make for the strait. Vessels from the Strait of Gibraltar making for Cape St. Vincent with southerly winds frequently find themselves too near the shore in the Gulf of Iuelva, a condition which frequently happens with coasting steamers, and they find from experience that with those winds they have to give the shore a good berth on their way from Cadiz for the strait, or for the above cape. In this last passage, if they do not take the necessary precautions, they find themselves hampered with Cape St. Mary, and in general overrun Cape St. Mary, owing to the current setting then to the westward. Vessels obliged to wait off Cadiz in a hard Fendaval, whet!ler cruising or for any other reason, must not depend too much for their position on the reckoning; for they will always find themselves set 24 into thfe Gulf of Huelva, and will become entangled with the Arenas Gordas when they are considered to be on the meridian of Cadiz. In such cases it is necessary to carry all the sail they can to keep to windward and compensate for the current, and more readily to gain the parallel of the strait. Strength of the Current in Cadiz Bay.-It is difficult precisely to define the strength of the current in Cadiz Bay in a strong Vendaval; but we consider ourselves as by no means exaggerating when we give it a maximum of two miles an hour between Capes Trafalgar and St. Vincent in a N. E. and northerly direction in the middle of the bay, and in a N.W. direction in the vicinity of the coast. This being the case, it is always better to avoid lying by the wind too long in a Vendaval between Capes Trafalgar and Santa Maria, it being far better to get into Cadiz if possible, or keep in the mouth of the strait to run in, if it should be convenient. In the usual weather when the land and sea breezes alternate with easterly and westerly winds, the currents are not strong ill Cadiz Bay. With established easterly winds the tendency of the waters is from East to West, and the reverse with westerly winds, excepting in the western mouth of the strait, where the current is always easterly. On the coast no other current is known than that of the tide, and this is more or less strong and of greater or less extent off shore, according to the age of the moon. Northerly Currents.-After several days of hard southerly winds, those from the opposite quarter get up; the ocean waters experience the same reaction; and although the current does not so readily change its direction as the wind does, it nevertheless soon stops and follows it, to make good the equilibrium in the equatorial regions by obeying the impulse of the N.W. wind. On the northerly wind establishing itself after the southerly wind has ceased, it brings with it the cold atmosphere belonging to it; and in consequence a greater atmospheric pressure on the surface takes place. The waters coming from the northern seas naturally seek their way to the southward; and as the current is thus formed by the aggregate force of the wind from the Polar regions, a current from North to South is produced with the same strength as we have already mentioned. If the wind has a tendency to come from the N.E., the pressure of the atmosphere will be greater and the surface will have a considerable depression of level, probably as much as it acquires in elevation with the opposite wind. 25 The current which ebbs then from the English and St. George's Channels combines with the general current and that from the Bay of Biscay, (where the depression produces a remarkable difference of level,) running together in the offing of the coast of Portugal, a portion entering the Gulf of Cadiz, through which it flows, and taking its course afterwards along the African coast. In the Gulf of Cadiz with this current there is no risk whatever, for it rather sets vessels from the coast, and is never so strong as the current of the South. It is observed, if a considerable lowering of the level of the sea takes place in the bays and harbors, that high water does not rise to its usual height and the tidal hour is earlier. If the wind should have a tendency to the N.W. there is also a depression of the waters from North to South, but not so considerable. With this wind, very strong sometimes, the waters are transferred to the S.E., a portion of them passing into the Bay of Biscay, where indeed they accumulate, producing an easterly current along the shore and making it southerly along the Portuguese coast. It may be concluded that the N. W. wind falling obliquely on the general current from North to South, it compels this to take a S. E. direction. When this current falls on the Spanish shore its N. W. front is divided, the coast obliging it to take two directions, one part running to the eastward along the shores of Cantabria, and the other to the South along those of Galicia and Portugal. Currents on the Western Coast of the Peninsula.-On the western shore of the peninsula the currents are strong, and in its immediate neighborhood run from South to North, and North to South, according to the prevailing wind. But in the offing they incline to the N. E. or S. E., according as the wind may be S. W. or N. W. Against these on-shore winds vessels must therefore take precaution, for if the S. W. wind is blowing, or even the N. W. also, the vessel will drift to the shore. Experience has shown that allowance must be made for drift by steering more westerly courses than the lay of the coast would require to keep clear of it, especially when it is blowing hard. Currents previous to the Wind. —It is observed on the coast of Galicia, and the same would naturally occur on the coast of Portugal, that, on one or even two days previous to a gale, the current sets towards that point of the horizon from which it will eventually come; that is, when the current sets to the South without any apparent cause, the FVendaval will come in a gale, and a similar result follows when the current sets to the North. So that the fishermen who have most to do with allowing for currents know very well by them when a N. E. or S. W. wind is about to set in. 26 Strength of Currents on the Western Coast of the Peninsula. — The current generally produced by the wind sets to the N. E. and North when that is from any point between South and West, and it sets to the South when the wind is anywhere between West and East from the northward. In winter the current sets mostly from some point between North and East. and in summer from some one between North and West, and its hourly rate is about two miles, awd even more with a strong Vendaval. The navigator who finds himself off Cape Finisterre with a Vendaval to beat against must be careful of the shore in bad weather, for he will be drifted insensibly to leeward until he has passed Cape Prior. With respect to ships off Cape St. Vincent bound towards Cape Finisterre with fresh N. E. winds, they will find enough to do to overcome the current they will meet with along the coast. And with fresh N. W. or S. W. winds, there is also a rise in the level of the sea in all the estuaries and ports of the peninsula; the reverse of what takes place at Cadiz and in the Bay of Biscay with N. E. winds. Tides. —This phenomenon preserves all its regularity on the shores of which we are treating, and a supplement of waters, as the pilots oall it, can only be observed when N. W. winds prevail. That is, when the said winds prevail a large mass of waters is accumulated in Cadiz Bay, and every high water rises above the usual level, and makes the time of high water later. The samle occurs on the coasts of Portugal and Galicia, and this delay in the time of high water and increase in the rise of the tide becomes greater the further it is to the northward. Propagation of the Tidal Wave.-The tidal wave of flood, as it flows from South to North in the Atlantic Ocean, naturally enters the Bay of Cadiz before it reaches the Portugese coast, as well as that of Galicia. This progress of the waters originates a current called tide, which on the African coast spreads itself according to its configuration; that is, from S. W. to N. E.; in that of Cadiz from South to North, inclining to the N. W. according to the trend of the coast, and finishes by running to the West on the coast of Algarve, doubling Cape St. Vincent, from whence it takes a northerly direction along the coast of the peninsula. All this takes place on the flood, for on the ebb the water retraces the above course in the opposite direction, and the various currents it forms also assume the opposite directions. The current of tide runs only at a short distance from the shore, and only surpasses this distance at the heads of the tides. The general currents above described in no way interfere with this singular phenomenon, and only tend to increase or diminish its current when favorable or unfavorable. Equinoctial Tides.-When the high water of syzygy happens near the vernal equinox (March) and a heavy Vendaval is blowing, so considerable a rise of tide takes place in the bays and ports, that the jetties and the low lands about the shore are inundated, and sometimes donsiderable damage is done. At Cadiz not only are the highest parts of the sides of the jetties whitened by the foam, but the sea also threatens the very walls of the city. The current of the flood is more or less increased in such cases and the tidal establishment of the port is delayed. Tides in the Mediterranean and Gibraltar Strait.- -With respect to tides of the strait, we have already noted what takes place, and we will record here some facts in corroboration of it. It is generally considered that the Mediterranean has its peculiar tides. But this conclusion is not altogether sufficient. A portion of its waters, particularly that between the meridians of Capes de Gat and Trafalgar, is entirely obedient to the luni-solar influence, following the prescribed course, and is lost in the West by becoming mingled with the great tidal wave of the ocean in its course from South to North. This portion increases until it attains the height of twelve feet at the times of the syzygies, and this difference of level remains established, as we have already observed. When this takes place, two currents are produced on both the shores of the Mediteranean towards the West, or, rather, perhaps against the general current to the eastward. The coasting vessels which avail themselves of this current to get through the straits against westerly winds, trip their anchors when the moon appears in the horizon, for then it is that the tide begins to raise the level of the waters. During the ebb the tidal wave follows the reverse order, taking its course in the ocean from North to South, and in the strait and part of the Mediteranean from West to East, but gradually decreasing in this sea and vanishing after passing the meridian of Malaga, and these phenomena are reproduced off the middle of that headland. The failure of the Mediterranean tides is attributed to the extreme narrowness of the strait, the conclusion being that the great mass of the ocean tidal wave is thus prevented from entering it. But we consider that a more logical reason may be advanced to account for it. If we consider the general features of this sea, we find it divided into numerous compartments, many of which appear to constitute small lakes, nearly all of them being insensible to the luni-solar attraction, and only in its central portion, which is the most important part and free from islands, do we see the waters uniformly obeying the law 28 of luni-solar influence and attaining at springs the height of six feet.* We may, therefore, deduce from the foregoing that the cause of there being no uniformity of tides in the Mediterranean must be attributed to its special formation; that is, to the subdivision into small portions by the receding and projecting of its line of coast, and by the islands which are off its northern and southern shores. Laying aside the reason of this singular condition of the case, it is certain that the tides of the Strait of Gibraltar are a powerful auxiliary in passing it from East to West with westerly winds, and the coasters, which,are sailing vessels, know how to profit by it, and do so without any great difficulty. Strength of the Tidal Stream.-One mile an hour may be accepted as the mean velocity of the tide at spring tides on the coasts of which we have been treating, but in the channels it reaches to three and even four miles an hour, according to their direction. And the same takes place on the ebb. In the vicinity of the western entrance of the Strait of Gibraltar the ebb is always stronger than the flood, and its strength increases in proportion as it has passed Cape Trafalgar. Establishment of the Port. —Such is the name assigned to the hour of the first high water immediately after the noon of the day on which the syzygies occur, or rather, perhaps, the days of conjunction and opposition of the moon. This hour is nearly constant for the same place in normal conditions of weather, etc., and the observations for its determination are confirmed at the anchorage, and also at the bars over which the tide passes. Variation of Tide Time.-However small the difference from the normal character of the weather, the actual period of high water varies a good deal, being affected according to atmospheric pressure and the effect of the wind. In consequence of these variations, the hour of high water is later, because there is a larger collection of waters; while at other times it is earlier, because there is less-a consideration which should be allowed in foretelling the time of high water when a vessel intends entering a port of small depth, and where it is indispensable to go in precisely at high water, as well as when leaving it. The establishment of the ports are drawn up in tables for the use of * Captain Smyth, in the course of his exploration of the Mediterranean coasts, took an opportunity of observing the tides in the channels of Karkenna and Jerba within the Gulf of Kabes, and he found a rise at springs of 1.7 in 5.6 feet, and also that the tide rose eight feet in a fresh Levanter. The losses which Count Pedro Navarro experienced in the Island of Jerba (Geloes) on the 30th of August, 1510, were augmented by the impossibility of the people embarking to save themselves in his galleys, from his boats having remained aground at low water when the tide ebbing out exposed so much of the shore of the island. 29 navigators. The times stated in them are always the means of a multitude of observations made under favorable circumstances at every place; and the navigator must make allowance for the earlier or later period of high water, according to the actual condition of the weather. In bays and harbors of considerable depth, such differences may be neglected; but they require special attention at places of small depth, or when passing over bars or rocks of scanty depth of water. Establishment of the Bay of Cadiz. — With respect to the Bay of Cadiz, lh. 30m. may be considered the establishment on all parts of the coast. But as the tidal wave progresses through all its channels, bays, and harbors, it alters, being later at each place, so much so that while at the entrance of the Bay of Cadiz it is lh. 24m.; in the channel of Carraccas it is 2h. 30m.; at Chipiona, it is 1h. 34m.; and at Bonanza, it is 2h.; at the bar of Huelva it is lh. 54m., and at its mole it is 2h. On the coasts of Portugal and Galicia the establishment is somewhat later; for while at Cascaes it is 1h. 40m., and at Lisbon it is 2h.; in the mouth of the Douro at Oporto it is 2h. 30m.; at Finisterre it is 3h.; at the Sisargas it is 3h., and at Corunna 3h. 30m. Range of the Tide. —Such is the name given to the whole rise of the tide, or the difference of level between high and low water at the time of the syzygies. The height of the level of high water is more subject to change than the establishment of the port. In the tables above mentioned, the mean of a multitude of observations, under normal conditions at the ordinary syzygies, is called the range of the tide. Range of the Tide in the Bay of Cadiz and on the Coast of Portugal.-The greatest height which the tidal waters attain in the Bay of Cadiz is from twelve to thirteen feet as a mean result at ordinary springs, and fourteen to fifteen feet on the coast of Portugal and Galicia. At equinoctial springs three to four feet high must be added to that height, unless any atmospheric change takes place. But it is very well known that the maximum height of the tide never coincides with the time of high water at the syzygies, but that it is from thirty-six to forty-eight hours later; consequently, the navigator, bound to a port having a shallow bar, must bear in mind that the highest tide will always be that corresponding to the second or third day after new or full moon. Streams of the Tide.-Certain threads of the tidal stream appear always to take place as the consequence of the general current continuing until they disappear entirely. This phenomenon, constantly 30 occurring in the Strait of Gibraltar, is scarcely perceptible at its westernfentrance. They are found more especially off the salient points of the coast, and with more intensity off those which project at right angles to it. Hence, off Cape Trafalgar the stream which bears its name is perpetual. Cause of the Streams.-To all appearance these errant streams of tide are produced by the encounter of two opposite currents; and from what has bean observed in the strait, that the strength of it increases with the tidal stream, attaining its greatest strength at halftide, when the streams of flood and ebb are at their maximum velocity. The Cape Trafalgar Stream. —The errant stream off Cape Trafalgar is most violent, without failing its utmost strength in either tide, whether it be ordinary spring s or neaps. It extends off to the S. W., beyond and passing over the Aceitera Rock, until it becomes lost in the general current. When the swell or sea runs in the same direction as the errant stream the waves rise so much as nearly to break, which leads to the suspicion that there are rocks in localities where they are unknown. It is advisable, therefore, for vessels to avoid them, and to keep further even from Cape Trafalgar. when there is a high sea running. Errant Streams outside of the Straits.-Although these errant streams are common enough to the eastward of the strait, they are not to be found to the westward of it. From this, it is natural to infer it should be so, because the general easterly current carries them into the Mediterranean until they subside; while, in the western entrance of the strait, they only begin to form themselves off Capes Trafalgar and Espartel. Errant Streams of Cape St. Vincent. —In the Gulf of Cadiz to the West of those capes these errant streams are unknown, and only outside Cape St. Vincent, and about three miles from it, now aDd then one is found, which, on account of the scarcity of them, has been taken for a rock. But this may be entirely attributed to the shock of the general current which runs on the coast of Portugal with the stream of flood which sweeps out of the Gulf of Cadiz. Similar threads of errant currents are formed on the coast of Galicia, which sometimes alarm navigators, as they occasion appearances as if formed by rocks. These threads may be the effect of the tidal stream as it leaves the estuaries, meeting the general current along the coast. Rollers. —Such is tile name given by the Spanish navigators, and vaga de Maar among the Cantabrians and Galician seamen, to the swell which collects on coasts, occasioned by the on-shore wind, but which does not itself reach the place where it is observed. 31 In the Gulf of Cadiz it is often observed, particularly in winter. A swell comes from the S. W., attracting attention by the noise which it makes by breaking on reefs. These noisy waves are the forerunners of the Vendaval which prevails beyond the horizon, and which sometimes is not long in coming, bringing along with them dense and heavy clouds which darken the atmosphere, while the waves inundate the coasts. This swell is the precursor of the wind which produces it, and sometimes this wind does not reach the place where the swell is observed, being opposed by another more powerful current of air. But by the magnitude of the waves and the direction of their course, an opinion may be formed of the kind of weather which prevails in the district from whence they come, in the same manner as we can form an opinion of the wind which prevails in the loftier tracts of the atmosphere by the direction and swiftness of the clouds* which it carries along with it. On the coasts of the Gulf of Cadiz this swell is the certain indicator of the Vendaval, and sometimes it will foretell the wind even for two days. On those of Portugal and Galicia, whether it comes from S.W., *West, or N. W., it is always a sign of the same weather prevailing in those directions, and its presence prognosticates the coming of the wind which sends it. There are occasions when it delays much its arrival on the coast of the peninsula, and at other times the wind which produces the swell does not come at all for reasons already stated. But in general it is the signal of the wind which is about to prevail. " Clouds are the surest indications of the direction the wind is following in the upper and lower regions of the atmosphere, for they show the direction in which the upper serial currents are moving over that which we experience on the surface of the globe. The higher and lighter clouds are seen to move frequently in a direction contrary to that of the wind that is blowing below, and when this is observed we may prepare, before long, for the wind which is (as it were) thus promised, which is initiated in lofty regions, for it is certain that atmospheric currents are formed gradually from the higher to the lower parts, and in a manner more or less oblique. From these small woolly but higher clouds, which are seen to move from S. W. to N. E., seamen know that the S. W. wind will soon follow, whatever other wind may be blowing at the time, with its corresponding weather. A still higher stratum of clouds will enable the seamen to prognosticate the wind which will follow in a district more or less extensive, particularly evident on clear nights. We allude to what are called shooting stars. From time immemorial it has been believed by navigators that the wind will come from the point of the horizon indicated by them as from whence they came, and careful observations of Mr. Coulier Gravier, and which he is still following, partly confirm this assertion. This philosopher has observed that those meteors move in the higher regions of the atmosphere, and that they reveal the direction of these serial currents in which they move, a revelation which coincides with barometrical indications. These currents on approaching the earth's surface disturb the most dense vapors, as is well shown by the barometer, which indicates the approaching aerial currents, and fortells the direction of those luminous displays which leave behind them the exhalations called shooting stars.-Researches on Meteors by M. Coulier Gravier. 32 N. W. Swell.-A N. W. swell is very common in winter on the western coast of the peninsula, and in March and April is almost incessant on the African coast. It is very well known to those navigators who make the voyage from the straits to the Antilles, who begin to experience it as soon as they reach the meridian of the Canaries. They consider it to result from those heavy N. W. gales which come from Davis' Straits, and they are confirmed in this opinion by the fact that when they reach the meridian of Newfoundland the swell disappears, owing, they consider, to the impediment presented by the great bank. This swell makes terrible havoc on the coast of Africa, rendering it unapproachable for long intervals of time, and vessels which unhappily get on shore on that coast while it prevails soon go to pieces and the crews are drowned. Vessels which are accustomed to lie in Jeremias Bay and the coast about Laraiche as far as Cape Blanco for shelter from the Levanters, have good opportunity of observing this swell, which produces a mass of breakers on the rocks and distant banks which lie off the coast. Such heavy swell being observed by a vessel she should on no account approach the shore under sail, for she might get becalmed and then thrown on the reefs, or might, in order to prevent it, be obliged to drop an anchor that might never be recovered. The N. W. swell attains colossal dimensions on the West shore of the peninsula, and on the coast of Spain. It shows itself in mountains of water of so wide a base that they attain a height of sixty to seventy feet, and acquire a force that would destroy the strongest vessels;* sailing vessels finding themselves hampered by such seas near the coast have narrowly escaped a horrible wreck by a merciful interposition of Providence, in a favorable off-shore wind, by which only they have been saved from destruction. Barometric Oscillations.-When the barometer merely shows the weight of the atmosphere, it is even then useful to consult, for the sake of knowing the changes which take place in it as the vast laboratory wherein the most destructive tempests and the most astounding meteoric phenomena are produced. We know that the rising and falling of the mercury in the barometer are the result of the actual pressure of the atmosphere on the surface * Admiral Fitz Roy, in the Thetis frigate, observed sixty-six feet as the height of the wave in a gale in the Bay of Biscay. The following are quoted by the "Annuario:" The heights of waves in wide and deep seas in a gale of wind may be estimated as between thirty-five and forty-five feet from the summit to the base. There are authorities which assign forty-seven feet as the height, with a distance between them of six hundred feet, and a rate of traveling of thirty miles an hour.N. M. 1854, p. 49. In seas not very deep, waves attain an immense height, and have been observed more than one hundred feet high near the Eddystone in the mouth of this channel. —=. Ml. 1835, p. 609. 33 of the mercury contained in its cistern. A rising of the mercury shows an increase of atmospheric pressure on the surface in the cistern. This occurs with winds from the northern quarter; and, consequently, a rising in the mercury will always indicate a tendency of the wind to come from that quarter which is also always the coldest. Again, on the contrary, with a fall of the mercury in the tube it rises in the cistern, showing a lesser pressure on its surface, and this is the case when winds from the southern quarter prevail, which again are also the warmest, and therefore a falling in the mercurial column is a prelude to winds from that quarter of the horizon. Between these two extremes there is room for a multitude of' gradations, according to the density or lightness of the atmosphere, and hence the study of the oscillations in the tube of the barometer enlightens the navigator in the subject of atmospheric changes and enables him to foretell what will occur. Still it must be remembered that if for the most part the warnings of the barometer coincide with atmospheric changes, they do not always accompany each other. Notice of Southerly Winds. -A fall in the barometer that precedes rain on our coasts generally indicates southerly winds, which are warm, and, crossing the ocean, come loaded with vapor. Consequently, the barometer falling will always indicate an expansion of the atmosphere occasioned by warm winds from intertropical regions, but gives no indication whether from East or West of South, or whether it will be accompanied by heavy or light rain. Notice of Northerly Winds.-Again, the rising of the mercury reveals a condition of the atmosphere entirely opposite to the foregoing, because it is owing to northerly and northeasterly winds, which are always the coldest and most dense, and because they pass over large continents they come to our shores in general dry and clear. The atmospheric pressure indicated by the barometer also shows us different heights above the surface of the sea. A rise in the mercurial column, or a depression of the surface in the cistern, always accompanies a depression in the level of the sea, and this is detected in the harbors where the high waters do not attain their usual level, and the time of high water is earlier. The contrary takes place when the mercury rises in the cistern, for then the least pressure raises the level of the water and the time of high water is later. Thus it is that the pilots of the ports, fishermen, and others acquainted with the sea, foretell by means of these differences of height the probability of' northerly or southerly winds. In fine weather the level of the water is much lower than ordinarily with northerly winds and a low thermometer, and the contrary takes Hydro. No. 1.-3 34 place when the wi nd is southerly and the temperature high. All this is observed most satisfactorily in the ports of the Mediterranean which are not subject to tides. When the barometer rises or falls slowly for two or three consecutive days, its indication may be most assuredly depended on; but rapid changes indicate wind or bad weather. The thermometer generally follows its movements in a manner contrary to those of the barometer; that is, it rises when the barometer falls, and vice versa. A high barometer and a low thermometer always foretell northerly winds, and barometer low with thermometer high southerly winds. The changes of the barometer off Cadiz are very remarkable. In the course of five years' observations in the Tower of Tavira it never varied above an inch. In January, 1858, it; attained its highest reading with a northerly wind and clear sky; and it was at its minimum in November of the same year, with a heavy southwester and torrents of' rain. Other observations before us at the Astronomical Observatory of San Fernando at eight every morning from the first of January to the end of July, 1865, show that the whole range of the barometer was 1.024 inches; the highest, which was 30.6, occurred in February, 1864, with an E.N.E. wind light, thermometer 38~. The lowest was 29.5 in March of the same year, with strong southerly winds and rain, tllermometel, at 54~. In the Gulf of Cadiz the changes of the thermometer are very small. The small variation of its climate is its best praise. Situated in a temperate part of the world, and far from the snowy peaks of mountains., it is not subject to much change of tempe rature. The sky is mostly clear and but little rain falls there. Nor is it much visited by thunderstorm. But it has a reminder of the Levanter of which we have already spoken. Coast of Portugal. —How different from this is the weather of the coast of Portugal and also Galicia, where it rains during a great part of the year, because here it is that those watery winds which come across the Atlantic from S.W. to N.W. discharge the showers with which they are loaded. For the same reason the barometer changes are greater on these coasts than in the Gulf of Cadiz, and this is proved to us by the observations extending through a period of two years at Lisbon. From these observations it appears that the range of barometer was small; that the highest reading of the barometer was 30.5 with the 35 wind at N.E. light and clear in February, 1865, the thermometer being at 540~. Fog. —This vapory condition of the atmosphere is another of the enemies which the navigator has to contend with, very often to his loss, for they not only blind him to external objects, but at the same time allow him to be driven along with the surface current of the ocean. According to scientific men, fogs are occasioned by th- difference of temperatures between adjoining regions of the ocean, and their occurrence is at the mouths of estuaries, the land in the vicinity of which sends forth a vapory atmosphere which is condensed with the cold atmosphere of the low capes. Fogs on the Coast of Spain.-The coasts of Galicia and Portugal are much visited by fog, and principally at the mouths of the estuaries. But they are most frequent in moderate and wet winters. Fogs in the Strait. —In the Gulf of Cadiz they are occasionally very enduring, especially at its western entrance. At the termination of the easterly wind they usually occur there, appearing like a barrier to it, gradually advancing to the eastward until they completely cover it, and clearing away as soon as the westerly wind is fairly established. The fogs which collect about daylight at the mouths of the estuaries of the Portugal and Galicia coast generally clear away about noon. Fogs on the Afiican Coast.-On the coast of Africa there are also, in the early morning or later, these same fogs, and generally with N. E. winds. Sometimes they will extend over the entire strait, forming in the western part of it like a wide curtain, and as night approaches completely cover the whole coast. Sometimes they are so close down to the surface of the sea that it is common to see the masts and rigging of vessels above these fogbanks, while their hulls are entirely concealed by them. Fortunately this occurs in quiet weather, when vessels under sail make little or no progress, which adds to the chance of bells, fog-horns, or any such noisy instruments being heard, and thereby keeping clear of each other, numerous as they may be, as in the Strait of Gibraltar. Nevertheless, these precautions are not always sufficient to prevent collision between vessels, for the streams of the currents will drift several at once, occasioning their fouling in spite of their attempts to prevent it; and if on these occasions there should be added a strong tide, the consequences become still more serious. Steamers under such circumstances slow their speed, making their positions known by the steam whistle, and generally suffer least, as they always have the means of keeping out of each other's way. 36 Haze.-A hazy state of the atmosphere is almost as bad as fog, if happily it is not so dellse. This occurs in times of great heat, and on the coasts of Portugal and Galicia is most frequent with N.E. winds. In the summer-time in the Gulf of Cadiz, especially with light southerly winds, the haze on the horizon is considerable, and the effect of it on vessels and buildings near the sea is so great as to alter their form in appearance, and throw out the points of the shore as if they were lifted above the water. A considerable amount of haze generally indicates humid and wet weather, and easterly winds with a tendency to the South. During a dry winter in these localities, thick fogs will occur and not admit the shore to be seen except at a very short distance. A general fog. more tepid still, will occur (at this season with the Vendcval. These become so extensive as to cover the whole coast under our consideration. Navigators who may be making the land under these unfavorable circumstances are frequently at a loss to determine what land it is they may have in sight, for notwithstanding their reckoning may be good, the heights of the interior are still concealed from them. Evein the objects on the shore are so distorted that white towers and such like buildings are often mistaken for vessels under sail. And if the coasts they are on have outlying reefs and are shoal to approach, they are in the risk of getting aground, unless some break indicates their presence. Landfalls.-On these coasts there are three very remarkable points for a landfall, and these are Cape Spartel, Cape St. Vincent, and Capo Villano or Finisterre. The first is always used by vessels bound to the Mediterranean and those coming from America, which run on some parallel southward of lat. 360, on account of the northerly winds not allowing them to make Cape St. Vincent. The same landfall is made generally by other vessels from the westward, which have had to make northing whether bound to Cadiz or the Mediterranean; and those also from European ports to the northward make Cape Villano, whether they may be bound to any of the estuaries or ports of Galicia and Portugal, or Cadiz, or the Mediterranean. Vessels bound to the Mediterranean, and running on the parallel of the strait, should always make Cape Espartel their landfall in preference to Cape Trafalgar. Cape Espartel is high, bold, and conspicuous; Cape Trafalgar is low and surrounded by reefs, and when the vessel's position has not been confirmed by known points of the and, the landfall which should be adopted ought always to be con 37 spicuous and bold, one that imay be seen from a great distance also by night, and better if it shlould hlave at light, anld can be approached without any risk. Cape Trafalgar may be made by vessels bound to the Mediterranean that have already confirmed their position by seeing Cape St. Vincent, Cape St. Mary, etc., and with N.E. winds, because it is then probable that the Levanler will be blowing violently in the strait, and it is better that they should then keep the Spanish coast on board. Cape St. Vincent is generally preferred as a landfall on account of its conspicuous nature, as well as its freedom from rocks, and its projecting outside the line of coast., which allows of vessels making it without being hampered by the shore North and South of it. Besides which it is admirably marlked by the height of.Monchique. which can be seen at a great distance. But in time of war it has been avoided as a landfall, because it has been infested by privateers aInd ships of the enemy. Cape Villano is always preferable as a landfall to Cape Finisterre, because it is high and projects out to the N.W., and therefore is always adopted by vessels from the English or St. George's Channels. These indeed generally avoid making Cape Prior, that they may keep clear of the currents and heavy seas and winds common to the N.W. face of the Peninsula. Villano is easy to make, not only on account of its advanced position outside of this coast, but also from its peculiar form. When made from afar it has the appearance of an old castle, the effect of a peak on its summit; and when seen isolated it assumes the appearance of a vessel rigged as a sloop or cutter. It is seen before Cape Tourinana, because it is higher and more remarkable, although it does not project so much. The Cies Islands and Cape Le Roca.-Vessels from the westward bound to Lisbon or Vigo and confident of their reckoning have the Cies Islands and Cape Roca as landfalls, both of which are easily made. Vessels bound to Oporto will have been careful of' the shore unless certain of their reckoning, for this port being situated on ground of much sameness and uniformity, it is not easy to recognize afar off, when the coast should not only be very clear but its configuration (listinct. All the points we have mentioned being well suited for a landfall, are happily provided with excellent lights, which enable a vessel to approach them without risk by night. The light, how ever, recently established on Cape Spartel has been the cause of a remarkable mistake. Three vessels coming from the westward made that cape by night, their commanders being ignorant of a light having been placed there, mistook it for Tarifa, which has also a fixed white light, and they were 38 consequently embayed and lost in Jeremias Bay, no doubt considering that bay to be the mouth of the strait; two of these were English and one French. The light was established on the 15th of October, 1864. It would be desirable that some modification should be introduced into this light off Cape Spartel so that it could never be mistaken for that of Tarifa. It should not be forgotten that this light, being situated in an uncivilized country, might be neglected to be lighted on some night (as will be remembered) and the navigator who, under similar circumstances, might make Cape Espartel without seeing the light, might run into the same fatal error. Making Cadiz.-A ship bound to Cadiz from America, unable to make Cape St. Vincent, if her reckoning be good, might make the land somewhere of the bay. The elevated heights of San Cristoval and Ubrique, visible from a great distance in clear weather, are excellent marks for it. San Cristoval, known to navigators under the name of' Cabeza del Noro, is 1, 755 metres (5,758 feet) high, and may be seen from a vessel twenty-five to thirty miles fiom the bay. Neither of these heights can possibly be mistaken for any other, because they only are to be then seen above the horizon. Coming from the Canaries a vessel may lookout for Cadiz if her reckoning be good and she has favorable winds; but if these be to the southward of east, and an easterly wind be observed in the strait, she ought to make for Cape Spartel, and get a fresh departure so as to make sure of Cadiz Bay. And should this be at night, the lights of Cape Espartel and Trafalgar will be still more certain means of giving her her position and the proper course to be steered. Making Cadiz in Hazy Weather. —It might happen that a vessel has hazy weather for making Cadiz, and yet she might clearly see the Height of Beba and that of San Lucar not far from it. The first is a hill of gentle slope rising above the adjacent land, and is distinguished by a white house called Beba or Breba, situated three miles S. 62~ E. of Chipiona, and is seen from the whole neighborhood of Cadiz. A vessel situated a little north of its parallel would soon make out the ex-convent of' Ragla, the town of Cbipiona, and other buildings on the coast, the whiteness of which would render them visible in spite of the haze, should there be any. If the hill should be so enveloped in h-aze that neither the small heights nor the buildings of the coast can be seen, the color of the water near the shore will indicate ils proximity to the seaman, and the lead will soon verify-his position. At a distance of four to five leagues fiom Cadiz, when from W.S. W. to S. of it, he knows the soundings are 39 clear sand, and if it be loose blackish clay lie will be on the parallel of the bay. Navigation.-Vessels from the Strait of Gibraltar bound to Cadiz should keep the Spanish coast in hand, and may pass inside of the Aceitera Rock, and even the Conil Reefs if she have on board a pilot for their channels, and the vessel should be of proper draught. The steamers which trade along the coast can, and do. adopt this navigation; for, without losing any distance, they are sheltered from the wind, which about here blows with considerable violence. The navigator, however, wvho has not sufficient experience, should keep outside of all these dangers, especially if his vessel is large and has only sail. In such case it will be sufficient to keep at four miles from the coast, and bring Cadiz light to be N. by E.; shouldc steer to the northward, so that she should have the tower on her starboard hand, and pass as near as safe to the reefs off Point San Sebastian, so as to avail herself all she can of the wind on first standing into the bay. Making Cadiz in an East Wind.-Should the tide not answer, or if it be evident that on gaining San Sabastian Point the ebb will have made, (which is a point that should be studied beforehand,) the navigator must be contented to stand off and on between Cadiz and Cape Roche, where the wind will not be so strong as in the entrance of the bay; and as soon as he has reason to believe that the tide is making at Cadiz, he may run for the entrance of the bay with the view of taking the harbor. He should endeavor always so to manage his boards as to be at the entrance of the channel by the time the flood has gained its greatest strength, with the view' of making the teast possible number of boards. It would not be prudent to beat in against a head awind on an ebb tide unless at neaps, and even then not unless the vessel be a fast sailer. If, on making Cape Trafalgar, there is much ground sea, a vessel should not attempt to pass inside of the Aceitera and other danlgers; she should rather increase her distance to five miles from the coast, as much for avoiding the streams of current off the cape as for keeping in depths of 15 to 18 fathoms; and when she has gained the meridian of Cadiz light she should steer so as to keep in depths in rwhich the sea will not break, and edge as near as she can with safety to the reefs of San Sebastian, so as to gain all she caIn on her first reach into the bay. Precautions on passing inside the Conil Rock.-A vessel after having adopted the passage inside the reefs might desire to get outside of them, which she might do by passing between the Meca and Conil 40 Reefs, or between these and Cape Roche, taking care to determine her position well by good cross-marks, so as to be able to select the proper course to take her mid-channel; and her captain bearing in mind that the flood tide always sets to the N. W. If the ground swell is very heavy it will break on nearly all the rocks, and will run high in the channels, and therefore in such a case the navigator must not think of adopting the inner route. When bound to Cadiz from the strait, and the ship is on the meridian of Cape Plata, the easterly wind will slacken, and it may be observed that the westerly wind is blowing at sea. The vessel must then keep on a southern parallel so as to be able to pass from ten to twelve miles from Cape Trafalgar, with the view that, when the westerly wind reaches her, she may be able to stand on to the entrance of the bay. Precautions in passing the Strait when bound to Cadiz. —In winter-time the same precaution must be observed coming from the strait, but from another motive; since it frequently happens that, while there is a fresh easterly wind in the mouth of the strait, the Vendaval will be prevailing to the westward. Hence the navigator, on gaining the meridian of Tarifa, finding the easterly wind veering to the southeast, should keep towards the African shore; for he may be sure that as he reaches Cape Spartel, the wind will draw to the southward and get steady at southwest; then being well clear of the Spanish coast, he will easily clear all the reefs and run free for Cadiz Bay. Precautions for San Lucar or Huelva. —The same course should be observed, and the same precaution followed, by vessels bound to San Lucar or Huelva; that is, with easterly wind prevailing, they should keep in hand the Spanish coast whether they pass inside or outside of the shoals or reefs. From Cadiz to the Strait in the Easterly Wind.-Vessels from Cadiz or any of the western ports bound to the strait with an easterly wind, should hug the shore as much as possible; in doing which they will find shelter from the sea. Thus they may easily get as far as Cape de Plata, from which they might stand out and work to the eastward in the middle of it should there not be much sea. By this means they will profit by all the currents setting them to windward. If, on arriving off Cape Trafalgar, there is observed to be too much wind in the strait to admit of their working against it, it will be better to cross the entrance of it with the wind free, and seek refuge under Cape Espartel. It is of no consequence anchoring five or six miles to leeward of this cape, as it soon can be made up; for when the vessel is sheltered from the sea, and Jeremias Bay might be gained, there a vessel may wait until the easterly wind is blown over. From Cadiz to the Strait in the Westerly Wind. —From Cadiz or ports west of it, there is no difficulty in getting to the strait with a westerly wind. As westerly winds are favorable for crossing it, it is sufficient, as soon as a vessel is clear of the reefs of San Sebastian, if on leaving Cadiz she run to the southward until she finds herself S.W. of Conil, and then lay her head S. E. for the middle of it. If there should be much ground sea, on leaving Cadiz she might steer S. by W. or S. S. W., so as to pass clear of the shoals on the coasts and afterwards lay her head South, S. S. E., and in proportion as she draws into the strait. By Night. —Whichever navigation is adopted by night the lights of San Sebastian, Trafalgar, and Espartel will give the navigator his position so well as to enable him to shape his proper course. In fact, the navigation of the strait by night may be made with the utmost facility. Cross-bearings of the lights of Point Europa and Acho, of Ceuta and Tarifa, and this with those of Espartel and Trafalgar, (land again this coast with that of Cadiz, will always give the navigator his position, and with these he may navigate from the strait to Cadiz, and vice versa. The character of the lights on the coast of Spain are so arranged that they cannot be mistaken for each other, and their particulars are to be found in the usual books. If a vessel for Cadiz be coming firom the westward, and she eincounter a strong Levanter off Cape St. Mary, she should work to windward between the parallel of Cadiz and the coast of Huelva, so as to avoid the strong wind in the parallel of the strait, as well as the sea which it raises; and she had better keep to the coast from the moment she can lay up for the Broa de San Lucar. Coasting vessels working from Agnamonte, or Huelva to Cadiz, and from Cadiz to the strait, often anchor when they find themselves met by the easterly wind. They will lie at anchor off some beach during the height of the wind and avail themselves of the nights when, besides not being so strong, the wind becomes more N.E. The ebb tide should be profited by as much as possible, for at springs it helps a vessel to windward veiy much. From Cadiz with the Vendaval.-The greatest difficulty a vessel has to overcome, whether from the westward or from the strait, is when she has to deal with a Vendaval in rainy wet weather, which prevents anything from being seen of land or sea. If the commander should not have previously obtained his position, and thus be ready with the course he will run into the bay with, it would be better for him to 42 haul out than to get entangled wvith the coast, and keep, if lie can, on the parallel of the strait, in order that, in case of mischief, he can run for it. If he be caught by it on the meridian of Huelva or Agnamonte. he should endeavor to wait, under all possible sail, to make up for the current, which, along with the tide, will set his vessel into the Gulf of Huelva, and he should make her boards so as will keep her best' from this danger until the weather clears and will enable him to make tile land to obtain afresh her position. As the coast in the vicinity of Cadiz and the whole circuit of the Gulf of Huelva is low, it cannot be seen from a vessel until she is close to it. In this case she may have recourse to the lead, and determine her distance from it by the depth of water and the character of the bottom. The depth of a hundred fathoms off Cadiz and the Gulf of Huelva is more than twenty miles from the shore. Navigation from the Strait with a S. W. Wind -On crossing from the strait to Cadiz with a fresh S.W. wind, a vessel must be careful to make such courses as will free her from the effect of the current, which will drift her towards Conil and Santipetri. Similar precaution should be taken by those which are for making Cape St. Vincent with the same wind and weather, to avoid being set down towards San Lucar and Huelva, and also those again which are taking the opposite direction. The steam packets which frequent the coast know from experience that it is essential to keep well clear of the coast on crossing the Gulf of Cadiz when blowing strong from seaward, so as to avoid being set down towards it, whether off Cape St. Mary, the Arenas Gordas, Chipiona, or the Conil Reefs. With foul winds, or even those from North to East on the contrary, they close with the shore, for the currents then set them from it. Navigation from the Strait to the Portugese and Galicia coast.Vessels from Cadiz or the Strait of Gibraltar bound to the coast of Portugal or Galicia will make their passages as we have already shown in each particular case, making for Cape St. Vincent with the view of doubling it at a convenient distance. And this cape being clear, may be approached as near as they please. If vessels near it with a fresh S. W. breeze, they should give it a good berth so as to pass it well free; and if bound to Vigo, the Bay of Biscay or the Channel, they should take care to make a more westerly course than is required by the trend of the coast, because the current produced by this wind sets a vessel towards the shore. It must also be remembered that the Vendaval obscures the daylight, 43 and a vessel ihay find herself aground when she is considered clear of all danger. Should the vessel be bound to Lisbon, Capes Espartel and La Roca will be seen during the day, and their lights at night, to show the position of the estuary; but if she be destined for Oporto, and a Vendaval, with dismal, blowing weather prevails, it would not be prudent to close with the coast, for this being very rocky near it, and the heights of the interior difficult to make out, a vessel will be at a loss to make sure she is on the parallel on which she can approach the Douro. For the Coast of Galicia with a Vendaval. —Should the vessel be bound to Vigo or any other estuary, she may stand along the coast between the mouth of the Mino and Cape Silliero, taking clare with such weather not to overrun her distance, for the currents twill set the vessel to the northward, and how much, it will be difficuit to determine. Having made the Cies Islets, which are high and remarkable, she may take Vigo Inlet, or continue for her port, if it be North of them. Vessels bound to Corunna or Ferrol in a eindaval must also take care not to overrun their distance, for they will find a difficulty in recovering it to windward. When the S.W. wind is attended with very thick weather the coast of Galicia is completely obscured, ird it is necessary to see much of it to make it out. With such a destination she should make Capes Finisterre, Tourinana, or Villano, and keeping the coast in hand, run along it at a convenient distance, not to lose sight of it, for the port of destination. After doubling Cape Villano the wind will be more favorable. If a vessel, considering herself off Cape Finisterre, should find the coast so obscured that she cannot make sure of it, it will be most prudent to stand off and on, keeping sufficient sail on her to prevent falling to leeward, and waiting till the weather clears so that she can make the coast satisfactorily. Cases are known when the breakers on the reefs have been close to a vessel from which the trend of the coast could not be seen, nor headlands nor lights by night. In such cases doubt must prevail, and the best plan is always to stand off and wait for clearer weather. Navigation from North to South on the Coast of Galicia and Portugal.-The reverse navigation-that is, from North to South-may be made with the utmost freedom from anxiety; because, being the season of the Northers, a vessel has but to run along the coast. But it is not so in winter-time and with the Vendaval, for she has then a head-wind, dirty weather, a heavy sea, and contrary current. On the 44 coast of Galicia she may hlave recourse to any one of its opetn and safe estuaries; but on that of Portugal she can only reckon on (a very few\ ports and all of them with bars. A vessel running from North to South on their coasts witlh a fresh N. W. wind, must be very careful of her course. With this wind, which is on shore, she must take care to keep to the westward of the course required by the line of coast, for the vessel will be drifted towards the shore. Fortunately, those N. W. winds are not so much attended with dirty weather as those from S. W.; land although they bring heavy showers with much wind, these are always followed by clear intervals, which allow of the coast being seen, and the vessel may recognize her position from time to time. Navigating from S. to N. on the Coast of Portugal and Galicia. The most troublesome navigation on the coasts of Portugal and Galicia is that from South to North, in the season of the Northeasters, and these generally prevail with but slight interruptions all the summer, and especially in those years which navigators have called the years of Northers. Even in the passage from Cape St. Vincent to the Estuary of Ferrol, there are many instances in which vessels have been from one to two months making it. When northerly winds prevail, and which wvill vary between N.N.E. and N. N. W., the navigator in an ordinary bad-sailing, square-rigged vessel has a trying task of it. Powerful vessels at once stand off the coast a long distance so as to avoid the strength of the current, which is always heaviest in-shore, and succeed in getting ia slant of wind from N. W., with which they make very fairly to the N. E.; but small craft and coasters find themselves obliged to consume their provisions under the lee of some cape or point, avoiding the regular ports, so as not to increase their expenses by duties. Should the vessel which is making her passage under such circumstances be fast and her commander acquainted witll the coast, lie can profit by these unfavorable conditions. To effect this he will avail himself of every slight alteration in the wind, taking care to be near the coast at nightfall when it comes from the N. E., and stand out at daylight so as to tack in-shore about noon and again get hold of the coast. If with this lie can manage to combine the favorable set of the tide, he will forward his voyage far better than those navigators who, from fear of the shore, keep it at a great distance without profiting by the changes favorable to them, either in-shore or out on the offing. When the northerly winds bring much sea the voyage is necessarily delayed, for this completes a combination of opposing conditions for 45 the nlavigator and obliges hiim to remainl for days and perhaps sweeks under the shelter of Cape St. Vincent, at Setuval, Cascaes, Peniche, etc., and it is seldom that the coasting craft escape without having recourse to all those acllhorages. Steamers. which are vessels that go lording it over the sea, make their passages along the coast either way. They keep off the coast to seaward, but, making it for the sake of their position, always pass inside the Berlings, either by day or night, unless, indeed, the weather is so obscure that they have no chance of seeing them. It must be observed that the foregoing directions which we have g,iven for the coasts under our consideration, in reference to the winds and currents which prevail on them, must not be looked on as perfect; they are the result of the observations of seamen who have often frequented them and know them well, but cannot be expected to provide remedies for all emergencies. Every year, every), season, even every day, peculiarities may be observed in the relation of winds and currents on these coasts that lead us to doubt, sometimes, whether sufficient data has been collected for those who have endeavored to describe them for the benefit of navigators. It is quite beyond our conception to account for why, in the the years of prevailing east winds, these winds do prevail more persistently than in any others; and why, in years of westerly winds, northerly winds, etc., these will prevail over the rest. Experience teaches us that there are huge anomalies in atmospheric and oceanic circulation without our being able to give the reasons which produce them. Our duty, therefore, is to collect and present to seamen tables of meteorological observations accompanied by some reflections, in order that those may use them who frequent our shores. Meteorology, yet in its infatncy, can do little; but thanks to its cultivation in a multitude of observatories, itllas commenced its progress from such information collected from all parts of the world where human wisdom has penetrated; and it may be presumed that in a few years we shall be able to gather some fruits from all those able minds incessantly laboring with the phenomena whiclh we so frequently admire in the great celestial vault Meanwhile England has established with some effect centres of meteorological observation, with the view of fortelling the weather which may take place in certain localities in the course of twenty-four hours or so, with the assistance of one of the most powerful auxiliaries8 46 yet invented, the electric telegraph. We allude to the "Forecasts of Weather,' published by the Meteorological Department of the Board of Trade, circulated throughout Great Britian for the information of shipping, and especially those proceeding to sea. A similar centre of observation has been established at Paris, although hitherto (July, 1866) not with the result hoped for, possibly from so much extent of continent intervening between it and the sea, perhaps causing a change in the stormy weather in its progress so far inland as to interfere with the forecastings. This does not apply to the United Kingdom, which is more dispersed and occupies a better position for such kind of observation. P.; RIUDAVETS Y TUDUR&E July, 1866. The foregoing concludes our translation of Senor Tudure's elaborate paper on the Strait of Gibraltar and the adjacent coast-one that cannot fail to prove of service to the navigator. Having thus dealt with the ocean side of the strait, in a future number we may probably call the seaman's attention to its Mediterranean side. BUREAU OF NAVIGATION, NAVY DEPARTMENT, Washington, January 31, 1868.