rect judgment on matters of great political importance. His natural ability, the education he received in his youth, his great experience,-in any of these respects how few can pretend to be equal to him! Let the comparison be made, for instance, with regard to the policy proper to be adopted in the government of Ireland. The Duke was born in that country, and has passed many years in it; he is perfectly familiar with the history, habits, and feelings of the people; there is scarcely a family in it, of any distinction, with the members of which he is not well acquainted; he possesses also, in common with the other members of the Government, private sources of information as to the designs and means of the agitators and leading parties in that country. Yet what is more common than to hear men declaiming on the folly or tyranny manifested by him and his colleagues in their government of that part of the empire? To say in behalf of such men that they have a right to judge of the conduct of Ministers, for that Ministers, like other men, are fallible, is not a sufficient excuse. They have not a right to judge, unless they have reasonable grounds for their judgment. Ministers are fallible: but the thing chiefly to be lamented is, that a great number of petulant murmurers are not sufficiently sensible of their own fallibility. For if a man of great natural ability, carefully educated, and of vast experience, be fallible, surely the ill-educated, both destitute of knowledge and, for the most part, of ability and leisure to acquire it, must be still more fallible. Το express opinions with the utmost confidence on subjects of which they have little or no knowledge,-what can be said of such a practice, but that, while they are ever ready to disparage and accuse their rulers, the only thing they make plain is their own conceit, ignorance, and folly? But let us forbear from enlarging further on this subject, lest, in our praise of this great man, we incur the risk of assuming a tone of extravagance. Let us avoid this error, mindful of the remark made by a sagacious historian, that panegyrics on great men are usually most abundant when a decline has taken place in the practice of their virtues; the praise of virtue, and even pleasure in contemplating it, being unfortunately compatible with the practical neglect of it. Moreover, in praising such men with the view of recommending them as models for imitation, what need of any urgent vehemence? Let us not doubt that our countrymen will have good hearts of their own. Far distant, we hope, is the day when England, in her sons, shall have to rely on that sickly kind of virtue which, not inbred, but imitative merely, and sustained by extrinsic appliances, shall need to be perpetually nursed and fostered by exhortation and example. It was not so with those bright luminaries "placed in the moral firmament by a potent hand" whom we are accustomed most to admire. In the day of Plassy, from which our Eastern empire dates its origin; again on that memorable day which gave occasion equally for our triumph and grief, when the enemy, who had been long pursued and sought and waited for, were at length seen without possibility of further escape from conflict; and on that other day, no less memorable, when the formidable line, marshalled by no ordinary hand, stood opposite, awaiting the signal from their "mighty Paramount," and the moment was come, on which manifestly hung the fate of many generations in many nations;-on those occasions, England's great Commanders did not, we may be sure, stop to consider what had been done at any former time by others in the like circumstances; their own hearts sufficiently prompted them; and their brave followers, even of the lowest rank, on hearing words of encouragement addressed to them, cried, "Do not speak to us, we know our duty." And as no nation or individual, whose laudable aim it may be to run a high course of greatness and glory, can accomplish that aim without having many battles to fight, great difficulties and dangers to encounter; so it is certain that those difficulties and dangers will be insurmountable except by innate strength of mind, sometimes, it may be, kindled into action by the record of deeds wrought by former men of renown, but chiefly to be established and perfected by self-culture and by communion with a higher influence, suggestive and auxiliar to our original nature. In minds so constituted and improved, assuring themselves on a foundation which cannot be shaken, and thence "gathering a force and faith which human nature in itself cannot attain," those virtues happily will flourish which are the sure defence of nations-a strict sense of duty, the highest appeal which Nelson himself could think of as fit to be addressed to men whose bravery, he knew, little needed any incentivestedfast principles of justice and honour, which, while they impress on the patriot's heart a respect for the rights and feelings of others, render him inflexible in maintaining his country's cause against oppression and wrong, incapable alike of being seduced by the wiles of the aggressor, or intimidated by his menaces and power. A WORD UPON TRADE-WINDS. So then we went afore the wind, Hence we nor squall nor crosses feared, No tacking as the breezes veer'd, For we were in the Trades.-GALLEY RHYMES. EVERY Ocean-seaman must well remember the feeling of calmness which comes on a ship's company, when after a rough passage across the Bay, and baffling winds in the Horse Latitudes, the vessel enters the Trades, and, with well-filled sails, rolls away before a sea which seems to threaten to mount the taffrail. It is a feeling in which even the very ship, inanimate as she is, seems to partake. This phenomenon has excited the surprise of many who "wonder" at every thing; but the cause and effects are now pretty well understood, and promise shortly to be much more so. The subject is of very great importance; and the attention of scientific men is now earnestly directed towards that branch of the system and science of navigation which seems most imperfect. The astronomical part of navigation, on which the place of the vessel depends, has been carried to a considerable degree of perfection; and our philosophical mariners, or our mariners philosophically directed, ought now more exactly to register currents and winds, their strength and direction, and all concomitant circumstances. Without copious experiments, and numerous matter-of-fact statements, we cannot hope to lay the foundations of an explanatory system of the Aërian Tides; nor bring the reflections and researches of such men as Hippocrates, Aristotle, and Pliny, among the ancients, and Galileo, Bacon, Halley, Mead, Toaldo, De Luc, Romme, Dampier, Capper, Kirwan, Redfield, and Reid, among the moderns, to decisive conclusions. Trade-winds is the term applied by seamen to certain constant winds blowing within or near the tropics, because of their great utility in promoting navigation and commerce. They occur in all open seas on both sides of the equator, and to the distance of about 30° north and south of it, though variable winds are often found within 28° of the Line in the eastern parts of the ocean. The same term is given to various local and periodical breezes, but the strict use of the word trades is applied specially to those winds which perpetually blow from one quarter of the compass, under a uniform and constant cause. "The general trade-winds," says Dampier, "are only in the Atlantic Ocean which parts Africa from America, in the East Indian Ocean, and in the Great South Sea;" the last being the vague geographical denomination of the Pacific Ocean, in his day. Though the ancients studied meteorology, and wrote upon its phenomena, they were unacquainted with trade-winds; indeed they seem to have been unknown even to modern seamen up to the time of Columbus, who appears to have gathered a notion of them during his residence at the Canaries. Columbus was a very observant man, and it is recorded that, in all his voyages, he was very careful to keep an exact journal of every occurrence which took place; always specifying what winds blew, and how far he sailed with each particular wind. He had, however, a difficult task in undertaking his first expedition in 1492, when he boldly steered due west, over a vast and unknown ocean, with no other pilotage than what was based on well-founded hopes and rational conjectures. His crew were alarmed, and their terror was not unnatural, at finding that the wind always blew from the north-east and east, since they apprehended they would thereby be prevented from returning to Spain. From this epoch the navigation of the Atlantic, and the trade-winds, became familiar to seamen; and a passage out in their track and a return in the region of variable winds, was soon an every-day practice. But Galileo appears to be the first who thought of assigning a reason for the phenomenon; and he, in embracing the Copernican system, considered that the tradewinds originated in the revolution of the earth round its axis, and in the circumstance that the atmosphere, though it participated in that motion, could not follow with equal speed the progress of the dense parts of our planet, and that a motion in the air was thus produced, which was contrary to that of the earth's rotation. About seventy-six years after this view had been promulgated, Dr. Martin Lister started another hypothesis, the which, however, never told. He conjectured that the tropical or trade-winds arise, in great part, from the daily and constant exhalations of a sea-plant called the Sargasso, or Lenticula marina, which grows in vast quantities from 18° to 36° north latitude, and elsewhere upon the deepest seas. For the matter of wind, coming from the breath of one only plant, must needs be constant and uniform; whereas the great variety of trees and plants at land furnishes a confused matter of winds. Hence, he adds, it is, that these winds are briskest about noon; the sun quickening the plant most then, and causing it to breathe faster and more vigorously. Lastly, the direction of this wind from east to west, he attributes to the general current of the sea; for a gentle air is observed to be constantly led along with the stream of a river: nor must it be omitted that every plant is an heliotrope, bending itself after the sun, and consequently emits its vapour thitherward: so that the direction of the trade-wind is, in some measure, also owing to the course of the sun. Had Lister's satirical and humorous friend, Dr. William King, applied his flapper as promptly as he did on another occasion, this opinion had never taken rank under the imposing Q.E.D. He who wishes to ponder on the profound proposition, will find it embalmed in the Philosophical Transactions for 1683, No. 156. To return to a sounder pabulum. In the first stages of the tradewind studies, the strongest proof of the Galilæan hypothesis was the circumstance that they occur only in the lower latitudes, where the terrestrial surface in its revolution round its axis has to make a large circle in twenty-four hours, and consequently must move with a greater degree of rapidity than in the higher latitudes. This opinion was therefore so plausible, that it obtained general adoption until 1686, when Captain Halley published his Historical Account of Trade-Winds and Monsoons, in the 183rd Number of the Philosophical Transactions. This was a very different essay to that of Lister, which almost immediately preceded it; and the attempt to assign the physical cause of those winds was founded upon a very superior basis. Halley had collected more extensive information respecting them, and was better qualified for handling his materials. In weighing his evidence he soon discovered several facts which were incompatible with the axiom of Galileo. The two most decisive were, that there were no trade-winds close upon the equator, where the diurnal motion of the earth is the greatest, and that they are influenced by the seasons-circumstances which would not happen if those winds were only caused by the action of the globe's gyrations. The facts collected by Halley have not been materially increased in number since his time, but they have been determined with additional exactness; and the whole scheme is largely indebted to the close observation given to it by the intelligent Dampier. The Halleian theory -seconded by that of Hadley *-rests on the well-established principle that wind is only a current of air, or a part of our atmosphere in a state of more or less rapid motion, and that its principal cause is a partial or local rarefaction of the air by heat. It is obvious that when the air is heated it becomes specifically lighter, and in this state must ascend; the less rarefied or colder air rushes into its place to restore the equilibrium, and thus forms the current of air called wind. If the globe were one vast ocean, we might, upon philosophical principles, fairly presume upon the resultants. A current of air would naturally follow the course of the sun. But this general effect and circumstance will be modified in a hundred ways, when we suppose islands and continents placed in the Though Hadley is correct in theory, he is greatly out in many of his deductions; as, for example, his making the trade-wind blow due east at the equator, and stronger there than elsewhere. way, of various magnitudes and forms, some flat in their surfaces, others interrupted and mountainous. The winds cannot then appear as they would if the surface of the globe were uniform: and if in any parts they preserve the force and direction which it should seem from theory they ought to have, this can only happen in seas of vast extent. These admitted data led the ingenious M. Romme into general reflections on the great movements of the atmosphere-movements which arise from the attraction of the sun, and from its heat. The motions derived from the first cause are similar to the perturbations in physical astronomy, viz., to those in the moon's orbit; and M. Romme has investigated them by nearly the same method as that which Newton employed in his eleventh section. Thus, he first finds the force with which an aërian molecule is attracted towards the sun; he then resolves this force into two, one tending towards the centre of the earth, and the other parallel to a line drawn from the centre to the sun; a second resolution is made, and one resolved force tends to or from the centre, and the other is tangential. The former force in the production of winds it is not necessary to consider, since its chief office is to alter the form of the atmosphere, and to give a spheroidal shape. The tangential force is that on which, the earth being in motion, the winds depend, and is easily computed; it varies as 2 sin. O cos. 6, or as sin. 2 0, 0 being the distance of the sun from the zenith of the place. M. Romme again resolves it into two forces, one perpendicular to the parallel in which the molecule is situated, the other in the direction of the parallel; and in the terms of the hour-angle, the azimuth, &c., he finds by a simple process, expression for these forces. From those expressions it is easily shown, that, if the earth revolve round its axis, currents of air, or wind, must take place from the east to the west, and towards the equator, the last winds must modify the effects of the former, which are supposed to arise from the forces acting in the directions of parallels to the equator. Such is the ingenious formula of M. Romme, and whilst some of our readers are making its application, we will proceed with the others to the general view of our topic. The rarefaction produced in the atmosphere by the apparent diurnal progress of the sun is unquestionably the origin of the trade-winds, the heat thus caused in the air being strong enough to produce this effect to an extent of about 60° of latitude. In this immense space of circumference, every part of which is presented in succession to the sun, the rarefied air is replaced by the colder and denser air which rests over the region contiguous to the region of the trade-winds, and this transposition of air is the trade-wind. As the difference of the density of the two currents of air which come in contact is not great, the wind is of moderate force. If the wind could move with a degree of velocity equal to the progress of the sun, it would blow from the north on the north of the places which are under the influence of the perpendicular rays of the sun, and from the south on the southern side of such places; but the velocity of the wind is infinitely less than that of the earth, hence it follows that the wind has hardly taken the direction which is imparted to it by the rarefaction of one place, when the place of the greatest rarefaction has already changed, having proceeded farther west. makes the direction of the wind decline to the place of greater rarefaction, and thus the northern wind is converted into a north-eastern, and |