159 tropical regions. It is thus that while the weather in summer is fine, the wind generally becomes stronger with us as the day advances, and lulls away towards the evening, which gives, to that time of day, the eneffable sweetnefs we have all so often experienced.

This may be called a faint embrio of the sea breezes of tropical regions. On the more northerly coasts of Greece, the Levant, and the African fhores of the Mediterranean, the sea breeze is distinctly perceived, during the summer season.

Such are the effects arising from the diurnal changes in our northern climates; the effects of the annual revolution are still more sensible. To this cause we are to attribute the prevalence of the west winds, during summer, even in our climate, and the much more marked prevalence of them, during that season in Spain, and France. For the continent of land to the eastward, being much more heated by the long continued action of the sun's rays upon it, during summer, than the waters of the Atlantic ocean, the wind is perceptibly drawn towards the east during that season.

But the effects of the seasons, in altering the winds in those countries which approach towards the tropics, are much more powerful than with us. For when the sun approaches the tropic of Cancer, and acts perpendicularly, or nearly so, during the whole course of a lengthened day on the countries of Persia, Bengal, China, and the adjoining states, the surface of the land there, at that period, becomes so much more heated than the sea to the southward of it, that the current of the general trade wind is interrupted so as to flow, at that season, from the south to the north, which is

a direction opposite to that it would have assumed, if no land had been placed there. But as the high mountains in Africa continue extremely cold during all seasons of the year, the low countries of India, to the eastward of it, become, in summer, so much hotter than Africa, at that season, that the air is naturally drawn from thence to the eastward. Thus it is, that the trade wind, in the Indian ocean, from April till October, (that is, during the summer months,) blows in a north-east direction, which is precisely the reverse of that of the general trade wind, in open seas, in the same latitude. But when the sun leaves the northern hemisphere, and retreats towards the tropic of Capricorn, these northern countries are allowed to cool, and the general trade wind is then suffered to resume its natural direction.

Such are the obvious causes of that periodical shifting wind in the Indian seas, which has been denominated the monsoon. To account for the small variations in its direction, which are observed in the different tracts of those seas, will be an easy exercise to. any one who has made himself master of the rationale of the phenomena here explained. At present, it would lead to too great length to take notice of them. By inspecting the map, the attentive reader will obferve, that no monfoon takes place to the fouthward of the line, excepting in that part of the ocean adjoining to the large and newly explored island, called New Holland; an ifland fo much exceeding, in fize, any other island on the globe, as to deserve, in a certain sense, the name of a continent. In that part of the globe, the same causes concur to produce a monsoon

1

as in the northern hemisphere, and similar phenomena are also experienced. From the month of October till April, (that is, during summer in the southern hemisphere) the monsoon sets in from the N. W. to S. E. directly opposite to the course of the general trade wind, as happens also in the northern ocean, during their summer; and here also, as in the northern hemisphere, the general trade wind resumes its usual course, during the winter season.

Nothing can more perfectly fhow the justnefs of the theory of monsoons here given than this single fact does; and though the writer of this essay thinks it of much more consequence to make useful discoveries than to be at much trouble about ascertaining to whom these discoveries of right belong, yet he hopes it will not be deemed impertinent in him, after a silence of 18 years, now, for the first time, barely to hint that the above explanation of the monsoons was first published by him, in the Encyclopedia Britannica, in the month of July 1773, while Mr Cooke was yet out on his first voyage of discovery, and from which he did not return till seven months after this essay was published, at which time the writer of this essay, from the state of the winds that had been observed, without hesitation foretold what has since been found to be truth by succeeding navigators, that there did not exist, nor ever would be found any continent, or large islands in the southern hemisphere, near the tropics, unless it was New Holland alone. He takes notice of this circumstance here, chiefly because it affords the strongest proof that can be required of the justness of the explanation given, and also because it thus re

VOL. vii.

X

moves a possibility of accusing him of plagiarism at present, as every idea he has borrowed from that ef say, he can lay claim to as his own.

In a future number, some periodical winds that take place in particular parts of the torrid zone, which are of less extensive influence than the monsoons, together with the smaller deflections of the monsoons themselves, will be taken notice of, At present, the reader fhall be no longer detained than merely to point out to him one of those beautiful and beneficent arrangements in nature, which the attentive observer has so often occasion to remark, and to admire.

In the great South Sea, and Atlantic Ocean, where the general trade winds invariably prevail, a fhip can sail, very easily, between the tropics, from east to west, by the help of the unchanging easterly wind that there prevails; but when he attempts to sail to the eastward, in the same seas, he finds it is impofsible the wind blows cóntinually against him. He has no other resource, therefore, than to stand either to the southward, or the northward till he gets into high latitudes, where the trade winds do not prevail.

:

There he meets with variable breezes, by the aid of which he is enabled to prosecute his voyage with effect. But if land fhould have run along, in a direction nearly parallel to the equator, within the limits of the trade winds, so as to have prevented a ship from getting into the latitude of the variable winds, what would have happened if the general trade winds had there invariably prevailed? All navigation eastward must have been interrupted, as the winds would have been continually opposite to the course of the vessel.

Instead of this destructive arrangement, we have seen that the very lands in India which prevent a fhip from reaching to the latitude of variable breezes, naturally, and necessarily produce, first a diurnal sea and land breeze to help them out, or into a harbour with ease, almost in any situation; and next, the monsoons, which by blowing six months in one way, and six months in the opposite direction, afford a sure and easy mode of navigating in those seas, in all directions, if the proper seasons be only adverted to.

How wonderful, O Lord! are all thy works; in wisdom and in mercy hast thou made them all!

OBSERVATIONS ON WATSON'S HISTORY

For the Editor of the Bee.

Of those who have laboured in the field of modern history, the first place is perhaps due to Robertson, an historian who unites, in the highest degree, the profound views, and accurate knowledge of the philosopher, with the bold and beautiful imagination of the poet. He is one of the most singular examples of genius being made entirely subservient to truth. Genius has always certain topics upon which it loves to dwell, certain views which it loves to take, and favou rite characters which it delights to describe; but the unvaried aim of this writer is philosophical truth, and his favourite topic, universal virtue. Though possessed of a mind naturally fitted to contemplate only what