and to acquaint him, that with his last breath he besought the gods to prosper him in all his undertakings, and make him sole monarch of the universe; adding, that he thought it needless to beseech him to punish those traitors who had treated him with such cruelty, as it was the common cause of kings. Then taking Polystratus by the hand, "Give him," said he, "your hand, as I give you mine, and carry him, in my name, the only pledge I am now able to give of my gratitude and affection." Having uttered these words he immediately expired in the arms of Polystratus. Alexander soon after arrived at the spot, and beholding the body of Darius, burst into tears, bewailing the cruel lot of a prince who, he said, had deserved a better fate. He immedietely pulled off his own military cloak, and covered the corpse, and causing it to be embalmed, sent it in a rich and magnificent coffin to be interred with the other Persian monarchs.

CIRCLE OF THE SCIENCES, WITH SUITABLE REFLECTIONS.

ARTRONOMICAL SKETCHES.NO. V.

THE seas cover three-fourths of the surface of the earth; but we are not to conclude that this is an inconvenience to mankind. Rain, which is so essential to the comfort of human life, and without which vegetation could have no existence, must first be raised up in vapours from the sea, by the action of the sun, before it can be formed into clouds, and fall in fruitful showers on the land. If the land occupied three-fourths of the surface of the earth, and the seas only one-fourth, the consequences would be the destruction of all vegetable substances for want of moisture; and the land between the Tropics would be in danger of being burnt by the intense heat of the sun. To prevent this, the great Creator has nicely balanced the land and sea on the surface of the earth; so that the land has only that quantity of moisture which is necessary for the produc

tion of the various fruits of the earth, &c., and for the comfort and support of the animal creation.

The earth, in its annual revolution round the sun, passes through all the signs of the Zodiac. The sun and earth are always in opposite points of the heavens. When the sun enters Aries or Libra, the days and nights are equal in every part of the world, except at the poles of the earth.

When the sun enters Cancer, on the 21st of June, the South Pole has been destitute of the solar light for three months; nor can the sun shine upon that Pole, until the expiration of three months more. When the sun enters Libra, on the 23d of September, the North Pole loses the light of the sun, and is not revisited by that luminary, until the expiration of six months. S that each Pole has but one day and one night in the year, each day and each night being six months long.

These various and important changes are caused by the annual revolution of the earth round the sun, and the declination of its axis, or the angle which the plane of the Ecliptic makes with the plane of the Equator, which is 23° 28'.

If the axis of the earth were parallel with the axis of its orbit, our days and nights would be always equal. In this arrangement of the axis of the earth and the Ecliptic, we should have no diversity of seasons;-no interchange of winter, spring, summer, and autumn? and these northern parts of the world would be rendered nearly uninhabitable for want of heat and sustenance. The influence of the sun would not be sufficiently powerful to produce vegetation in sufficient abundance to supply our wants; we should know nothing of the delights of a summer's morning or evening; and our fields, gardens, &c., would present to our view little else than empty wastes and solitary and barren places. In the equatorial regions, an excess of heat from the rays of a vertical sun, shining day by day and year after year on the same line, would render them intolerable, and endanger the safety of the world. But from the present arrangement of the planes of the Equator and the Ecliptic, we behold the infinite wis

dom and goodness of God toward mankind, in placing or balancing the earth in such a position toward the sun, as to produce the various seasons of the year, to vary our days and nights, and to cause these high northern regions to become nearly as delightful, as beautiful, and as fruitful, as any other parts of the earth; while the heat of the sun is so diffused along the tropical regions, as to render them not only inhabitable, but beautiful and fruitful in the extreme.

CABINET OF NATURE.

RIVERS.

THE next feature of the earth's surface which may be noticed, is, the rivers with which it is indented in every direction. These are exceedingly numerous, and seem to form as essential a part in the constitution of our globe, as the mountains from which they flow, and as the ocean to which they direct their course. It is reckoned, that in the old continent, there are about 430 rivers, which fall directly into the ocean, or into the Mediterranean, and the Black seas; but in the new continent, there are only about 145 rivers known, which fall directly into the sea. In this innumeration, however, only the great rivers are included, such as the Thames, the Danube, the Wolga, and the Rhone. Besides these, there are many thousands of streams of smaller dimensions, which, rising from the mountains, wind in every direction, till they fall into the large rivers, or are carried into the ocean. The largest rivers in Europe are the Wolga, which, rising in the northern parts of Russia, runs a course of 1700 miles, till it falls into the Caspian sea-the Danube, whose course is 1300 miles, from the mountains in Switzerland to the Black sea-and the Don, which runs a course of 1200 miles. The greatest rivers in Asia are-the Hoanho, in China, whose course is 2400 miles-the Boorhampooter, the Euphrates, and the Ganges. The longest river in Africa, is the Nile, the course of which is estimated at 2000 miles. In the continent of America,

the rivers appear to be formed on the grandest scale, both as to the length of their course, and the vast body of waters which they pour into the ocean. The Amazons, the largest river in the world, runs a course of above 3000 miles across the continent of South America, till it falls into the Atlantic ocean, where it discharges a body of waters 150 miles in breadth. Next to this is the river St. Lawrence, which is more than 2400 miles from its mouth through the lake of Ontario to the lake Alempigo and the Assiniboils; and the rivers La Plata and Mississippi, each of whose courses is not less than 2000 miles.

When we consider the number and the magnitude of these majestic streams, it is evident, that an enormous mass of water is continually pouring into the ocean, from every direction. From observations which have been made on the river Po, which runs through Lombardy, and waters a tract of land 380 miles long, and 120 broad, it is found, that it moves at the rate of four miles an hour, is 1000 feet broad, and 10 feet in depth, and, consequently, supplies the sea with 5068 millions of cubical feet of water in a day, or a cubical mile in 29 days. On the supposition that the quantity of water which the sea receives from the great rivers in all countries, is proportional to the extent and surface of these countries, it will follow, that the quantity of wa ters carried to the sea by all the other rivers on the globe, is 1083 times greater than that furnished by the Po (supposing the land, as formerly stated to contain about 49 millions of square miles,) and will supply the ocean with 13,630 cubical miles of water in a year. Now, reckoning the ocean, as formerly, to contain 296 millions of cubical miles of water, this last number divided by the former, will give a quotient of 21,716. Hence it appears, that, were the ocean completely drained of its waters, it would require more than twenty thousand years before its caverns could be again com

* Buffon makes this result to be 812 years, in which he is followed by Goldsmith, and most subsequent writers; but he proceeds on the false assumption, that the ocean covers only half the surface of the globe, and that it contains only 85 millions of square miles, and he estimates the average depth of the ocean to be only 440 yards, or one-fourth of a mile.

pletely filled by all the rivers in the world running into it, at their present rate.

Here two questions will naturally occur- -Whence do the rivers receive so constant a supply of waters ? and, why has not the ocean long ago overflowed the world? since so prodigious a mass of water is continually flowing into its abyss. This was a difficulty which long puzzled philosophers; but it is now satisfactorily solved, from a consideration of the effects of evaporation. By the heat of the sun, the particles of water are drawn up into the atmosphere, from the surface of the ocean, and float in the air in the form of clouds or vapour. These vapours are carried, by the winds, over the surface of the land, and are again condensed into water on the tops and the sides of mountains, which gliding down into their crevices and caverns, at length breaks out into springs, a number of which meeting in one common valley, becomes a river; and many of these united together, at length form such streams as the Tay, the Thames, the Danube, and the Rhine. That evaporation is sufficient to account for this effect, has been demonstrated by many experiments and calculations. It is found that, from the surface of the Mediterranean Sea, which contains 762,000 square miles, there are drawn up into the air, every day, by evaporation, 5280 millions of tons of water, while the rivers which flow into it yield only 1827 millions of tons, in the same time; so that there is raised in vapour from the Mediterranean nearly three times the quantity of water which is poured into it by all its rivers. One third of this falls into the sea before it reaches the land; another part falls on the low lands, for the nourishment of plants; and the other third part is quite sufficient to supply the sources of all the rivers which run into the sea. This is in full conformity to what was long ago stated by an inspired Naturalist: "All the rivers run into the sea, and yet the sea is not full; unto the place from whence the rivers came, thither do they return again;" but, before they regain their for mer place, they make a circuit over our heads through the regions of the atmosphere.