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such a with. It appears certain, therefore, that the four fundamental rules of arithmetic were known, in some nations, in very early ages of the world ; though at what time they were discovered or invented cannot now be exactly ascertained.

The Greeks were the first European people among whom arithmetic arrived at any great degree of perfection, and they made use of the letters of the alphabet 10 represent their numbers. The Romans followed a like method, and, besides characters for each rank of classes, they introduced others for five, fifty, and five hundred. Their method is still used for distinguishing the chapters of books and some other purposes. From the Romans arithmetic came to us ; but the common arithmetic ainungit us, which makes use of the ten Arabic figures 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, was utterly unknown to the Greeks and Romans, and came into Europe from the Arabians by way of Spain. The Arabians are said to have received them from the Indians. This most perfect method of fupputation is supposed to have taken its origin from the len fingers of the hand, which were made ule of in computations, before arithmetic was brought into an art. The Eastern missionaries assure us, that to this day the Indians are very expert at computing on their fingers without any ase of pen or ink. And the natives of Peru in SouthAmerica, who do all by the different arrangement of grains of maize, are said to excel, both for certainty and dispatch, any European with all his rules.

NUMERATION

TEA
EACHES to read or write any proposed fum, and to

find the different value of any given number of figures.

E X A M P L E S. Write down in words at length the following numbers : 12, 24, 52, 365, 960, 1008, 1760, 8766, 25020.

Write down in figures the following numbers: Twentyfive. Forty-five. One hundred and fifty. Four thousand and four. One thcusand eight hundred and ten. Sixtyfix thousand. Seven millions two thousand three hundred and twenty-nine. Eighty-four millions. Nine hundred and fix millions, four hundred and ten thousand, five hundred and forty-one.

No. 1. CHRONOLOGY.--Chronology is the art of measuring and distinguishing time past, and referring each evant to the proper year. Its use is very great, being called one of the eyes of history. Epocha, in chronology, is a term or fixed point of time, whence succeeding years are numbered or computed. That principally regarded among Chriftians is the epocha of the Nativity of our Saviour; that of the Mahometans the Hegira ; that of the Jews the Creation of the world ; that of the ancient Greeks the Olyinpiads; that of the Romans the Building of their city, and that of the ancient Persians and Affyrians the epocha of Nabonaffar king of Babylon, its inftitutor, 746 years B. C. The building of Rome took place 753 years B. C. The Olympics or Olympic games, so famous among the Greeks, were instituted in honour of Jupiter. They were holden at the beginning of every fifth year, on the banks of the Alpheus, near Olympia, in the Peloponnesus, now the Morea, to exercise their youth in five kinds of combats. Those who were conquerors in these games were highly honoured by their countrymen. The prize contended for was a crown made of a peculiar kind of wild olive, appropriated to this use. The Olympiads ended with the year of Chrift.440, making in all 364. The Hegira, or fight of the impoftor Mahomet, the founder of the Mahometan religion, from Mecca to Medina, happened A. D. 622*. The computation of years from the birth of Christ did not begin to be used in history till the fixth century. The current year of the Chriftian æra is 1810. N. B. A. M. denotes Anno Mundi, the year

of the world; U. C. Urbe conditâ (ab, from, being understood) the building of the city, ...c. of Rome; B. C. before See Chron. and Biog. Exer.

Chrift;

B 2

No. 2.

and

Chrift ; A. C. Ante Christum, before Chrift; A. D. Anno Domini, in the year of our Lord.

SOLAR SYstem.-By the solar system is meant the order and disposition of the several heavenly bodies, which revolve round the Sun, as the centre of their motion, and receive from it their light and heat. These celestial spheres consist of planets and comets. Under the denomination of comets are comprised Mercury, Venus, the Earth, Mars, Jupiter, Saturn, the Georgium Sidus, Ceres, Pallas, and Vetta. The last four bave been recently discovered. See Exercises on the Globes, 4th edition.

Mercury is said to be about 37,000,000 of miles from the fun; 'Venus 68,000,000 ; the Earth 95,000,000 ; Mars 145,000,000 ;

Jupiter 495,000,000 ; Saturn 908,000,000 ;

Georgium Sidus about 1, 800,000,000 of miles distant from the sun.

The hourly motion of Mercury in its orbit is about 109,000 miles ; Venus 80,000 ; the Earth 68,000 ; Mars 55,000 ; Jupiter 29,000; Saturn 22,000. Saturn is supposed to be more than 90 times as big as the globe which we inhabit. According to the fanie calculation, Jupiter is above 200 times larger than the earth.

It has been remarked, that the planets, and all the innumerable hoit of heavenly bodies, perform their courses and revolutions with so much certainty and exactness, as never once to fail ; but, for almost 6000 years, come constantly about to the same period, without the difference of the hundredth part of a minute.

It is also observed by Mr. Hervey, that " it may seem unaccountable, to an unlearned reader, that astronomers should speak such amazing things, and speak them with such an air of assurance, concerning the distances and magnitudes, the motions and relations of the heavenly bodies. I would defire, continues the fame ingenious writer, such a person to consider the case of the Eclipses, and with what exactness they are calculated. They are not only foretold, but the very inftant of their beginning is determined. The precise time of their continuance is assigned ; assigned almoit to the nicety of a moment, and what is still more surprising, for the space of hundreds or thousands of years to come.

thousands three

As this is a matter of fact absolutely indisputable, it is also a very obvious yet solid demonstration, that the principles of science, on which those calculations proceed, are not merely conjecture, or precarious supposition, but have a real, a certain foundation in the nature and conftitution of things."

How vast His power, that launch'd those thining orbs
In empty space, and bade them circling roll
Their mighty rounds, eclipfing and eclips'd,
In mystic dance; from age to age upheld,
Unerring in their course! Beyond that sun,
Afar, ten thousand thousand systems roll,
And countless orbs, the seats of life and joy,
Revolving worlds that crowd the vast profound,
And dread Omnipotence aloud proclaim,
But far transcend the reach of human thought,
To scan their distance, magnitude, and laws.

CRIRIE.

No. 3. Comets. Comets are defined to be folid compact bodies, like other planets, and regulated by the fame laws of gravity; They move about the fun in very eccentric orbits, and are of a much greater density than our earth; for some of them are heated, in every period, to such a degree as would vitrify or dissipate any substance known to us. Comets are always attended with long transparent trains, or tails, issuing from that side of them which is turned away from the sun : that which appeared in 1680 drew after it a tail of fire that was computed to be 80,000,000 miles in length. The use of the comet's “ huge vapoury train" is

-perhaps to shake
Reviving moisture on the numerous orbs
Thro' which his long ellipsis winds; perhaps
To lend new fuel to declining suns,
To light up worlds, and feed the eternal fire,

THOMSON.

There are supposed to be a considerable number of comets belonging to the solar fyftem ; but the periods of

B 3

[graphic]

Chrift; A. C. Ante Christum, before Chrift; A. D. Anno Domini, in the year of our Lord.

No. 2.

SOLAR SYSTEM.-By the solar system is meant the order and disposition of the several heavenly bodies, which revolve round the Sun, as the centre of their motion, and receive from it their light and heat. These celestial spheres consist of planets and comets. Under the denomination of comets are comprised Mercury, Venus, the Earth, Mars, Jupiter, Saturn, the Georgiuin Sidus, Ceres, Pallas, and Vefta. The last four have been recently discovered. See Exercises on the Globes, 4th edition.

Mercury is said to be about 37,000,000 of miles from the fun; 'Venus 68,000,000 ; the Earth 95,000,000 ; Mars 145,000,000 ; Jupiter 495,000,000 ; Saturn 908,000,000 ;

and

Georgium Sidus about 2,800,000,000 of miles distant from the sun.

The hourly motion of Mercury in its orbit is about 109,000 miles ; Venus 80,000 ; the Earth 68,000"; Mars 55,000 ; Jupiter 29,000; Saturn 22,000. Saturn is supposed to be more than 90 times as big as the globe which we inhabit. According tɔ the sanie calculation, Jupiter is above 200 times larger than the earth.

It has been remarked, that the planets, and all the innumerable host of heavenly bodies, perform their courses and revolutions with so much certainty and exactness, as never once to fail ; but, for almost 6000 years, come constantly about to the same period, without the difference of the hundredth part

of a minute. It is also observed by Mr. Hervey, that " it may seem unaccountable, to an unlearned reader, that aftronomers should speak such amazing things, and speak them with such an air of assurance, concerning the distances and magnitudes, the motions and relations of the heavenly bodie. I would defire, continues the fame ingenious writer, such a person to consider the case of the ECLIPses, and with what exactness they are calculated. They are not only foretold, but the very instant of their beginning is determined. The precise time of their continuance is assigned ; assigned almost to the nicety of a moment, and what is still more surprising, for the space of hundreds or

thousands

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