fuch a wish. 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 difcovered or invented cannot now be exactly afcertained. The Greeks were the firft European people among whom arithmetic arrived at any great degree of perfection, and they made ufe of the letters of the alphabet to reprefent their numbers. The Romans followed a like method, and, befides characters for each rank of claffes, they introduced others for five, fifty, and five hundred. Their method is ftill ufed for diftinguishing the chapters of books and some other purposes. From the Romans arithmetic came to us; but the common arithmetic ainongst us, which makes ufe of the ten Arabic figures 1, 2, 3, 4, 5, 6, 7, 8, 9, o, was utterly unknown to the Greeks and Romans, and came into Europe from the Arabians by way of Spain. The Arabians are faid to have received them from the Indians. This moft perfect method of fupputation is fuppofed to have taken its origin from the ten fingers of the hand, which were made ufe of in computations, before arithmetic was brought into an art. The Eaftern miffionaries affure us, that to this day the Indians are very expert at computing on their fingers without any ufe of pen or ink. And the natives of Peru in SouthAmerica, who do all by the different arrangement of grains of maize, are faid to excel, both for certainty and difpatch, any European with all his rules. NUMERATION TEACHES to read or whce of any given number of EACHES to read or write any propofed fum, and to figures. EXAMPLES. Write down in words at length the following numbers: 12, 24, 52, 365, 960, 1008, 1760, 8766, 25020. and four. Write down in figures the following numbers: Twentyfive. Forty-five. One hundred and fifty. Four thousand One thousand 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 ufe is very great, being called one of the eyes of hiftory. Epocha, in chronology, is a term or fixed point of time, whence fucceeding 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 Olympiads; that of the Romans the Building of their city, and that of the ancient Perfians 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, fo famous among the Greeks, were inftituted in honour of Jupiter. They were holden at the beginning of every fifth year, on the banks of the Alpheus, near Olympia, in the Peloponnefus, now the Morea, to exercife 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 ufe. The Olympiads ended with the year of Chrift 440, making in all 364. The Hegira, or flight 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 Chrift did not begin to be used in hiftory 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, i. e. of Rome; B. C. before See Chron. and Biog. Exer. B 2 Chrift; fuch a wifh. It appears certain, therefore, that the four fundamental rules of arithmetic were known, in fome nations, in very early ages of the world; though at what time they were difcovered or invented cannot now be exactly afcertained. The Greeks were the firft European people among whom arithmetic arrived at any great degree of perfection, and they made ufe of the letters of the alphabet to represent their numbers. The Romans followed a like method, and, befides characters for each rank of claffes, they introduced others for five, fifty, and five hundred. Their method is ftill ufed for diftinguishing the chapters of books and fome other purpofes. From the Romans arithmetic came to us; but the common arithmetic amongst us, which makes use of the ten Arabic figures 1, 2, 3, 4, 5, 6, 7, 8, 9, o, was utterly unknown to the Greeks and Romans, and came into Europe from the Arabians by way of Spain. The Arabians are faid to have received them from the Indians. This moft perfect method of fupputation is fuppofed to have taken its origin from the ten fingers of the hand, which were made ufe of in computations, before arithmetic was brought into an art. The Eaftern miffionaries affure us, that to this day the Indians are very expert at computing on their fingers without any ufe of pen or ink. And the natives of Peru in SouthAmerica, who do all by the different arrangement of grains of maize, are faid to excel, both for certainty and dispatch, any European with all his rules. NUMERATION TEACHES or wue of any given number of EACHES to read or write any propofed fum, and to figures. EXAMPLES. 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 thoufand eight hundred and ten. Sixtyfix thousand. Seven millions two thousand three hundred Nine hundred and fix millions, four hundred and ten thousand, five hundred and forty-one. and twenty-nine. Eighty-four millions. No. 1. CHRONOLOGY.-Chronology is the art of measuring and diftinguishing time paft, and referring each event to the proper year. Its ufe is very great, being called one of the eyes of hiftory. Epocha, in chronology, is a term or fixed point of time, whence fucceeding 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 Olympiads; that of the Romans the Building of their city, and that of the ancient Perfians and Affyrians the epocha of Nabonaffar king of Babylon, its institutor, 746 years B. C. The building of Rome took place 753 years B. C. The Olympics or Olympic games, fo famous among the Greeks, were inftituted in honour of Jupiter. They were holden at the beginning of every fifth year, on the banks of the Alpheus, near Olympia, in the Peloponnefus, now the Morea, to exercife 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 ufe. The Olympiads ended with the year of Chrift 440, making in all 364. The Hegira, or flight 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 Chrift 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, i.. e. of Rome; B. C. before See Chron. and Biog. Exer. B 2 Chrift; Chrift; A. C. Ante Chriftum, before Chrift; A. D. Anno Domini, in the year of our Lord. No. 2. SOLAR SYSTEM.-By the folar fyftem is meant the order and difpofition of the feveral heavenly bodies, which revolve round the SUN, as the centre of their motion, and receive from it their light and heat. Thefe celeftial fpheres confift of planets and comets. Under the denomination of comets are comprised Mercury, Venus, the Earth, Mars, Jupiter, Saturn, the Georgium Sidus, Ceres, Pallas, and Vefta. The last four have been recently discovered. See Exercises on the Globes, 4th edition. Mercury is faid 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 9c8,000,000; and the Georgium Sidus about 1,800,000,000 of miles diftant from the fun. 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 fuppofed to be more than 90 times as big as the globe which we inhabit. According to the famie 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 fo much certainty and exactnefs, as never once to fail; but, for almoft 6000 years, come conftantly about to the fame period, without the difference of the hundredth part of a minute. It is alfo obferved by Mr. Hervey, that "it may feem unaccountable, to an unlearned reader, that aftronomers fhould fpeak fuch amazing things, and fpeak them with fuch an air of affurance, concerning the diftances and magnitudes, the motions and relations of the heavenly bodies. I would defire, continues the fame ingenious writer, fuch a person to confider the cafe of the ECLIPSES, and with what exactnefs they are calculated. They are not only foretold, but the very inftant of their beginning is determined. The precife time of their continuance is affigned; affigned almost to the nicety of a moment, and what is ftill more surprising, for the space of hundreds or thousands |