was concluded that its weight could not have fallen much short of 200 pounds. All the stones when first found, were friable, being easily broken "between the fingers; this was especially the case where they had been buried in the moist earth, but by exposure to the air they gradually hardened. Such were the circumstances attending the fall of these singular masses.

“The specimens obtained from all the different places are perfectly similar. The most careless observer would instantly pronounce them portions of a common mass, and different from any of the stones commonly seen on this globe."

Sect. II.

Of the different Systems.

208. The systems, which were generally received among the ancients were very erroneous. Ptolemy, who has given his name to the earliest known system, supposed the earth to be at rest in the centre of the universe, and all the other heavenly bodies to revolve round the earth in the following order ; viz. the Moon, Mercury, Venus, the Sun, Mars, Jupiter, and Saturn. But this system will not account for the different appearances or phases of Mercury and Venus, and consequently cannot be true.

209. This system was soon qualified in some degree among the Egyptians. They observed that Mercury and. Venus were never at a great distance from the sun; whereas, if they revolved round the earth, as they supposed the sun itself did, they would sometimes be in opposition to the sun, as the other planets are. Hence they were led to suppose that Mercury and Venus moved round the sun, as secondary planets move round their primaries, and were at the same time carried with the sun round the earth. This theory accounts for all the phases of Venus and Mercury; but it will not account for the different (direct and retrograde) motions of the exterior planets.

210. Of the ancients, however, the Babylonians, and afterwards Pythagoras, (about 500 years before the Christian era,) are said to have considered the earth a planet, revolving round the sun, like the other planets. Though we can hardly conceive how the truth should have been lost, when once discovered and promulgated, yet this knowledge of the true solar system was very soon lost; and was not revived till about the middle of the sixteenth century. Copernicus, from whom the true system is called Copernican, supposed the earth to turn on its axis every day, and revolve round the sun every year.

These two motions explain, with the utmost facility, all the phenomena of the stations, motions, and phases of all the other heavenly bodies; whence arises the strongest possible proof of the correctness of his supposition, and confirms beyond a doubt the truth of his system. For nothing can be consistent with itself but truth.

211. Notwithstanding the simplicity of this theory, Copernicus found in his time an able astronomer, who rejected the evidences of the truth of his discovery. Tycho Brahe, a Danish nobleman, was anxious to reconcile the appearances of nature, with the literal interpretation of some passages of scripture. He therefore supposed the earth immoveable in the centre of the orbits of the sun and moon, without any rotation on its axis ; but he made the sun the centre of the orbits of all the other planets, which therefore revolved with the sun about the earth. This system is called the Tychonick. The principal objection to it is its want of simplicity; also the necessity of supposing that all the heavenly bodies move round the earth every day. Some of the followers of Tycho gave a rotatory motion to the earth, and this was called the Semi-Tychonick sys

But the Copernican system has now superseded all others throughout Christendom.

tem.

SECT. III.

Of Leap Year.

212. The solar year, or the time of the sun's passing from an equinox to his return to the same again, consists of 365 days, 5 hours, 48 minutes, and 57 seconds. Hence it is plain, that if we reckon only 365 days to a civil or common year, the sun would be in an equinox, say the vernal, later in every succeeding year, than in the preceding, by 5 hours, 48 minutes, and 57 seconds; that is, nearly a quarter of a mean day.' So that if the sun entered Aries on the 20 March one year, he would enter it on the 21 four years after, and on the 22 eight years after, and so on. Thus in a comparatively short time, the spring months would come in the winter season, and the summer months in the spring season.

213. To prevent the confusion, which would result from this reckoning, in every fourth year, generally, a day is added to February, viz. in such years as may be divided by 4 without a remainder. Such years are called Bissextile, or Leap years. But this is plainly allowing too much; for the excess over 365 days is not equal to a quarter of a day, by 11 minutes, 3 seconds. This would amount to a whole day in about 130 years. To prevent the error, which would thus result, it was settled by an act of parliament, that the years 1800 and 1900, (though divisible by 4,) should not be leap years. And afterwards the closing year of only every fourth century should be a leap year. If this method be adhered to, the present mode of reckoning will not vary a single day from true time, in less than 5000 years.

!

Sect. IV.

Of Old and New Style.

214. Among different ancient nations, different methods of computing the year were in use. Some determined it by the revolutions of the moon some by that of the sun.

But none (so far as we know) made pro) er allowance for deficiencies and excesses. Twelve moons fell short of the true year; 13 exceeded it; 365 days were not enough; 366 were too many. To prevent the confusion resulting from these erroneous estimates, Julius Cæsar reformed the calendar, by making the year consist of 365 days, 6 hours, (which is hence called a Julian year,) and made every fourth year consist of 366 days. This method of reckoning is called Old Style.

215. But as this made the year somewhat too long, pope Gregory XIII., in order to bring the vernal equinox on the 21 March, ordered 10 days to be struck out of the year 1582; calling the next day after the 4th, October, the 15th. And by omitting 3 intercalary days in 400 years, he intended that the civil and solar year should keep together. This form of the year is called the Gregorian Account, or New Style. Though this alteration was immediately adopted throughout the greatest part of Europe, it was not admitted by the English till the year 1752. The error at that time amounted to nearly 11 days, which were taken from the month of September, by calling the 3d of that month the 14th.

SECT. V.

Of Cycles.

216. Under the Art. ECLIPSES, it was stated that the line of the moon's nodes went backwards, completing a

revolution in little less than 19 years. This period is the Cycle of the Moon, usually called the Golden Number. The conjunctions, oppositions, and other aspects of the moon are within an hour and a half of being the same as they were on the same days of the month 19 years before. Consequently, very nearly the same order of eclipses occur every nineteenth year. To find the Golden Number for any year, add 1 to that

year,

divide the number by 19, and the remainder is the GOLDEN NUMBER. If nothing remains, the GOLDEN NUMBER is 19.

217. The Cycle of the Sun is a revolution of 28 years; in which time the days of the months return again to the same days of the week; the sun's place to the same signs and degrees of the Ecliptic on the same months and days, so as not to differ a degree in 100 years; and the leap years begin the same course over again, with respect to the days of the week, on which the days of the months fall. To find the Cycle of the Sun, add 9 to the given year, divide by 28, and the remainder is the CYCLE OF THE Sun, for that year. If nothing remains, the Cycle is 28.

218. In the subjoined table, the Golden Numbers under the months stand against the days of new moon, in the left hand column. It is adapted chiefly to the second year after leap year, and will indicate the time of new moon, (within 1 day,) till the year 1900. A perfectly correct table of this kind cannot be easily constructed.

To show the use of this TABLE, suppose I want to know nearly the time of the new moon in Oct. 1822. By the above Rule, I find the Golden Number for this

Under the month Oct. in the TABLE, I find the Golden Number 18 placed against the 14th day in the left hand column; that is, it is new moon on the 14th day, or near it. The error cannot exceed 1 day.

year to be 18.