riod, as the equinox, which once fell on the first of May, now took place on the first of April. This led ultimately to the discovery, that the equinox preceded about 2160 years in each sign, or 25,920 years in the 12 signs; and this induced them to try if they could not form a cycle of the two. On examination, they found that the 600 would not commensurate the 2160 years in a sign, or any number of sums of 2160 less than 10, but that it would with ten, or, that in ten times 2160, or in 21,600 years, the two cycles would agree: yet this artificial cycle would not be enough to include the cycle of 25,920. They, therefore, took two of the periods of 21,600, or 43,200; and, multiplying both by ten, viz. 600×10=6000, and 43,200×10=432,000, they found a period with which the 600 year period, and the 6000 year period, would terminate and form a cycle. Every 432,000 years the three periods would commence anew: thus the three formed a year or cycle, 72 times 6000 making 432,000, and 720 times 600 making 432,000.
Again, to shew this in another way: the year of 360 days, or the circle of 360 degrees, we have seen was divided into dodecans of 5 days, or degrees, each; consequently the degrees or days in a year or circle being multiplied by 72, that is, 72 × 360 gives 25,020, the length of the precessional year. In the same way the Hindoos proceeded with the number 600, which was the number contained in a year of the sun; they multiplied it by 72, and it gave them 43,200: but as the number 600 will not divide equally in 25,920, and they wanted a year or period which would do so, they took ten signs of the Zodiac, or 10 times 2160, the precessional years in a sign, which made 21,600, thus making their Neros year ten periods, to answer to ten signs; then multiplying the 43,200 by 10 they got 432,000: thus, also, they got two years or periods commensurate with each other, and which formed a cycle, viz. 21,600 and 432,000, each divisible—the former by 600, and the latter by 21,600. As the latter gave a quotient of 20, in 20 periods of 21,600 years, or 432,000 years, they would have a cycle which would coincide with the Neros; and which is the least number of the signs of the Zodiac, viz. 10, which would thus form a cycle with the Neros.
| Thus a year of the Clo or Cli or Cali Yug, or age, or 600, is | 432,000 |
| Then a year of the double Neros, or 1200, will be | 864,000 |
| Of a triple ditto | 1,296,000 |
| And of a quadruple | 1,728,000 |
| And of a year formed of the ten ages or Neroses altogether, or of the 6000 years, | 4,320,000 |
And this long period they probably supposed would include all the cyclical motions of the Sun and Moon, and, perhaps, of the Planets. Whether this was the result of observations some will hesitate to admit. Persons of narrow minds will be astonished at such monstrous cycles; but it is very certain that no period could properly be called the great year unless it embraced in its circle every periodical movement or apparent aberration. But their vulgar wonder will perhaps cease when they are told that Mons. La Place has proved, that if the periodical aberrations of the Moon be correctly calculated, the great year must be extended to a greater length even than the 4,320,000 years of the Maha Yug of the Hindoos. And certainly no period can be called a year of our planetary system, which does not take in all the periodical motions of the planetary bodies.
As soon as these ancient astronomers had found that the equinoxes had the motion in antecedentia, or preceded, they would, of course, endeavour to discover the rate of the precession in a given time. It is evident that this would be a work of very great difficulty. The quantity of precession in one year was so small, that they must have been obliged to have recourse to observations in long periods, and it is not very surprising that they should at first have been guided, in part, by theory. The orderly arrangement of nature appeared so striking to the Greeks, as to induce them thus to accou⟨n⟩t for the Planets being called Disposers, the appellation (as we learn from Herodotus) first
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