Vietnam or Thailand ? Vote for the TOP Country of the Week !
Updated: June 23, 2025
I do not see how the heliacal rising of Sirius in any one year could help them to determine its length. By comparing two successive years they could of course have got at a sidereal year; but this is what they did not do; hence the irregularity which produced the canicular cycle.
Great progress was made when systematic observations began, such as following the motion of the moon and planets among the stars, and the inferred motion of the sun among the stars, by observing their heliacal risings i.e., the times of year when a star would first be seen to rise at sunrise, and when it could last be seen to rise at sunset.
They approximated to the truth in reference to the solar year, by observing the equinoxes and solstices, and the heliacal rising of particular stars. Plato and Eudoxus spent thirteen years in Heliopolis for the purpose of extracting the scientific knowledge of the priests, but they learned but little beyond the fact that the solar year was a trifle beyond three hundred and sixty-five days.
This first appearance actually took place on the Saturday following. The first day of the Muhammadan month Jamada' l akhir, corresponding to the heliacal rising of the moon on that occasion, was Saturday, May 19. I therefore believe that this great battle took place on Saturday, May 19, A.D. 1520, a date almost synchronous with the of the "Field of the Cloth of Gold."
As instances of the one we have the observation of the Egyptians, that the rising of the Nile corresponded with the heliacal rising of Sirius; the directions given by Hesiod for reaping and ploughing, according to the positions of the Pleiades; and his maxim that "fifty days after the turning of the sun is a seasonable time for beginning a voyage."
They approximated to the truth in reference to the solar year, by observing the equinoxes and solstices and the heliacal rising of particular stars.
Obviously with a calendar of 365 days only, at the end of four years, the calendar year, or vague year, as the Egyptians came to call it, had gained by one full day upon the actual solar year that is to say, the heliacal rising of Sothis, the dog-star, would not occur on new year's day of the faulty calendar, but a day later.
Yet, according to the calculations of Biot, the heliacal rising of Sothis at the solstice was noted as early as the year 3285 B.C., and it is certain that this star continued throughout subsequent centuries to keep this position of peculiar prestige.
It is indeed certain that, if the reckoning by heliacal risings of Sirius did not begin in 1322, we must go nearly 1460 years back for its origin; since it must have been adopted when that event preceded only for a short time the annual inundation of the Nile.
The Egyptians, for all the common purposes of life, called the day of the heliacal rising of the dogstar, about our 18th of July, their new year's day, and the husbandman marked it with religious ceremonies as the time when the Nile began to overflow; while for all civil purposes, and dates of kings' reigns, they used a year of three hundred and sixty-five days, which, of course, had a movable new year's day.
Word Of The Day
Others Looking