Equinox

“ If the vernal equinox, the season at which in the temperate regions the whole face of nature testifies to a fresh outburst of vital energy, had been viewed from of old as the time when the world was annually created afresh in the resurrection of a god, nothing could be more natural than to place the resurrection of the new deity at the same cardinal point of the year. ”

“ In the early ages, when Median and Egyptian mythologies took their rise, Taurus was at the spring [235] equinox in conjunction with the sun, and was, therefore, slain by its overwhelming brightness; but at the autumn equinox that same constellation, in opposition, rose when the sun set, and all night long was visible. In Median art, it is the Bull immolated by the sun in springtime that is represented. In Egyptian symbolism, it is to the Bull triumphantly traversing the sky by night, in the autumn season, that attention is directed. ”

“ There are two equinoxes, but men pay more honour to the equinox in the sign of Capricorn than to that in the sign of Cancer.862 Surely the reason for this is evident. Since the sun begins to approach us immediately after the spring equinox,—for I need not say that then the days begin to lengthen,—this seemed the more agreeable season. For apart from the explanation which says that light accompanies the gods, we must believe that the uplifting rays863 of the sun are nearly akin to those who yearn to be set free from generation. ”

“ For when they are at the spring equinox they affect the new shoots of the arboreal crops, such as grapes and figs, and whatever matures with them; at the summer solstice, the gathering and storing of the crops, and in Egypt, peculiarly, the rising of the Nile; at the autumn solstice they concern the sowing, the hay crops, and such; and at the winter equinox the vegetables and the kinds of birds and fish most common at this season. Further, the equinoetial signs have significance for sacred rites and the worship of the gods; the solstitial signs, for changes in the air and in political customs ”

“ When the earth has advanced to the autumn equinox, the axis is inclined neither toward nor away from the sun. The latter is then perpendicular over the equator and day and night are of equal length all over the earth. When the earth reaches the winter solstice the north pole is inclined away from the sun, and now it is summer in the southern hemisphere. At the vernal equinox again there is no inclination of the axis either toward or away from the sun, and once more day and night are everywhere equal. ”

“ Now, in 1257 years the Earth performs 1257 annual and 459,109 daily revolutions, after which the vernal equinox was found to occur on the 21st of March, true or solar time; thus concurring with the vernal equinox of 325. But the erroneous Julian calendar would make the Earth perform 459,119 daily revolutions to complete the 1257 years, a discrepancy of ten days, making the vernal equinox to fall on the 11th instead of the 21st. It will be seen by the diagram that the ten days were deducted from October, in 1582, making it a short month, consisting of only twenty-one days. ”

“ At noon on the day succeeding the equinox the sun bears to the left of the so-called First Point of Aries (celestial vernal equinox) . The sun according to terrestrial direction always bears south by true compass at noon, yet the First Point of Aries being at an infinite distance always bears the same by absolute direction. If this point could be seen and a bearing of it taken [Pg 46] by compass simultaneously with the sun, it would be, perhaps, S. 1° W. and so on widening the angle, roughly speaking, a degree each day. ”

“ Sidereal time is numerically measured by the hour angle of the equinox, which represents the position of the equinox in the daily rotation. The period of one rotation of the equinox in hour angle, between two successive upper meridian transits, is a sidereal day. It is divided into 24 sidereal hours, reckoned at upper transit which is known as sidereal noon. The true equinox is at the intersection of the true celestial equator of date with the ecliptic of date; the time measured by its daily rotation is apparent sidereal time. ”

“ If, therefore, in fig. 18, we draw two perpendicular lines q e s, p e r to represent the directions of the sun at the solstices and equinoxes, p corresponding to the vernal equinox and r to the autumnal equinox, the apogee must lie at some point a between p and q. So much can be seen without any mathematics: the actual calculation of the position of a and of the eccentricity is a matter of some complexity. ”

“ The equinoctial, which is a great circle traced in the starry heavens by the imaginary extension of the plane of the terrestrial equator, is intersected by the ecliptic, or apparent path of the sun, in two points diametrically opposite to one another, called the vernal and autumnal equinoxes. The vernal equinox is the point through which the sun passes in going from the southern to the northern hemisphere ”

“ But the Shepherds minded not Arts and Sciences.
The first month of the Luni-solar year, by reason of the Intercalary month, began sometimes a week or a fortnight before the Equinox or Solstice, and sometimes as much after it. And this year gave occasion to the first Astronomers, who formed the Asterisms, to place the Equinoxes and Solstices in the middles of the Constellations of Aries, Cancer, Chelæ, and Capricorn. ”

“ Where these two planes cut each other we have the equinoxes, because the intersection of the planes defines for us the vernal and the autumnal equinoxes; when the sun is highest and lowest half-way between these points we have the solstices. In a period of 25,000 years the star which is nearest to an equinox will return to it, and that which is nearest a solstice will return to it. ”

“ Tice calculates the equinoxes of the planets from their aphelia and perihelia, and accounts for the disturbing force of a planetary equinox on the supposition that the planet at its equinox is at its greatest distance from the solar equator, and hence exposed to only one pole of the sun. Thus, when the earth is at its vernal equinox, the north pole of the sun is invisible, and we are exposed to the full influence of its south magnetic pole. Terrific energy is then interchanged, disturbing both the atmosphere of the earth and that of the sun. ”

“ His supreme merit, however, consisted in the establishment of astronomy on a sound geometrical basis. His acquaintance with trigonometry, a branch of science initiated by him, together with his invention of the planisphere, enabled him to solve a number of elementary problems; and he was thus led to bestow especial attention upon the position of the equinox, as being the common point of origin for measures both in right ascension and longitude. ”

“ In common with most others, the Mosaic system of annual feasts groups itself readily around the vernal and autumnal equinoxes. In Lev. xxiii., where the list is most fully given, they seem to be arranged with a conscious reference to the sacred number seven (compare Numb. xxviii.) . Those belonging to the vernal equinox are three in number; a preparatory day, that of the Passover, leads up to the principal festival, that of unleavened bread, which again is followed by an after-feast, that of Pentecost (see Passover, Pentecost) . Those of the autumnal equinox are four ”

“ And the Colurus Æquinoctiorum passing through the point in the middle between those two Stars did then cut the Ecliptic in . 6°. 44': and by this reckoning the Equinox in the end of the year 1689 was gone back 36°. 44'. since the Argonautic Expedition: Supposing that the said Colure passed through the middle of the Constellation of Aries, according to the delineation of the Ancients. The Equinox goes back fifty seconds in one year, and one degree in seventy and two years, and by consequence 36°. ”

“ But it is clear that as the full moon is opposite the sun, and as to fulfil the condition described we have seen that she must be crossing the equator from south to north, the sun, opposite to her, must be at the part of his path where he crosses the equator from north to south. In other words, the time of year must be the autumnal equinox. ”

“ Now, let us suppose that, at a time when the ellipticity is great, the movement known as the precession of the equinox has changed the incidence of our seasons, so that our summer happens in perihelion and not in aphelion, while that of the southern hemisphere occurs in aphelion, and not, as at present, in perihelion. Under such conditions, the climate of the globe would experience a complete change. ”

“ When at their equinoxes the other planets undergo a like experience, and indirectly, through the sun, we share in the resultant electrical excitement. Such is the theory, and on such foundations does it rest. Historical records and the reports of the weather bureaus furnish endless confirmations, for every storm finds an equinox to bear the responsibility. In order to include all actual phenomena, the duration of an equinoctial period is put at one-fourth the planet's year, so that each planet spends halt its time in creating disturbances throughout the solar system. ”

“ The equinox is not very far off, and then, you know, we shall get less and less sun,--so little, as to be of no great use to us. We want day-light to get through the ice, and we shall have a long hundred leagues of it between us and clear water, even were we to get under way to-morrow. Remember what a serious thing it would be, to get caught up here, in so high a latitude, after the sun has left us! ”