Page images
PDF
EPUB

the astronomical year. In 1582 this difference had accumulated, until it amounted to over 11 days, of course the equinoxes, and solstices, no longer happened on those days which had been appointed to them, and the celebrations of the Church festivals, were consequently much deranged. The Council of Nice, which sat A. D. 325, had decreed that the great festival of Easter, should be celebrated in conformity with the Jewish Passover, which was regulated by the full moon following the vernal equinox. Now the decree did not say that this festival, upon which all the others depend, should be on the first Sunday after the full moon following the vernal equinox, but on the Sunday following the full moon, on or after the 21st of March, this being the day, at that time, of the vernal equinox. Pope Gregory XIII., who occupied the pontificate in 1582, determined to rectify this error, which was thus made known, not from any series of observations for that specific purpose, as at the present day, but by the accumulated error becoming so great as to introduce confusion. At this time the vernal equinox really occurred, according to the civil reckoning, on the 11th of March, ten days earlier than the time decreed by the Nicene Council. To remedy this defect, Gregory directed that the day following the 4th of October, 1582, should be reckoned the 15th, instead of the 5th, thus restoring the vernal equinox to its former position, by omitting altogether ten days. To prevent the accumulation, he directed the intercalary day to be omitted on every centurial year; this would have answered every purpose if the difference, which had caused the error, had amounted to a day in 100 years, but it did not, for it was but a little more than of a day, hence omitting the intercalary day every 100th, or centurial year, omitted of a day too much, which, in the course of 400 years, amounts to 1 day. It was, therefore, further provided, that although the intercalary day was ordinarily omitted each centurial year, it was to be retained every 400th year, thus the centurial years 1600, 2000, and 2400, are bissextile; but the years 1500, 1700, 1800, 1900, 2100, 2200, &c., are common years. This correction is sufficiently accurate for all purposes, the slight remaining error will only amount to a day after an interval of 144 centuries. The time of the vernal equinox now is, and always

GREGORIAN CALENDAR.

65

will be, the 21st of March. The correction introduced into the calendar by Gregory, was not adopted by the English, until the year 1752. At this time the difference between the Julian and Gregorian calendars was 11 days; it would have been 12 days, but the latter had omitted the intercalary day in the year 1700, as we have already stated. It was, therefore, enacted by Parliament, that 11 days should be left out of the month of September of the current year, by calling the day following the 2d of the month the 14th, instead of the 3d. The Greek Church have never adopted this Romish or Latin correction, and consequently, the Russians are now 12 days behind us in their reckoning, and the Christmas festival, which happens with us December 25th, occurs with them January 6th, or Epiphany day, according to our reckoning, and which is sometimes, even now, called " Old Christmas day." The Julian and Gregorian calendars are designated by the terms "Old Style," and "New Style." Thus, by successive improvements, which have been almost forced upon the world, the calendar has been perfected, until it answers all the purposes of civilized life.

"Mind

"Time," says Young, "is the stuff that life is made of," and we do well, therefore, not to waste such a precious possession. We remember the inscription on the dial in the Temple, at London : 66 Begone about your business," a wholesome admonition to the loiterer, and the no less appropriate device, once stamped on the old Continental coppers, a dial with the motto, your business." There is enough to do, and time enough to do all that ought to be done. "There is a time for all things," says Solomon, let us then, be careful and do all things in the proper time. The French Chancellor d' Aguesseau, employed all his time. Observing that Madame d' Aguesseau always delayed ten or twelve minutes before she came down to dinner, he composed a work entirely in this time, in order not to loose an instant; the result was, at the end of fifteen years, a book in three large volumes quarto, which went through several editions.

No man, we venture to say, ever accomplished more, and to the better satisfaction of all interested, than Benjamin Franklin, another economiser of time, One of his greatest discoveries was

made in France, and that was, Sun-light was cheaper than lamplight, and better, too. A severe reprimand, from a man of his standing, and industry, upon the customs of the French court, spending the night in mirth and revelry, and sleeping all the day. It is said there is a moral in every thing, to the moralizing mind. Since, then, "Time once gone, ne'er returns," let us make the best use of it; not sad, or serious, merely, but sober and reasonable-ready to labor in the hours of labor, and to rest in the hours of rest. We shall not, then, look back on misspent moments, with that feeling so aptly expressed in the German: "Ach wie nichtig, ach wie flüchtig !” Ah, how vain, ah, how fleeting!

The flight of Time, which is silently, but surely and uniformly, bearing us from scenes, loved, perhaps, too well, cannot be too accurately marked. The correction of the calendar, by Julius Cæsar, has done more to perpetuate his name than the victories he won for Rome, and the name of Gregory XIII. has more of meaning in it, than that of a mere Saint, in the Romish calendar. There is something pleasing, and yet mournful, in thus minutely contemplating the passage of the year, and we would do well to imitate the good old custom which our forefathers followed, and on the first day of the New Year, make the first entry in our new account books:

Lans Deo.

[merged small][ocr errors][merged small]

CHAPTER VI.

Dials and Dialing.

This shadow on the Dial's face,
That steals from day to day

With slow, unseen, unceasing pace,
Moments, and months, and years away,
Right onward, with resistless power,
Its stroke shall darken every hour,

Till Nature's race be run,

And Time's last shadow shall eclipse the sun."

J. Montgomery.

In the preceding chapter, we have made frequent use of the word day, and have throughout meant what is called a mean Solar day. We have already shown that the Siderial day is the time of an exact revolution of the earth on its axis. This day is shorter than the Solar day, by about 4 minutes. We have also alluded to the apparent motion of the sun in the heavens, showing that if to-day he came to the meridian at the same time with any particular star, to-morrow the star would come to the meridian before the sun, which had apparently changed its place in the heavens. Let us consider to what the difference between Solar and Siderial time is really owing, and see how much the Siderial day should be

[blocks in formation]

shorter than the Solar, to do which we will have recourse to a diagram

Let A B C D, represent the earth's annual orbit, showing the earth in four different positions, and let a be the situation of some particular meridian, that of Greenwich, for example. Now, on the supposition that the earth does not rotate on its axis at all, suppose it moving in its orbit, in the order of the letters; it is not difficult to see that the effect will be the same, as though the earth, remaining at rest in its orbit, had turned once on its axis during the year, but in a contrary direction to its present diurnal motion. Thus, while at A, the sun would be on the meridian a, but at B, one fourth of a year after, the sun would set in the east, and at C, half a year afterwards, it would be midnight at the same meridian, a. At D the sun would just begin to rise in the west, and finally at A would come to the meridian again. It will now be understood, that although the earth does turn on its axis, during its yearly circuit, yet this day as really occurs as if the earth had not the diurnal revolution, hence the number of rotations, measured by the sun's coming to the meridian, will be less than the number as announced by a star, by one day, and therefore the Siderial day must be shorter than a Solar day, by the proportional part of a revolution, which is thus divided up among, and added to the 365 Solar days of the year. Upon the supposition that the mean Solar day is just 24 hours in length, the Siderial day will be, the one-three hundred and sixty-fifth and one-fourth, of 24 hours, shorter, i. e. 3m, 56s, very nearly, and a star, in consequence, will come to the meridian 3m, 56s, sooner than the sun, each day, or will gain so much on the sun daily.

We have more than once intimated that the time elapsed between a star's leaving the meridian, to its return to it again, viz : 23h, 56m, 4.01s, is the precise measure of a rotation of the earth, and for this reason astronomers prefer to regulate their time keepers to show what is called Siderial time. Now, suppose to-day to be the 14th of April, which is near the time of vernal equinox, the precise point where the ecliptic intersects the equator, we will imagine to be shown by a bright star. By means of his transit instrument, the astronomer ascertains exactly when this star is on his meridian, and just then sets his clock going, the hands showing at the time Oh, Om, Os, and at the same time the town-clock, we

« PreviousContinue »