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plaio, on the same day. We know from scientific observation, that in the month of June the atmosphere is at its highest point of dryness, and that the average number of days on which rain falls is lower than the
average of any other month of the year. With these established facts to contradict the prophecy, it is predicted by Moore's Almanac, that from the 10th to the 20th of June in the year 1829, the atmosphere will be moist, with raio and thunder in many places. If any farmer believe this nonsense, it is highly probable that from the 10th to the 20th of June he may lose some days of actual fine weather, in the dread of the rain which the almanac predicts, and thus his hay will remain on the ground, instead of being safely in the rick; and, further, that when he hopes for the fine weather which the same almanac ensures from the 24th to the end of the month, he may experience a heavy rain, and be driven on to the periodical rains of the middle of July, with no consolation for his losses but the conviction that it is better to trust to common-sense and experience, than to false predictions, expressly manufactured to impose upon the ignorant.
The · Astrological Predictions of Mundane Affairs,' with which the most popular of our almanacs are still illuminated, are not more distinguished for veracity than their predictions of the weather. We do not suppose that many persons seriously believe in these absurdities; yet when they are perused by many thousands, as they still are, it is iinpossible that the mind should be able wholly to resist the influence of the deception; and in proportion as such thoughts find a place in the mind, will sound knowledge and a pure love of truth be shut out. As a matter of curious interest, we shall again give a specimen from the almanacs before us of the little variation which has prevailed for one hundred and fifty years in the language of imposture : Andrews' News from the Moore's Almanac, 1771, Moore's Almanac, 1829, Stars, 1678, July.
July. Sudden fears possess some
There is some bustle in the In this month there are no places–Jupiter turns retro-world about this time, and less than five conjunctions, grade, and Mars comes to where armies are blows must three of which happen in the conjunction with Saturn at be expected. Jove affronts ascendant of Rome, the very the month's end. Weighty both the Sun and Mercury, and focus of papal powers, and a matters under consideration some sly contrivance brought fourth on the very verge of in some parts of Europe. Fly- to light. I hope no holy plot. that sign. Here is a concating reports from beyond sea. Some good news from abroad enation of circumstances; the Those places under Gemini about this time, and some effects of which may be exagain concerned. The influ- ships despaired of likely to pected to produce serious ence both of Saturn and Mars come home safe.
events in the Catholic church they are perhaps now sensible
-perhaps the death of his of, to their detriment or dis
It cannot fail to be perceived, that the tone of these predictions is not in the slightest degree altered by the progress of knowledge. The prophecy for 1829 would read just as consistently in the Almanac of 1678; and that of 1771 would be just as reasonable and true, if transposed to 1829. In-' deed, we have observed in our inquiries into this subject, that the very slightest changes fit the predictions of a past year for revival, in some
future attempt at delusion. It is really wonderful, that such a clumsy imposture should so long have held a place amongst a thinking people, Several gross improprieties, however, have within the last year been removed from the old almanacs; and it is observable, that their attempts at delusion are very much softened. It is to be desired, that all astrological predictions should be removed from these productions; and they may then fairly be considered as amongst the most useful works of reference. We earnestly desire to see them become instruments of good, instead of continuing vehicles of evil.
The divisions of time are either natural or artificial. The natural divisions are the day, the lunar month, and the year. The artificial divisions are the week, hour, minute, and second. The year is divided into 12 parts by the revolutions of the moon, with a remainder of about 11 days. How comes the day to be divided into 24 parts, called hours, rather than into any other number? and how happens it, that the hour is subdivided into 60 minutes, and the minute into 60 seconds ? Having occasion for smaller portions of time than a day, this natural unit of duration was divided by man as nature had divided the year, by the revolutions of the moon; that is the day properly so called, or the interval from sunrise to sunset, was divided into 12 parts, and the night into 12 parts; and as the month, or 12th part of the year, contained 60 such parts, namely, 30 days and 30 nights, so the hour, or 12th part of the day, was divided into 60 parts, called minutes, and the minute subdivided in a similar manner into 60 seconds. But the hour was formerly, among the Greeks, a 12th part of the interval from sunrise to sunset, and thus, instead of being a fixed and definite period, was of different lengths at different seasons. Indeed the hour, considered as the 24th part of the apparent entire revolution of the sun, would not he exactly the same through the year, since the days themselves, which are measured by the return of the sun to the same meridian, are unequal. They increase for a certain period from a few seconds to half a minute, and then decrease in a similar manner; so that we are obliged to strike a balance, or take an average of all the days in the year, and divide this average into 24 parts, in order to give to the hour a definite, fixed length. A good clock that goes uniformly, and is so regulated as to agree exactly with the sun at the beginning and end of the year, would indicate hours and minutes of a uniform length, according to the above method of taking an average or mean, But an accurate clock so adjusted, would differ from the sun in the course of the year about 16 minutes, or a little more than a quarter of an hour, being sometimes faster by this quantity, and sometimes slower. It would agree with the sun four times in the course of the year, namely, (at tho
present time) on the 15th of April, 15th of June, Ist of September, and 24th of December; and it would differ most from the sun about the middle of the intervening periods. The difference, however, between the clock and the sun, would not be the same in each case. The following are the differences in question, between the clock and sun at the time of their greatest departure froin each other in the several periods above mentioned ; 11th of February, 14' 36.6''; 15th of May, 3' 65.6''; 26th of July, 6' 7.3"; 3d of November, 16' 16.9".
The want of equality in the length of the solar days may be thought to imply a want of unformity in the apparent diurnal inotion of the heavens, or in the real motion of the earth on its axis. This is not, however, the
We have never been able to detect the slightest irregularity in these motions. The day, as measured by the return of a star to the meridian, or to the same point of the heavens, is always the saine. It will naturally be asked then how it happens that the solar day, or period measured by the return of the sun to the meridian, should be different at different times of
This arises from two causes. If the sun's centre and a star were on the meridian at the same instant to-day, to-morrow when the star arrived at the meridian, the sun would be advanced towards the east about one degree, or two of its diameters, which would require, according to the uniform rate of the diurnal motion, about four minutes of time for it to reach the meridian. Thus a solar day is made up of a sidereal day, always the same, and a certain portion more. Now these additional portions are unequal. We have said that the sun will be found to have left the star, upon the return of the latter to the meridian, having departed from it toward the east. But these departures will be unequal, since the sun's apparent motion among the stars, produced by the real motion of the earth in her orbit, is alternately accelerated and retarded. This is one cause of the inequality of the solar days. Another is, that the sun's path among the stars is sometimes perpendicular to the meridian, and sometimes oblique. It is manifest, that if the sun, after coinciding with a star should move a degree north or south, instead of easterly, it would return to the meridian at the same time with the star, making a solar and sidereal day the same; and, according as the path of the sun approaches more and inore to a perpendicular to the meridian, is the solar day, increased, other things being the same. Now the sun's path is actually sometimes perpendicular to the meridian, and sometimes oblique. Its course among the stars is not exactly east, but is generally inclined, sometimes to the north and sometimes to the south. In this manner it happens that the days, as measured by the sun, alternately increase and decrease, and the time shown by the sun, as upon a dial, for instance, is called apparent time. On the other hand, the time furnished by a good clock, as above described, is called mean time. The difference, amounting, when greatest, to about 16 minutes, is called the equation of time.
Days. The day is made to begin at different times in different countries. With the Italians, for instance, it is considered as beginning at sunset; with the modern Greeks, on the other hand, it is supposed to begin at sunrise while with us, and many other people, its commencement dates from midnight. According to the two former modes, it is necessary to alter clocks and watches continually for the purpose of making the hours begin with the day. The manner of beginning the day at midnight seems to be decidedly the most convenient for the ordinary business of civil life. In this. case, the same piece of work is seldom divided between two days, as must frequently happen when the day is inade to begin at sunrise or sunset. With us it is rarely necessary to look at the clock or the sun to know what day of the month or week it is. Astronomers, however, find it most convenient to begin the day at noon, 12 hours after the commencement of the civil day, as the time of noon can be accurately determined by observation. They are accustomed, moreover, to count the hours continuously from 1 to 24, whereas, in civil reckoning, the hours being counted from 1 to 12, and then repeated, it is necessary to distinguish the two series by A. M. and P. M. Navigators also begin the day at noon, and count the hours from 1 to 24, after the manner of astronomers; but they begin their computation 12 hours before the commencement of the civil day, and consequently 24 hours before the commencement of the astronomical day.
Weeks. The week approaches pretty nearly to a quarter of a lupation; but it bas no very obvious foundation in nature. It appears, notwithstanding, to have prevailed very extensively over the world, and from the earliest times; and what is still more remarkable is, that the days of the week are so generally named after the sun and planets. This manner of distinguishing the series of seven days, “is found to be the same among the ancient Egyptians, Indians, and Chinese. Still the order is not that of the distances, mag. nitude, or brightness of the planets. It is an order that is apparently arbitrary, or which is at least founded upon reasons not known to us."* Sunday is the Sun's day, Monday is the Moon's day, Tuesday, Wednesday, Thursday, and Friday, are derived from Tuesco, Woden, Thor, and Freya, the Saxon names of Mars, Mercury, Jupiter, and Venus.
Months. The months, with the exception of February, are either of 30 or 31 days; and the following lines, intended to assist the memory, are as useful as they are trite :
u Thirty days hath September,
April, June, and November,
* Bailly's Histoire d'Astronomie,
February hath twenty-eight alone,
Our names of the months have come down to us from the Romans; January is said to be derived from Janus, an ancient king of Italy, February from februo, to purify ; March, from Mars ; April from aperio, to unfold; May, from Maia ; June, from Juno ; July and August were 80 damed in honor of Julius and Augustus Cæsar.. Before the tiine of Julius Cæsar, these months were called Quintilis and Sextilis, being the fifth and sixth months, reckoning, as the Romans did at that time, from March, as the commencement of their year. September, October, November, and December, signify the seventh, eighth, ninth, and tenth months from March, when the year began.
Year. The year is a striking period of time obviously marked by the return of the sun to the same point in its course through the heavens, and its consequent effects in renewing the productions of the earth. The year in civil reckoning, that is, the period of the seasons, is not exactly the time of an apparent revolution of the sun in absolute space; in other words, it is not strictly the time employed by the sun in returning to the same star, since those points of the sun's course (or the ecliptic), on which the seasons depend, shift backward a little (50'') while the sun is going round. This is called the precession of the equinoxes. Now the sun is about twenty minutes, according to its ordinary rate of 360° in a year, in moving through this space of 50". Hence the year of the seasons, technically called the tropical year, is about twenty minutes less than a sidereal year, or a complete period through the heavens. But this precession of the equinoxes, which thus shortens the year of the seasons, and which is caused by the attraction of the sun and moon exerted upon the matter accumulated about the equator, is not always the same. It is sometimes greater, and sometimes less. It is a little more now than it was two thousand years ago, the necessary consequence of which is, that the year is shorter than it was. The difference for the period above mentioned amounts to about 11 seconds.
As the year of the seasons, 365 days, 5 hours, 48 minutes, 50 seconds, does not consist of a certain number of entire days, it has been found difficult to allow for the fraction of a day, and keep the months to the same season. It is important, in civil reckoning, to have the year consist of a certain number of entire days; and Julius Cæsar, in framing the Calendar that is still in use under the title of the Julian Calendar, proceeded upon the supposition, that the year was 365 days and a quarter or 6 hours. He accordingly provided, that the civil year should be 365 days for three years in succession, and the fourth 366, thus making the average length 365%.