This term refers to the New Moon or the synodic month, which is the period between two New Moons. A lunation is the exact moment of the Moon's conjunction with the Sun. A Lunation is a
conjunction of the Sun and Moon, a 'New Moon.' In our ephemeris all New Moons, Full Moons, and eclipses are plainly marked at the head of the pages. When a lunation falls within three degrees of
an aspect to any of the planets or other vital points in the radical horoscope it has a marked effect upon affairs during the current month, and will easily take the place of an aspect of the
progressed Moon which is needed to fructify the planetary indications then in force. Even apart from primary directions, if a New Moon falls in close conjunction with a malefic, it will produce
trouble in minor matters, and conversely, a lunation which falls on the place of Jupiter or Venus will make things pleasant.
When a New Moon is a solar eclipse it produces first, the usual effect of a lunation during its current month, if in aspect with any of the radical planets, and secondly, similar effects during the months of the following year when aspects of the same nature are formed with the place of the eclipse. That is to say, if the eclipse fell in the twelfth house in Leo, square to Mars in Scorpio, in the third house, then it would produce enmity with brothers and sisters during the month of August when the eclipse was formed. In november when the lunation occurs in Scorpio more fuel will be added to the fire by the square with the eclipse. In February when the Sun is in opposition to the eclipse there will be more trouble from the same source, and also in May when the last square occurs. Conversely, if the initial aspect of the eclipse is good, more benefit will be experienced during the months then sextiles and trines are formed.
The cycle of lunations is nineteen years; for example, in July 1900 the lunation occurred on the 26th of July in three degrees of Leo, and in 1919 another lunation will occur on the 26th of July in three degrees of Leo. Thus the student may calculate the lunations of future years with sufficient accuracy for all practical purposes.
Eclipses may also be calculated for future years in a similarly easy rough and ready manner if the student has the ephemerides for past years. During her monthly course the Moon zigzags across the ecliptic, and at the conjunctions, or New Moons, is generally a number of degrees away from the ecliptic. Under such conditions we have just an ordinary New Moon. In order to have a total solar eclipse the Moon must be directly in the Sun's path as seen from the earth, and the declination of the Sun and Moon must be practically the same; also the moon must have practically no latitude.
There are never less than two eclipses in a year, and they are solar, nor are there ever more than seven, but these extreme numbers happen very seldom. The usual number of eclipses is four; two solar and two lunar eclipses, and they usually come in pairs and six months apart. The Full Moon preceding or following a solar eclipse is usually a lunar eclipse. Also if on pair of eclipses occurs in February, look for the other pair in August.
Bearing the above in mind, eclipses in any year may be found with fair success by the following simple rule:
(1.) From the year for which eclipses are wanted, subtract 18. The resulting year we will call the 'eclipse year.'
(2.) Search the 'Eclipse Year' for New and Full Moons which are eclipses. Note their dates only.
(3.) In the year previous to the 'Eclipse Year,' note the dates and zodiacal places of the lunations which occur about eleven days after the dates obtained in the 'Eclipse Year.' These are dates and places of eclipses in the year wanted.
In order to test the simple rules of thumb here given, let us imagine this is the year 1910, and that we want to find the first solar eclipse occurring in 1915. We take an ephemeris for 1897 which is eighteen years earlier than 1915, and look for the first solar eclipse.
We find a solar eclipse on the 1st of February 1897. To ascertain the date and degree of the Zodiac in which this eclipse will fall in 1915, we look for information in the ephemeris for 1896, which is one year earlier than the 'Eclipse Year' 1897.
There we find that the first New Moon which occurred after February 1st, fell in the afternoon of the 13th of February, in twenty-four degrees, nineteen minutes of Aquarius, and we therefore judge that there will be a solar eclipse on the 13th of February 1915 in twenty-four degrees, nineteen minutes of Aquarius. After completing our calculations we cease to make believe about living in 1910, and take up the ephemeris for 1915 to see if our rules have given the right result; and we find that a solar eclipse did occur on the morning of the 14th of February 1915, in Aquarius, twenty-four degrees, forty-two minutes, proving the rule to have given an essentially correct result.