Recently I was reading Cooper’s 1814 translation of Placidus’ Primum Mobile and going over the charts in the section Thirty Remarkable Nativities in which Placidus discusses the chart of King Charles V of Germany (23 Feb 1500 – 21 Sep 1558). Even though the king was born in Ghent, Belgium, presumably at 3:39 AM local time according to Placidus, he casts the chart for The Hague in Holland. Placidus shows how his method of primary directing planets reveals the date of death of the king. In the discussion of the king’s demise, Placidus also makes use of the method of “embolismic lunations” as a predictive technique, which he explains as follows:
Embolismic lunations are a calendrical reference to an ’embolismic year’, which is one that contains 13 lunations instead of the typical 12, due to the insertion of an ’embolism’. The site https://digital.library.mcgill.ca/ms-17/apparatus.php?page=Glossary defines ’embolism’ like this:
“Because the Julian solar calendar is 365 days long, and 12 lunar months of 29½ days total 354 days, the age of the Moon on any given calendar date increases by 11 days each year. When the accumulation tops 30 days, the maximum length of a calculated lunar month, an additional 13th lunar month is deemed to be inserted within the calendar year. This additional intercalated lunation is called an “embolism” and a year with 13 lunations is ’embolismic’.”
Astrologically speaking, an ’embolismic lunation’ is simply a return of the Moon to the same phase-angle or relative position it held with respect to the Sun at the moment of birth. On average, the Sun and the Moon return to their natal phase angle every 29.530589 days. In other words, the mean period of the Sun-Moon phase angle return is 29 days, 12 hours, 44 minutes. However, owing to the eccentricity of the Moon’s orbit around Earth and slightly to the Earth’s elliptical orbit around the Sun, the period from one Sun-Moon phase-angle return to the next can vary by up to seven hours. It is possible to calculate dates of Sun-Moon phase angle returns in an Excel spreadsheet by repeatedly adding 29.530589 days to the birth date and then adjusting the chart for match the exact phase angle at birth. Fortunately, some astrological software offers phase-angle returns as an option.
According to DeVore’s Encyclopedia of Astrology, Placidus “applied the term Embolismic Lunation to a Figure cast for the moment of the Moon’s return to the same relation to the Sun that it occupied at birth. It was made the basis for judgment concerning the affairs and conditions of the ensuing year of life.” (italics mine)
If I understand the technique correctly, you first identify the embolismic return for the start of a given year of life (the annual solar return date). The embolismic lunar return so identified then maps onto that entire single year of life, and it can be progressed at a rate of one tropical year (365.24219 days) equals one synodic lunar cycle (29.530589 days), which calculates to be 12.368267 days of life during the solar return year for each day of the synodic lunar month. In other words 1 day of the embolismic return cycle equals12.3682668 days of life during the solar return year, which (doing the division) is equivalent to a progression rate of 0.080852073.
To summarize my understanding of the technique, each synodic lunar period of 29 days 12 hours 44 minutes 2.8 seconds is regarded as equivalent to a tropical year of life. Doing the division of a year by a synodic month, we find that there are 12.368 ’embolismic returns’ during each tropical year. The first embolismic return after birth corresponds to the first year of life; the second return, to the second year of life; and so on. The embolismic returns can be read in very much the same way as we read solar return charts, both as stand-alone charts and also in comparison with the natal chart. Themes highlighted in this way are likely to play out during the year of life corresponding to the embolismic return. Basically, emobilsmic returns are a form of progressing the natal chart by synodic lunar months measured by repeating natal Sun-Moon phase angles.
Let’s look an an example. The child actress Heather O’Rouke (1975 – 1988) died at age 12 of sepsis and cardiac arrest. She has a Rodden rated AA chart and was born 27 Dec 1975 at 00:28 AM in San Diego, CA. She died on February 1, 1988 at the age of 12.0988 years (36 days after her 12th birthday). As mentioned in the above paragraph, 36 days of life (dividing by 12.36826) corresponds to 2.9 days of an embolismic return.
Using Alphee Lavoie’s software, I calculated her embolismic return at the time of her demise to have occurred on 15 Dec 1976 at 8:22:42 PM (tz 8) at her birthplace.
The phase return lunation cycle corresponding to the period 27 Dec 1987 to 27 Dec 1988 is the phase angle return of 15 Dec 1976, which lasts until 14 Jan 1977. Because she died 36 days after her 1987 birthday, we calculate 36 days divided by 12.368, giving 2.9 days after 15 Dec 1976, which brings us to the span 17 Dec – 18 Dec, 1976 as the ‘progressed’ embolismic lunation period for the date of her death. The resulting ‘progressed’ embolismic chart looks like this:
The above embolismic chart covers the 12.37-day period from 25 to 37 days following her solar return of 1987 when she turned 12 years old. It cautions that she is in a difficult period, especially because the Moon (to whom the return belongs) almost exactly squares a debilitated Saturn on the Ascendant of the return.
Return Saturn Rx in Leo (a sign of its detriment) rules the return 6th of health problems and conjoins the return Ascendant. It is a night chart, so Saturn is the out-of-sect malefic in the embolismic return chart. Her natal Ascendant ruler Venus applies to oppose Saturn and has just completed a square with Uranus, which is angular conjunct the IC. Uranus here could indicate unexpected disruptions in home and family.
Next let’s superimpose the embalismic chart on her natal chart.
Superimposing the charts, we see that lunation Jupiter, which rules the natal 6th and the embalismic 8th, occupies the natal 8th and closely conjoins the natal lunar south node, suggesting significant and potentially life-threatening health problems. The return Moon in Scorpio applies to oppose return Jupiter in the natal 8th house.
A value of the embalismic lunation is its ability to highlight the major emphasis for a given month of the solar return year.
There is a lot of detail in this post. If you notice any errors in my calculations, please let me know so I can correct them.