The Moon, with her borrowed light, is the image of generation, of the ever renewing cycle of life and death. She is an image of the light of the spirit incarnating into the mortal realm and so it might be of interest to look from another angle at the Trutine of Hermes that we discussed not so long ago. (The Trutine of Hermes)
Tables of numbers rarely capture one’s attention but sometimes they might deliver a valuable insight if looked at not as a means to simplify a calculation but at what they are intended for.
If you look at the table for calculating the period of gestation used for the Trutine of Hermes you can make some interesting observations. You can also make a logical induction about one the traditional concepts of the nature of the Moon. This can be found for example on p.502 of William Lilly’s Christian Astrology or in the mathematical works of Johannes Schöner.
The table covers a gestation period from 258 to 288 days with the mean placed at 273 days or 39 weeks. The Moon above the horizon at birth is considered an indicator for a shorter gestation period, while the Moon below the horizon indicates a longer period of gestation. Interestingly enough the shortest period given in the table is when the Moon is conjunct the Descendant, and not the Ascendant as one would normally conjecture. The Moon conjunct the Ascendant indicates the mean time. The longest period of gestation has the Moon one sign below the Descendant. Each day of gestation is measured with an increment of 12 degrees, which is just slightly less than the size of one lunar mansion (12 degrees 51 minutes) or the daily mean motion of the Moon (13 degrees 11 minutes).
What does all of this mean? If we consider that we are dealing with the stage of “ripeness” of the embryo which is what birth is, then the image of a Full Moon is appropriate. The table encompasses a cycle which stretches roughly from one Full Moon to the next. If you recall our discussion of the cycle of lunation in connection with the Part of Fortune we noted that at the Full Moon both the Part of Fortune and the Moon are in opposition to the Ascendant, that is conjunct the Descendant. So the Moon in the birth chart conjunct the Descendant is an image of early ripeness or of an embryo that has quickened rapidly.
Morever the use of the Trutine attempts to measure, in retrospect, the time from birth to conception where the Moon is considered to take the position of the Ascendant at birth. Here the New Moon is an image of conception.
I have transformed the table into its general form:
We see that the table makes a simple corollary between the time of conception and birth. The Moon whatever its true position at conception is conjunct the natal Ascendant and is invested with the quality of “New Moon” while the Moon at birth, as indicator of “ripeness” is invested with the quality of the “Full Moon”. The position of the Moon above or below the horizon is in this case not viewed from the standpoint of sect but from visibility. The Moon above the horizon in the birth chart is then an indicator of a fast gestation period as compared to the slower gestation period when she is below the horizon at birth.
Altair Astrology 