I’m still thinking about my husband’s question about the sex of his sister’s baby. A colleague points out that Mercury’s location in feminine Pisces and quite close to superfemme, dignified Venus in Pisces would make it more feminine than masculine in this chart. That would tip the balance toward girl-baby, not boy-baby. I can see that.

For bonus points, I decided to consult The Book of Instruction in the Elements of the Art of Astrology by the Persian scientist/astrologer/philosopher al-Biruni, written in 1029 AD or so. He’s got lists of Arabian parts (lots) for determining this and that. One of them is called “As to whether expected birth male or female.” Perfect, I thought.

Then I looked closer. In my edition of the book, the formula is given as Ascendant + Moon’s dispositor – Moon. But somebody wrote a double-headed arrow over that to indicate that the planets should be transposed, and that the formula ought to be Ascendant + Moon – Moon’s dispositor. Which to use? Heck, let’s calculate both.

I will spare you lots of boring math. You’re welcome. The first formula puts this lot at 2 Gemini 31, telling me to look at its ruler, Mercury. The second formula puts it at 13 Pisces 23, suggesting Jupiter is my key planet. That’s the way you work with parts or lots, by the way; you figure out where the lot is, and then look at its planetary ruler to see what you can learn. (You can look at the lot itself, but the planetary ruler is typically more important.)

How’s Mercury? Oriental, so masculine; but in Pisces with Venus, which is pretty feminine. Sextile Jupiter and Moon in feminine Capricorn. How’s Jupiter, on the other hand? Masculine planet in a feminine sign, conjunct the Moon (which is nearly angular, so accidentally strong), sextile the Mercury/Venus conjunction in Pisces. Girl power continues to predominate.

So maybe it’s a girl.

My sister-in-law is pregnant. Driving home after visiting her last month, my husband wondered aloud, “I wonder if she’s having a boy or a girl?” I looked around, made a note of the town we were passing through and the time, and put up a chart when we got home.

Chart data: 30 March 2008, 8:12pm EDT, Palmer, MA USA (72W20 42N10)

William Lilly says, to determine whether male or female, “See to the ascendant, the Lord that Sign, the Sign of the fifth and Lord of the fifth.” I trust you already know which signs are masculine and which are feminine? No? Okay, fire and air signs masculine; earth and water signs feminine.

He also advises us to look at the nature of the planets themselves. Lilly says the masculine planets are Saturn, Jupiter, Mars and Sun; Moon and Venus are feminine; and Mercury changes. I’ll explain more about that in a moment.

On to the chart at hand. For this horary, we can’t go to the first and fifth houses as directed, because the querent is asking about his sister, not himself (indeed). We have to turn the chart. What we’re doing is identifying the correct houses for the person asked about.

My husband is the querent. He asked the question about his sister. Siblings are found in the third house. So his sister’s “ascendant” for the purposes of following Lilly’s rules is Sagittarius, the sign on the 3rd house cusp. Sagittarius is masculine. Jupiter, Sag’s ruler, is a masculine planet. But it’s in Capricorn: feminine. So that’s two votes for boy, one vote for girl.

His sister’s baby is the 5th from the 3rd: the 7th. Aries on the 7th house cusp: masculine. Mars, Aries’ ruler, is a masculine planet. It’s in Cancer: feminine. Two more votes for boy, one more for girl.

So I suspect it’s going to be a boy. The tendency is toward the masculine side, with four votes to two. But just for fun, I want to see what the Moon is up to. Lilly says, if the testimonies are split, have a look at the Moon. You want to see what sign it is in, and whether it’s applying to a masculine or feminine planet.

Moon in this chart is in Capricorn: feminine. It’s applying to Mercury. It figures! Mercury, the gender-bender, changes gender depending on what it’s near and where it is relative to the Sun. Mercury is in feminine Pisces and recently conjunct Venus in Pisces. That’s a lot of girl power. But Mercury is also what’s called “oriental of the Sun” in this chart. That is, if we cycle the planets around so that Sun is on the Ascendant (i.e. sunrise), we’d see that Mercury will have risen first, in which case “he is reputed Masculine” as Lilly says.

But that’s still a lot of girl power. This one’s tough. I think I’ll go on record and say it’s going to be a boy. But I’m maybe 60% sure of that. We’ll know by the end of August, I hope!