In Book I of Valen's
Anthologies, chapter 4. (page 8 of the Riley pdf) he describes several methods for finding the ascendant. The first of these uses the dodekatemorion.
Having determined accurately the sun's degree position at the nativity, note where the dodekatemorion falls. The sign in trine to the left of this position will be the Ascendant, or the equilivalent sign (i.e. either masculine or feminine), providing you take into account the distinction between night and day births. For example: let the sun be in Aquarius 22*. The dodekatemorion of this point is in Scorpio...
dr. farr, you posted on another thread these two methods for finding the dodekatemorion:
Dodekatemorion is used (in natal, event and mundane charts) to see the additional ramifications of the "shadow" of the planet (or degree or Lot) in the chart; there are 2 types of dodek: Egypitan and Pauline:
-in Egyptian you multiply the degree and minutes of the planet (or Lot) by 12, then subtract 30 for every sign it crosses (starting with the sign the planet or Lot is in), and when you cannot subtract 30 anymore, that is where the dodek (shadow) falls
Example: what is the dodek of Saturn in 15Aries00?
Answer = 15 x 12 = 130; subtract 30 for every sign starting with Aries: so -Aries = 100 left; minus Taurus = 70 left; minus Gemini = 40 left; minus Cancer = 10 left; since you cannot subtract 30 from 10, the dodek of Saturn falls @ 10Leo.
-in Pauline, multiply by 13 and use the same type of subtraction by 30
Example: what is the Pauline dodek of Sun in 22Aquarius00?
Answer: 22 x 13 = 286; subtract 30 for every sign (starting with the sign the Sun is in) so that would be 9 signs (270) which leaves 16 as remainder; therefore the dodek of the Sun would fall @ 16Scorpio.
My understanding is that Valens would have been using the Egyptian method and not the Pauline method. Now, Valens in Book I does not state which he uses, nor does he describe how he got to Scorpio. Lastly he does not say at which degree of Scorpio (one of the reasons attempting his "adventures in finding the Ascendant" is, er, difficult.)
What is interesting about this paragraph is that if we do the math, 22x12=264, so 8 (30*) signs with 24* remaining. Counting from 0* Aquarius as you show above, we come to 0* Libra, with the dodek of 22* Aquarius being at 24* Libra. Well. That's not Scorpio.
If we use the Pauline method then we have 22x13=286, or 9 (30*) signs with 16* remaining. Counting from 0* Aquarius that brings us to 16* Scorpio. hmmmm.
Either Valens was using the Pauline method, or...
Occam's razor?
Using the Egyptian (x12) method, if we start the count at 22* Aquarius, we count 8 signs to get to 22* Libra (240* from 22* Aquarius) then add 24* to bring us to....wait for it...16* Scorpio.
Could it be that we are meant to start the count from the exact degree of the planet whose dodek we are trying to determine? That would be the simplest answer.