Reading Morin’s Astrologia Gallica, one has to get used to Morin’s manner of assigning rulers to the astrological houses. According to Morin’s theory of determinations, everything contained within the boundaries of a house is determined toward the significations of that house. The contents of a house can include zodiac signs and parts of signs, planets, planetary aspects and antiscions, fixed stars, and so on. The most powerful determination occurs at the cusp of the house, and the weakest determination belongs to the end of the house, near the cusp of the next house. Planets toward the end of a house conjoin the cusp of the next house and share in the determination of the next house.
Morin uses the Regiomontanus system of house division. It frequently happens that one sign is on the cusp of a house and part of the next sign lies within that house but occupies the cusp of the next house. In this case, the ruler of the sign on the cusp is the principal ruler of the house, but the ruler of the next sign functions as an additional ruler of the house that contains the initial part of the sign. Let’s look at an example.
In Book 15 he discusses the chart of Francisco Gomez Cortez, born in Olinda, Brazil, on 4 October 1627 at sunrise. The chart Morin presents has errors in calculation. He, or his assistant who calculated the chart, did not properly account for the southern latitude of Olinda, whose coordinates are 8.0134° South, 34.8544° West. Morin apparently calculated sunrise for the moment the center of the disc of the sun crossed the eastern horizon (not accounting for refraction). By modern calculations, this occurred at 5:46:24 AM LMT. (The upper disk of the sun crossed the horizon at about 8:43 AM LMT). Here is the chart, based on Morin’s data but more accurately calculated in Janus 6 software:
Morin notes that Libra rises, making Venus the ruler of the degree of the Ascendant. In turn, Venus lies in Virgo where she conjoins Mercury, the domicile ruler of Virgo. (Morin also regards Mercury, the dispositor of Asc-ruler Venus as the “secondary ruler of the Ascendant.”). Morin then attributes this native’s interest and skill in arithmetic, writing, painting, music, and dance to the Asc-ruler Venus conjunction to Mercury in Virgo, where Mercury has the dignity of rulership. A modern astrologer might view Neptune in the 1st in Libra as signifying an interest in music, creative writing, dance, and art. Also, Mercury (secondary ruler of the Ascendant) is stationing direct in 26 Virgo in partile semi-sextile to Neptune in 26 Libra, closely linking the native’s interests and motivation to Neptunian themes.
In addition, Cortez followed a military profession, was skilled in gladiatorial art, and once unintentionally killed someone in a quarrel that ended in a physical fight. Morin attributes these traits to pugnacious Mars being an additional ruler of the 1st house because a segment of the sign Scorpio, ruled by Mars, occupies the 1st house. In fact, about 14 degrees of Scorpio, almost half the sign, lie in the 1st house. Even though Scorpio rules the latter part of the 1st house, Mars closely trines the Asc-degree and the Sun on the Ascendant in the 1st, indicating that Mars has a powerful influence on the physical and mental makeup of this person. His military career is consistent with the 10th-ruler Moon sextile the Sun on the Ascendant and Mars, an additional ruler of the 1st house because of Scorpio in the 1st.
The influence of Mars trine the Sun on the Ascendant, says Morin, is also seen in the physical appearance of this native. He has reddish hair, freckled skin, and many yellowish marks on his face, hands, and body. In addition, Mars as a ruler of the Ascendant is strengthened in its martial nature by its conjunction in the 8th house with fixed star Aldebaran “the Eye of the Bull” at 4 Gemini 34′, a star of the nature of Mars which grants courage and military honors.
In summary, Morin views the 1st house as being ruled by Venus as ruler of Libra on the Ascendant, Mars as ruler of the portion of Scorpio contained within the 1st house, and Mercury as dispositor of Venus and “secondary ruler” of the Ascendant. Although he does not mention it, Venus and Mercury are also rulers of the 8th house, which contains Mars, perhaps indicating the potential for Cortez to unintentionally kill a man during a verbal altercation in which they came to blows.
Anthony Louis - Astrology & Tarot Blog 
thanks anthony… this is another wacky concept to go with all the other wacky concepts surrounding the topic of houses…
i’d like to elaborate on my previous comment… the fact is astrologers read a chart with bias and they are generally oblivious to the bias… there are different ways of emphasizing the astrological ingredients – signs, houses, planets and aspects.. in morins case, he emphasizes houses over aspects… i say this based on what i read in this post… he is trying to rationalize the role of mars via this house concept….
why not see how it is mars in aspect relationship to the sun and moon, as opposed to mercury and venus for example?? the reason – less emphasis on aspects and more emphasis on wacky house concepts..
venus-mercury conjunctions show up regularly in artists – composers of music in particular, but the combo here is not connected directly to either the sun or moon.. the inner planet mars on the other hand connects with the lights and the ascendant.. if one is given over to putting greater emphasis on houses and neglects the importance of aspects – they will perhaps come up with this crazy concept..
i continue to favour whole sign houses, as it maintains a greater emphasis on the sign relationships… incorporating the ascendant and midheaven into a house system has created a large number of different house systems.. in this chart it is not a problem as the signs maintain a 12 house relationship to the 12 sign positions.. i don’t read mars in the 8th here, and i don’t agree with the houses as boxes concept because it over rides the importance of the sign relationships..
OK, so I am sitting at my desk with The 144 Doors of the Zodiac the Dwad Technique by Thyra Escobar next to me. I just finished my Kabbalah class at the Chabad and thought I could not feel any more stupid then when that ended. But amazingly, never say never. There appears to be no bottom to how dumb I am. I read “144” end to end (short book) three times and understood NOTHING!!!!!!! Is there anything you can tell me about me (Oct 24th 1946 NYC NY 5.40pm) Dwadwise..I hate to have spent $15 on incomprehensible stuff. I am going to go back to reading Little LuLu comic books. XXX Jane