Jean Baptiste Morin de Villefranche – in short Morin – lived from 1583 until 1656. He was one of the most influential astrologers ever, also because of the effective prognostications that have been attributed to him.
His lifework is the Astrologia Gallica, a voluminous series of 26 parts.
In book 17 Morin describes the houses and he holds a plea for the system of Regiomontanus. But he also concludes that the Regiomontanus system shows problems in polar regions and therefore he defines a variant on Regiomontanus. Doing so, he defines a new house system that later has been named after him.
Just like Regiomontanus he divides the equator in twelve equal parts. The horizon and the meridian already divide the equator in four equals parts. Therefore we can start our division from the horizon (eastpoint) or from the meridian (MC), the result is the same.
Morin constructs great circles through the twelve points on the equator. Regiomontanus does the same but Regiomontanus defines the circle so they run through the northpoint and southpoint on the horizon. Morinus choose to run these great circles through the poles of the ecliptic.
This has a peculiar effect: Morinus does not use any relation with the horizon. His system is independant of geographic latitude and is also not effected by the polar problem. It does not matter if you calculate for 0º or for 89º latitude: the result is the same.
(I hope to add soon an illustration for this system).
This also means the MC will almost never coincide with the cusp of the tenth house. The difference however is limited to a few degrees. But the ascendant almost always shows serious differences with cusp 1, even more if the location of birth is far away from the equator.
The system never became popular. Even Morinus himself did not use his own system but continued using Regiomontanus. Holden describes a book by Edward Lydoe who used the system. Some years ago several articles were published by Chris Stubbs who uses the Morin division also in combination with the results of Gauquelin. Stubbs also introduced a variant of Morin houses.
As far as I know this system has not be used any further.
The Stubbs variant
Christ Stubbs proposed in 1987 to use the cusps according to Morin as the midpoints of the houses. He actually created a new system that I describe separately as the Stubbs system.
We know Morin himself used the cusps as the beginning of each house as you can see in his own horoscope.
You can calculate the cusps for Morin houses with the following formula:
tan L = cos e * tan(ramc + ad)
ad means ascensional difference, if you add this to the right ascension of the MC you will get the oblique ascension.
The value for the ad is:
- cusp 10: 0
- cusp 11: 30
- cusp 12: 60
- cusp 1: 90
- cusp 2: 120
- cusp 3: 150
Often you need to correct the outcome for the correct quadrant. If the result of tan(ramc + ad) is between 0º and 90º, you do not apply a correction. If this value is between 90º and 270º, you need to add 180º to the resulting longitude. Between 270º and 360º you need to add 360º.
The location is again Enschede (52º 13′ N and 6º 54′ E). Date and time November 2, 2016 (Gregorian calendar), 21:17:30 UT. This results in a sidereal time of 0:35:23.6 (decimal 0.5899018653) and an angle E of 23° 26′ 13.56586091” (decimal 23.437101628).
MC: 9.62989868323 Converted to degrees and minutes: 9°37′48″ Aries
Asc: 123.507983345667 = 3°30’28” Leo
cos e = cos 23.437101628 = 0.9174972619 ramc = sideral time * 15 = 8.8485279795
tan L = cos e * tan(ramc + ad) this results in tan L = 0.9174972619 * tan(8.8485279795 + 0) tan L = 0.9174972619 * 0.1556755643 = 0.1428319040 L = 8.1286851908 8º 7' 43" Aries
tan L = cos e * tan(ramc + ad) this results in tan L = 0.9174972619 * tan(8.8485279795 + 30) tan L = 0.9174972619 * 0.8054160913 = 0.7389670585 L = 36.4631803133 6º 27' 47" Taurus
tan L = cos e * tan(ramc + ad) this results in tan L = 0.9174972619 * tan(8.8485279795 + 60) tan L = 0.9174972619 * 2.5846447895 = 2.3714045174 L = 67.1352838053 7º 8' 7" Gemini
tan L = cos e * tan(ramc + ad) this results in tan L = 0.9174972619 * tan(8.8485279795 + 90) tan L = 0.9174972619 * -6.4236157080 = -5.8936498236 L = -80.3701013160 + 180 (çorrection for quadrant) = 99.629898684 9º 37' 48" Cancer
tan L = cos e * tan(ramc + ad) this results in tan L = 0.9174972619 * tan(8.8485279795 + 120) tan L = 0.9174972619 * -1.2415942652 = -1.1391593387 L = -48.7220340324 + 180 (çorrection for quadrant) = 131.2779659676 11º 16' 41" Leo
tan L = cos e * tan(ramc + ad) this results in tan L = 0.9174972619 * tan(8.8485279795 + 150) tan L = 0.9174972619 * -0.3869003602 = -0.3549800211 L = -19.5438457294 + 180 (çorrection for quadrant) = 160.4561542706 10 gr 27' 22" Virgo
- Callanan, Thomas – The Astrology of Jean Baptiste Morin, http://www.skyscript.co.uk/morin.html
- Holden, Ralph William – The elements of house division. Romford, 1977.
- Morin, Jean-Baptiste. Vert. James Herschel Holden – Astrologia Gallica. Book 17: The Astrological Houses. Tempe, AZ, 2008.
- Munkasey, Michael – The Astrological thesaurus, p. 424. Book 1. St. Paul, 1993.
- Spat, Werner – Das “Ideale” Häusersystem. In Meridian jg. 1994, nr. 4. Juli/aug. 1994 (german).
- Stubbs, C. – Heaven’s Message (Letter to the editor). Astrological Journal Vol. 29 Nr. 6. November/December, 1987.
- Stubbs, Chris – Het Mars-effect en het sectorsysteem van Morinus. Urania vol. 97 nr. 4. Oktober 2003. Online http://wva-astrologie.nl/images/pdf/ura974.pdf (dutch).
- Stubbs, Chris – Nogmaals het Morinus sectorensysteem. Urania vol. 100 nr. 1. April 2006. Online: http://wva-astrologie.nl/images/pdf/ura100-1.pdf (dutch).
- Wharton, George – The Cabal of the twelve Houses Astrological from Morinus. Translation of a part of the Astrologia Gallica, book 17. Published by John Gadbury in 1659.