Logarithms · Astrological definition of Logarithms · Astrology Encyclopedia  ·  February 24, 2018, 8:16 GMT

Right now: Moon at 18°46' Gemini, Sun at 5°40' Pisces

# Logarithms

## Logarithms - Astrology Encyclopedia

Definition of Logarithms Proportional parts of a quadrant, expressed in numbers, whereby calculations of the planets' places at a given hour, or the Arc of Direction for a given date, can be made by simple addition and subtraction rather than by multiplication or division. They were invented in 1614 by Baron Napier of Murchiston for use in his astrological calculations. Tables of Logarithms are in common use in all schools by students of trigonometry. Tables of natural, proportional and logistic logarithms are also available, each designed for different uses. An improvement in logarithms was introduced by Henry Briggs in 1624.

The astrologer uses Diurnal Proportionate Logarithms in making numerous calculations, but their average use is in calculating the planets' places for a given birth hour. If it is desired to reduce daily motion to hourly motion by the use of Logarithms, proceed as follows:

Subtract the positions of the desired planet on two successive days to determine its daily motion. Also compute the elapsed time between your birth moment adjusted to local mean time, and the previous noon or midnight - dependent on whether your ephemeris for that year gives noon or midnight positions.

Suppose you are seeking the Moon's position for an elapsed time of 7h 35m on a day in which its daily motion is 14° 27': In the tables, select the column with 14 at the top; run down the column to 27; and set it down; also for 35 in the 7 column; thus:

D.M............ 14º27' prop. log. .22034

Elap.T. ....... 7h35m prop. log. .50035

Looking for this in the tables you would (Apolo Note: there is a huge logarithm table in the original book which would take impossibly long to reproduce - sorry!) find .72061 at 34 in the 4 column: 4°34'. Add this to the Moon's longitude on the previous noon or midnight, and you have the position for the desired moment. In the case of a planet, note whether it is retrograde, in which event the distance of travel during the elapsed time is subtracted from the previous noon or midnight position.

Verify all Data. When adjusting the planets' places for a given birth moment, cultivate the habit of forming a mental approximation of the intermediate position for a given interval of elapsed time, before you verify it by a calculation. Comprehension of what you are doing is superior to the mere following of a formula. Also bear in mind that exact calculations to an approximate birth moment, or one that is not authentic and precise, is like holding a stop watch on a race when you do not know where the starting line is located. Whoever said "time is of the essence" should have been an astrologer. Is this date before standard time was used in that community? If so, what zone? Is that a Julian or a Gregorian date? Did they observe Daylight Saving Time at that season of the year? These are only a few of many questions that involve discrepancies amounting to hours - so what matter items which at most involve minutes, perhaps only seconds? Exact work is to be admired, but not in trying to make a silk purse out of a sow's car. Verify the authenticity of your data first. If you cannot do that, insert only even degrees, and interpret on the basis of Solar Houses.

(Nicholas deVore - Encyclopedia of Astrology)

The other dictionary entries:

A

Accidental Ascendant · Accidental Dignity · Acronycal · Acronycal place · Active Influence · Adept · Adjusted Calculation Date · Line of Advantage · Affinity · Afflicted · Astrological Ages · Air Signs · Albedo · Almanac · Almuten · Altitude · Ambient · Anahibazon · Anareta, anaretic · Anaretic Point. Anaretic Place · Androgyne, androgynous · Angels · Angle · Angstrom · Angular · Angular Velocity · Anomaly · Anipathies · Antipathy · Antiscion · Antisedentia · Aphelion · Apheta · Aphorism · Apogee · Apparent Motion · Application · Appulse · Apsis · Aquarius · Arabian Points, or Parts · Arc · Arc of Vision · Ares · Aries · Armillary Sphere · Ascendant · Ascending · Ascension · Ascension, Signs of Long · Ascension, Signs of Short · Ascensional Difference · Aspect · Aspectarian · Asterism · Asteroids · Astral Body · Astral Light · Astral projection · Astrolabe · Astrology · Astromancy · Astrometeorology · Astronomical unit · Astronomos · Astronomy · Astrotheology · Aten · Athazer · Aura · Aurora Borealis, Northern Lights · Inclination of Axis · Axial rotation · Azimene · Azimuth

B

Baal · Tower of Babel · Babylon · Babylonian · Barren Signs · Beholding Signs · Bel · Belts of Jupiter · Benefic Aspects · Besieged · Bestial signs · Bicorporeal · Bi-Quintile · Birth Moment · Birth Stones · Bitter Signs · Blend · Brahmanaspati · Broken Signs · Brutish signs · Buddha

C

Cabala, Cabalism · Cacodemon · Cadent · Caduceus · Calendar · Cancer · Cappella · Capricorn · Caput Draconis · Cardinal Signs · Casting the Horoscope · Cataclysmic Planet · Catahibazon · Cauda Draconis · Cazimi · Celestial Sphere · Ceres · Chaldaeans · Chaldaean Oracle · Changeable Signs · Character · Character of Planets · Characteristics of the Signs · Chart · Chronocrators · Chronos · Circle · Circles of Position · Cities, Sign Rulership · Clairaudience · Clairsentience · Climacterical Conjunction · Climacterical Periods · Climate · Cold planets · Cold Signs · Collection of light · Colors · Combust · Comets · List of Periodic Comets · Comet 1925a · Collision with Earth · Commanding Signs · Common Signs · Conception · Conceptive Signs · Configuration · Conjunction: Conjoined to · Conjunction, Superior and Inferior · Constellations · Contact · Contra antiscions · Converse Directions · Coordinate · Copernican System · Corona · Correction · Co-signficator · Cosmecology: the ecology of the cosmic · Cosmic · Cosmic Conditioning · Cosmic Cross · Cosmic Philosophy, or Cosmism · Cosmic Psychology · Cosmical · Councillor Gods · Countries · Crepuscule · Crescent · Critical Days · Critical Degrees · Crooked Signs · Crucial Degrees · Culminating · Culmination · Culminator · Cusp · Cycle · Cycles · Jupiter Cycle · Pluto Cycles · Neptune Cycle · Uranus Cycle · Saturn Cycles · Cycles - Tabulated data

D

Day · Day House · Day of Week, to determine · Daylight Saving Time · Day Triplicity · Debility · Decade · Decanate, Decan · Decatom · Decile · Declination · Decreasing or Increasing in Light · Decumbiture · Deductive Type · Deferent · Degree · Degree Rising · Individual Degrees · Individual Degree Tables · Aries Individual Degrees · Taurus Individual Degrees · Gemini Individual Degrees · Cancer Individual Degrees · Leo Individual Degrees · Virgo Individual Degrees · Libra Individual Degrees · Scorpio Individual Degrees · Sagittarius Individual Degrees · Capricorn Individual Degrees · Aquarius Individual Degrees · Pisces Individual Degrees · Delineation · Depression · Descendant · Descending · Destiny · Detriment · Dexter · Dhanus · Dichotome, or Dicotome · Dignities, Debilities · Dignities and Debilities · Dionysian Period · Directions. Progressions · Dispositor · Dissociate Signs · Distance · Diurnal · Dog Days · Dog Stars · Domal Dignity · Dominical Letter · Doryphory · Double-bodied or Bicorporeal Signs · Dragon's Head. Dragon's Tail · Dumb Signs · Duration of Life · Dwa-da-shamsa · Dysis

E

Eagle · Earth Shine · Earth Signs · East · Easter · Eccentric · Eclipse · Eclipse of Thales · Ecliptic; Via Solis, the Sun's path · Ego · Elections · Electric planets · Elements · Elevation · Elevation of the Pole · Elevation by Latitude · Eleveation by House Position · Elongation · Embolismic Month · Emerge · Emotional Natures · Enneatical · Epact · Ephemeral Map · Ephemeral Motion · Ephemeris · Epicycle · Epoch · Signs of Equal Power · Equation of Time · Equator · Equinox · Equinoctial Signs · Era · Eros · Erratics · Esoteric · Essential Dignities · Eudemon · Exaltation · Executive Type · Exoteric · Externalize · Extra-sensory Perceptions

F

Face · Fall · False Angle; False Arc · Familiarity · Fate · Feminine Signs · Feral · Figure · Fire Signs · First point · Fixed Signs · Fixed Stars · Flexed · Fortified · Fortitude · Fortuna · Fortunate Signs · Fortunes · Four-footed Signs · Fourth Dimension · Free-Will · Friendly planets · Fruitful Signs · Frustration · Gabriel · Galactic Center · Galactic Latitude · Galaxy · Notes of the Gamut · Gemini · Gems · Genethliacal Astrology · Genethlialogy · Geniture · Geoarc · Geoarc Figure · Geocentric · Astrological Geomancy · Gibbous · Giver of Life · Gnomes · Golden Number · Arc of Gradial Transit · Grand Cross · Grand Trine · Gregorian Calendar · Guarded

H

Hayz · Hearing · Heart of the Sun · Heliacal Rising · Heliacal Setting · Heliarc · Heliarc Figure · Heliocentric · Heliocentric Astrology · Heliocentric Longitude and Latitude · Helios · Hemisphere · Hermaphrodite · Hermes · Hermetic · Herschel · Hexagon · Hindu Astrology · Home, Day or Night · Homodromi · Honors · Horary Astrology · Horary Circles · Horary Time · Horimea · Horizon · Horizontal Aspects · Horizontal Parallel · Horoscope · Hour Angle · Hours · Houses · Meaning of Houses · First House · Second House · Third House · Fourth House · Fifth House · Sixth House · Seventh House · Eighth House · Ninth House · Tenth House · Eleventh House · Twelfth House · Houses, Reciprocal Action of Opposite · Solar Houses · House Ruler · Intercepted House · House: Diurnal, or day; Nocturnal, or Night · Tables of Houses · Human Signs · Hyleg · Hylegiacal Places · Hypogeon

I

Ides · Period of Illumination · Immersion · Impeded; Impedited · Imperfect Signs, Broken Signs · Imum Coeli · Inclination · Inconjunct · Increasing in Light · Increasing in Motion · Individual Houses · Inferior Planets · Infortunes · Ingress · Initiating Signs · Initiative Type · Injunct · Inspirational Natures · Intellectual Natures · Interlunar · Intercepted · Interpolation · Interpretation · Invariable Plane · Inversion · Ishtar · Isis and Osiris · Issat

J

Joined to · Joy · Julian Calendar · Julian Day

K

Kabala · Kakatyche · Karma · Katababazon · Kether · Key-Cycle · Kosmos · Krishna · Kronos

L

Labha bhava · Lagna · Lagna Sphutas · Latitude · Laya Centers · Leap Year · Leo · Life · Light · Collector of Light · Light of time · Light Planets · Light, Velocity of · Light-year · Lights · Lilith · Local Mean Time · Logarithms · Longitude · Lord · Lucifer · Luminaries · Lunar · Lunar Declination · Lunar Mansions · Lunar Month · Lunar semicircle · Lunar Year · Lunation · Embolismic Lunation · Periodical Lunation · Synodical Lunation

M

Magic · Magnetism · Magnitude · Major Planets · Malefic · Mansions of the Moon · Map · Marduk, or Asaru · Mark, Noon or Midnight · Martian · Masculine Degrees · Masculine planets · Masculine Signs · Maternal Signs · Matutine, Matutinal · Maya · Mean Motion · Mean Time · Measure of Time · Medical Astrology · Medium Coeli · Mediumship · Medusa's Head · Meridian · Meridian Distance · Meridional · Mesmerism · Metonic Cycle · Metonic Return · Micron · Midheaven · Midpoint · Milky Way · Minute · Moderators · Modus Rationalis · Moisture · Monad · Month · Month · Motion · Movable Signs · Mundane Aspects · Mundane Astrology · Mundane Directions, or Directions in Mundo · Mundane Parallel, or Parallel in Mundo · Music of the Spheres · Mutable Signs · Mute Signs · Mutilated Degrees · Mutual Application · Mutual Reception

N

Nadir · Naibod's Table of Times · Natal Astrology · Native · Nativity · Natural Day · Nebo · Temple of Nebuchadnezzar · Nebulae · Negative Sign · Neomenium · Neptune · New Year's Day · Night Houses · Ninib · Moon's Nodes · Nodes of the Planets · Nomes · North Point · Northern Signs · Nova

O

Obeying Signs · Oblique Ascendant · Oblique Ascension · Oblique Descension · Oblique Sphere · Occidental or Oriental · Occultation · Occursions · Occursor · Old Style · Opposition · Omniverse · Orbit · Orbital revolution · Oriental · Orbs · Orphic Mysteries · Ortive Difference

P

Pantheism · Pantheon · Parallel · Pars fortunae; Part of Fortune · Partile · Passive · Pavanna · Penumbral Eclipse · Peregrine · Perigee · Perihelion · Periodical Lunation · Phase · Phases · Phenomenon · Philosophy · Philosopher's Stone · Phoenon · Pisces · Classifications of Planets · Planetary Ages of Man · Planetary Anatomy · Planetary Angels · Planetary Colors · Planetary Days · Planetary Flavors · Planetary Forms · Planetary Hours · Planetary Jewels, or Precious Stones · Planetary Metals · Planetary Motions · Planetary Objects and Substances · Planetary Pathology, or physical ailments · Planetary Pattern · Planetary Periods, or Cycles · Planetary Physiology · Planetary Physiques · Planetary Psychology · Planetary Significators · Planetary Significators - Horary · Planetary Significators - Mundane · Planetary Spirits · Planetary Vegetation and Herbs · Planetary Vocations and Avocations · Planetary Years · Platic · Pluto · Point of Life · Point of Love · Polar Elevation · Polarity · Pole - of the Ascendant; of the Horoscope · Ponderous, or Ponderable planets · Posited · Positive sign · Practical Natures · Precession of Equinox and Pole · Precession of the Equinoxes · Predictions, in Mundane Astrology · Predictive Astrology · Prenatal Epoch · Prescience · Primary Directions · Prime Vertical · Primum Mobile · Principal Places · Process · Profections · Prognosis · Progressed Horoscope · Progressions · Progressions vs. Directions · Progressive Solar Revolution · Prohibition · Promittor · Proper Motion · Prophecy · Proportional Arcs · Prorogator · Psychography · Psychometry · Psychophobia · Ptolemaic Astrology · Pyrois

Q

R

Radical · Radical Position · Radix · Radix System · Rahu · Rapt Motion · Rapt Parallel · Under the Rays · Reception · Mutual Reception · Recessional Directions · Rectification · Recurrence Cycles · Refranation · Relative Houses · Retrograde · Retrograde Application · Revolution · Revolutionary Additives · Right Ascension · Right Distance · Right Sphere · Rising Sign · How to Approximate the Rising Time of a Planet · Rotation · Royal Stars · Ruler · Geographical Rulership · Ruminant Signs

S

Sagittarius · Saros · Saturn chasing the Moon · Saturnine · Saturnalia · Satellite · Satellitium · Scorpio · Secondary Progressions · Seer · Semi-Arc · Semi-Quintil · Semicircle · Semi-sextile · Semi-square · Significators of the Senses · Separating, separation · Sesqui-quadrate · Sesquiquintile · Seven · Sexagenary · Sextile · Sextiles · Sidereal Clock · Sidereal Day · Sidereal Time · Sidereal Year · Sign · Signs and the Disciples · The Symbology of Twelve Signs · Sign: Aries · Sign: Taurus · Sign: Gemini · Sign: Cancer · Sign: Leo · Sign: Virgo · Sign: Libra · Sign: Scorpio · Sign: Sagittarius · Sign: Capricorn · Sign: Aquarius · Sign: Pisces · Classifications of Signs · Sympathetic · Significator · Sinister · Slow of Course · Sol · Solar Astrology · Solar Cycle, or Cycle of the Sun · Solar Day · Solar Equilibrium · Solar Revolution · Solar Semicircle · Solar System · Solar System bodies: Sun · Solar System Bodies: Moon · Solar System Bodies: Mercury · Solar System bodies: Venus · Solar System Bodies: Earth · Solar System Bodies: Mars · Solar System Bodies: Asteroids · Solar System Bodies: Jupiter · Solar System bodies: Saturn · Solar System Bodies: Uranus · Solar System bodies: Neptune · Solar System bodies: Pluto · Solar Time · Solar Year · SOL-om-on · Solomon's Seal · Solomon's Temple · Solstices · South Latitudes · Southern Signs · Spectroscope · Speculum · Sphere · Sphinx · Square · Standard Time · Star of Bethlehem · Stars · Stationary · Stations · Stellium · Strength of a planet · Succedent Houses · Sunspot Cycle · Supercycle · Superior Planets · Synodical Lunation · Synthesis · Syzygy

T

Tables of Houses · T-cross · Taurus · Telepathy · Telescope · Temporal Houses · The Terminal Houses · Terms of the planets · Testimony · Tetrabiblios · Tetractys - ten symbolic dots · Tetragon · Thema Coeli · Throne · Time · Time. Correction of Mean to Sidereal Time · Transit · Transit of a planet across the Sun · Transitor · Translation of Light · Transmutation · Trigon · Trigonocrators · Trimorion · Trine · Trinities · Triplicities · Tropical Signs · Tropical Year · True Solar Day · Trutine · Twilight

U

Umbral Eclipse · Under the Sunbeams · Unfortunate Signs · Urania · Uranian · Uranian Astrology · Uranus

V

Vernal Equinox · Vertical · Vespertine · Via Combusta · Vibrations · Violent Signs · Virgo · Visibility · Vital Signs · Vocal Signs · Signs of Voice · Void of Course · Vulcan

W

War Time · Watchers of the Heavens · Water-bearer, Waterman · Water Signs · Wave Length · Weak Signs · Whole Signs

Y

Year

Z

Zodiac · Zodiacal Aspects · Zodiacal Directions · Zodiacal metals · Zodiacal Parallels · "Zodiacus Vitae." The Zodiac of Life. · Zero Hour Circles · Zenith

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