Midpoint dial

Meaning

A midpoint dial is a way of drawing a chart so that selected aspects become conjunctions. The most used is the 90° dial: the zodiac is cut into four quarters of 90° each and the quarters are laid on top of one another. Each planet's place on the dial is its longitude modulo 90, that is, what is left after taking away whole multiples of 90°.

• 0° Aries, 0° Cancer, 0° Libra and 0° Capricorn all go to 0° on the dial.
• A planet at 15° Taurus (longitude 45°) goes to 45°; one at 15° Scorpio (225°) goes to 45° as well.
• The first 30° of the dial hold the cardinal signs, the next 30° the fixed signs, the last 30° the mutable signs: 0° of any cardinal sign is 0 on the dial, 0° of any fixed sign is 30, and 0° of any mutable sign is 60. Ebertin prints this as a conversion table (p. 11) [5].

The 90° arc is then drawn round a full circle, so every dial degree takes up four degrees of the drawing.

Why the hard aspects line up. Two planets in conjunction, square or opposition differ by 0°, 90° or 180°, all multiples of 90°, so after folding they stand on the same dial degree. The semi-square (45°) and sesquiquadrate (135°) put them exactly across the drawn circle from each other (p. 3) [5]. The whole family of "hard" aspects in 45° steps can therefore be seen along one line through the centre.

Other dials. The same folding works with other arcs:

A smaller dial finds more contacts, but also more chance ones. The 90° dial is the working standard in cosmobiology. Ebertin found the 45° circle less satisfactory for reading a chart, because it leads on to 22.5° angles that he did not regard as confirmed, but useful for graphic ephemerides (pp. 8–10) [5]. Witte himself worked with a 360° dial; Uranian astrologers use it alongside the 90° dial [4].

Origin and history

The Hamburg School used movable dials as calculating aids for planetary pictures. Alfred Witte developed a rotating 360° dial. Ebertin describes it as a degree disc about 15 cm across, pinned at the centre over a sheet on which the factors were marked round a circle, with 0° Cancer as the zero, and used to measure distances and midpoints; its drawbacks were that turning it lost the link with the zodiac and that the degrees were too close together to set accurately (pp. 7–8) [5].

The sources differ on who first folded the circle. Witte-Verlag, Ludwig Rudolph's Hamburg publishing house for the school (founded 1927), took over the distribution of Witte's degree dial (Gradscheibe), nomogram and tables, and says that in 1931 Rudolph introduced 90° and 45° dials, which fold the zodiac so that the hard aspects can be read more easily [4]. Ebertin's account credits the idea to Witte himself: because Witte stressed the angles made by halving the circle again and again (180°, 90°, 45°), he thought of a 90° disc, and he also devised a 45° circle (p. 8) [5].

Reinhold Ebertin made the 90° dial central to his method; he calls it the most important aid for cosmobiological work (p. 1) [5]. He described it in Das 90°-Arbeitsgerät in der Praxis ("the 90° working device in practice"), published by his own house in Aalen as the first of his Kosmobiologische Studien. By Ebertin's account the German book appeared several times from 1949 onwards, each time improved and enlarged (p. v) [5]; its second edition is dated 1954 [2]. The English Applied Cosmobiology (1972) is its fourth revised and enlarged edition, expanded into a general textbook (title page; p. v) [5]. When Applied Cosmobiology appeared, the dial came in three forms: a metal drawing board with a transparent calculating disc and small magnets for the factors, a cardboard version, and a pocket version in a wallet (p. 1) [5].

In cosmobiology the chart drawn for this kind of work is called a cosmogram (Kosmogramm); Ebertin uses the word throughout Applied Cosmobiology [5] and in the title of his The Contact Cosmogram (Ebertin-Verlag, 1974). His chart forms print the ordinary 360° circle inside and the 90° circle outside, always with 0° Cancer at the top rather than the Ascendant on the left, so that charts can be compared and transits entered in the same place (pp. 13–16) [5].

Ebertin also applied the folding to time. In the 45° graphic ephemeris the positions of the planets over a year or more are plotted modulo 45° as lines across a graph, and the natal positions are drawn as horizontal lines. Wherever a moving planet's line crosses a natal line, the two are in one of the five hard aspects: conjunction, semi-square, square, sesquiquadrate or opposition [3]. Ebertin's firm published these graphic 45° ephemerides from 1948 (p. 202) [5].

How it is used

• Setting up. The planets and angles are marked on the dial at their folded positions.
• The pointer. A pointer turning on the centre is set on one factor. Any pair of factors standing at equal distances on either side of it has its midpoint at (or on the axis of) the pointer. This is how pictures are read off without calculation. On Ebertin's calculating disc the pointer is an arrow, and an inner scale runs from 0° to 45° in both directions from it, so that equal distances can be read at once (pp. 11, 23) [5]. The pictures found are then looked up in his Combination of Stellar Influences [1] [5].
• Orb on the dial. Ebertin allows 1½° for a midpoint; when in doubt the arrow may be moved up to 1½° either side, but no further (pp. 23, 27) [5]. See orb.
• Both ends of the line. Because folding throws away the whole quarters, a pair balanced about the far end of the pointer's line can also belong to the planet under the pointer, and a pair balanced about the near end can turn out to be a 45° contact. Working by hand, practitioners check both ends; calculating the actual midpoint settles it. As Ebertin notes, the two midpoints of a pair always lie at the two ends of one diameter (p. 26) [5].
• Transits and directions. Moving the pointer to a transiting or directed position shows at once which natal points and midpoints it reaches. For solar arc directions Ebertin puts a second copy of the chart on a larger disc underneath and turns its 0° Aries mark forward by the arc for the year in question, so that every directed factor can be compared with the natal ones at once (p. 38) [5].
• The Aries Point. 0° on the dial stands for the beginning of all four cardinal signs; see Aries Point.

On this site. The Midpoints panel folds each longitude onto the chosen dial as longitude mod dial: 90° by default, with 45°, 22.5° and 360° as options. The pointer is drawn as a full line through the centre and can be dragged round the dial, stepped with the keyboard, or set by clicking a point. A shaded wedge shows the orb either side of it. Lines join each pair whose midpoint (the shorter-arc midpoint, folded) lies under the pointer within the orb; the two planets of such a pair sit either side of the line, like a mirror image. The planets and midpoints under the pointer are listed, and distances on the dial are the orbs shown in the lists.

Examples

Albert Einstein (14 March 1879, 11:30 local mean time, Ulm). Folded onto the 90° dial, the planets fall at: Mercury 3°09′, Saturn 4°11′, Venus 16°59′, Mars 26°55′ (cardinal third); Neptune 37°52′, Pluto 54°44′, Jupiter 57°29′ (fixed third); Uranus 61°17′, Moon 74°32′, Sun 83°30′ (mutable third).

• Hard aspects together. Mercury (3°09′ Aries) and Saturn (4°11′ Aries) are conjunct in the zodiac and a degree apart on the dial.
• A pair balanced about the pointer. Set the pointer on Pluto at 54°44′. The Sun is 28°47′ one side of it and Mars 27°49′ the other: the Sun/Mars midpoint (25°13′ Aquarius, dial 55°13′) is 0°29′ from Pluto, Pluto = Sun/Mars.
• The far end. Set the pointer on Saturn at 4°11′. Uranus (61°17′) and Neptune (37°52′) balance around 49°35′, the far end of the line. Their true shorter-arc midpoint is 4°35′ Cancer, dial 4°35′, 0°23′ from Saturn: Saturn = Uranus/Neptune, a square in the zodiac.

See also

Midpoint sort lists the midpoints in dial order, which is the same information as the dial in table form.