Astro*Carto*Graphy has its roots in astronomical
diagrams used to show solar and lunar eclipse paths, and versions of these
which appeared in the 1930s and 1940s in
magazines. The astrological renditions of these maps would occasionally add other planets along with the eclipse paths, but did not, as a rule, show more than one or two bodies at a time. More recently, in 1957 Donald Bradley's "What's Ahead for the World" feature in the 1958 American Astrology Digest included hand-plotted maps showing the rising setting and culminating lines of all planets over the entire world at the time of the 1958 ingress of the Sun into Sidereal Capricorn. After that, on occasion Bradley would publish world maps with only one or two lines on them which he wished to emphasize, or detail maps showing planetary influences for a region in which a notable event had occurred.
In 1966, in his "Solunars" column, Cyril Fagan laid out a precise description of the purpose and method of the mathematical and interpretive techniques underlying Astro*Carto*Graphy, as he approached the problem of how a young woman of his acquaintance could improve her lot in life by relocating to a place where benefics rather than malefics were angular, as they were in her natal chart. Though he did not use a map per se, Fagan explained the method of constructing one using rise-set data from an astrological almanac. In that same year, a computer-drawn map generated by astrologer and programmer Gary Duncan was used for a mundane forecast in Llewellyn's Moon Sign Book.
Unaware of these predecessors and their work, Jim Slayden (Jim Lewis) came to astrology in the early 1970s, taking up work for American Astrology's Personal Service Department in 1971. Here, he became personally acquainted with Bradley and with the work of Fagan, who had died the previous year. Their emphasis on the importance of planetary angularity and on referring all
elements of the birth chart to the place of current residence later
led Slayden independently to the idea of plotting rising and setting lines for natal charts on a map of the world and applying them to natal work. Fagan and Bradley were, of course, proponents of the sidereal zodiac, so it's worth noting that Jim himself disagreed heartily with them on this point, despite his admiration for their work with the planets.
Exactly what we mean by "lines of rising and setting" can be seen in this illustration showing areas of daylight and dark across the globe as it would look on an early morning in fall for Central Time in the US. The leading edge of sunrise can be seen on the left of the curved line, while the place where the sun is setting can be seen on the right where the light area is divided from the dark. The line in the middle shows the place at which the sun is directly on the meridian at local noon, while a similar line on the opposite side of the globe would show the place where the sun was directly on the meridian at local midnight.
When we extend this mapping idea to the planets, we have the basic principle of the Astro*Carto*Graphy map - that at any time, including the time when a person is born, the sun and all other planets have lines representing rise, set,noon and midnight positions. The noon and midnight positions are more commonly called upper (noon) and lower (midnight) culmination.
Though the use of maps like these had been mentioned in connection with natal astrology before Jim Lewis's time, this writer has not found them actually used for that purpose until Jim began offering them to his clients in the early 1970s, actually drawing each one by hand, an arduous process which has since been replaced by detailed and precise computer rendering. He not only promoted these maps as useful for natal work in an age of instant communication and world travel, but also was the first to develop a complete system of interpretation. This is an important point, as Jim's approach is unique in taking into account the web of interactive relationships found in the whole birth chart when considering how the geographical factors shown by the planetary lines will actually work themselves out in practical terms.
An astrologer taking a look at a birth chart, first evaluates the relative strengths and weaknesses of each of the planets, based on sign and house position as well as aspects. Certain planets in and of themselves are "difficult" (particularly the two "malefics," Mars and Saturn) and may become quite problematic when poorly aspected or when poorly placed by sign. However, such naturally difficult planets can indicate areas of personal strength when they are well-placed and well-aspected. In contrast, certain planets such as the natural "benefics," Venus and Jupiter (and, according to to some, the Moon) tend to indicate areas of strength in a person's chart unless they are strongly aspected by malefics and poorly placed by sign.
A trained interpreter examining an Astro*Carto*Graphy map for a
client first considers
the relative strengths or weaknesses of the planets in the standard birth
chart. Jim Lewis said that several factors were important in doing this:
A planet which shows difficulty in relation to these factors, might be what Lewis called a "shadowed" planet, one representing some suppressed part of the psyche. The energies inherent in any birth planet can be enhanced or released through contact by transiting and progressed planets, contact by a planet in another person's chart, or via a planetary line of angularity as shown on an ACG map. In the latter case, this release can be powerful, and thus can be problematic if the planet in question is shadowed. When planets are well-placed and well-connected in the birth chart, on the other hand, the location of their various lines can be useful in determining the kind of direction one's life might take. This can be done through either moving to a location where one line or another (or combination of lines) is strong, or by enhancing one's contacts with people and businesses in certain locales. That ability to change one's life by changing one's location is the unique gift of Jim Lewis's Astro*Carto*Graphy.