The Outlandish Companion - Diana Gabaldon [110]
First, the local birth time is expressed in GMT4 (not necessary for Jamie’s chart). This is then adjusted, including factors of longitude of the birthplace, to give a final sidereal or star time, which is expressed on a twenty-four-hour clock.
To get the correct placement of the zodiac signs around the chart, this sidereal time is looked up in a book of Tables of Houses. This gives the right degree of each sign to put on the cusp of each of the twelve segments around the chart, called houses. The degree, and sometimes the sign on each cusp, changes with latitude for the same sidereal time used. The tables are given in whole degrees of latitude, so you have to calculate the difference for the exact latitude with which you are working. You will see on Jamie’s chart that the third house contains all of the sign of Capricorn, and all of Cancer is within the ninth house. This is called interception, and happens in latitudes of more than 50 degrees, north or south.
Finally, the positions of the planets need to be calculated, and the planets put on the chart. The planets’ positions at midnight (or sometimes midday) for every day are given in a book called an ephemeris. To calculate the correct place for each one, the time of birth (GMT) is expressed as a fraction of twenty-four hours. You work out how far the planet moves in the twenty-four hour period, which includes the birth time, then multiply this answer by the fraction you obtained earlier.
For example, for someone born at 6:00 A.M.—this is .25 of the day. If the planet moves 1 degree in twenty-four hours, the movement at 6:00 A.M. is fifteen minutes. For people born a long way from Greenwich, the birth date used may actually be the day before or the day after the one given. Here in South Australia we are 9.5 hours ahead of Greenwich, so someone born at, say, 2:00 A.M. on October 9, would use a GMT time/date of 4:30 P.M. on October 8.
The erection of the chart is a mathematical exercise, but the reading of it relies on the interpretation of the astrologer. Each planet is associated with a variety of objects and principles, and each sign gives certain qualities to planets in that sign. The house is the area of the person’s life in which the planet operates. For example, Mercury represents (among other things) communication, senses, intellect, travel, writing, and speaking. Taurus qualities include being stubborn, patient, thorough, practical, and stable. So someone with Mercury in Taurus likes to have all the facts and think things over before making a decision (thorough and patient, thinking, stable—no quick decisions). This person learns better by doing than by hearing or reading (practical intellect), and rarely gives up on a project (stubborn). Their memory is good and these people are generally good at business and management (practical and thorough in communication).
Of course, the entire chart must be considered, so if there are several other factors indicating this person will be impulsive, the above will be tempered by this.
Finally, if Mercury is in the seventh house, which is the house of relationships, there will be good communication within marriage, and your partner will be an intellectual equal, witty, and talented. This position indicates good communication with the public, in areas such as counseling or law.
The other major consideration is the angle between the planets, called an aspect. The significant aspects are:
0 degrees—conjunction
60 degrees—sextile
90 degrees—square
120 degrees—trine
180 degrees—opposition
The angle doesn’t need to be exact. For all except the sextile, the usual orb, or amount of difference from the exact allowed, is 8 degrees; for the sextile it’s 4 degrees. These numbers are not absolute. Some astrologers use 10 degrees if the sun or moon is involved, others use 6 degrees for all aspects, but the ones I use are common.
The aspects are shown on the charts as follows.