General Rules, Abbreviations, Tools Needed and "Do you have a computer?"
As we have stressed throughout Volume I of The Only Way to Learn Astrology, our books are not the run-of-the-mill astrology books. They are textbooks or manuals taken from our years of classroom experience. Therefore, our approach to teaching you the mathematics of erecting a horoscope is based on what worked best for our students. There are some basic rules that must be understood, and there are also some tools you will need.
But before we even get to rules or tools: "Do you have a computer?" A large percentage of budding astrologers are computer savvy and will relish that they do not have to worry about any kind of mathematical calculations. All you need is a good astrological program, push a few buttons and voilà the chart is completed! But voilà, you could have made a mistake and you'll never know that you did! Also, most of the astrological certificates of competence or astrological exams still expect full knowledge of chart calculation. So, please read this first part of the book, try to understand what makes the world go round, familiarize yourself with some of the technical terms, and realize that some of the tools are needed even if you work with computers.
Please Read Whether You Use a Computer or Not! Rule Number 1 — Accurate Birthtime:
In order to erect an accurate natal horoscope, you need the correct time of birth. The most valid source for birth time information is a certified copy of your Birth Certificate on file with the State Board of Health in the state of your birth. In most Western countries (the Americas, Europe, Australia) documents like birth certificates can be obtained in City Halls, Bureaus of Vital Statistics or Boards of Health, in the capital city of the state or country where you were born. Ask for the Birth Registration with the time listed. In the U.S. it is called "the long form."
If this document fails to indicate the birth time (which can happen), then you will have to turn to some other source for this data, a baby book, a birth announcement, the family Bible, or mother's medical records in the hospital of birth. The personal recollection of family members like "mother thinks it was about six in the morning" is not good enough. For even though your mother was certainly there, she was concerned with more pressing matters than watching the clock, and memories of birth dim with passing time. Base your source for the birth time upon a written record, whenever possible, even when a search requires persistence, diligence, and time, or you may later discover that your mathematical efforts in calculating a horoscope have been for naught. If you are dealing with clients, and after such a search you are still unable to determine an accurate time of birth, explain to the person that you cannot guarantee an accurate interpretation. This will save you embarrassment.
There is an astrological axiom worth remembering: "The accuracy of your interpretation can be no greater than the accuracy of the birth time, date, latitude and longitude used to erect the horoscope." Because of the speed of the Earth's rotation, a new degree of the zodiac crosses over the Midheaven every four minutes. So use every means at your disposal to get the most accurate birth data possible.
Rule Number 2 — Check and Recheck:
Even to the most experienced professional astrologer it is important that all mathematical calculations used in erecting the horoscope be preserved, for a variety of reasons. We highly recommend that as you calculate new horoscopes, you do the math on the blank side of the chart form you use. Check and recheck your calculations for possible errors. (This also becomes an important instruction when entering data on the computer: check and recheck your entries!)
Rule Number 3 — Mathematical Equivalents:
Familiarize, or better yet, memorize the following:
60'(minutes) of longitude = 1° (degree) of longitude
1° (degree) of Earthly longitude = 4'(minutes) of time
15° (degrees) of Earthly longitude = lh (hour) of time (4x15=60')
30° of zodiacal longitude = 1 sign (in the zodiac)
12 signs = 360° or the entire zodiac
Most of this world, except the United States, works and lives with the 24-hour clock. That means there is no 2:00 AM versus 2:00 PM to get confused with. In fact to avoid any such mix-ups or confusion, the military long ago switched to the 24-hour clock. At least the entire unit knows that 14:00 o'clock means it's 2:00 PM and the right time to attack.
In other words, the 24-hour clock simply goes from 0:00 o'clock until 24:00 o'clock. 6:00 o'clock means 6:00 in the morning, no question there, and 18:00 o'clock means 6:00 in the evening.
For ease of calculation and to circumvent unnecessary mistakes, we are using the 24-hour clock.
Rule Number 5 — Basic Tools Needed to Erect and Understand a Horoscope:
1. Ephemeris (pronounced ef-EM-er-is). This is the basic reference book that provides the daily position of each planet for midnight (the beginning of the day) calculated for Greenwich, England, which is located at 0° longitude. An ephemeris is probably an astrologer's most important tool, a "must own" regardless if you do your math by hand or by computer. Ephemerides can be purchased for one year, ten-year, 50-year or hundred-year intervals. For accuracy, our favorite ephemerides are The American Ephemerides published by ACS Publications. In the past these books were available for either Noon or Midnight; but since much of the world, except the United States, has adopted the 24-hour clock and the day starts at midnight, midnight is used by almost everyone nowadays.
2. Atlas. In order to find the longitude and latitude of any given birthplace, you need an atlas. Many computer programs store thousands of well known cities in their memory, but you will still need to find the less known towns in the world. A good atlas will tell you what time zone applies to a particular area, as well as when that time zone became effective. Just as important, an atlas shows you when daylight (aka summer time) and wartime apply. We use
The American Atlas: US Latitudes and Longitudes, Time Changes and Time Zones as well as The International Atlas: World Latitudes, Longitudes and Time Changes, both published by ACS Publications.
2 a) International Atlas: There's another big difference between the United States and the rest of the world — and in order to use the atlases well, you need to understand this. When we say October 15, 1967 we express it as 10/15/1967 or first the month, then the day and then the year.
The rest of the world expresses first the date, then the month and then the year, not only verbally but also in writing. It then reads: 15/10/1967. This is not so troublesome when we are talking of dates more than 12, such as the 15th of October, since there is no month that could be 15 and therefore we get alerted. But if the date is October 4, 1967 or in the United States 10/4/1967, an international atlas would express it as 4/10/1967.
The ACS International Atlas (in their 1995 revised edition) has solved the problem by spelling out the month: 4 Oct 1967. But older versions, as well as other world atlases will be written as 4/10/1967. So check carefully; this is a very important fact that all United States schooled people have to remember — especially when finding periods of daylight savings or war times in foreign countries.
3. Book of House Tables. (This tool is only needed for those who do their math by hand.) There are many different types of house systems — all valid and each having its own supporters. We recommend the Koch system; it follows the Placidus principle, but bases the intermediate house cusps on geographical location.
4: Calculators. For those of you who do not use computers, it is permissible to bring a calculator along when taking any astrological exams. The math is easier to calculate and you can be more exact if you use a calculator.
Rule Number 6: Understanding Longitude and Latitude
Geographically, the Earth is divided by two imaginary sets of circles. One set of circles uses the Equator as a reference point running from east to west, and is used to measure distance north or south of the Equator. This is called latitude.
Turn to the map on page 6 and note that there are numbers given in the right-hand borders of the map. These latitude measurements are commonly referred to as parallels. Locate the 40th parallel as it extends across the map. Note that Denver, Colorado is located close to this line. Therefore, we would describe Denver as being at a latitude of about 40° north of the Equator. Beijing, China is also located on this line, so is Madrid, Spain. In other words, these cities are more or less on the same latitude as is Denver, Colorado.
Since all these places have approximately the same latitude, we must find another way to locate them so as to differentiate one city from the other.
We stated earlier that the Earth is divided by two sets of circles. The second set of imaginary circles divides the Earth longitudinally from pole to pole — these are the meridians of longitude. All places on the same longitude line have noon at the same instant, no matter how far north or south of the Equator they are.
If you look at the map on page 6 you will see numbered lines running from top to bottom. These are the lines of longitude, and the one numbered 0° is the Prime Meridian at Greenwich, England. All places in the world are considered to be east or west of Greenwich, or the 0° (Prime) Meridian.
So, by longitude we designate a geographic location as being east or west of Greenwich, and by latitude we designate a location north or south of the Equator.
When you say that some place is at such and such longitude and latitude, it indicates a certain place beyond all possibility of confusion. Thus, Denver's latitude is 39°N45' (or nearly 40° as previously stated), the longitude is 104°W59' (W = west). Beijing, China is located at 39°N55' (N = north) 116°E25' (E = east); Madrid, Spain is at 40°N24' and 3°W41'. Even though they all are near the same degree of latitude, the longitude distinguishes and locates them as being in entirely different places on the Earth's surface.
Rule Number 7: Some Notes on Time
Time on Earth is based upon the motion of the Earth around the Sun. As earthlings, we like a certain order in our lives and want to know what day it is, what time, what year, and so on. In order to do this, we have to go against the true laws of nature, since the Earth does not move at a constant speed. So, the day does not have exactly 24 hours, and at the end of every four years we have to add an extra day (leap year) to compensate for our irregular motion. This same principle of being practical applies to the time zones or meridians established on Earth.
The Sun in relationship to the Earth appears to move 60 miles every four minutes. 60 miles equals 1° on the map. Therefore, the Sun's motion is 2° in eight minutes; 5° in 20 minutes; and 15° in 60 minutes (or one hour). For every 15° the Sun is one hour away from the 0° Prime Meridian at Greenwich. Since the Sun rises in the east and sets in the west, if it is noon at Greenwich and we go 30° to the East, it will be 2:00 PM; the Sun has already been there and gone. On the other hand, if we go 60° west of Greenwich, we know that it must be four hours earlier (60 -f 15 = 4). The Sun going from east to west
has not yet reached this point; therefore, 12 noon at 0° Prime Meridian will be 8:00 AM at 60° west. Yet please understand, when you pick up the phone in Los Angeles and talk to your friend in Switzerland, it is the same moment in time for each of you, but since you are in different locations, the time on the clock differs. Los Angeles at 9:00 o'clock in the morning, will be 18:00 o'clock (or 6:00 pm) in Switzerland.
Rule Number 8: Meridians:
To simplify matters, most meridians are established at intervals of 15° longitude, or one additional hour for each meridian. There are many meridians, starting in Greenwich at 0° (the Prime Meridian), then moving east every 15° to 180° east (which happens to be NZT or New Zealand Standard Time) Going west from Greenwich, we arrive at 180° west. (See a complete list of standard time zones, courtesy Lois Rodden in the appendix, page 270.)
For the United States, you will meet some very familiar meridians or time zones. Such as EST or Eastern Standard Time at 75°W 00' or PST identifying the Pacific Standard Time meridian at 120°W 00'. Actually the United States encompasses 8 time zones (Atlantic Standard Time at 60° West to the Nome-Bering Standard Time at 165° West). But most of the continental U.S. falls into four time zones, between 65° and 125° west longitude. (See the map on page 6.) New York City is located at 73°W57' (° = degree,1 = minute) and thus falls in the 75°W meridian, or 5 hours earlier (west) than Greenwich. In fact, the entire state of New York uses the 75° west longitude meridian line; thus, if it's midnight in Greenwich, it is 19:00 or 7:00 PM clock time (of the previous day) in all of New York State. This is called 7:00 PM EST (Eastern Standard Time).
Rule Number 9: Daylight Savings Time:
There is another time problem that needs your careful attention: daylight savings time (also called war time in times of war). This is an artificial arrangement which needs to be accounted for in chart calculation. The atlases we use are extremely helpful in finding out what areas were on war time or daylight savings time and when.
In the U.S. until 1971, each state and county did pretty much as they pleased about this. A federal law was finally adopted to avoid confusion and nearly the entire country now starts DST on the first Sunday in April and goes back to regular ST on the last Sunday in October. But since we are a free and democratic nation, the "entire country excludes the state of Arizona which never adopts daylight savings.
Europe has as many (or more) anomalies; the other continents also have many past and present contradictions. From February 9, 1942 until September 30, 1945, the entire U.S. and Europe observed war time. In Europe, most countries now observe DST, but some were quite late in adopting this; Switzerland, for example, only started in 1981. In 1974 there was an energy crisis and the entire U.S., except for Arizona, Idaho, and Oregon, went on daylight savings time on January 6 until October 27. In Illinois and Pennsylvania, the clocks are set to DST, but not in the hospitals. Until 1959 Illinois continued to use standard time when recording on birth certificates.
As you can see, unless you refer to some atlas with longitudes, latitudes and time changes, this can be a very complex situation. Astrological atlases can be bought in most bookstores, you can order them from ACS, or consult your library or some other official source for accurate information.
Remember: With daylight savings time as well as war time, the clock is set one hour ahead, so you must subtract one hour from the given birth time before you start your calculations
Rule Number 10: Sidereal Time (or Star Time)
You will encounter this time term many times in astrology. It is related to the motion of the zodiac — starting at the 0 point of Aries — as Local Mean Time is related to the Sun's motion. (Local Mean Time was used before the time zones were universally adopted in the late 1800's in the United States. Local Mean Time is roughly equivalent to what we would read on a sundial.) Since 0 Aries rises and sets faster than the Sun, sidereal time is faster than, or ahead of solar time. Remember: solar (or sun time) is the basis of our clocks on Earth. Most ephemerides list sidereal times for each day, so you will not have to do your own calculating. However, we want you to understand this term when you see it.
Sidereal time, as given in the ephemeris, is the point of the zodiac overhead at midnight expressed in hours, minutes and seconds rather than signs, degrees, minutes and seconds. Each sign of the zodiac is measured by two hours of sidereal time, starting with 0 Aries. Thus all 12 signs will be accounted for in a 24-hour day. If the sidereal time says 2 h (hours) 0 m (minutes) 0 s (seconds) it really says that Taurus is now overhead. A sidereal time of 6h 0m 0s equates to Cancer overhead. Ephemerides list sidereal times for each day, so you will not have to do your own calculating. However, we want you to understand the principle here.
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