TIME AND PLACE 17
you will find London, and close thereto a place called Greenwich. That is the location of the world’s greatest observatory, and for purposes of astronomical calculation all places on earth are considered as being so and so many degrees west or east of Greenwich.
Thus, by latitude we obtain the location of a certain place north or south of the Equator.
By longitude we designate its position east or west of Greenwich.
When the location of a place is stated in terms of latitude and longitude it marks a certain spot beyond all possibility of confusion with any other place, and gives the astrologer one of the primal factors necessary to calculate a scientific horoscope—place.
Latitude is the principal factor in locating the signs of the zodiac by means of “Tables of Houses,” which apply to all places in a certain degree of latitude. These tables are as nearly unchangeable as the fixed stars to which they apply; they remain the same from year to year, at least the change is so small as to be unappreciable in a lifetime.
Longitude is the prime factor in all calculations connected with the movable planets. To calculate their places at the time of a person’s birth it is necessary to have an astronomical almanac for the year of birth. This is called an ephemeris because it records the ephemeral or momentary position of the planets as seen from the observatory at Greenwich each day at noon.
