It is an astrological technique that shows on a world map where each body of your natal chart stood at an angle (rising, setting, overhead or at the lowest point) at the moment you were born. It was developed by astrologers between about 1930 and 1960 and popularized by Jim Lewis in the 1970s and 1980s. Each body gives four lines, so the Sun to Pluto plus the North Node make 44 lines.