Astrology has been part of world culture for thousands of years. Jyotish, the astrology of ancient India, continues in an unbroken succession of teachers to this day. The legacy of the Chaldeans, the astrologers of Mesopotamia is recorded on clay tablets. The Ancient Egyptians set their agricultural calendar to ten star day periods in which one bright star held sway. Sothis, the the ten day period or decan in which the star Sirius in the constellation of the Great Dog rose before the Sun, marked the time of the flooding of the Nile. The decanal belt of 36 stars lies south of the ecliptic, the apparent path of the Sun.