The Midheaven is often called the “M.C.” (Medium Coeli), and the opposite point is called the “I.C.” (Imaum Coeli). They are the points of the Ecliptic which cut through the meridian of a place at any given time. CHAPTER IV PLANETARY TRANSITS In order that prognostications made from the horoscope of birth may be pointed as to time it is necessary to know the positions of the planets for several years in advance. Such calculations are easily effected by a knowledge of the periods of the planets--that is to say, the times in which they return to the same positions about the same time of the year. Thus Uranus returns to its place after a period of 84 years, Saturn does so after 59 years, Jupiter in 83 years, Mars in 79 years, in all cases almost to the day. Mercury also returns in 79 years. But as very few people possess records of the planets’ places for these long periods, the following table of the longitudes of the planets for the next 12 years has been prepared. The positions are given for the 1st of each month, and the longitudes held by the planets are given in even degrees. These tables are very useful in tracing the transits that occur in connection with the horoscope for the year. Thus we have found that by adding the number of degrees corresponding to the age of a person to the Midheaven at birth, we obtain the Progressed Midheaven, and in the Tables of Houses we may also find the corresponding Progressed Ascendant. By adding the same number of degrees to the place of the Sun at birth we obtain also the Progressed position of the Sun.