"...it was not until his thirtieth year, in 1890, when the progressed Jupiter arrived at the place of the radical Sun, that the effect of the radical Asc. conjunct Saturn was removed and a period of prosperity commenced, for in that year the Astrologer's Magazine (now Modern Astrology) was commenced, and all other pursuits were put on one side in order to take up the study of Astrology as a life work. Thenceforward all other progressed positions, no matter how severe or evil, must be moderated by this benefic progress of Jupiter over the Sun, trine Moon; for to considerably accentuate this benefic influence, Jupiter at the same time by progression reaches the parallel of the Sun at birth, a position which will remain in force for a great many years." (Progressed Horoscope, pgs. 228-9)
Among other duties, Alan Leo and his associates had a lively mail-order chart business, and wrote and published many books and articles. He died in 1917. Of his seven major books, Charles Carter famously said, "They were not well put together but one could find a very great deal of information in them if one knew where to look."
This is one of the best books on progressions ever written. Look carefully and you will find a great many things in it.