On Friday 21 February 2020 I had the great pleasure of chatting with Chris Brennan of The Astrology Podcast about a blog post I did regarding the switch from Regiomontanus to Placidus houses in England, starting at the end of the 17th century. This podcast is due to be published by the end of February.
One of the questions Chris raised, which I couldn’t answer off the top of my head, was whether Zadkiel in his 1852 abridged version of Lilly’s Christian Astrology had converted Lilly’s charts from Regiomontanus to Placidus. Having dug out my copy of Zadkiel’s book, I can now say that the answer is “no.” Zadkiel simply copied Lilly’s charts verbatim with their Regiomontanus cusps. As far as I have been able to discern, however, nowhere does Zadkiel explain that despite his advocacy of Placidus houses, he is presenting Lilly’s charts in Regiomontanus form.
Several factors make it clear that Zadkiel uses Placidus houses. First, he has eliminated Lilly’s tables of Regiomontanus houses from the beginning of the abridged version. Oddly, he has not provided any tables of houses but instead refers students to use a Table of Houses when casting charts without specifying a publisher or specific text. Perhaps there was a standard table of houses in use in England in the 1850s, so there may have been no need to be more specific. Historically the tables of houses published in the mid- to late 19th century in England were of Placidus houses. R.C. Smith (aka Raphael) published a popular astrological almanac with tables of Placidus houses in 1821, making the Placidus system widely available to the public from that date forward.
What makes it clear that Zadkiel is using Placidus houses is his example chart on page 20 in which he is showing students how to cast a horoscope. This chart is clearly cast with Placidus cusps.
On page 21 Zadkiel writes: “If the student look for 0 [degrees] Cancer on the 10th house [cusp] in the table of houses for London, he will find the longitude of the six eastern houses, as here noted …” In this horoscope the cusps are of Placidus houses, so Zadkiel is clearly using a Placidus table of hosues to construct his chart. Starting in the late 17th century under the influence of the prominent astrologer John Partridge, British astrologers began to reject the use of Regiomontanus houses and instead adopt Placidus houses as their standard of practice.
Nonetheless, when Zadkiel reproduces Lilly’s charts, he simply copies Lilly’s original cusps, which are Regiomontanus and he does not explain, as far as I have been able to find, that Lilly was using Regiomontanus. When I first read Zadkiel’s book back in the 1970s, I assumed that everything was done in Placidus houses. It was not until the Regulus edition appeared mid-80s that I realized Lilly was using Regiomontanus.
An online copy of Zadkiel’s abbreviated version of Lilly’s 1647 text can be found at this link: An Introduction to Astrology