Tag: Astrology

Tannstetter’s Wall Calendar for 1513

The top and bottom sections of Georg Tannstetter’s astrological wall calendar for 1513. This calendar, like thousands other like it, has suffered through the centuries. The middle portion of the calendar has been lost. BSB Einbl. Kal. 1513a.

From about 1505 until the late 1520s Georg Tannstetter produced astrological wall calendars like this one, often in both Latin and German. Most of his calendars were calculated for Vienna, where he was a master at the university at first in the liberal arts faculty and later in the medical faculty. His name and reputation was also attached to a few calendars printed for more distant cities. These calendars offered a range of astrologically useful information, e.g., the place of the moon for every day of the year, phases of the moon (new, first quarter, full, last quarter), good and mediocre times to let blood, when to take medicines, to bathe, to wean children, and when to plant or sow seeds. A handy legend graced the top of most calendars, explaining the common system of symbols used to denote these various activities.

Detail of the top woodcut showing the Nativity scene on the left and the scene of the magi on the right.

The calendars were always adorned with woodcuts across the top and down the sides. In some cases, such as Tannstetter’s wall calendar for 1517, the woodcuts were related to the heavens. On most calendars, however, these woodcuts seemed merely decoration and were almost certainly recycled by the printer. On this calendar for 1513, the woodcuts across the top show the Nativity (including the Star of Bethlehem) and the magi. A common exception to this practice was the woodcut at the bottom of the calendar that usually depicted the rulers of the year and any eclipse that might occur that year.

Detail of the astrological woodcut at the bottom of the calendar. In this case, Mars and Venus are rulers of the year, and there is lunar eclipse in Pisces.

This woodcut not only conveyed relevant information about the coming year, so recycling them would be difficult, it also linked visually the calendar to the printed judicia or annual prognostication for that year.[1] Like other authors of calendars, Tannstetter also composed each year a new judicia in which he forecast what would likely happen in the coming year, including the likelihood of war, famine, or plague, the fortunes and setbacks for various people—e.g., farmers, university masters, clergy, merchants, aristocrats—kingdoms, and rulers. He also offered weather predictions for the coming year, sometimes up to three days on either side of each quarter moon. As with the wall calendars, these annual prognostications were often published in both Latin and German. The title-page woodcut on these judicia were often the same one found at the bottom of the calendar.

The title-page woodcut from Tannstetter’s Judicium Astronomicum for 1513 is the same one found on the bottom of his calendar for that year. BSB Res/4 Astr.p.510,25.

Both the wall calendars and the annual prognostications were hugely popular in the early 16th century. Unfortunately, ephemeral printings were not valued enough to be saved in large numbers. In the case of wall calendars, their large format made them difficult to save, so even fewer survive.


  1. Sometimes the woodcut at the bottom of the calendar was the generic zodiacal man.  ↩

Astrologer Ralph Kraum’s Copy of the Tuckerman Tables

In the early 1960s Bryant Tuckerman realized that the latest computer technology could be put to good use calculating historical planetary positions.[1] He published a two-volume ephemerides, providing tables of planetary positions from 601 BCE to 1649 CE. The “Tuckerman Tables” quickly became the standard reference for historians of astronomy. While more recently on-line resources might have begun to erode the usefulness of the “Tuckerman Tables,” they remain an excellent resource when working with old reports of planetary positions, especially conjunctions, oppositions, and other inter-planetary aspects.

Historians of astronomy were not the only group of scholars who turned to the “Tuckerman Tables” when evaluating historical sources and events. Astrologers eagerly purchased and used these tables in their efforts both to understand the past and to assess astrology’s ability to explain the present. One such astrologer was Ralph Kraum, who in March 1965 purchased his copy of Tuckerman’s Planetary, Lunar, and Solar Positions, A.D. 2 to A.D. 1649 at five-Day and Ten-Day Intervals direct from the American Philosophical Society for $7.50. Kraum’s copy is filled with charts and fragments of astrological and astronomical calculations as he cast nativities for a wide range of historical figures. In many instances, he recorded the person’s name on the piece of paper as well as his own name and the date. On 6 April 1965, one of the first nativities he calculated with Tuckerman’s tables was Emperor Justinian’s, which he compared against the chart found in Maurice Wemyss’s More Notable Nativities. Unfortunately, Kraum did not record either the final version of this chart or his interpretation of it. On 1 July 1965 Kraum calculated the planetary positions for Montaigne’s natal chart, and again compared his numbers to Wemyss’s chart. Appropriately, in 1965 Kraum calculated planetary positions for Nostradamus’s nativity and then in 1967 Kraum twice calculated various data for John Dee’s nativity. In 1969 he calculated planetary positions for Elizabeth of York, wife of King Henry VII. He noted that Elizabeth’s birth date was uncertain. On the back of a receipt for a “400 day globe” that he purchased for $2.94 from E. W. Reynolds in October 1953, Kraum evaluated some possible dates for Elizabeth’s birth before concluding that she “must have been born on 1465 Feb. 11.” Ferdinand V and Isabella of Spain attracted Kraum’s attention in 1965. Dozens of other slips of paper bear the traces of Kraum’s efforts to calculate horoscopes for historical figures.

Kraum’s efforts to calculate famous nativities was not merely a hobby. He was continuing a practice that astrologers had begun at least as early as the fifteenth century, when Martin Bylica amassed a collection of hundreds of horoscopes. He returned to these charts again and again, refining his calculations, adding notes and highlighting different features, and adjusting his interpretations. By the sixteenth century collecting and comparing famous nativities had become a key aspect of an astrologer’s professional. The Italian astrologers Luca Guarico and Giordano Cardano competed with each other through their published collections of genitures. The practice of calculating and recalculating horoscopes in order to understand better how to interpret the celestial positions continues even today. When Kraum scoured his copy of the Tuckerman Tables for the data that he could use to evaluate and judge the work of his predecessors, he was practicing critical astrology. For centuries astrologers have turned a critical eye on their own work and that of their predecessors and competitors.[2]

In addition to horoscopes for famous people, Kraum left the remnants of his efforts to calculate the important celestial data for eclipses and significant planetary conjuctions—he covered more than dozen sheets of paper calculating relevant data for the Saturn-Jupiter conjunction that occurred on 18 December 1603 and compared his results to those by an astrologer named Robson.[3] Kraum was also interested in historical transits of Venus, calculating planetary positions for the a number of them as early as 23 May 60 CE.[4] Kraum seems to have been particularly interested in the transit on 24 November 1639 (England was still using the Julian calendar; according to the Gregorian system, this transit occurred on 4 December 1639).

Ralph Kraum’s copy of the Tuckerman Tables, opened to the pages for the 1639 transit of Venus (Source: Author’s collection).
Ralph Kraum’s copy of the Tuckerman Tables, opened to the pages for the 1639 transit of Venus (Source: Author’s collection).

The transit that year was the first observed by European astronomers: Jeremiah Horrocks and William Crabtree. Horrocks had corrected previous astronomical tables that had indicated that Venus would just miss the sun—he probably corrected Philip Lansberge’s tables. Lansberge seems to have rejected Kepler’s elliptical orbits and thus predicted that Venus would just miss the sun. Horrocks recalculated the positions and predicted that Venus would in fact cross in front of the sun’s disc.

Kraum put a small checkmark in the margin to note the date for the transit of Venus (Source: Author’s collection).
Kraum put a small checkmark in the margin to note the date for the transit of Venus (Source: Author’s collection).

Kraum covered three sheets with numbers and astrological data. How long the transit lasted, the positions of the planets (including Uranus, Neptune, and Pluto), the medium coeli and the ascendent. He also noted twice that Horrocks was the first person to witness a transit of Venus.

Kraum’s efforts to determine the relevelant astrological information from the transit of Venus in 1639. Kraum also noted on this piece of paper that Horrocks was the first person to observe a transit of Venus (Source: Author’s collection).
Kraum’s efforts to determine the relevelant astrological information from the transit of Venus in 1639. Kraum also noted on this piece of paper that Horrocks was the first person to observe a transit of Venus (Source: Author’s collection).

Unfortunately, Kraum did not record how he interpreted this information. As with his other astrological calculations, he was doing more than simply passing time. Kraum was trying to use astrology to understand his world, and the transit of Venus offered him some glimpse into that world. As did the conjunctions between Saturn and Jupiter.

Kraum enjoys two claims to fame. Beyond the world of professional, practicing astrologers, Kraum gained renown for his famous clientele—he was a prominent astrologer to the actors in Hollywood. Notably, he was one of Ronald Reagan’s early astrological counsellors. Apparently, during his acting years Reagan began seeking advice from astrologers, long before Nancy brought Joan Quigley into the White House. Amongst astrologers, Kraum gained some fame for his work on the Saturn-Jupiter conjunction that occurred in 1365. He clearly spent considerable time and energy thinking about this conjunction. The most complete and elaborate chart to survive in this book is Kraum’s chart for this conjunction.

Kraum’s chart for the Saturn-Jupiter conjunction. He returned to this chart at least twice to correct or add information (Source: Author’s collection).
Kraum’s chart for the Saturn-Jupiter conjunction. He returned to this chart at least twice to correct or add information (Source: Author’s collection).

Here Kraum adapts the theory of great conjunctions, which correlated the conjunctions between Saturn and Jupiter with broad, large-scale changes on earth. There were three types of conjunctions: great conjunctions occurred every 60 years, greater occurred every 240, and greatest occurred after 960. The rarer the conjunction the greater the effects on earth. These effects ranged from the rise and fall of religions and kingdom, to the appearance of plagues and epidemics. Kraum seems to be applying a form of this theory in his analysis of the “Mutation Conjuction” in 1365.

We may not agree with the intellectual system of astrology, but it cannot be dismissed as simple or uncritical. The trail of intellectual breadcrumbs Kraum left behind provides tantalizing glimpses at the rigor of his system and the self-imposed evaluation that occurs. It is hard to see these scraps of paper as part of some elaborate ruse to swindle customers out of their money. It also does not seem that Kraum was disingenuous in his belief. Moreover, Kraum’s work reveals a person skilled in positional astronomy, a person who seems almost to enjoy the calculations. Whatever he was doing, it cannot be equated to horoscopes in the daily newspaper or written off as the dogmatic ravings of a money-grubbing fraudster.

[This post was originally “An Astrologer’s Intellectual Breadcrumbs” at PACHS. Josh Spero’s post on second-hand books and their owners, at History Today, prompted me to repost it here.]


  1. Tuckerman wrote his program in Fortran and compiled it on an IBM 704. Then, when he calculated the positions for his second volume, he opted for “the faster, and more advanced solid-state [IBM] 7090.”  ↩

  2. Whatever charges might be leveled at astrology, the lack of critical self-analysis is not one of them. Given the intellectual framework within which astrology makes sense, astrologers have long been admirably evaluative of their own practice and the conclusions they have drawn from their charts. Astrologers apply this criticism equally to competing astrologers as well as to their own work.  ↩

  3. Vivian Robson, perhaps?  ↩

  4. I confess that I was surprised to see his interest in transits of Venus. I did not realize that astrologers found these transits to be astrologically meaningful. But for Kraum they seem to occupy a position at least as important as eclipses.  ↩

Weekly Roundup: History of Science Videos & NSF Report

The History Channel Distorts History

A number of the videos at the History Channel’s “Enlightenment” page deal with the history of science—on Isaac Newton, the Scientific Revolution, and a series Beyond the Big Ban: Copernicus, Beyond the Big Ban: Galileo and Beyond the Big Ban: Newton. Some gesture to interesting points, e.g., the interaction between science and religion in the 16th and 17th centuries, but most repeat heroic tales and neat stories of discovery through flashes of brilliance. Unfortunately, the History Channel didn’t enlist the expertise of many historians and fewer historians of science (the eminent Owen Gingerich makes two cameo appearances). Scientists, however, are well represented. I wonder how different these videos would have been if they had consulted more scholars with expertise in the history of early modern science.

Newton the Genius

In Newton’s Apple: Science and the Value of a Good Story Ned Potter is right: telling a good story is more important, perhaps more important than being accurate. His comment about lists of great scientists underscores his point:

Search online for any list of history’s greatest scientists and you’ll find the same names: Albert Einstein, Charles Darwin, Marie Curie, Sigmund Freud, Louis Pasteur, and so on. The order may change, but the name on top will almost invariably be that of Isaac Newton.
We can argue over such lists — they’re mostly harmless fun — but we can agree that Newton earned his place there.

I don’t think such lists are “mostly harmless fun.” Such lists tell a good story and reinforce a particular image of science, one that misleads and distorts its history and development. They are built on the pillars of the lone genius waging war with the weapons of rationality, empiricism, and experiment to overcome church, benighted society, and ignorant political leaders. Potter’s own description of Newton conforms to this model. Newton alone, in his spare time, invented reflecting telescopes and calculus, and explained light and colors. Only as an aging genius, in his later years, Newton fiddled with alchemy and Biblical chronology.

He published his Principia Mathematica in 1687. In his spare time he designed the first reflecting telescope, laid the foundations for calculus, brought us the understanding of light and color, and in his later years – it would be disingenuous to leave this out – tried his hand at alchemy and assigning dates to events in the Bible.

Newton turns out not only to have been a genius in science but also in self promotion.

NSF, Astrology, and the Pig-Ignorant American Public

The release (or at least the summary of the release) of the latest NSF survey on attitudes about science and technology has prompted the standard handwringing and fretting. Of particular concern is the fact that 1 in 4 Americans Don’t Know Earth Orbits the Sun. Yes, Really, which echoes One in four Americans unaware that Earth circles Sun. The Telegraph jumped on the bandwagon with One in four Americans ‘do not know the Earth circles the Sun’ and The Space Reporter sprinkled a little history onto its summary of broadcast soundbites and published factoids, Study finds nearly 25 percent of Americans don’t know the Earth orbits the sun.

Another predictable worry is the “More than half of US millennials think astrology is a science,” repeated in Science News and Slashdot and then with some added commentary (and the standard ambiguities and imprecisions in terms like “horoscopes” and “astrology”) at Mother Jones. Richard Landers worries about possible design flaws in the NSF’s study: NSF Report Flawed; Americans Do Not Believe Astrology is Scientific.[1]

All this anxiety is part of a more general claim that Americans struggle with science, respect scientists, survey finds.

The NSF report generating all this incredibly repetitive and generally uncritical “news” is the most recent Science & Engineering Indicators 2014 – (NSF), a biennial report that “highlights some major developments in international and U.S. science and engineering.” The part of the report that has attracted the most attention is chapter seven and the various Appendix Tables (astrology that most resilient of science’s hobgoblins enjoys its own table, Appendix table 7–13). What if we look at chapter seven of the NSF report a different way?

Sure, on average, respondents answered only 65% of the “factual” questions correctly, but that percentage has been steadily increasing, up from 59% in 1992 (according to ‎Appendix table 7–8).

Respondents were asked the following questions about science (“Don’t know” responses and refusals to respond were counted as incorrect):
Physical science—

  1. The center of the Earth is very hot — 84% got this right.
  2. The continents on which we live have been moving their locations for millions of years and will continue to move in the future — 83% got this right.
  3. Does the Earth go around the Sun, or does the Sun go around the Earth? — 74% got this right.

    • 3a. How long does it take for the Earth to go around the Sun? (Asked only if the respondent answered correctly that the Earth goes around the Sun.) — 55% got this right.
  4. All radioactivity is man-made — 72% got this right.
  5. Electrons are smaller than atoms — 53% got this right.
  6. Lasers work by focusing sound waves — 47% got this right.
  7. The Universe began with a huge explosion — 39% got this right.

Biological science—

  1. It is the father’s gene that decides whether the baby is a boy or a girl — 63% got this right.
  2. Antibiotics kill viruses as well as bacteria — 51% got this right.
  3. Human beings, as we know them today, developed from earlier species of animals (a footnote indicates that only 1,152 of the 2,256 respondents were asked this question) — 48% got this right.[2]

Biologists should probably be worried that respondents seem to know less about biology than they do about the physical sciences.

The Appendix tables are full of other interesting information that has not attracted any attention while the media fixate on the astrology-loving geocentrist Americans. Apparently only 33% of respondents have a grasp on “scientific inquiry,” as demonstrated by their (in)ability to answer two probability questions and either a question about theory-testing or a question about why its better to use control groups in drug tests (see ‎Appendix table 7–11).[3] 70% of respondents claim not to know much about the causes of environmental pollution, according to another table. Another table indicates that males and females would be “happier” if their sons and daughters chose to be engineers rather than scientists.

Parental happiness about child’s career as
Scientist Engineer
Male Daughter Son Daughter Son
Male 81% 82% 86% 88%
Female 80% 79% 82% 83%

Engineers are, no doubt, “happy” to learn of this parental esteem.

Despite science purportedly being an international collaborative project, the NSF’s 2014 Science & Engineering Indicators digest of the report makes it a nationalist concern:

Many other nations, recognizing the economic and social benefits of such investment, have increased their R&D and education spending. These trends are by now well-established and will challenge the world leadership role of the United States [page 2].

This rhetoric recalls the debates recently last year in England about investing more in domestic R&D. Kieron Flanagan wrote a nice piece in The Guardian about the problems of framing debates about science and basic research in terms of national boundaries, Does the UK need to spend more on basic research?.


  1. Perhaps we should also worry about the term “scientific,” which is notoriously difficult to define.  ↩

  2. A subset of these questions was used in determining the trends in “factual knowledge” reported in Appendix table 7–8:  ↩

    • The center of the Earth is very hot.
    • All radioactivity is man-made.
    • It is the father’s gene that decides whether the baby is a boy or a girl.
    • Lasers work by focusing sound waves.
    • Electrons are smaller than atoms.
    • Antibiotics kill viruses as well as bacteria.
    • The continents on which we live have been moving their locations for millions of years and will continue to move in the future.
    • Does the Earth go around the Sun, or does the Sun go around the Earth?
    • How long does it take for the Earth to go around the Sun?
  3. “Scientific inquiry” here could be applied to most rigorous, rational, evidence based activities.  ↩

Astrology and Relationships

Over the last few days the Smithsonian Magazine has been drawing attention to their recent blog post about astrology and relationships (see this search): “Good News: Astrology Doesn’t Impact the Success of Your Marriage.” Unfortunately, the post missed an opportunity to ask interesting questions about why the study attacked astrology and why it represented as it did, and about why astrology remains such a mesmerizing target for scientists and science cheerleaders.

The Smithsonian Magazine’s tweets about astrology and relationships.
The Smithsonian Magazine’s tweets about astrology and relationships.

The post summarizes a study from 2007, which found little correlation between sun signs and choice of spouse, and an earlier study, which concluded that further research was needed to “to find out whether astrology columns really are just a bit of harmless fun or whether people’s behaviour is influenced without them realizing it.” Beyond link bait, it is unclear what the Smithsonian post was intended to accomplish. It invokes that old chestnut that reduces astrology to sun signs. As the comments indicate, it does not engender debate or discussion but rather encourages people to retrench into tired old positions. On the one had, the post reassures opponents of astrology of their righteous opposition and confirms for them that astrology lacks evidentiary support. On the other hand, the post goads proponents of astrology to point out the fallacious arguments that undergird the attacks.

A more interesting starting point would have been to ask: Why did the author of the study reduce astrology to sun signs? Further, why did he assume sun signs compel people to marry certain people?[1] That assumption contradicts the traditional aphorism: “The stars incline they do not compel.” Consequently, astrologers since Ptolemy have explained how astrology cannot be a precise, predictive science, certainly not when it comes to predicting human behavior. Who, then, believes that sun signs, one small facet of a much larger astrological edifice, can compel people into action? What does framing an attack on astrology in this way accomplish? Why, given the long history of attacks on astrology, did the author of the study think his criticism would be successful?[2]

Like all attacks on astrology, this one has a long history, complicated by the many different ways astrologers have claimed the stars and planets influence marriage. Ptolemy devoted a chapter to marriage in his Tetrabiblos. There he offered all sorts of guidelines for characterizing a marriage, such as:

Marriages for the most part are lasting when in both the genitures the luminaries happen to be in harmonious aspect, that is, in trine or in sextile with one another…

Or in other places he indicates what sorts of spouses people tend to marry:

If Saturn is similarly in aspect with the sun, they [women] marry sedate, useful, industrious husbands; if Jupiter is in aspect, dignified and magnanimous; Mars, men of action, lack in affection, and unruly; Venus, neat and handsome…

In Ptolemy’t discussion, astrological configurations portended certain circumstances but did not necessitate them. The configurations Ptolemy highlighted were much more complex than merely sun signs and often included detailed analyses of both the husband’s and the wife’s genitures as well as a comparison of the two.

Subsequent astrologers refined, modified, and extended Ptolemy’s doctrine. Nearly every early modern book on astrology includes rules for how to interpret celestial influences on marriages.[3] These guidelines range from a generic comment about seventh house being the house signifying marriage to John Middleton’s detailed discussion of whether or not a person will get married, when, how often, whether it will be a harmonious marriage, etc. As the various interpretations proliferated, so too did the attacks. Critics as different as the religious reformer Jean Calvin and the philosopher Pierre Gassendi wrote a scathing critiques of judicial astrology in which they rejected the astrologer’s ability to predict anything specific about a marriage, including whether a person would be happy in a marriage. The clergyman John Edwards, pointed out that whether or not astrology can make general predictions, astrology cannot predict particular aspects of a person’s life. He singles out marriage as one such aspect.

More than four centuries ago both opponents and proponents of astrology had already agreed that astrology could not make precise predictions about marriages. Why, then, bother trying to demonstrate that there is no correlation between sun signs and choice of a spouse? Whose interests are served by spending the time and effort on such a study? Who is the author of the study and the author of the post trying to convince? Why does astrology continue to serve as the paradigmatic pseudo-science? And what do attacks on astrology reveal about the social nature of scientific knowledge?


  1. The post gestures at the difference between astrology and horoscopes but does not explore that difference in any interesting way. The second study cited, concludes more ambiguously than the post suggests.  ↩

  2. These questions should not be understood as a defense of astrology. Rather, they merely raise questions about the unexamined assumptions and conventions that  ↩

  3. Modern texts on astrology might also include discussions about marriage. I don’t know anything about modern astrology textbooks, so I can’t say.  ↩

Pseudo-science, Pseudo-academia, and Snake Oil

A roundup of articles related by the pejorative “pseudo:”
Last month Mark Thomas attacked genetic ancestry companies, claiming that “there is usually little scientific substance to most of them and they are better thought of as genetic astrology.” Martin Richards and Vincent Macaulay responded by defending genetic ancestry science: It is unfair to compare genetic ancestry testing to astrology. Once again astrology is the paradigmatic pseudoscience. And once again, what counts as science is anything but obvious and universally agreed upon—the comments introduce a third model of science built around the ideal of “lay Genetic Genealogists who do some A+ research.”

In the NY Times we read about the proliferation of “pseudo-academic journals” that charge authors to publish articles: “Scientific Articles Accepted (Personal Checks, Too).” Open access, we are told, is the root of this pseudo-academic underworld of pay-to-publish and pay-to-present science. But page fees are common in scientific publishing and predate open access. Both reputable and disreputable open access journals charge authors to publish material. The “well-regarded, peer-reviewed” PLOS charges $1,350-$2,900 depending on the journal, with reductions for authors from less affluent countries. The journals and conferences referred to in the article may very well be pseudo-academic, but not because they charge authors to publish.

Finally, science sheds the light of truth into the murky world of snake oils and patent medicines: “What’s in Century-Old ‘Snake Oil’ Medicines? Mercury and Lead.” The chemist, Mark Benvenuto, directed the research that analyzed patent medicines from the early part of the century. They found that they contained mercury, arsenic, and lead. He is generous, however, in not condemning the makers of these medicines, perhaps a tad too generous: “Back in the day, this was a very trial-and-error kind of field,” Benvenuto said in an interview. “The stuff that we think of as dangerous now, though it was dangerous, was as cutting-edge as they had at the time.”

While Benvenuto’s work will add some detail to our knowledge of what these medicines contain, it is not particularly revelatory. In 1915 the FDA fined Dr. Tutt’s $300 for “misbranding” their pills. The judgement included an analysis of the pills:

Moisture (per cent): 04.9
Ash (per cent): 0.86
Aloes (per cent) about: 53
Wheat starch (per cent): 4.2
Total sugars as invert (per cent): 8.7
Mercurous chlorid (per cent): 26.94
Each pill contains 0.0448 gram, or 0.69 grain, mercurous chlorid (calomel).
Average weight per pill (grams): 0.166

That Dr. Tutt’s Liver Pills contained mercury is not news.