John Pazmino
 NYSkies Astronomy Inc
 2008 December 15 
    Marcus Manilius was a 1st century AD poet, who wrote 
'Astronomica'. This is a long poem of astronomy and astrology of his 
era. The original was probably is circulation in his time, but was 
lost until the 1400s. After recovery, it was routinely distributed 
thru the present era. 
    On 2008 October 24-25 the first international conference about 
Manilius and Astronomca, 'Forgotten stars', was held in New York. 
Organized by Dr Katherina Volk, Columbia University, and Dr Steven 
Green, Leeds University, it met in the Kellog Center, 118 St and 
Amsterdam Av, Morningside Heights, Manhattan. 
    I attended the Forgotten Stars meeting from my interest in 
astronomy history and the furtherance of astronomy culture in the City 
with NYSkies. I present here highlights, combining material from the 
15 or so speakers on the both days and adding some of my own 
Marcus Manilius 
    We really know next to nothing at all about the person, not even 
his age when he wrote the poem! This is not too surprising being that 
ordinary inhabitants in the Roman or other early culture were poorly 
chronicled. They may have been tracked for commercial, civic, and 
political purposes, but there records were on perishable media. Only 
the higher society folk were preserved in permanent form like statues, 
monuments, mosaics. 
    That he lived during the reign of Augustus Caesar is pretty clear 
from the text. The early parts of Astronomica were written while 
Augustus was emperor; the later sections, after his death. The work is 
filled with ululations to Augustus and the Roman Empire. Allusions by 
much earlier authors to a 'Manilius' of about 80 BC must refer to an 
other person not related to the present fellow. 
    He probably lived in or near Rhodes He called himself 'Roman' 
being that Rhodes was then thoroly integrated into the Roman Empire. 
I may note that after the Romans faded from Rhodes and the rest of 
Asia Minor, the Byzantine emperors continued to call themselfs 
'Romans' as successors to the old emperors. 
    Manilius got some good education to command a rich vocabulary, 
compose verse, and exercise technical concepts. He also shows 
awareness of other litterature of his time, which would have been 
tough to get at without some privilege. Yet, there is no good 
indication that he traveled about or shifted residence during his 
    To acquire an education, Manilius likely had some enhanced 
standing, there being no public or cheap private schools. He could 
have enjoyed company of other learned folk. 
    He was at least a young adult, to allow sufficient years to 
enculturate himself. How long he lived after the 'Astronomica' is 
unknown. Mind well that in the 1st century a male human lifespan was 
only about sixty years. 
    The stock picture of him, in a flowing robe leaning over a star 
globe, is pura mente a modern image. We plain don't know what he 
looked like. 
    The prime manuscript, while likely in routine circulation when 
new, disappeared by the 5th century AD. The events cited in the work, 
plus his explicit references to Augustus, date the Astronomica to 
about 20 AD.There are several allusions to it in following centuries 
but no solid quotes from it. 
    Our present study of Astronomica banks off of manuscripts first 
uncovered in 1417 by Bracciolini. Regiomontanus in 1782 rendered the 
first current edition for general circulation. Since then, there were 
numerous new translations and commentaries. 
    The work is in five 'books', as first-level divisions of ancient , 
books were called. The material we have seems to be complete, altho 
here and there there are missing lines or phrases that were supplied 
by comparing various copies. 
    It is written in Latin of a unconventional flavor, well beyond 
that learned in high school or lower college. Because the book is 
really a humongous poem, the language is hardly plain text. Manilius 
chooses words and constructs to fit the versification, derailing 
attempts at progressive reading. 
    Making matters harder for modern readers is that many editions of 
the Latin text miss out the macrons of vowels, thwarting proper accent 
and rhythm. A trivial example is the word 'regina'. Without other 
indication it can be sounded 'REH-jih-na' or 'reh-JEE-na', according 
as the 'i' is long or short. An intimate knowledge of vocabulary can 
resolve the choice in most modern translations. 
    This loss of vowel strength infects current pronunciation of 
astronomy words. The phrases 'gamma virginis' and 'theta orionis', 
names of certain stars, are typical. I hear 'GA-ma virr-JIH-niss' for 
'GA-ma VIRR-jih-niss' and 'ZEE-ta o-RIGH-yo-niss' for 'ZEH-ta o-ree-
    I just have to mention the case of two electric power companies I 
deal with, Orion Power and Orion Electric. They are separate 
enterprises with no relation to each other. A one calls itself 'oh-
RIGH-yonn; the other 'O-ree-yonn'! 
    In some cases which I had to inquire after, texts themselfs vary. 
So I have to allow for a star in the Pleiades 'meh-ROH-pee' and 'MEH-
roh-pee'. One must be really correct, the opposite writing having a 
    If you ask, yes, I so hear 'MEE-rohp' among Americans as well as, 
for the cluster, 'PLEE-aydz'. 
    Some transcriptions use the 'u' for both 'u' and 'v', further 
forcing pauses in the pace of reading. 
    In spite of these obstacles, for the fan of Latin, Astronomica 
illustrates how fluid the language is and how adaptable it is to build 
modern vocabulary. 
    Poetry was a common way of writing articles in the Roman and Greek 
times. They are mostly descriptions or narratives. Astronomica is a 
tuitional piece, supposedly for teaching some astronomy/astrology to 
some targeted lectorate.
    Apart from the lack of any meaningful numerical work -- every 
thing is in verse! -- it's not clear who was supposed to take tuition 
from it. Certainly not the layman in the street, whose Latin was a 
rough and tumble tongue. Likely not a ruler or politician for it deals 
with a subject too technical, even with its gushy praises. Probably 
his other learned friends? Students of astronomy? 
    Maybe it was an exercise in self-instruction. One way to 
understand a new subject is to write an article about to teach it to 
an imaginary reader. The piece is not published or distributed, but 
kept for personal use.
    One important point to note is that Astronomica, unlike the 
Almagest, is NOT an instruction book for doing any actual figuring of 
the planet locations or motions. There aren't any base data to do 
that. More over, all number work is discussed in poetic words, making 
it pretty tough to follow and apply. 
    The plausibly best target is us today! Astronomica happens to be 
the one and only astronomy/astrology work of substantial size and 
depth from the 1st century AD. There is nothing else near in time to 
compare or complement. 
    It is a bit dicey for us to assign a ranking of importance to it. 
It is not clear if the material in Astronomica really represents the 
knowledge in general acceptance then or stuff that Manilius concocted 
away from mainstream practice. 
    The far and away easiest and good translation is 'Manilius - 
Astronomica' in the Loeb Classical Library series of ancient 
litteature. Published by Harvard University Press, it is on shelf at 
scholarly book stores and central outlets of large libraries. The 
edition I crammed with for the conference seems to be the latest 
printing of 2006. 
    The Latin and English are on facing pages, with the translation of 
a more narrative form than poetic. This does ease the reading but it 
is still a tough trip thru the words. 
    The book has a deep letterpress about Manilius and the poem, a 
sexy map of the Roman world, several clarifying diagrams and tables, 
starchart of Manilius's constellations, explanation of astrological 
    It, like all in the Loeb series, is pocket-size (for a large 
jacket), comfortable to read while riding. Many delegates at Forgotten 
Stars had copies to hand to follow the speakers or to refresh during 
the breaks. 
    You should explore the Loeb Classical Library for other science 
and astronomy works, otherwise hard to find in convenient form. The 
price of a given volume varies widely, from a few dollars to about 25 
dollars, depending on store. 
    The Latin text is also in Internet. The file may be too large to 
print all at once. You may want to dump the file into a wordrpoc to 
partition it into more manageable pieces. 
Forgotten Stars
    The conference was held in a top-floor hall at Kellog Center with 
sweeping panoramas of the Columbia campus and the City. Some delegates 
remote from the City were awed at how densely built up Manhattan was 
so far from 'downtown'. They were even more amazed when they learned 
that the core campus was built, with mid-rise 'skyscrapers' in about 
    As an astronomy issue, not captured by most delegates, the scene 
at night was incredibly subdued. Where are all the grotesque lights so 
characteristic of other towns? There were many individual glaring 
lamps in view  but the general spectre was a majestic darkness with 
soft lights here and there, almost as if, unknown to the visitor, the 
entire island of Manhattan was replaced by a rural landscape. 
    This was one demonstration of how it is feasible to maintain and 
enjoy an exalted urban life using sustainable principles, such as 
deeply abated reckless nighttime illumination. The benefit for 
astronomers is a vastly lower insult against the heavens at night. 
    The room was fitted with about 80 seats in theater setting, 40 on 
each side of the center aisle. At first there ws only a lectern in 
front with no obvious means for visuals. The room was deep enough for 
maneuvering, a litterature table, coatrack. 
    The receptions and breaks were taken in an adjacent hall with 
assorted sweets and drinks. This room had no seats or tables to set 
plates and glasses on. We improvised with the wide radiator sills 
under the windows. 
    For so specialized a topic within a small intersect of classicists 
and astronomers, the attendance was quite full. Of the 80ish seats in 
the lecture hall, about 3/4 were occupied. As with many other 
conferences, the audience for particular speakers was erratic, from 
about the full roster to only twenty or so. 
    The age range was from college graduates thru those needed canes. 
There were about half male and half female but hardly any 
'minorities'. All spoke English quite well, some far better than the 
typical American. Many have accents, but none so thick to impede 
    Every one, of all ages, was thoroly erudite and learned. They all 
at least could read Latin. Many could speak it by reading passages 
from Manilius or other texts. Some knew other early languages and 
sprinkled their banter with snippets from them. 
    Some came from Columbia University, many from other American 
colleges. And there were delegates affiliated with major universities 
of Canada, England, Germany, Ireland, 
    During the intermissions they spoke on a fantastic variety of 
topics, not only Manilius or only classics, with evidence of careful 
inquiry and examination. Several asked me questions about New York, 
which I was pleased to answer. The older folk appeared to be well-
traveled, with comments derived from around the world they visited or 
lived in. 
    Entirely unlike most conferences, there were just about NO visual 
presentations! Only the very last speaker had a digital slide show. 
All the others merely dialoged at the lectern. Most speakers offered 
handouts to follow the dialog. I found it clumsy to shift attention 
from paper to speaker, so I put the handout away and listened. 
    One booboo was in making announcements. The session chair spoke 
away from the microphone, not thru it. The voice for the rear rows of 
seats may have been a bit weak to hear. 
    Handouts were offered by most, if not all, speakers. They were 
left on the litterature table in stages, the new ones set out for the 
ensuing sessions. While this seemed to be a reasonable way to get the 
papers into the delegates's hands, it somehow didn't quite work out. 
During each speaker's turn, some delegates scurried to the table to 
hunt up the matching handout. 
    I myself ended up taking many duplicate papers because between 
sessions they were shuffled around on the table. Duplicates I vetted 
during the breaks were returned to the table, but when I got home i 
still had several extras. These I'll bring to the next NYSkies Seminar 
as take-homes. 
    I took several extras of the conference schedule and poster for 
the next Seminar. The poster, also on the conference website for 
printout, has the stock Manilius picture with his name 'M. Manilius 
Romanus'. This is actually one of a set of four of astronomers of the 
ancient world. The others are Aratus Graecus, Ptolemaeus Egypticus, 
Azophi Arabicus. This last fellow I hardly call 'ancient', he being 
from the early Islamic era. He is also known as Alhazen. 
    One handout had some copies without staples, so the separate 
sheets were laid out. Some delegates suddenly found during that 
speaker's talk they were missing a sheet. They scooted back to the 
table to fetch it. 
    Despite these glitches, I have the bulk of the papers to fill out 
my 'Forgotten stars' file for future recourse. 
The belt!
    To capture the spirit of the meeting I wore my astronomy belt, 
with the four astronomers just mentioned on it. They are scattered 
against a background of a chart of the heavens. It's really a neck 
tie, but I simply no longer cotton to conventional neckties. I looped 
it over my slacks belt and made a simple overhand knot at one side. 
There was enough tongue to hang down with Manilius's picture in open 
    Everyone went nots about it! Some wanted to get one for themselfs. 
They at first thought it was a belt on the European fashion. Even 
after explaining that it's a necktie, they still wanted one.
    I got the tie so long ago I utterly do not recall from where. If 
from a store, the place is likely no longer around. If I got it at, 
say, the Northeast Astronomy Forum or Astronomical League meeting, I 
for sure haven't seen it there for decades. 
    Manilius lived in the grand epoch of Rome, when the regime was 
considered favored by celestial powers. Julius Caesar and then 
Augustus promoted themselfs as blessed by the gods, many being 
configured in the heavens as planets and constellations. If not the 
very god, his tools ar props were among the stars. In some situations, 
the alignment of planets in the zodiac was jimmied to justify the 
emperor's actions or status. 
    The astrology practiced was based on Greek astrology. Rome often 
assimilated Greek gods into their own, changing the names or merely 
Latinizing them. 
    The society was a polytheistic one, with deities for just about 
every thing in life. The public routinely appealed to their favorite 
deities, privately or in ceremonies, to enhance life. Since many 
deities were celestial in character, it is likely that the layman knew 
at least some of the constellations to recognize their gods. 
    Astrology was routinely employed by rulers and officials to 
demonstrate the legitimate status in the empire. Augustus, as example, 
regularly included astrological devices on his coins and monuments. We 
see Capricornus (probably his Moon sign at birth), a stylized comet, 
cosmosphere, star associated with a figure of the emperor. 
    Hence, astrology was simply part of the native culture, and 
remained so until monotheism took hold many centuries later. In this 
regard, Manilius was just discussing what was a common feature of his 
time and not pushing some new or special theme. 
    Most of Astronomica is devoted to explaining the interactions of 
the the stars and signs, with many examples taken from his recent 
history. These help to fix the epoch of the poem by boxing it among 
its stated events. 
    However, Manilius describes many astrology features not part of 
regular astrology. If we judge by the authority for mainstream 
astrology, Ptolemaeus's Tetrabiblos of the mid 2nd century AD, 
Manilius has many extra goodies. 
    It is not at all well understood if these were in fact part of 
astrology in the Manilius time, the regular astrolofy was not quite 
stabilized, or Manilius added them himself. Never the less, like the 
features that survive into today's astrology, they are just as worthy 
or worthless. 
    Astrology has many features of little or no use for astronomy. 
One, which earned Manilius some vigorous criticism, is his treatment 
of the astrological houses. The concept is that a planet's power is 
modulated by both its place in the ecliptic and that in the client's 
horizon. The latter factors in the client's location on earth, to 
impute a terrestrial factor in addition to the celestial one of the 
signs along the zodiac. 
    However, there is no natural or obvious points and planes linking 
the ecliptic and the horizon to bank a set of divisions. There are at 
least three planes to play with: horizon, celestial equator, ecliptic. 
There are at least three poles: celestial north, ecliptic north, 
zenith. And there are at least four origins: ascendent, vernal 
equinox, north (or east) point, medium coelum. By mix-&-match among 
these pieces, many schemes of houses, as the terrestrial slices of the 
ecliptic are called today, grew up over the ages. 
    Each has its adhaerents among astrologers, to the point of bitter 
and contentious arguments. Some methods are valid only for the mid 
north latitudes, where astrology developed in the western world, but 
give ludicrous results in far north or south latitudes. Others are not 
defined too far from the equator. 
    Until the late 20th century[!] the most common house system was 
the Placidus method. This came about because charts and tables for it 
were cheap and widely available. To use other house plans, the 
astrologer had to buy or borrow rarer and more costly publications. 
    With the diffusion of home computers in the closing decades of the 
last century, astrologers can now choose which house method they want 
from the selection offered by many astrology programs. For us 
astronomers only two make any sense. 
    The equatorial or equal or polar houses are congruent with 2-hour 
spacing of hour angle. The zenithal or horizon or azimuthal system 
aligns with verticals of azimuth,  degrees apart. Between these two a 
planet's place in the local sky, as distinct from within the zodiac, 
can be assessed relative to the meridian or north point. 
    I'm not all that surprised that Manilius screwed up with his 
description of houses. To properly calculate the boundaries of the 
houses, some hefty (for his time) maths are required. Manilius may 
simply have lacked the needed arts and skills. 
    There is none of any modern sense of the term in Astronomica. 
Manilius followed the prevailing polytheistic practice where there was 
a deity for just about every fixture and facet of life. He calls on 
these deities repeatedly in his book and moralizes about them and 
their representations in the heavens. He treats the hordes of gods like 
we today treat our single god of Christianity or Judaism. Hence, what 
we call 'mythology' and 'folklore' was the 'religion' of the era and 
not just a collection of fairy tales. 
    Manilius lived a day or two by sea from Palestine, where Judaism 
was the prime belief system. He lived during the time allocated to 
Jesus. He says nothing that can be interpreted as acknowledgement of 
these schemes of life. He could have simply not known of them, passed 
them up to keep the polytheist system, or was smart enough to be nice 
to Augustus. 
    Judaism was on the outs with the Roman rulers. It would be risky 
to play it up in a freely distributed literary work. Christianity may 
simply not yet been established in Manilius's life. Jesus was still 
around, probably not yet fully accepted as a new religious figure. 
    The complete absence of any civil or commercial records for Jesus 
is used to dismiss his actual existence, he being a myth. However, the 
lack of documentation for Manilius, who is very definitely a real 
person, weakens that one argument. Yet it to me seems a bit odd that, 
under Augustus, citizens were not thoroly accounted for, if so no 
other reason than to keep them in line.. 
    As an astronomer/astrologer, he shows no inkling that there was a 
'Star of Bethlehem'. That apparition would have been as blatant a 
celestial sign as there could be and would be still fresh in minds of 
those who saw it only 20ish years earlier. Or, the Star of Bethlehem 
could have be an artificial device with no physical being. We have 
utterly no separate observation of the Star besides that in the New 
    It would be one hell of a discovery in history if there was a 
documented person who was acquainted with Jesus, Jewish leaders, or 
witnessed some biblical incident and then commented about them in 
realtime. All the statements about Jesus, in the New Testament, are 
from decades or centuries later. 
    Astronomica exhibits a knowledge of astronomy far beyond what a 
layman Roman would possess, again pointing to some elevated erudition 
in the author. He does make many blunders, some serious, yet innocent 
in the context of the poem. Incredible as it may seem, these mistakes 
are among the very same ones committed by astrologers today! 
    To cite just one he louses up the division of the ecliptic into 
four equal quadrants. He makes the ascendent (I use the Latin 
derivative), mid-heaven, descendent, and sub-heaven at equal spacing 
around the ecliptic and then divides each quadrant into three equal 
segments to form the 'houses' of astrology. Thus each house is a 30 
degree slug of ecliptic fixed on the horizon. 
    This is wrong, in spite of his earlier careful description of the 
ecliptic as an inclined great circle against the celestial equator. 
Such a circle will present greater and lesser fractions of arc between 
ascendent and mid-heaven as the sky goes thru its diurnal rotation. 
The other three segments expand and contract is step with this first 
one. The houses, if still equal thirds of each segment, are then of 
unequal length of ecliptic, changing continuously hour by hour. 
    In fact, there IS such a scheme of houses in modern astrology, but 
it is now only one of about twenty different schemes in circulation. 
So badly do astrologers agree on what is the 'correct' way to lay out 
the houses, that computer astrology programs allow a choice of house 
to plot on the wheel chart! 
    Manilius doesn't mention the variation of house size with hour. He 
just sets them out as the orthogonal cut of the ecliptic. Perhaps 
because of this error, he goofs with finding the ascendent itself. He 
notes that it is 90 degrees, three signs, east of the mid-heaven point 
of the ecliptic. This is completely wrong save in the peculiar case 
when the equinoctial points are rising and setting. 
    For just a second example, he mixes up the circumpolar circle with 
the arctic circle. The latter is fixed by the obliquity of the 
ecliptic. because the obliquity changes only slightly over many 
centuries, this circle is fixed on the globe at about 66-1/2 degree 
    The circumpolar circle is a function of observer latitude on 
Earth. It is the radius, equal to your latitude, from the north 
celestial pole within which stars never set. They are the semperpatent 
stars. At the North Pole itself, this circle is 90d wide, coinciding 
with the horizon. At the equator, it is 0 degrees radius, or a point 
on the horizon. for New York it is about 40 degrees radius, cutting 
just at the last star in the Big Dipper's handle. 
    He knows and describes the constellations. He misses a couple but 
n the main he goes thru the 'classical' groups as we know them. He 
uses variant names for some, like Equus for Pegasus, Deltoton for 
Triangulum (which was at that time two overlapping triangles, like on 
the Sky Ceiling of Grand Central Terminal, and 'Helice' for Ursa 
    He lists the stars in each, discusses their place in the 
constellation creature. These are plotted in the Loeb edition on two 
starcharts, north and south hemisphere. He seems not to specificly 
catalog the stars, like Hipparchus or Timocharis did, but appears to 
just look up and pick 'enough' stars to fill out the constellation.
    The creatures are the 'classical' ones, the ones still in use 
today. The anatomical alignments were standardized by the turn of the 
1st millennium, so a star could be noted as in a this or that part of 
the creature's body.
    There are large gaps in the sky where there were no 
constellations. These were filled in with new ones in modern times, 
since the early 1600s. Some are in the 'north' sky, that visible from 
the Mediterranean latitudes. The other is a vast circular region 
around the south celestial pole, not known in ancient times. Manilius 
notes no stars in these areas, not even to say they are outside a 
Anatomical details 
    Manilius along the way in Astronomica gives detailed information 
about the anatomy of the constellation creatures. He notes that 
Sagittarius is always in profile, so he shows only his right eye (like 
the Jack of playing cards). Virgo has Icarus-like wings, Taurus has 
only the fore end in the stars, Pisces are two fish tied together, and 
so on. 
    If seems that some when in the previous century or two, somehow 
the constellation creatures were nailed into the stars. Before then, 
they were symbolic figures sitting in the area od stars assigned to 
them but not formally delineated.
    He also understands that some constellations were altered, perhaps 
recently relative to his time. He shows that Scorpius lost its claws 
to Libra. Such statements could, if other contemporary writings turn 
up, give deep insight to the formation of our constellations and maybe 
into some arcane feature of Greek and Roman culture. Did a committee 
look over the existing set of star grups and straighten them out? Was 
there some map, like in a palace floor, with the authority to set the 
constellations 'in stone'? We don't know. 
    We had a couple failed attempts to redo the constellations. 
Schiller in the 1700s worked the stars into figures from the Christian 
bible. The zodiac was the twelve Apostles, stars north of the zodiac 
were cast into figures from the New Testament; south, Old. This was a 
dismal failure, with floods, epidemics, wars, deep winters, failed 
farms. The attempt was quickly junked. 
    In the 1950s[!] Hans Rey wrote a book that had stick figures among 
the stars that resembled the creatures. For the most part these were 
OK but several were out of whack. Ursa Major faced EAST and squated on 
its hind feet. Pegasus was a complete horse facing NORTH with enormous 
wings, Cetus was a tea-kettle whale facing WEST. There were other 
alterations. Disease sweeped over the people. empires collapsed, 
burning sulfur spilled from the sky, tornados tore up whole cities. 
    In his later editions, Rey put the figures right-way-round with 
new connecting lines. And all was well over the land and seas. 
    Whether the calamities were CAUSED by or only URGED by the stars 
is a whole other story. That's what astrologers have to worry about.
    While the constellations were configured in standard poses by the 
time of Manilius, there was one that slipped thru the cracks, an 
important one. Cetus is part of the saga of Andromeda, starring 
several constellation overhead and in the south in evening during 
'Forgotten stars'. It was the creature threatening to gobble up 
Andromeda until Perseus rescued her. Manilius gives a detailed account 
of this story. The other constellations (leaving out Cepheus) are in 
proper configuration. Cetus is mentioned in only vague words. 
    As it turned out in all future history. there is NO definite 
description of Cetus! Altho the word is zoologicly a whale, the 
constellation was never shown as a whale. It was depicted as a 
fanciful monster with piscine fins, so it is a sea animal. About the 
only agreement is that the tail is to the west near Aquarius and the 
head is to the east near Aries. 
    Each uranographer, cartographer of the heavens, made up his own 
grotesque monster, while carefully keeping the standard poses of the 
other constellations. The only significant change is that the clothing 
may reflect the contemporary dress of the century. 
The Sea
    There are several constellations grouped that relate to water. 
Today astronomers call this region 'The sea'. There seems to be no 
interaction among these groups but it is a curiosity that water 
constellations are gathered here. 
    The constellations are Delphinus, Capricornus, Aquarius, Piscis 
Austrinus, Pisces, Cetus, Eridanus. They span a large section of the 
autumn evening sky, like during 'Forgotten stars'. Manilius in his 
speculations about the relations among constellations does not 
specificly mention this aggregation with such a common feature. 
    Astrology and astronomy of the transmillennium period of Manilius 
colminates in understanding the erratic motions of the planets. It is 
the mathematical and intellectual success of mastering the planetary 
system that makes Greek science so, well, awesome. If the heavens 
contained only the fixed stars, the study of astronomy would be more 
like that of geography.  
    Manilius, despite his intent to teach astronomy/astrology in his 
poem, just about totally neglects the planets! He gives only brief and 
simple description of them. He offers no example of how the planets 
move and how their positions are calculated. 
    He misses out all study of the Moon, her phases, irregularity of 
movement, nodes and apogee, eclipses. The Moon was, of all the 
planets, the most tricky to deal with and get the numbers right way 
round for. Yet the position and motion of the Moon are crucial for 
astrology for finding, among other things, the Moon sign at birth. 
    I myself see this a astounding for in his time the work of, say, 
Hipparchus and Apollonius, with their orbit model of the planetary 
motion, was circulated among learned folk. 
    Thus, Astronomica is like a discussing of a street, explaining its 
alignment, profile, markings. Having done that, there is then nothing 
substantial about the location and movement of traffic. 
    Comets in the Greco-Roman era, and all the way thru the 1600s, 
were fearsome phaenomena in the sky. COming without warning or obvious 
cause, they shined brightly over the landscape with hideous shape and 
size. They moved about the stars with their own mind, growing and 
shrinking at will. The trampled over the constellations, within and 
without the zodiac with capricious speed and direction. 
    Unlike the planets, they yielded to no effort at prediction or 
analysis. What they meant was anyone's guess, and every one did make a 
guess. Uniformily it was for some catastrophe, sometimes proved true 
by a shortly-after disaster. Note that 'disaster' litterally means 
'wrong, or bad, star'. 
    Manilius offers several explanations for comets, the same ones 
as those carried forward into the 1600s, One item seemed specially 
curious. He hazards that a comet is a star that is attracted by the 
Sun and then released back to heaven! This sounds awfully close to 
recognizing the sight of a comet near the perihelion of its path!! 
    However, there seems to be no independent mention by others that 
such a fact was known. Comets CAN appear to approach and then reproach 
the Sun. Others have such cockeyed paths that there seems to be 
relation to the Sun at all. Halley's comet in 1986 seemed to past by 
the Sun rather than loop around it. The Sun could merely have been in 
the way of its heading.
    Comet Holmes, quite a year ago in 2007, was a faint known periodic 
comet attracting no public attention. Suddenly it just blew up! The 
luminance equaled other bright stars in the sky such that people 
watched it from Manhattan street corners! and it shined in a night sky 
far from the Sun. 
    With the extreme variation of comet paths and the overall rarity 
of bright showy comets, it is hard to believe that there was a 
positive awareness that comets came onto the Sun, whipped around it, 
and flew back to deep space. 
Other worlds
    In Manilius's time it was realized that the stars were very far 
away. How far was a matter of philosophic argument. They could not be 
close, else they would show a perspective shift from place to place on 
the Earth. By the way, it was a well-known fact that the world is 
round, like a sphere. There was no 'flat earth' mindset, even among 
the public. 
    The distance from earth to Sun was unknown but appreciated to be 
pretty huge. It was already by Manlius's day worked out that the Sun 
was about 40 times farther away than the Moon, The Moon was reasonably 
accepted to be 30 Earth diameters away. Hence, a working figure for 
the Sun's distance was, uh, 1,200 times the Earth's diameter! 
    This a way too short, but to the ancient world it was humongous. 
In would make the Sun in linear size about 12 times bigger than Earth, 
an other amazingly huge statistic. 
    If the Sun was removed far enough to dwindle to a point to the 
bare eye, one arcminute diameter, how far would it stand? It would be 
about 31 times farther from Earth than the real Sun, or 31 
astronomical units. 
    This would put the Sun out near Pluto. In the ancient world it 
might as well be in heaven itself. The cosmos to the Greek and Roman 
mind was a compact place, with planets circling in nested spheres with 
narrow kerfs between them. The stars were in a outmost shell beyond 
the planets. 
    The Sun at 31 AU would still be a blinding dazzling 'star'. It 
would light up the ground with the strength of about 1,000 Full Moons. 
By the 1600s it was recognized that the stars are vastly more remote 
than the planets. They could not be reflecting sunlight, but are orbs 
producing their own light. They could be entire other suns. 
    Since the stars are way dimmer than that by orders, they must be 
much farther away. May they be really as points? From them we would be 
mere points. Manilius doesn't quite propose that there are worlds out 
there like Earth, probably because he believes, in other parts of 
Astronomica, that the heavens exist to interact with Earth and not 
just stand around it. 
    At the same time, it seems that he, and probably others unknown to 
us, had the suspicion that the cosmos is a lot bigger than commonly 
allowed. It could be so big that from an other star we would be 
vanishingly small to its eye. 
    Such immense remoteness would call into question the source of a 
star's light. This was not specificly brought up until the 1500s with 
the debates about the heliocentric system of planet orbits. If the 
stars are really vastly remote, they can't be reflecting sunlight. 
They must produce their own light, and, thus, be suns in themselfs. 
Ergo!, as suns they got planets. Manilius makes no such speculation. 
    Manilius employs virtually no maths in Astronomica. Here and there 
are simple arithmetic, all coded in poetry. Since computation of the 
motion and position of the planets is essential for a proper working 
of astronomy/astrology, this absence of mathematics at first seems 
    He limits to descriptions of the planets and their qualities when 
in a this or that part of the zodiac, without showing how to find when 
a given planet is a particular sign. In this respect, Astronomica is a 
failure for instructing the reader in the actual practice of astrology 
or astronomy. 
    Why would Manilius, a well lettered fellow, skip math? There are 
two plausible causes, among many, that I can appreciate, First is that 
it would be essentially hopeless to write any but the simplest of 
arithmetic into poetic verse. Try coding 
    (ecliptic latitude) = (longitude of ascending node)
                        + (inclination) * sin(argument of latitude)' 
in iambic pentameter. 
    The other, prevalent today!, is the general aversion to maths 
among even knowledgeable fans of astronomy. Virtually every book, 
magazine, article written for amateur astronomers dutifully shivs all 
but the most trivial mathematics from it. Computations may be 
described in qualitative terms but the material offered does not allow 
the reader to personally exercise the maths. 
    Of worse a state is the litterature that plays down mathematics or 
puts it as too advanced and beyond the reader. The amateur astronomer 
is led to believe that he not only does not but can not progress into 
the more independent levels of the profession. 
    The result is rather pathetic. On the whole, amateur astronomers, 
while enthusiastic about the profession, are constrained to marvel at 
pictures and films and to recite facts and figures about the stars. 
    So, it is possible that Manilius was such an 'amateur astronomer', 
lacking the math skills needed to complete Astronomica as a workbook. 
    By the way, this dismathematication, if there be such a 
pedagogical term, pervades many 'amateur' pursuits. As just one 
example, in New York there is substantial fandom of rapid transit. 
There are several transit clubs, with newsletters, excursion trips, 
libraries,. Fans are commonly densely rich with descriptions of all 
aspects of transit operations, to the point of arguing for possible 
modification of existing lines or construction of new ones. 
    However, a vanishingly few are able to compute the angle of 
banking for a curved track, dispatching of trains thru a junction, 
placement of signals blocks. The means to do these tasks is to hand in 
transit litterature and the maths can be done with a calculette. Yet 
instantly a fan approaches the need for such work, he flees like loose 
litter before an oncoming train.  
    We really don't know why or how the constellations were deployed 
across the stars as they are, why Corona is near Bootes, Orion near 
Lepus, and so on. Except for the ones in the Andromeda story, the 
constellations seem to be aloof from each other, each with its own 
story unrelated to its neighbors. Even for the Andromeda group, the 
only cohaesive grouping of stars with any logic or reason to them, 
there are the intrusions of Pisces and Triangulum among them. 
    At any rate, Manilius in Astronomica indulges in the interaction 
among groups. He alludes to Sagitta being with the bird constellations 
of Cygnus, Lyra, and Aquila (Lyra was also a Vulture). The arrow us 
used to catch birds in flight. 
    He elsewhere makes out the Milky Way as the Forum in Rome, on 
account of the gathering of stars along it, like crowds of people. He 
allies some stars to the honor of Augustus and his administration of 
the empire. May some of this musing be patronage? The emperor relished 
such praise and invoked the stars to prove his rank and status. 
    The influence of stars outside the zodiac is the realm of 
extrazodiacal astrology. This is a niche or fringe field, essentially 
disregarded by today's mainline astrologers. 
    In fact, astrologers often ignore the actual stars along the 
zodiac and fixate on the downrange elongation of the planets from the 
vernal equinox. Saturn does such-&-such because it is in the 5th 
degree of Gemini, not because it also sits with star mu Geminorum near 
that point. 
    As precession pulls the vernal equinox uprange, to the west, along 
the ecliptic the stars against a given degree of the ecliptic also 
slide west. That caused the signs to be offset from the constellations, 
with, say, sign of Gemini covering most of present day Taurus. I can't 
say for sure, but the neglect of the very stars may be the astrologer's 
work-around against the effects of precession. 
    This topic wasn't part of the presentations, but came up in the 
banter of the breaks and reception. Manilius seems to say nothing 
about time and calendar as such. he lived in a period when the 
calendar was revamped by Augustus out of a confused application of 
Julius's reform a generation earlier.
    Julius Caesar in the 40s BC cleaned up the Roman calendar in 
several ways. he regularizd the month names and days in each month. he 
introduced leapday to help keep the seasons in line with the dates. He 
renamed the fifth month from Quintilis to Julius, our July. 
    The year then began with March, as it did until the 1600s. As each 
country shifted the year start to January, the instant final old year 
was allowed only ten months. 
    However, no attempt was made to rename the months to reflect their 
new sequence. October, the old eighth month, is still October, now the 
tenth month. The last old month was February, given the days left to 
finish out the year, then 29 day. The day count per month remained the 
same with the shift of year start, so February inside a year still has 
a shortfall of days compared to the other months. 
    The Julian reforms, constituting the Julian calendar still used 
for various cultural functions, was not applied consistently across 
the empire. Leapdays were added by local officials as they wanted and 
day count per month was erratic. By Manilius's youth, there was a 
dispersion of calendar which Augustus had to deal with. 
    Hence I suppose that Manilius engaged in debates, in the local 
forum, about the calendar and the ideas Augustus was considering. Such 
arguments would include discussion about astronomy concepts, solar 
motion, seasons, lunar pahses, and all that.
    Augustus, amoong other things, put the leapday plan on a definite 
footing, declaring 8 AD to take a leapday and to add one every four 
years there after. This time the reform stuck, right up to today. 
    In addition to getting leapday back on track Augustus took over 
the sixth month Sextilis as his own Augustus, our August. He noted 
that it had only 30 days against Julius's month of 31. He captured one 
day from February at the end of the year. This made Augustus also 31 
days but left February with only 29, where it stands today. 
    However, before Augustus and even before the Romans built their 
calendar a few centuries earlier, we astronomers have to place events 
in a consistent continuous chronology. We can't cite dates in what 
ever calendar happened to be in force for each event. The conversions 
among them would be an irritating chore. 
    We created an artificial Julian calendar that rolls back from 8 
AD, with leapdays every fourth year no matter what. We use the months 
and days of the Julian calendar. Thus we can speak of an event taking 
place on 14 April 2351 BC when there was no April or concept of 'BC'. 
This is a means of allowing computations under a uniform system of 
chronology, however far back we care. For all future events we use the 
Gregorian calendar, likely no matter if it is tinkered with many 
centuries from now. 
    Ny the way, the switch from Julian to Gregorian in 1582 was not 
simultaneous all over the world. Many countries stayed with Julian for 
decades and centuries after then. Russia, for instance, went to 
Gregorian in the 1920s, which explains why the 'Great October 
Revolution' is celebrated in November. 
    Astronomy computer programs invariably force the Julian-Gregorian 
change in 1582 regardless of where the observer is located. It is 
crucial to examine results for observers in places that did not go 
over to Gregorian in 1582. Serious mistakes can come from this slip of 
Croton gatehouse 
    If you come to Columbia University for any visit, you should treat 
yourself to a walk around the campus and nabe. There are dozens, if 
not a hundred, points of interest to enjoy. These are ampla mente 
discussed in visitor guides. I here briefly point out only four. 
    At 119th St and Amsterdam Av stands a Croton gatehouse. This is a 
stone sqaurish blockhouse on the corner, fenced in and disused. It is 
sometimes called a pump house, but the Croton water works had little 
pumping. It was a free-falling flow of water from the mountains in 
upstate New York, as is the present evolved system. 
    It is landmarked and subject to restoration in a historical 
context. It governed the flow of water thru the Croton aqueduct, which 
here runs under Amsterdam Av, sealed and abandoned in place. 
    The Croton project took about ten years to build ub the 1830s-40s 
and today is the oldest continuously operated water works on earth. 
When the City studied the water supply of European towns, preparing 
for its own new system, it learned that what ever reliable plentiful 
sanitary water the towns had was furnished by the remains of Romans 
water works! 
    Hence, the Croton system was modeled after the Roman method and is 
the first such water service built in some 1,500 years. The last 
before it perhaps was that of Constantinopolis in the 300s AD. 
    There are many relics of the Croton project. They are under 
consideration for a 'Croton trail' of pylons and markers along the 
aqueduct route, similar to the Heritage Trail in Lower Manhattan. The 
entire path, except for short segments, is under city streets. It 
could stretch from Van Cortlandt Park, across the Harlem River on High 
Bridge, thru the lakes in Central Park, to the New York Public Library 
on 42nd Street. 
Columbia Sundial
    About halfway between College Walk and Butler Library on the 
north-south axis of the core campus, is a two-tier drum. People use it 
as a stool to set on, but otherwise give little attention to it 
despite its commanding location and hefty 3ish meter diameter. . 
    It has two sunken bronze tablets with markings for dates and one 
for a motto 'Horam expecta veniet' (Expect the hour; it will come). It 
appears that the date tablets are symmetrical across the geographic 
meridian of the University. 
    When installed it had a 180cm granite sphere on top as the gnomon, 
but now it is missing. When the shadow of the ball sat across the 
instant date, on both tablets, it was local noon. I don't know if a 
correction was built in for equation of time. 
    In 1946 the sphere was removed because of cracks that threatened 
to spall off dangerously large pieces. Its seat on the drum was filled 
with a newer stone to level off the top surface. 
    In 2001 the ball was discovered in private hands in Ann Arbor, 
Michigan, intact as it was in the 1940s. On and off the University and 
concerned patrons are trying to recover the sphere, refurbish it, and 
place it back on the sundial. 
Pupin Hall
    When the original campus was planned in the late 1890s, the 120th 
Street side was reserved for science pavilions. Three were marked 
across this side, of the size and bulk of present Pupin Hall. 
    When this one pavilion was constructed in the 1920s, it was merely 
the 'physics hall'. It was named in the 1930s for physicist Mikhail 
Pupin of Columbia, who died shortly before. 
    Pupin Hall has the first high-elevation observatory ever built and 
remains today the highest such facility above grade level. The 
original telescope was replaced about 10 years ago with several 
smaller ones, which are used for public viewing on certain nights. 
    In the halls of the many floors are intriguing displays about 
physics, astronomy. There seems to be no published guide for them. I 
suppose each office takes care of its own exhibits with little regard 
to those of other offices. 
    Mikhail Pupin is also honored near Madison Sq by a bust at the 
Serbian Christian Church. Now out of sight from the street, it'll be 
moved to a vacant pedestal in front of the church. This pedestal 
stands next to a matching one occupied by Nikola Tesla. 
116th Station
    This station, at 116th St and Broadway, is more spacious and airy 
than others along the Upper Broadway line. Parsons, the chief engineer 
for the New York underground railroad, was a trustee of Columbia at 
the time as well as an 1882 graduate from its old campus. He was proud 
of the new campus next to his subway, so he designed this station more 
lavishly than the others. 
    The station's mezzanine once was reached from the street thru a 
headhouse in the mall of Broadway, like those at 96th St, 72nd St, and 
Bowling Green (off-street). In about 1966 it was removed and the 
mezzanine was extended to the sidewalks of Broadway. Stairs there 
communicate to the mezzanine on both sides of Broadway. 
    Every so often a movement springs up to build a replica of the 
headhouse as a visitors office for Morningside Heights and the 
University. Nothing so far came of this idea.
    The station was renovated in the 1990s, the mosaics restored, the 
white and blue tiles carried into areas where it was destroyed or 
never applied. There's an artwork on the downtown platform, a chair 
fixed to the floor, which you may sit on. The station is landmarked. 
    The decorations, of a Greek and Roman style typical of the early 
subways, repay closer inspection. The 'Columbia University' name 
tablet has a Lamp of Learning at its upper right and a Book of 
Knowledge at the upper left. The tablet is the largest, about two full 
meters long, of all on the initial section of the subway. 
    The shields along the top of the wall alternate Columbia's Alma 
Mater and '116'. This is a unique feature for this station. Other 
stations have a single caption in their name shields. 
    Friends ask me if the crossed lines in the border of the name 
shields are swastikas. Yes! The intersections of the rectilinear 
beading winding thru the frame deliberately form honest-to-goodness 
swastikas!! This device is found at certain other stations of the 
Upper Broadway line. 
    The design has nothing to do with the Nazi regime. The word, 
sounding German, is found in writings from the Middle Ages, at least, 
coming from, I'm told, India or Africa. The sign was a lucky charm 
from at least the Greek era and was in routine wide use in the time of 
Manilius. Hitler expropriated this ancient honorable symbol and 
stigmatized it. 
    The design, four Greek letters gamma butted foot-to-foot in a 
pinwheel pattern, is a 'gaamadion'. It gives good luck, fortunes, and 
well being to its bearer. This is the sense of the sign on the subway, 
despite what the kooks may argue. 
    In astronomy the gaamadion represents the diurnal motion of the 
stars about the north celestial pole, Thus it spins counterclockwise 
with the spar of the gamma trailing the upright. If the gammadion is 
part of a window or grill, one side shows it mirrored. The intent and 
meaning are the same. 
    Some artists and designers try to revive the traditional meaning 
by using the Greek name, but they scored little, if any, success. 
    Should an astronomer today study Astronomica? At the least, do 
take out a library copy and leaf thru it. If your Latin is rusted out, 
or you lacked it in your upbringing, read the English side of the 
text. It IS a tough plow on account of the poetic writing. The absence 
of numerical examples, all coded in verse, aggravates the chore to 
understand what's going on. 
    On the other hand, there is probably very little to actually learn 
about early astronomy. Manilius goes over the simple topics of the 
celestial sphere, shenanigans with the zodiac, and repeated excursions 
into his own stream of thought. All can be quite interesting but 
pretty sure not of much incremental value to you as an astronomer. 
    Yet as a period piece, a unique specimen of what a Roman person 
thought about the heavens, it can be extremely valuable. It also gives 
deep insight to the workings of a society under Augustus at the crest 
of imperial Rome. It will also give you an enriched Latin vocabulary, 
orders beyond the little dictionaries you made do with in school. 
    Astrologers tend to disregard Manilius, except to carry him as a 
legacy figure to substantiate their trade. Likely none ever read it, 
being that it is a poem and not a narrative text. All translations I 
came across are hardly easy for a modern person to comprehend. Hence, 
many of the astrological items in it are missed out from modern 
astrology, not that they could augment its validity. 
    The conference was a scholarly one, with speakers shifting between 
Latin and English, having just about no visuals but the handouts, and 
engaging in high-level chats. To blend in, you really had to be versed 
in many fields of history, language, astronomy, astrology, sociology, 
and to have a general world wiseliness about you.