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Astronomy is a very ancient science, divinely entrusted to
mankind from the time of Adam Protoplastus. It is by far the most
prestigious, insofar as what is celestial and sublime certainly
surpasses what is terrestrial and inferior. This divine astronomy,
I say, drawing its origin from the very senses of our eyes,
observing the wandering movements of the stars to the outer
reaches of the world, has vexed both the geniuses and the abilities
of the most eminent men for the long span of time since the
beginning of things. The majesty of the highest and thrice-greatest
God is surely so great that the wisdom of his works can not
be exhausted by any of his creatures.
But since the gaze of the eye alone was unable to capture
all the mysteries of the celestial theater - which are wonderful
beyond measure - and all the intricate-appearing differences,
for which subtlety and accuracy was needed, various craftsmen in
every age have contrived means and instruments by which their
vision might be aided in perceiving the obscure motions of the
stars. Hence, there are those columns, which Joseph, the writer
about Jewish matters, reports the descendants of Adam had built
in Syria and had their discoveries inscribed on them, so that
those who came after them would remember.1
The very great and
extravagant pyramids of the Egyptians and other peoples also
pertain to this. And many other devices that were constructed for
this purpose by the most ancient kings were once observed, such
as in India, Syria, Arabia, Chaldea, Ethiopia, Egypt - especially
one in the Colonnade of Alexandria2
- and also elsewhere
in the surrounding regions, where men diligently applied
themselves to the study of the stars. For, in astronomy it is
first of all necessary to obtain very many observations, taken
over a long period of time by means of instruments that are not
liable to error. And then, through geometry, using convenient
hypotheses that have been contrived, these observations are
arranged into continuous quantities and a motion that is both
circular and uniform (which celestial bodies natural strive for
and execute without ceasing). But through arithmetic, they are
arranged into discrete quantities, so that the circuits of the
celestial bodies are determined for particular times and
places.3
But from all those who have strenuously worked in this field,
only those observations that were recorded by
Timocharis,4
Hipparchus,5
Ptolemy,6
Albategnius,7
King Alphonso,8
and in the previous generation, Copernicus,9
have come down to us, although the
traditions of the two former, at least, depend on Ptolemy's
account.
One can understand which instruments these men chiefly used
for measuring the stellar phenomena from what they have written.
Among them I find these three to be excellent: the parallactic
rulers,10
the zodiacal armillaries,11
and the torquetum, which the
arabs preferred to use (as also the plane astrolabe). The rest
are of lesser importance. However, perhaps there were many others
that were not mentioned in the literature and have not at all come
down to us, which easily could have perished in the such great
confusion and so frequent changes of the world, in which so many
wars and devastations have occured repeatedly (which should be
lamented). More recent astronomers added the quadrant, the radius,
and the astronomical ring, and then also some of still less
value. However, the fact that the motions of the stars, which are
accurately considered in our time, do not at all so reveal
themselves as the calculation derived from the observations of
other experts, whether ancient or recent, predicts, causes us to
suspect, non unjustly, that the means and instruments that they
used in the course of observing were by no means free from defects
of every kind. Even if the rest of the data were ignored,
the locations of the fixed stars themselves, which are placed
differently than the Hipparchian designation indicates, as recounted
by Ptolemy and from him propagated to us, demonstrates
this sufficiently. This must have been the case even for the
ancients, when emperors and kings readily provided funds for
constructing such instruments, whereby they would be magnificently
made from a solid and metallic material and rightly have
suitable size. Even more so for those that Copernicus made at his
own expense in the previous generation, being sufficient neither
in the solidness of the material nor even the size proper to those
uses to which they were appointed, as is partly evident from
his book De revolutionibus,12
and partly from those instruments
considered to have been used by him that which still remain. One
of these, clearly a parallacticum, entirely made of wood, not
quite suitable for observations, is in my possession.
On this account, thinking carefully, ever since my youth,
whether it would not be possible for this insufficiency to be
relieved, I then went to the trouble of successively constructing
astronomical instruments with great care and at unbelievable
expense. With these it was possible to examine the stellar
phenomena more accurately than was done by our predecessors (without
meaning any disrespect).13
But although those that I made in my
youth, when neither my knowledge nor my judgement were sufficiently
mature, did not quite accurately attain the desired goal,
nevertheless, as I became older and my experience fuller, I at
length acquired other, larger and more excellent instruments and
I saw to it that they were skillfully elaborated, of such a kind
as perhaps hardly any earlier age has seen - ones that exhibit
the highest accuracy and dependability, as it was intended they
should. Moreover, I constructed various and multiple instruments,
for obvious reasons: First, because I would prove an observation
to be free of all error, by investigating the same one by different
means, and then, too, so that if some of them would produce
any hidden defect (also because Ptolemy is seen to complain
loudly about the same kind of instruments, which were made of solid
metal and once used to stand in the Colonnade at Alexandria),
others would then be at hand, which would correct it and demonstrate
their exact dependability, and in addition, so that the
observers' sharp-sightedness in sighting the instruments and
their diligence in reckoning - there should be at least six or
eight of them - to be compared in turn, might be examined, with
no one of them having knowledge of what another has determined.
To say nothing about the fact that the variety itself makes the
observers more diligent and more eager, and is in itself delightful.
It also happens that among those things that come to be
explored, some comply with certain devices better than with
others in order to be investigated properly, with the result that
some require certain known altitudes only, and certain azimuths
together with these, while several demand only distances, requiring
certain declinations, certain equatorial distances. Some
instruments are suitable for obtaining longitudes and latitudes
at the same time, and others right ascensions and declinations,
and so on with the rest of them, since being administrated by various
means, they better serve celestial observation. Therefore,
even for this cause alone a large number and variety of instruments
is certainly necessary.
Seeing that those things that are invented and built by men
in the exercise of the arts should be communicated, for a liberal
society of human beings and for the propagation of the arts to
posterity, I considered that so sublime and useful devices should
not be reserved for me alone, but shared with others, if (as I
hope) there are those to be found in other places, who are
touched by so difficult a concern. And to that end, I am
submitting to the press those devices which I have had in use
hitherto, delineated and represented by their images, insofar as
it was possible that these be executed so quickly. I wished to
present them to the public accompanied by a concise explanation
of each of them, as will be evident in the following pages. Moreover,
in arranging them, I have observed this method chiefly:
first I described those devices that investigate the altitudes
and azimuths of the heavenly bodies, some of which reveal only
altitudes, but some both altitudes and azimuths. Here the smaller
and less important instruments come first, and the rest, those
that are greater and grant more exact precision, follow. That takes
care of the first eight, although later, too, I display and
mention a certain very large quadrant, intended for altitudes
only, which I once used at Augsburg, in my youth. Why, for what
reason it was made, will be mentioned later.
Then follow the equatorial armillary instruments.14
The first among these,
the zodiacal armillary, exhibits the longitudes and latitudes
of the heavenly bodies with greater facility and dependability
than perhaps was done by the ancients. And since it does not hit
the nail on the head (as they say), for certain reasons set forth
there, three others follow, equatorial armillaries, the first of
which consists of three circles and an axis. The second requires
four with this. But the third, and the greatest, accomplishes the
whole matter with one and a half circles and an axis, stretched
around, as in the rest, and shows declinations as well as right
ascensions, together with the distances from the meridian, as
precisely as possible.
In the third group, I have arranged those instruments that
serve for examining the angular distances between the stars and
one for obtaining rather large distances as well as smaller ones,
so long as they do not exceed a sixth part of a circle. There are
among these four in number that are devoted to measuring
distances, although I also possess more, which it was not
possible to manage to draw and have cut into wood quickly enough.
Among the ones displayed here, there is one that takes down the
angular distances of the heavenly bodies even much greater than a
sixth part of a circle, up to a half circle itself.
Finally, a certain instrument that I used on the new star of
the year 1572, a star to be greatly wondered at, seeing as it was
located with the altitudes that were to be taken down in an
especially declined place, has been added after the previous group,
as has that enormous quadrant, which I mentioned previously, and
which I had built for me many years ago near Augsburg, in the
garden of councilman Paul Haintzel, whom I remember fondly. He
was very eager about these pursuits while he lived. Since it no
longer exists there - it lasted only for five years - I did not
wish to give it a place among the rest of the instruments that
measure altitudes, but rather I placed it at the end. And after
this, there is a certain steel quadrant, which I brought up
earlier, yet is placed here otherwise.
When that was done, I at last added a short description of
other of my instruments, which are not yet drawn and which I am
not ready to exhibit, where also is added some indication of those
that I am still thinking of constructing to great advantage. I
will communicate a fuller explanation of each of these - those
that are ready to use as well as others that are to be elaborated
- in due time, when the occasion warrants. But now, striving for
brevity, I found it agreeable to touch on those instruments that
pertained to this matter with at least a few words, even though
their images were not yet prepared.
Finally, as a finishing touch, I explain that very great
globe, made of brass, which comprehends 1000 fixed stars that
were placed by me with the greatest care and precision many years
ago now, insofar as something so difficult and serving multiple
uses can be elucidated in a few words. Then I come to the end of
the description of the instruments. To all this I have attached
some mention of those things that have been thus far accomplished
by me and those that remain to be completed in the future; and
then I have added a few particular letters of eminent men
commending the task at which I have labored. Indeed, in place of
a kind of appendix, it seemed reasonable to add in addition the
architectural work, portrayed and displayed, which reveals to the
eyes the structures that were designed by me and produced for
this use in the several years preceeding, granted that to certain
people it could seem to be not wholly necessary at this place,
since indeed those who will have wanted to apply serious
attention to them and are equal to administering the funds will
easily devise by themselves plans for the buildings brought together
here, especially when the appropriateness of the place has
been grasped. However, so that I might show in advance some kind
of idea in accordance with those things that have been elaborated
by me in the area immediately around them, I decided that it
would be not wholly beside the point if I would attach these
astronomical buildings, displayed together. And indeed, these are
just the things for which this book was completed, as will become
evident to one who is viewing them. But if other things have been
mixed in and added, the prudent reader will discern them by
himself without difficulty, so there is no need for me to advise
him. But to you, august Emperor Rudolph II, gracious lord, I
offer, relate, and dedicate this and my other astronomical labors,
humbly and with an effort devoted to the public good. For,
just as your imperial majesty, as the highest preeminence, far
surpasses other, lesser men, so too your imperial majesty is not
unaware that it is your honor and duty to emulate in immensity
the heaven and the celestial, which far surpasses the terrestrial
and the common. And for this reason these sublime studies should
be valued and cultivated.
That ancient poet Manilius seems to have reflected on this
when, writing about this celestial art to Augustus, the second
monarch of the Roman Empire,15
he distinguished it with this elegy,
not undeservedly:
[Moreover, nature proffered her aid
and of her own accord opened up herself,]
deigning first to inspire those kings
whose minds reached out to heights bordering on heaven.16
Therefore, most august caesar, kindly receive those tasks
that I have borne for many years now, almost from my childhood,
with untiring labor and at unbelievable expense, by which that
divine and greatly royal science of astronomy, which possesses a
chief place, before all others, might finally be restored to
wholeness and handed down to posterity more correct than at any time
before. I believe that both me and this work itself, which I
treat with remarkable enthusiasm in the following text, will be
as agreeable to you as possible. The more that the honor and
majesty of the best and greatest God, which shines in celestial
things more than in other aspects of this great world theater,
comes to be known more correctly, the more it is increased and
esteemed among the inhabitants of the earth; Moreover, since to
preserve, protect, and promote for all posterity these so
excellent things, which are almost extraordinary in human
affairs, will not diminish Your Imperial Majesty's fame and reputation,
may it shine brighter for that and endure as long as the
sun and heavenly bodies last, because from these alone, which are
perpetual and constant - of a celestial kind - one may acquire
an eternal name and undiminished honor. As for the rest, the
sublunary and terrestrial, just as they are liable to multiple
changes, so also whatever glory is obtained from them is fleeting,
fickle, and inconstant, and does not emulate eternity, as
do those celestial things about which I am speaking. May that
highest and inscrutible author of these things consider it worth
while to bestow on Your Imperial Highness a good mind, bodily
health, peace, and an abundance of the good things of this world,
with a calm and happy empire, chiefly for his glory and the
illumination of things created by him and for the benefit of your
subjects, for which I wish and pray humbly and from my heart.
May Your Imperial Highness be well and kindly receive this
little omen of this new year, which I offer with what reverence I
can as a token of my courageous and humble spirit. Communicated
from the Ranzov Castle, Wandesburg, which is near Hamburg, on the
border of Germany and the Cimbrian Penninsula, on the day before
the first day of January of the year 1598 of the common Christian
era.
1 Iosephus Flavius, Jewish historian from the
1st century A.D. He took part in the Jewish insurrection at the
time of the emperor Nero but he went over to the Roman side and
was called Flavius owing to the support of the Flavius family.
His Greek, originally Aramaic book The Jewish War,
describing the reasons for and events of the war in 66 to 73
A.D., is based on his experience. Jewish Antiquities
describes the history of the Judeans up the period of Nero. His
Autobiography and Contra Apion are his other
treatises dealing with the relations of Judeans and Romans. - In
Jewish Antiquities (I,68-71) he wrote: (Descendants of
Seth, the son of Abel)... "also discovered the science of
the heavenly bodies and their orderly array. Moreover, to prevent
their discoveries from being lost to mankind and perishing before
they became known - Adam having predicted a destruction of the
universe, at one time by a violent fire and at another by a
mighty deluge of water - they erected two pillars, one of brick
and the other of stone, and inscribed these discoveries on both;
so that, if the pillar of brick disappeared in the deluge, that
of stone would remain to teach men what was graven thereon and to
inform them that they had also erected one of brick. It exists to
this day in the land of Seiris." (translated by H. St. J.
Thackeray, Josephus in nine volumes, IV, Cambridge, Mass.:
Harvard Univ. Press; London: W. Heinemann, 1978). Cf. Opera
omnia I, 148, where Tycho paraphrased this passage and pointed
out that one of the columns was still in Syria (instead of in
Seiris, which is nowadays unidentified) in the time of Flavius.
On this basis he argued for the antiquity of astronomy:
"And in this way the knowledge of the stars got from the sons of
Adam to their descendants."
2 By the term porticus
Tycho meant here the
Museion in Alexandria, i.e. the temple of the Muses. This was a
famous school with a rich library, built by the Ptolemaic dynasty
at the end of the third century B.C., where scientific life was
concentrated for several centuries.
3 Here Tycho uses mathematical terms that are in
common use today: (continuae and discretae
quantitates).
4 Lived around 290 B.C. Together with Aristyllus he made up
the first catalogue of stars.
5 Greek astronomer (2nd
century B.C.) working mostly in Rhodes. He made extensive
observations of stars and planets, produced a new catalogue of
stars, discovered precession (by comparison with observations
made by Aristyllus and Timocharis), and improved the theory of
Solar and Lunar motion by introducing the eccentrics and
epicycles. He was also an outstanding mathematician -- he
developed trigonometry for both planar and spherical triangles
and he composed the first goniometric tables (of lengths of
chords).
6 Claudius Ptolemy (100 ? - 178), Alexandrian
astronomer, mathematician and geographer. His treatise
Megale syntaxis
(Great system) was translated into Arabic with the
title Almagest, which it retained in the Latin translation.
It was the basis of astronomy until Tycho's time. Ptolemy
summarized the knowledge of his predecessors, especially
Hipparchus (see footnote 5). His main original
contribution was the improvement of Lunar and planetary theories
(within the framework of geocentrical model). In the treatise
Geographike hyphegesis (Instructions on Geography,
abbreviated Geography) he explains the basis of geography
and cartography and he gives geographical coordinates of 8000
localities, measuring longitudes from the Canary Islands. Among
his other treatises, let us mention at least
Planisphaerium, with mathematical elements of stereographic
projection, Analemma, with elements of gnomonics,
Tetrabiblos, explaining astrology, Tabulae manuales, and
Optics.
7 Al-Battani (850
? - 929) wrote in al-Raqqa, along the Eufrates River, a series
of astronomical tables that were translated into Latin as De
scientia stellarum in the middle of 12th century by
Robert of Chester and later by Plato of Tivoli (Nuremberg, 1537).
Cf. Olaf Pedersen, Early physics and astronomy, Cambridge:
Cambridge University Press, 1993.
8 Alphonso X, the Wise (1221 - 1284),
king of Castille and Leon was well known as a lawgiver and writer.
He achieved recognition as a supporter
of the natural sciences, including astronomy. Around 1272 he
stimulated the completion of so called Alphonsine Tables,
one of the most widely used astronomical tables in the Middle
Ages. The tables were based on Toledean tables from the
eleventh century and they were refered to the year 1252 of
Alphonso's coronation. They were written originally in the
Castilian language, but they soon spread over the whole of Europe
in Latin translation (see e.g. E. Poulle, Les Tables
Alphonsines avec les Canons de Jean de Saxe, Paris 1984; they
are also included in the astronomical manuscript of the Czech
King Wenceslas IV from 1392 - 1393, held in Vienna,
Nationalbibliothek, cod. lat. 2352.). It was first printed in
1483 and other editions soon followed. In 1276 - 1277 Alphonso
commissioned a group of Jewish, Arabic and Christian scientists
(e.g. Rabbi Zag) to complete the astronomical encyclopedia
Libros del saber de astronomia (Book of knowledge of
astronomy, ed. Manuel Rico y Sinobas, Madrid 1863 - 1867),
partly based on translations of Arabic texts, and partly
original, with prefaces written by Alphonso himself. - On the
content of both treatises, see Owen Gingerich, "Astronomical
Scrapbook," Sky and Telescope 1985, 206-208.
9 Nicolaus Copernicus (1473 -
1543), Polish astronomer and author of the modern heliocentric
system. He was a clergyman and spent most of his life in service
to his diocese. The first treatise formulating his theory was the
Commentariolus (Nicolai Copernici de hypothesibus
motuum coelestium a se constitutis commentariolus), written
about 1530. Detailed explanation and argumentation was given in
his famous De revolutionibus orbium coelestium, published
in Nuremberg in 1543. Tycho Brahe referred to Copernicus as the
supreme astronomical authority and often compared their results.
10 That is, the triquetrum.
11 That is, the armillary sphere. Throughout
the text, Tycho used the plural of the noun armilla to
denote the armillary sphere, and we preserve this in our
translation.
12 Nicolaus Copernicus, De
revolutionibus orbium coelestium libri sex (On the
revolutions of the celestial spheres), Nuremberg 1543.
13 The phrase absit
invidia dicto (verbo) was often used by Titus Livius in his
treatise Ab urbe condita e.g. IX, 19 etc.
14 In the Tycho's text there is by mistake
armillae aequinoctiales.
15 Assuming that Tycho used the expression
Augustus in the sense
noble (as it is translated here), he really meant the second
Roman Emperor, i.e. Tiberius (governed 14 - 37 AD). If he had in
mind Augustus (governed 27 BC - 14 AD), he should have correctly
written that he was the first Roman Emperor. Marcus Manilius lived
and wrote during the epoch of both emperors but he devoted his work
to Tiberius only. His work was first published by J.J. Scaliger
(Paris 1579), hence the edition was accessible to Tycho.
16 Marcus Manilius, Astronomica I, 41-42. English translation
by G. P. Goold, Harvard University Press, London 1977, pp. 7 - 9.
The text in brackets was not presented by Tycho and is added here
to provide the context.
