123646
GAL 1 L
HIS LIFE AND WORK
BY J. J. FAHIE
MEMBER OF THE INSTITUTION OF ELECTRICAL ENGINEERS,
LONDON, AND OF THE SOCIETE INTERNATIONALE DES
&LECTRICIENS, PARIS
AUTHOR OF A HISTORY OF ELECTRIC TELEGRAPHY TO THE YEAR I$37
A HISTORY OF WIRELESS TELEGRAPHY, ETC.
WITH PORTRAITS AND ILLUSTRATIONS
LONDON
JOHN MURRAY, ALBEMARLE STREET,
RERRINT LIBRARY
** Sempre il novo che & grande appar menzogna
. . . al volgar debile ingegno ;
Ma imperturbato il regno
De' saggi dietro all'utile s'ostina.
Minaccia n& vergogna
No '1 frena, no '1 rimove ;
Prove accumula a prove !
Del popolare error 1' idol rovina,
E la salute ai posteri destina."
— PARINI : " L'Innesto del Vaiuolo."
"Anything new, which is great, appears false to the ordinary weak mind, but
the rule of the wise obstinately continues its way unmoved. Neither threats nor
shame checks or changes its course ; experiment follows experiment ; the idol of
popular error is throAvn down, and health to posterity is ensured."
DEDICATED
TO
ANTONIO FAVARO
PROFESSOR IN THE ROYAL UNIVERSITY OF PADUA, AND DIRECTOR
OF THE NATIONAL EDITION OF GALILEO'S WORKS, UNDER THE
AUSPICES OF HIS MAJESTY THE KING OF ITALY
IN ADMIRATION OF THE RESULTS OF HIS 25 YEARS7 ALMOST
EXCLUSIVE DEVOTION TO GALILEAN LITERATURE AND
AS A SLIGHT ACKNOWLEDGMENT OF THE HELP
HE HAS GIVEN ME IN THE PREPARATION
OF THIS VOLUME
BY HIS OBLIGED FRIEND
THE AUTHOR
PREFACE
THE history of the life and labours of Galileo is
pregnant with a peculiar interest to the general
reader as well as to the man of science and the
philosopher His brilliant discoveries the man of
science regards as his peculiar property ; the means
by which they were made and the development
of his intellectual character belong to the logician
and the philosopher ; but the triumphs and reverses
of his eventful life must be claimed for our common
nature, as subjects of deep interest and serious
meditation.
So wrote Sir David Brewster in the opening
paragraph of his biography of Galileo (" Martyrs of
Science," London, 1841). It is the object of the
present volume to give a fuller presentation, under
this three-fold aspect, of the life which Sir David
has only outlined.
In recent years materials for such a work have
been brought together which were not accessible
x PREFACE
when Brewster wrote. Imperfect collections of
Galileo's writings were published in Bologna 1656,
in Florence 1718, in Padua 1744, and in Milan in
1 808- 1 1 and 1832 ; but the first edition of anything
approaching a complete character is that of Alb£ri
in sixteen volumes, which was begun in 1842 and
completed in 1856. That even this collection is
defective in many important particulars is shown
by the fact that another edition was begun in 1890,
under the auspices of the King of Italy, and under
the direction of Professor Antonio Favaro of the
Royal University of Padua. Of this monumental
work, twelve out of twenty large volumes have
appeared. They contain all Galileo's works, the
works of adversaries annotated by him, and his
correspondence down to the year 1619, and supply
an inexhaustible mine for the student of science.
In exploring this for nuggets I have had the in-
estimable assistance of Professor Favaro, who has
given me many valuable hints, and has generously
placed at my disposal all his Galilean studies and
researches for the last twenty-five years. Thus I
am enabled to give a fuller and more comprehensive
history of the life and work of Galileo than has
hitherto been attempted, or, indeed, been possible.
Thanks mainly to Professor Favaro and his multi-
PREFACE xi
tudinous writings, my book contains much new
matter, and, what is more important, it avoids most,
if not all, of the numerous errors and fables which
previous biographers have little by little woven
into the life of Galileo.
For the benefit of students who may wish to
explore for themselves (and I promise them rich
harvests), I have given at the end of this volume
a short history of Galileo's writings, followed by
a list of works which I have consulted, and which
may be found useful. Speaking for myself, I have
to acknowledge my special indebtedness to (besides
the editions of Alb£ri and Favaro) the works of
Nelli, Venturi, and Drinkwater, and, coming down
to more recent times, those of Martin, Olney,
Von Gebler, and Favaro. The works of Nelli,
Venturi, Drinkwater, and Martin have been useful
to me in a general way. Mrs Olney's charming
volume and Favaro's " Galileo e Suor Maria Celeste "
have been largely drawn upon for Galileo's private
life, and for his correspondence with his daughter ;
while Martin, Von Gebler, and Favaro have been
the chief guides in my account of Galileo's relations
with the Roman Curia.
I have also to acknowledge my indebtedness to
Mr Arthur Berry, of King's College, Cambridge,
xii PREFACE
who very kindly read the proofs and made sugges-
tions of great value, which I was happy to adopt, and
to Mr H. H. Champion, The School, Uppingham,
for revising the scientific parts of my work. Mr
Champion not only corrected a few errors and
ambiguities into which I had fallen, but supplied
most of the material on which my rksum&s of the
Dialogues of 1632 and 1638 are based.
In my quotations of letters and documents I do
not in all cases give them in full. I mostly content
myself with extracts of the parts referable to the
particular matter in hand. I think it necessary to
point this out, as the quotations do not always
show where the ellipses occur.
CONTENTS
CHAP. j,AGK
I. EARLY YEARS TO APPOINTMENT AS PROFESSOR IN
PISA (1 564-1 589) I
II. GALILEO, PROFESSOR IN PISA (1589-1592) ... 22
III. GALILEO, PROFESSOR IN PADUA (1592-1610) . . 34
IV. GALILEO, PROFESSOR IN PADUA (1592-1610) — con-
tinued 59
V. GALILEO, PROFESSOR IN PADUA (1592-1610) — con-
tinued ......... 74
VI. GALILEO, PROFESSOR IN PADUA (1592-1610) — con-
cluded 98
VII. GALILEO QUITS PADUA AND RETURNS TO FLORENCE
(1610-1612) 116
VIII. GATHERING STORMS — FIRST APPEARANCE BEFORE
THE INQUISITION AT ROME — RETURN TO FLORENCE
(l6l2-l6l7) 146
IX. GALILEO IN FLORENCE (1617-1624) .... 178
X. FOURTH VISIT TO ROME — RETURN TO FLORENCE
(1624-1629) 204
XI. COMPLETION AND CONTENTS OF THE DIALOGUE ON
THE TWO PRINCIPAL SYSTEMS OP THE WORLD —
THE PTOLEMAIC AND THE COPERNICAN (1630-1632) 226
XII. PUBLICATION OF THE DIALOGUES — GALILEO AND
THE INQUISITION (1632-1633) .... 263
XIII. GALILEO AND THE INQUISITION (1632-1633) — con-
tinued 294
XIV. SENTENCE OF THE INQUISITION AND GALILEO'S
ABJURATION — EXILED TO SIENA (1633) . . 3**
xiii
dv CONTENTS
CHAP. TAGE
XV. GALILEO AT ARCETRI : COMPLETES HIS DIALOGUES
ON THE TWO NEW SCIENCES (1634-1636) . . 338
XVI. GALILEO AT ARCETRI — HIS LAST WORKS (1636-1641). 372
XVII. DEATH OF GALILEO— CONCLUSION (1642) . . . 400
BIBLIOGRAPHY ........ 433
LIST OF THE PRINCIPAL WORKS CONSULTED . . 435
INDEX 447
LIST OF ILLUSTRATIONS
PORTRAIT OF GALILEO IN 1635, AGED 72 . . Frontispiece
From Sustermans* picture in Uffizi Gallery, Florence
(Alinari Photo].
SUPPOSED BIRTHPLACE OF GALILEO, IN PISA . To face page 4
From photograph by Alinari , Florence,
MONASTERY OF VALLOMBROSA ....„„ 6
From a drawing "by A. H, Hallam Murray.
POSSENTI'S LAMP IN THE CATHEDRAL, PISA „ „ IO
From photograph by Alinari, Florence,
DIAGRAMS OF THE PULSILOGIA .... Page II
DIAGRAM OF THE BILANCETTA .... „ 1 6
FA9ADE OF THE UNIVERSITY, PADUA, tempo
GALILEO ....... To face page 34
From Favartfs paper in " Natura ed Arte" Milan% 1833.
GEOMETRICAL AND MILITARY COMPASS „ „ 42
From Favaro's *' Terzo Centenario di Galileo in Padova"
Florence^ 1892*
GALILEO'S HOUSE IN PADUA ..... „ „ 48
From Favaro's paper in " Natura ed Arte" Milan^ iSqj*
DIAGRAM OF AIR THERMOMETER ..... Page $2
From Nelli's " Vita c Commerdo Letter ario di GalUeo"
Lausanne^ 1793.
AULA MAGNA AND LECTURE-DESK, PADUA . . To face page 56
From Favaro's paper in "Natura ed Arte" Milan, 1893.
PORTRAIT OF GALILEO, AGED ABOUT 40 „ „ 74
From Favaro's " Terzo Centenario di Galileo in Padova^'
Florence,
CAMPANILE AND CHURCH OF SAN MARCO, VENICE „ „ 78
From pftotographby Alinari, Florence,
xvi LIST OF ILLUSTRATIONS
DIAGRAM OF GALILEAN TELESCOPE . . . Page 82
FACSIMILE SKETCHES OF JUPITER'S SATELLITES . To face page 90
From Fa.va.rrfs lt Terzo Centenario di Galileo in Padova> "
Florence, 1892.
DIAGRAM OF KEPLERIAN TELESCOPE . . . Page 94
GALILEO'S OBJECT-GLASS AND TELESCOPES . . To face page 96
From Fawtro's " Intorno ai Cannocchiali di Galileo"
Venice, igox.
DIAGRAMS OF SATURN'S RING .... Page 109
From Favaro's "Intorno alia Apparenza di Saturno
osseruata da Galileo" Venice^ TQOI.
SATURN'S RING AS SEEN BY HUYGENS ... „ IIS
From Huygen? £< Sy sterna Saturnium" The Hague, 1659.
THE TORRE DEL GALLO, ARCETRI, FLORENCE . To face page 238
From photograph by Alinari> Florence,
TITLE-PAGE OF DIALOGUE OF 1632 . . . „ „ 266
From Ventures " Memorie e Lettere di Galileo" Modena>
SANTA MARIA SOPRA MINERVA, ROME . . . „ ,,312
From old engraving tempo Galileo.
DIAGRAM OF PROJECTILE MOTION .... Page 357
PORTRAIT OF GALILEO, AGED ABOUT 75 . . To face page 384
From a copy of the picture (Sustermans* School) in the
Pitti Collection , Florence^ photographed by Alinari,
Florence.
GALILEO'S DESIGN OF PENDULUM-CLOCK . . Page 397
From Favaro's " Galileo e Cristiano Huygens. Nuom
documentisuW applicazione delpendolo alt orologio"
(" Nuovi studi Galileiani" Venice, 1891).
GALILEO'S MONUMENT IN SANTA CROCE, FLORENCE To face page 404
From photograph by Alinari^ Florence*
TRIBUNA DI GALILEO, FLORENCE ,...„„ 414
From photograph by Alinari, Florence,
GALILEO-HIS LIFE AND WORK
CHAPTER I
EARLY YEARS TO APPOINTMENT AS PROFESSOR
IN PISA
1564-1589
GALILEO GALILEI, one of the earliest and, perhaps,
one of the greatest of the experimental philosophers
of the modern world, and the father of telescopic
astronomy, is generally known in history by his
baptismal name, Galileo, alone, in accordance with
a custom of the Italians to call their great men
by their Christian names, or by nicknames derived
from some peculiarity of the individual or from the
place of his birth.
Galileo, as we shall continue to call him, was
descended from a noble family of Florence, which
was long and honourably connected with the govern-
ing bodies of the republic, fourteen of its members
having filled the highest posts on nineteen different
occasions between the years 1343 and 1528.
The original surname of the family, Bonajuti,
was exchanged for that of Galilei on the election,
A
2 EARLY YEARS [1564-
in 1343, of one of its members, Tommaso, to the
College of the XII Buonomini, or the Twelve Good
Men, as the ruling body of the republic was then
called. A grandson of this Tommaso, christened
Galileo, became a celebrated physician, and, in
1438, was appointed Professor of Medicine in the
University of Florence. He was elected one of the
Priori, or governing body, on two occasions, in
1430 and 1434; and in 1445 he filled the office of
Gonfaloniere or Chief Magistrate of the republic.
After a long and well-spent life he was buried
with public honours in the Church of Santa Croce,
Florence, where his grave is marked by a slab of
white marble let into the floor of the nave, near the
main entrance door. The stone bears a full-length
figure in bas-relief of an old man, robed, and wearing
the high folded cap used by the gentle folk and
scholars of the period. On the breast lies a closed
book, over which the hands are folded, and at the
feet is a Latin inscription, setting forth that "This
Maestro Galileo of the Galilei (formerly of the
Bonajuti) was in his time the head of Philosophy
and Medicine, who also in the highest magistracy
loved the republic marvellously. His son, Benedetto,
blest in the inheritance of his holy memory and
well-spent and pious life, has appointed this tomb
for his father, for himself, and for his posterity." l
Vincenzio, the father of our Galileo, was an
impoverished descendant of this noble house,
being the great-grandson of Michelangelo Galilei,
1 Ruskin, "Mornings in Florence," p. 14, speaks of this as "one of
the most beautiful pieces of Fourteenth (? Fifteenth) century sculpture
in this world,"
1 589] VINCENZIO GALILEI 3
a brother of the above-named Maestro Galileo, and
twice one of the Priori, in 1431 and 1438.
Vincenzio was born in 1520, and though, as we
have just said, of broken fortune, he was well
endowed on the intellectual side. He studied
music under Zarlino of Chioggia, a seaport town
fifteen miles south of Venice ; but in after years he
did not hesitate to attack the opinions of his old
master in his " Dialogo della Musica Antica et
della Moderna" (Florence, 1581), and c< Discorso
intorno alle opere di Gioseffo Zarlino" (Florence,
I589).1
These works display great knowledge and
laborious research ; and the first-named, especially,
has been of much assistance to the musical historian
of later days. One passage from the introduction
may fittingly be noted here, as it shows the same
spirit of free enquiry — free from authority and
tradition — which pervades all the acts and writings
of his distinguished son.
" It appears to me," he says, " that they who in
proof of any assertion rely simply on the weight
of authority, without adducing any argument in
support of it, act very absurdly. I, on the contrary,
wish to be allowed freely to question and freely
to answer without any sort of adulation, as well
becomes those who are sincerely in search of
truth."
Besides writing learnedly on the theory and
practice of music, Vincenzio was especially distin-
1 These and four other works of the same author are enumerated
in Favaro's " Bibliografia Galileiana," Rome, 1896. Other essays,
which were never printed, are now preserved among the Galileo MSS.
in the National Library, Florence.
4 EARLY YEARS [1564-
guished as an exquisite performer on the lute — an
instrument which he tells us was then better manu-
factured in England than in any other part of
Europe. He was also a skilful mathematician, and
had an extensive acquaintance with the languages
and literatures of Greece and Rome.
By his wife, Giulia Ammannati of Pescia,
Vincenzio had three sons, Galileo, Michelangelo,
and Benedetto, the last of whom died in infancy ;
and four daughters, Virginia, Anna, Livia, and
Lena. Of Anna we know nothing, and of Lena
very little.
Galileo, the eldest, was born in Pisa, where his
father was engaged in commerce, on I5th February
1564 — just three days before his famous fellow-
countryman, Michelangelo Buonarroti, closed his
eyes in Rome.
The first decade of Galileo's life, that is, down
to about 1575, was passed at Pisa, where, in the
frequent absences of the father on business, the
family lodged with a relative named Muzio
Tedaldi. In Pisa, then, and not in Florence as
has hitherto been supposed, Galileo received his
early education, partly at the school of one
Jacopo Borghini, and partly at home, where his
father helped him with his Greek and Latin
lessons.
At about the age of twelve or thirteen Galileo
was transferred to the far-famed monastery of
Vallombrosa, near Florence, to go through a
course of what,, according to the time, constituted
"the Humanities," or the literary education then
considered indispensable for a well-born youth.
Supposed Birthplace of Galileo, in Pisa.
1589] VALLOMBROSA 5
Here he made himself acquainted with the best
Latin authors, and also acquired a fair command
of the Greek tongue, thus laying the foundation of
the elegant and incisive style for which his writings
are so distinguished. With one of the monks he
began a course of instruction in logic, but from the
first he appears to have had little taste for this
subject, preferring what .scraps of elementary science
and philosophy he could pick out of the lessons.
From a contemporary document, first published
by Professor Selmi in I864,1 it would seem that,
while with the monks of Vallombrosa, Galileo was
so far attracted towards a religious life as to have
joined the novitiate of the Order ; but his father,
who had other designs for him, seized the oppor-
tunity of an attack of ophthalmia, and withdrew the
boy from the monastery. A letter of Muzio Tedaldi
to Vincenzio Galilei, dated i6th July 1579, and
congratulating him on the removal of his son, seems
to corroborate this story, and fixes the date with
sufficient accuracy.
This lovely spot has for English readers another
and more personal recollection. The Florentines
are proud to this day to remind one that our Milton
visited it more than once during his stay in Florence
in the autumn of 1638 and the spring of 1639. It
was with these visits in her mind that Elizabeth
Barrett Browning wrote : —
" Remembering Vallombrosa. Therefore is
The place divine to English man and child,
And pilgrims leave their soul here in a kiss."
It lies, as the name Vallombrosa imports, in a
1 "Nel Trecentesimo Natalizio di Galileo," Pisa, 1864.
6 EARLY YEARS [1564-
shady and sequestered vale. Hence Milton's lines
descriptive of Satan calling :
" His legions, angel forms, who lay entranced,
Thick as autumnal leaves that strow the banks
In Vallombrosa, where the Etrurian shades
High over-arched imbower."
— Paradise Lost^ Book I. lines 301-4.
We have said that in withdrawing his son from
Vallombrosa Vincenzio Galilei had other designs
for him ; but at first they -were not very ambitious.
Vincenzio, although of noble birth, had no property,
his income from trade was scanty and precarious,
and his family was large. Under these circum-
stances he destined his son to a career by no means
distinguished, though one that conferred wealth on
Florence, and therefore held in no small esteem by
her citizens — the boy was to be a cloth-dealer.
Now it must be told that from his early boyhood
Galileo was remarkable for intellectual aptitudes of
various kinds, coupled with considerable mechanical
inventiveness. His favourite pastime was the con-
struction of toy-machines, not the less ingenious
because they did not always work.1 As he grew up
he learnt from his father something of the theory
and practice of music, and became so skilful with
the lute as to excel him, good performer as he was,
" in charm of style and delicacy of touch. " He was
also, it is said, a creditable performer on the organ
and one or two other instruments, but the lute was
his favourite, and continued to be so through life.
As he found it a pleasure in youth, so it was a great
1 It is interesting to note that Newton showed a similar precocity
for things mechanical.
Monastery of Vallombrosa.
[To face fa 6.
1589] YOUTHFUL ABILITIES 7
solace in his later years — especially when blindness
was added to his other afflictions.
In the sister art his talent was equally striking,
and as a lad he showed considerable skill in drawing
and painting. In later life he used to tell his
friends that, had circumstances permitted him to
choose his own career, he would have elected to
become a painter. So well known was his youthful
talent as draughtsman and colourist that such
acknowledged artists as Ludovico Cigoli, Bronzino,
Passignano, and Jacopo da Empoli, often sought his
criticism of their works. Cigoli, in particular, was
wont to say that Galileo alone had been his teacher
in the art of perspective, and that whatever credit
he enjoyed as a painter was owing to his advice and
encouragement
In his youthful days Galileo was also very fond
of poetry, and later on in these pages we shall have
occasion to notice his essays on Dante, Ariosto, and
Tasso, as well as some verses and the fragment of
a play, all of which bear witness to, at least, a
cultivated taste.
In view of these great and varied abilities thus
early displayed (to which we must not forget to add
a good knowledge of Greek and Latin), the father
could not help concluding that his son was born to
be something better than a seller of cloths, and he
now resolved upon a scientific career. As, however,
it was necessary that the branch selected should
offer a prospect of profit, and as he had himself had
experience of the unremunerativeness of mathe-
matics and music, the profession of medicine was
decided on. Accordingly, on 5th September 1581,
8 EARLY YEARS [1564-
when seventeen and a half years old, Galileo was sent
to study medicine at the University of Pisa.1 As
before this time the family had returned to Florence
the youth was placed as a boarder in the house of
the relative before mentioned, Muzio Tedaldi, and at
once took up the usual courses in philosophy and
medicine, his teacher in the latter being Andrea
Cesalpino, the celebrated physician and botanist, who
filled the chair of medicine from 1567 to 1592.
Viviani, the first biographer of Galileo, and his
last and best-loved disciple, tells us that our youth's
attitude from the first in the philosophical classes was
not at all to the satisfaction of his teachers, owing
to the habit, inherited or acquired from his father,
of examining an assertion to see what it was worth,
instead of blindly accepting it on faith in the master,
or in deference to authority.2 In consequence of
this unheard-of audacity in one so young, he soon
acquired a reputation among the professors and his
fellow - students for bold contradiction, and was
dubbed " The Wrangler/' His eager questioning
of the dictates of Aristotle, Plato, St Thomas
Aquinas, and other ancient lights, found no favour
in their eyes. To the narrow conceptions of the
time, a philosopher needed only to know Aristotle
1 In order to reduce the expenses of a college training, Vincenzio
tried to obtain for his son one of the forty free foundations for
necessitous students attached to the University, but neither then, nor
at the end of the third year, when the request was renewed, was the
favour granted.
2 In the first volume of Favaro's edition of Galileo's works, there
are many pages of Juvenilia, or Commentaries (in Latin) on Aristotle's
"de Caelo" and "de Mundo," which were written about 1584, and
which are evidently notes of lectures he had been attending. They
show the close attention of the young student.
I589] BIRTH OF THE PENDULUM 9
by heart ; to understand hint was a secondary con-
sideration ; to contradict him was a blasphemy.
Galileo, however, would try to understand, and often
dared to contradict, and thus arose that feeling of
hostility which ultimately, as we shall see, drove
him from Pisa, and which endured for years after
he became famous.1
In 1581 Galileo made his first discovery, which
is characteristic of his observant eye. As the story
goes, the student of eighteen was one afternoon
performing his devotions in the Cathedral of Pisa,
and in full view of Maestro Possenti's beautiful
bronze lamp which hung (and still hangs) from the
roof of the nave. In order to light it more easily
the attendant drew it towards him, and then let it
swing back. Galileo at first observed this simple
incident, as thousands of othei worshippers had
done before him and have done since, i.e. in a
casual way, but quickly his attention became riveted
to the swinging lamp. The oscillations, which were
at first considerable became gradually less and less,
but, notwithstanding, he could see that they were
all performed in the same time, as he was able to
prove by timing them with his pulse — the only
watch he possessed!2
1 Thus, Father Castelli, the first disciple and lifelong friend of
Galileo, writing to him from Pisa in November 1613, says: "Of our
controversies (on the earth's motion) not a word is allowed to be said
— a thing which astonishes me. Your marvellous discoveries are
scarcely known here even by name."
54 Whether this be only a pretty fable, like that of Newton and the
apple, cannot now be decided, but it is, at least, certain that Possenti's
lamp was not the one which Galileo observed, since it was not made
until 1587, and was only hung in its present place on the 2Oth
December in that year.
io EARLY YEARS [1564-
After some experiments at home, he saw that an
instrument might be constructed on this principle
which should mark with accuracy the rate and
variation of the pulse. He gave shape to the idea,
and, imperfect though the instrument was, it was
received with wonder and delight by the physicians
of the day, and was long in general use under the
name of Pulsilogia. Santorio, who was Professor
of Medicine at Padua, has given representations of
four different forms of this instrument (in his
" Method! Vitandorum Errorum in Arte Medica,"
Venice, 1607), three of which we reproduce.
Fig. i consists merely of a weight at the end of
a string, which is held at the top of a graduated
scale. The string being gathered up into the
hand till the vibrations of the weight coincide
with the beatings of the patient's pulse, the length
is ascertained from the scale, which if great
indicates a languid, and if small, a more lively
action. In Fig. 2 the improvement is introduced
of connecting the scale and string; the length of
the latter is regulated by turning a peg, and a
bead on the string shows the measure* Fig. 3
is still more compact, the string being adjusted by
winding (or unwinding) upon an axle at the back
of the dial-plate. More than half a century later,
as we shall see in the course of our narrative,
Galileo utilised the same principle of the pendulum
in the design of an astronomical clock.
Up to the time of which we are treating, the
study of mathematics, although mentioned in the
rotuli of the schools, was practically neglected
in Italy. The names of Euclid and Archimedes
I>ossenti1s Lamp iu the Cathedral, Pisa.
{To face j. 10.
1589]
THE PENDULUM
ir
were little more than empty sounds to the students
who thronged the lecture halls of Pisa, of Bologna,
and even of learned Padua. Furthermore, Galileo's
1:
Hg.l
IO
20
30
40
50
60
70
80
90
100
Fig. 2.
Kg. 3.
a/
DIAGRAMS OF THE PULSILOGIA.
father, thinking that such studies by one intended
for the medical profession would be a waste of
12
EARLY YEARS [1564-
time, not only abstained from teaching the boy
what he knew himself, but endeavoured to prevent
his obtaining the knowledge from other sources,
assuring him that it would be time enough when
his medical studies were finished. Thus, up to
the close of his nineteenth year, Galileo knew little
or nothing of mathematics. But —
"There's a divinity that shapes our ends,
Rough-hew them as we will."
The natural and as yet hardly suspected bent
of the young man's mind now asserted itself, and
in a way not to be mistaken.
During the winter and spring of 1582-83 the
Court of Tuscany, according to custom, was resid-
ing at Pisa, and among the suite was one Ostilio
Ricci, an able mathematician, tutor to the Grand-
ducal pages, and a friend of Galileo's family in
Florence. Naturally, the tutor and the young
student became friends. Going on one occasion to
pay Ricci a visit, Galileo found him engaged in
giving a lesson to the pages on some problems in
Euclid. He did not enter, but, standing behind the
door, followed the lesson with a strange attention.
This was the beginning of a new sensation, a
craving of the intellect, under the influence of
which he found himself drawn repeatedly to the
pages' class-room. Each time, entering unobserved
and concealing himself behind a door, he listened,
Euclid in hand, to the teacher's demonstrations,
Henceforth mathematics were more studied than
medicine, for which, truth to say, he never had
any relish. Then, taking courage and confessing
his sin of curiosity, he begged the astonished
I589] MATHEMATICS 13
tutor to help him, which Ricci readily consented
to do.1
When Vincenzio learnt, as he did through Ricci,
that his son was devoting himself to Euclid to the
neglect of Hippocrates and Galen, he did his
utmost to divert the young man from this (as it
seemed to him) unprofitable study,2 But in the end
old Vincenzio had to learn the unconquerable power
of genius, and had to submit to it, just as the father of
the great Michelangelo had to submit, and under very
similar circumstances, one hundred years before.
Vincenzio's consent was probably hastened by
other considerations. With his large family and
small means he must have found it increasingly
difficult to keep his son at college. At any rate,
at the end of the third year (1584) he again peti-
tioned the Grand Duke, Ferdinando I., for one of
the forty free places founded in aid of poor scholars ;
but, owing to the hostility (to which we have already
referred) caused by "The Wrangler's" general
attitude and his marked disrespect for " authority/'
the petition was refused. Thereupon, after nearly
four years' residence, and without taking the
doctor's degree, Galileo was withdrawn from the
University, and returned to the parental roof in
Florence. This would be about the summer of
1585-
Professor Favaro, the latest and most accurate of Galileo's
biographers, is inclined to doubt this story, but, as they say in Italy,
Se non I vero^ t ben trovato.
2 Vincenzio's horror of mathematics or pure science as a means of
obtaining a living is justified by the fact that while the Professor of
Medicine in the University of Pisa received 2000 scudi a year, the
Professor of Mathematics had only 60 (^13) a year, or just 7^d. a
day!
I4 EARLY YEARS [1564-
Here, and chiefly under the guidance of Ostilio
Ricci, he devoted himself heart and soul to mathe-
matics and physics. From the study of Euclid he
passed on to the writings of Archimedes, whose
work in mechanics he was destined to continue,
and for whom he then conceived a veneration 'which
lasted through life.
In 1586, when fresh from the study of the great
Syracusan, Galileo constructed the hydrostatic
balance (la Bilancetta), for ascertaining with
accuracy the relative weights of any two metals
in an alloy. His short essay, descriptive of this
instrument, was circulated in MS. amongst his
friends, and was published for the first time, after
his death, in 1644.
He refers to the popular account of the way
in which Archimedes detected the fraud committed
by the goldsmith in the making of Hiero's crown.
The story is well known, but will bear repeating
as illustrative of some of the ways of scientific dis-
covery*
" What great things from small may be springing
Is proved by the engine's deep sob ;
And yet, after all, the beginning
Was the kettle that sings on the hob."
— J. E. CARPENTER, Songs.
Hiero had given a certain weight of gold to be
made into a crown. When the work was finished
a suspicion arose in the royal mind that the gold
had been alloyed with some baser metal, and he
applied to Archimedes in the hope of detecting the
supposed imposture. The weight of the crown
being correct, the problem was to measure its bulk ;
1589] ARCHIMEDES 15
for silver being, weight for weight, of greater bulk
than gold, any alloy of the former, in place of an
equal weight of the latter, would necessarily increase
the bulk of the crown. To measure the bulk, the
only known method for testing the purity of the
metal, was difficult without melting it into a regular
figure.
Archimedes, after many unsuccessful attempts,
was about to abandon the search altogether, when
the following circumstance suggested to his discern-
ing and prepared mind a train of thought which led
to the solution of the difficulty. Stepping into his
bath one day, his mind doubtless fixed on the object
of his research, he chanced to observe that, the bath
being full, a quantity of water of the same bulk as
his body must flow over before he could immerse
himself. He probably perceived that any other
body of the same bulk would have displaced the water
equally ; but that another body of the same weight,
but less bulky, would not have produced so great an
effect. In the words of Vitruvius, "as soon as he
had hit upon this method of detection, he did not
wait a moment, but jumped joyfully out of the bath,
and, running forthwith towards his own house, called
out with a loud voice that he had found what he
sought. For as he ran he called out in Greek,
1 Eureka ! Eureka ! ' I have found it out ! I have
found it out!" When his emotion had sobered
down, he proceeded to investigate the subject
calmly. He procured two masses of metal, each of
equal weight with the crown — one of gold, and the
other of silver ; and having filled a vessel very
accurately with water, he plunged into it the silver,
16 EARLY YEARS [1564-
and marked the exact quantity of water that over-
flowed. He then treated the gold in the same
manner, and observed that a less quantity of water
overflowed than before. He next plunged the
crown into the same vessel full of water, and
observed that it displaced more of the fluid than the
gold had done, and less than the silver, from which
he inferred that the crown was neither pure gold nor
pure silver, but a mixture of both.
Galileo doubted the correctness of this story, for
he says, the results of such a method are fallacious,
or, at least, little exact. After much thought on the
subject, he devised a "most exact " method, which
he believed was really the one employed by
Archimedes himself.
EG F C
Fig. 4.
Take a lever AB, Fig. 4, at least a yard long
(and the longer it is, the more accurate will be its
indications), delicately suspended from its centre C ;
and at the ends let there be means of attaching the
body (say an alloy of gold and silver) to be tested at
B, and its counterweight at A. First, take a piece
of pure gold and weigh it in air ; now immerse It
in water ; it will seem lighter, and the counterpoise
D must be moved from A to, say, E, to obtain a
balance. Then, as many times as the space CA
contains the space AE, so many times is gold
heavier than water. Proceed in the same way
I589] ARCHIMEDES OF HIS TIME 17
with a piece of pure silver. When placed in water,
it will seem to lose more of its weight than the
gold did, and its counterpoise will have to be
moved to, say, F, showing that silver is specifically
less heavy than gold in the ratio AE to AF.
Now taking the alloy, it is clear beforehand
that it will weigh less than an equal volume of
pure gold, and more than an equal volume of
pure silver. Weigh it in air and then in water,
when it will be found that its counterpoise must
be moved to some point between E and F, say
G. From this we learn that the weight of gold
in the mixture is to that of the silver as FG is
to GE.
After his work on the hydrostatic balance,
Galileo undertook an investigation of the centre
of gravity in solid bodies, the results of which
were embodied in an essay,1 which obtained for
him the title of " The Archimedes of his time/'
and which, with his previous work on the pendulum,
the hydrostatic balance, and one or two shorter
papers, made his name favourably known in Italy.
Among those to whom he thus became known we
must here mention one who was ever afterwards
his warm friend and patron, the Marquis Guidobaldo
del Monte of Pisaro, already himself a distinguished
mathematician. Struck by the originality displayed
in Galileo's essays, Guidobaldo opened a scientific
correspondence with the author, and took an early
opportunity of introducing him to the notice of
1 aTheoremata circa centrum gravitatis solidorum," first circulated
in MS. copies, and printed in 1638 as an appendix to his " Dialogues
on Two New Sciences."
B
i8 EARLY YEARS [1564-
Ferdinando L, Grand Duke of Tuscany, as a young
man of whom the highest expectations might be
formed.
This recognition of his rising talent was, of
course, very gratifying to the young man, but it
was a poor substitute for the gains of a practising
doctor, on which old Vincenzio had calculated, to
eke out his scanty income. Galileo himself saw
this, and, with the object of helping to maintain
his family, he gave private lessons in mathematics
and mechanics to students in Florence and the
neighbouring town of Siena.1 But his great ambi-
tion was to obtain a professorship in one of the
Universities, for which Italy was then and still
is famous. Accordingly, on the Professorship of
Mathematics in the University of Bologna falling
vacant (middle of 1587), Galileo made every
endeavour to secure it, but without success. The
post was given to Giovanni Antonio Magini, with
whom we shall meet later on, nominally as a friend
of our hero, but in reality one of his crassly irre-
concilable adversaries.
Late in 1587 Galileo made his first journey to
Rome, for what purpose history does not say, but
probably with the object of finding there some
opening, or in furtherance of his designs on
the chair at Bologna, which was still vacant,
Magini's induction dating only from 4th August
1 About this time, 1587-88, we hear of Galileo reading two papers
before the Academy of Florence, on the site and dimensions of Dante's
" Inferno," a subject which just then was being hotly discussed by the
literati of the Tuscan capital. For this task he was specially chosen
by Baccio Valori, the president, a fact which shows that his reputation
as a literary connoisseur was as well established, as that he was an
able mathematician,
i589] FIRST VISIT TO ROME 19
1588. However this may be, the visit was not
without result, for it led to his acquaintance with
Father Cristoforo Clavio, of the Society of
Jesus, already a celebrated mathematician, and
to whom the world is mainly indebted for the
reform of the calendar in 1582. Little did they
then think that the learned old Jesuit would
be a stout opponent of the new astronomical
teachings which the younger man would pro-
mulgate, but to which, before his death in 1612,
he was to become a distinguished convert, malgrt
lui.
Evidently while in Rome the two new friends
had been discussing mathematics, for on his return
to Florence Galileo sent a letter to Clavio, under
date, 8th January 1588 (the earliest of his letters
known to exist), in which he frankly states a
difficulty respecting the demonstration of a certain
theorem (lemma). Those, he says, to whom he
had already submitted it, were not satisfied ; there-
fore he could not be so himself. In this dilemma,
he solicits the learned father's opinion, adding that
if it, too, was unfavourable, he should not rest until
he had found such a demonstration as would be
convincing to all.
Galileo, always anxious to be earning something,
next applied for the Professorship in Padua Univer-
sity, rendered vacant by the death of Moletti in
January 1588, and in this connection he betook
himself to Venice ; but again he was unsuccessful.
Soon after, a similar post at Pisa, his Alma Mater,
became vacant, and, taking advantage of his recent
introduction to the Grand Duke, in whose gift the
20 EARLY YEARS [1564-
appointment was, he applied for it through the
Marquis del Monte. Once more he was unfortu-
nate, as the following letter of i6th July 1588 to
the Marquis shows.
"My wish regarding Pisa, about which I wrote
your lordship, will not be carried out; for I hear
that a certain monk, who lectured there formerly,
and then, on being made General of his Order,
retired, has resigned the Generalship, and has
again taken to lecturing; and that his Highness
has already appointed him to the post.
" Now, as here in Florence there was formerly
a Professorship of Mathematics, which was estab-
lished by the Grand Duke, Cosimo I., and which
many among the nobles would like to see revived,
I have petitioned for it, and hope to obtain it
through your illustrious brother's influence, to
whom I have entrusted my case. As there have
been foreigners here, with whom his Highness has
been engaged, I have not been able to speak on
the subject myself, and, therefore, I beg you to
write again and mention my name/'
Even in this fourth attempt he failed. Thus
for nearly two years, from about the middle of
1587 to the middle of 1589, Galileo saw all his
efforts to obtain employment in his own country
end in bitter disappointment Can we wonder
that, repulsed at Bologna, Rome, Padua, Pisa, and
Florence, he should turn his thoughts towards the
East as to a land of promise ? From some documents
recently brought to light by Professor Favaro, the
indefatigable editor of the latest collection of
Galileo's works, it appears that he was actually
engaged on this desperate enterprise at the moment
when at last the tide of fortune began to flow in
I589] PROFESSOR AT PISA 21
his favour.1 Towards the end of May 1589,
Galileo and a young Florentine patrician of his
acquaintance, Ricasoli Baroni, had decided to seek
together their fortunes in the East, when the
Mathematical Professorship at Pisa again fell
vacant. Once more he made application for the
post, and in due time, and through the joint
influence of the Marquis Guidobaldo and his
brother, Cardinal Francesco Maria del Monte, he
was awarded the prize. This was in July 1589,
when he was barely twenty-five and a half years
old. To be sure, the salary was insignificant, only
60 scudi per annum, or about ^13 of our money.
Moreover, the appointment was only for three
years, but renewable. But, any port in a storm;
and in Galileo's needy circumstances, even this
wretched salary was not to be rejected ; besides,
the office would enable him to make something in
addition by private tuition.
1 See Favaro's "Galileo e Suor Maria Celeste," Florence, 1891,
p. 25.
CHAPTER II
GALILEO, PROFESSOR IN PISA
No sooner was Galileo settled in his new office
than he resumed, and with increased diligence, his
physico-mathematical researches. In the first year
he carried to greater length his previous studies on
the centre of gravity, and arrived at results which
excited afresh the admiration of the Marquis del
Monte ; he discovered that peculiar geometrical
curve to which he gave the name cycloid, and
attempted the problem of its quadrature ; 1 and all
the while he was steadily revolving those novel ideas
on motion, which were creeping into his mind, and
which were to be the basis of his greatest and
latest work. In pursuance of these ideas, he now
began a systematic investigation (with experiment)
of the mechanical doctrines of Aristotle.
Galileo was not the first to call in question the
1 The cycloid is the curve described by a point in a circle (as the
nail in the rim of a carriage wheel) while it makes one revolution
along a horizontal base. Soon after its discovery, and on Galileo's
recommendation, it was applied in the formation of the arches of the
bridge (Ponte di Mezzo) over the Arno in Pisa. Galileo guessed that
the area contained between the cycloid and its base is three times that
of the describing circle, but he was unable to demonstrate this geo-
metrically — a task which his disciple Torricelli achieved soon after his
death.
22
1589-1592] TEACHING 23
authority of Aristotle in matters of science. It is
now known that the celebrated painter, Leonardo
da Vinci (1452-1519), held many views opposed
to the Aristotelian philosophy, and even anticipated
Galileo in some of his discoveries. But as da
Vinci's scientific writings (mostly short notes and
memoranda) remained in manuscript, practically
lost to the world, till I797,1 it is not likely that
his views were known to any one. Also Nizzoli,
Varchi, Benedetti, and others, had attacked in a
general way, or in particulars, the peripatetic
doctrines.
While, therefore, Galileo was not the first to
question the authority of Aristotle, he was un-
doubtedly the first whose questioning, as embodied
in his acts and writings, produced an effect in
men's minds which it would not be exaggerating
to call a revolution. The reason is not far to seek.
The spirit of free thought and free enquiry was
asserting itself in every department. As in the
reformation of religious doctrines, so in science,
men were beginning to shake off the old supersti-
tions. Galileo, in a word, came at the psycho-
logical moment, and, above all, he came armed
with a weapon of convincing force — experiment.
He was not content, like his precursors, with
merely giving an opinion, supported or not by
wordy metaphysical arguments, but what he
asserted as well as what he denied he proved
to ocular demonstration.
The results of his researches — the foundations
1 When Venturi brought them to notice in his " Essai sur les
Ouvrages Physico-Math&natiques de Leonard da Vinci," Paris, 1797.
24 PROFESSOR IN PISA [1589-
of dynamical science— are given at great length in
his treatise " De Motu Gravium," 1590, which, as
was his custom then, and for many years after, was
circulated in manuscript, and only appeared in print
two hundred years after his death.1 As most of
these early theorems were afterwards developed and
incorporated in his larger work, " Dialogues on Two
New Sciences" (1638), we shall reserve our notice
of them till we reach that period of his life. Here,
then, we need only say, that as fast as he succeeded
in demonstrating the falsehood of any of Aristotle's
positions he did not hesitate to denounce them
from his professorial chair, and perhaps with too
much energy, at least for his own comfort, since
the immediate result was to irritate more and more
his colleagues of the academic body, who, as we
have seen, were never too well disposed towards
him.
We must, however, say something here of his
celebrated experiments on falling bodies, on account
of their associations with the Leaning Tower of Pisa
— one of Italy's many curious monuments. Nearly
two thousand years before, Aristotle had asserted
that if two different weights of the same material
were let fall from the same height, the heavier
would reach the ground sooner than the lighter in
the proportion of their weights. The experiment
is certainly not a difficult one, but nobody thought
of that method of argument, and consequently this
assertion was received upon Aristotle's ipse dixit
among the axioms of the science of motion.
1 In Alberi's "Opere di Galileo Galilei," 16 vols,, Florence,
1842-56; or better, Favaro's new edition, where they are given more
accurately, and for the first time published completely.
i S92] CELEBRATED EXPERIMENTS 25
Galileo, however, now appealed from the authority
of Aristotle to that of his own senses, and main-
tained that, with the exception of an inconsiderable
difference due to the disproportionate resistance of
the air, they would fall in the same time. The
Aristotelians ridiculed and refused to listen to such
an idea. But Galileo was not to be repressed, and
determined to make his adversaries see the fact
as he saw it himself. So one morning, before the
assembled University, professors, and students, he
ascended the leaning tower, taking with him a
lo-lb. shot and a i-lb. shot. He balanced them
on the over-hanging edge and let them go to-
gether. Together they fell, and together they
struck the ground.
Neglecting the resistance of the air, i.e. suppos-
ing the bodies to fall in a vacuum, Galileo
had found them to be subject to the following
laws : —
1. All bodies fall from the same height in equal
times.
2. In falling the final velocities are proportional
to the times.
3. The spaces fallen through are proportional to
the squares of the times.
The correctness of the first law was easily
established by the leaning tower experiments, and
the better to prove the others he devised the
inclined plane — a long straight piece of wood, along
which a groove was accurately made, and down
which a bronze ball was free to move with the least
friction. With this he proved that, no matter what
the inclination of the plane was, and, consequently,
26 PROFESSOR IN PISA [I589-
no matter what the time was, the movement of the
ball was always in accordance with the laws.1
It might have been thought that such experi-
ments as these would have settled the question de-
cisively. Aristotle, the master, would certainly have
accepted them in disproof of his own dogma, but
his disciples were embued with no such frankness,
and would not be convinced. With the sound
of the simultaneously fallen weights ringing in
their ears, they still persisted in maintaining that
a weight of 10 Ibs. would reach the ground in a
tenth of the time taken by one of I lb.? because they
were able to quote chapter and verse in which
Aristotle assured them that such is the fact !
A temper of mind like this could not fail to
produce ill-will towards one who felt no scruples in
exposing such folly. With the exception of the new
Professor of Philosophy, Jacopo Mazzoni, the whole
body of the teaching staff, as well as the heads of
the University, now turned against our young
iconoclast.
For some time these feelings of animosity had
no serious effects, but, no doubt, Galileo was " boy-
cotted" and subjected to many petty annoyances.
Soon, however, a wholly unforeseen circumstance
came to the aid of the Aristotelians, and led to
Galileo's retirement from Pisa. Giovanni de Medici,
the natural son of Cosimo I., was at the time
Governor of Leghorn. He had a bent for
mechanics, and was not unskilled as an engineer
1 Naturally these experiments would show the necessity of some
accurate measurer of time, and so we are not surprised to learn that
Galileo again occupied himself with the pendulum as such a measurer.
See Favaro's " Galileo e Suor Maria Celeste," p. 32.
I592] RETURN TO FLORENCE 27
and architect. Amongst other contrivances, he had
just designed a monster dredging machine, which
he wished to employ in clearing the harbour of
Leghorn. A model was submitted to the Grand
Duke, by whom Galileo was commissioned to
examine and report upon it. He did so, and
declared it to be useless, an opinion which sub-
sequent experiment (with an actual machine) fully
confirmed. That the discomfited inventor should
be mortified at this failure is natural ; but that he
should for no other reason be angry with Galileo,
and should seek to injure him, is not so intelli-
gible. However, so it is stated, and the young
prince was easily induced to join hands with the
Aristotelians in an onslaught on their common
aversion. Hisses were now heard at his lectures ;
cabals were started at Court; and, altogether, the
position speedily became so intolerable that
Galileo resigned his post, before the three years'
term had expired, and once more returned to
Florence. This was about the middle of 1592.
Other circumstances of an economical character,
no doubt, contributed to this decision. We have
seen that out of his salary of ^13 per annum he
was expected to contribute (and did so willingly)
to the support of the family ; but miserable as the
stipend was, he seldom received the whole of it. It
was the custom in Pisa to put the professors under
stoppages for all lectures not given, and at the end
of the scholastic year they were, as a rule, called
upon to refund a sum corresponding to the number
of lectures missed, and proportional to the salary.
Now, owing to an inundation of the Arno, Galileo
28 PROFESSOR IN PISA [1589-
was unable to take up his post on the opening day
of the session ; and on another occasion, while in
Florence on some urgent business, a sudden illness
of his mother detained him some days over the
specified time, yet, although he wrote to the head
of the University explaining the causes of his deten-
tion in each case, the rule was rigorously enforced
— in the first year to the extent of one-tenth of
his salary ! l
Indeed, his retirement from Pisa was no new
or sudden resolution. He had not been many
months there, when the ever-pressing money
difficulty, and the undisguised antipathy of his
colleagues, made him think of throwing up the
post. Thus, it appears from his correspondence
with the Marquis del Monte that early in 1590 he
sought his friend's aid in obtaining the Mathe-
matical Chair of Padua, which was vacant since
January 1588 by the death of Moletti; but at this
time as well as later (early in 1592) his efforts were
not successful.
To this period belong most of Galileo's literary
productions. His "Capitolo in Biasimo della
Toga," written in 1590, is a fragment of a play, an
amusing though somewhat licentious burlesque, in
which he ridicules the University ordinance com-
pelling the professors to wear the gown, not only
1 To eke out his pittance Galileo had to give up much of his time
to the drudgery of private lessons. On the strength of a letter to his
father, dated I5th November 1590, and asking fora copy of the works
of Galen, some of his biographers conclude that he was then practising
as a physician, or reading with medical students ; but it is more
likely, as Professor Favaro says, that " Galen was wanted, not for the
purpose of coaching, but for the many anti-Aristotelian arguments
which the work contains " (" Galileo e Suor Maria Celeste," p. 26,)
,S92] TASSO AND ARIOSTO 29
when actually engaged in lecturing, but when
passing through the streets and visiting their
friends. This was another cause of offence to the
academic body, and the author was set down as
a man of easy morals, and little mindful of the
professorial dignity.
About the same time Tasso's "Jerusalem
Delivered" was being hotly criticised at the
Accademia della Crusca of Florence. This cele-
brated academy, the first of its kind, and still
flourishing, was founded 1582 by Cosimo I., Grand
Duke of Tuscany, to maintain the purity of the
Italian language, or, as the name (Crusca = bran)
imports, to sift the flour from the bran. In the
exercise of this praiseworthy object the academy
often gave offence by condemning all works which
did not conform to its rules, and among the works
thus censured was the "Jerusalem Delivered " of
Torquato Tasso. Galileo must be held to have
contributed to this result by his very severe
critique on the style, construction, and characters
of the poem. He is said to have known by heart
the " Orlando Furioso" of Ariosto, whom he called
the divine, but, according to all competent critics,
his appreciation of the one is as excessive as his
disparagement of the other.1 The following
sentences will give an idea of this too scathing
production : "I am sometimes aghast at the
foolish things this poet sets himself to describe."
"To my mind this poet is poor and miserable
1 His copy of the "Orlando Furioso" has been preserved. It is
full of notes and corrections which critics say are just and ingenious.
See " Postille air Ariosto " in Alberi's vol. xv., or Favaro's vol. ix.
30 PROFESSOR IN PISA [1589-
beyond all expression, whereas Ariosto is rich,
magnificent, admirable." " Eh, Signor Tasso,
you understand nothing of your art, you besmear
much paper and only make in the end pap for
cats." In later life Galileo considerably modified
his views, but still could only relish Tasso after
Ariosto " as one relishes cucumbers after melons." l
Besides these effusions, Galileo has left us
the outline of a comedy in prose, for writing
which some of his biographers blame him much,
and still more for preserving it; also a number
of sonnets, some of which are of doubtful
authenticity, and ought, perhaps, to be credited
to his son Vincenzio, a MS. volume of whose
verses, dated 1637, is now in the Riccardian
Library, Florence. Amongst his friends in later
life was Antonio Malatesti, the poet and friend
of Milton, to whom a copy of his " Sphinx," or
poetical enigmas, was presented. This curious and
somewhat irreverent work has prefixed a number
of commendatory verses, amongst which is a sonnet
by Galileo on the telescope, which he presented to
the Grand Duke.2 This and three other sonnets
have been printed in Alb&ri's edition, 1842-56, since
1 See his letters of 5th November 1639, and iQth May 1640, both
addressed to his friend, Francesco Rinuccini. At the time Tasso was
under restraint in a kind of maison de sant^ and this controversy with
the della Cruscans grievously wounded him. But in the end it tended
more to spread the knowledge, and with that knowledge the fame,
of his " Gerusalemme Liberata," than permanently to injure it. For
a long time it was thought that Galileo's essay, " Considerazioni al
Tasso," had perished, till the Abbe Serassi discovered a MS. copy
about 1780, whilst collecting materials for his "Life of Tasso,"
published in Rome in 1785.
a u Notes and Queries" (1853), vol. viii. p. 295, where the verses
are given.
i592] A SPECIMEN OF POETRY 31
which Professor Favaro has collected three others,
and a longer piece which, from internal evidence, he
assigns to the period of Galileo's professorship in
Pisa, 1590-92. This we venture to reproduce as
a fair specimen of our philosopher's versification
recently brought to light.
" Oh poveri Dottor mal arrivati !
Voi siete stati pure i bei minchioni
A dare agli scolar tanti capponi,
Con rischio d'esser tutti condennati.
" Qui non si guarda che sien mandati
Editti, Bandi, Prescrizioni j
Qui non val nulla Monsignor Capponi
Per dio, n'avete ad esser gastigati.
" Venite qua ; non e una vergogna,
Un vituperio espresso, una pazzia,
Un obbrobrio da mitera e da gogna,
" Avere i polli in casa, e darli via
Senza ragione e quando non bisogna,
A chi viene a can tar la Befania ?
" E poi a una genia
Che per saziar loro ingordigia Jhterna
Avrian data la stretta a vita eterna ?
" In questa lor Taverna,
Cioe congrega di gran Tavernieri,
Hanno condotto un Conte, ed un Alfieri,
" Che son due masnadieri,
Ch& Tun de1 ghiotti & Re, Taltro e Monarca :
Guai a colui che con costor s'imbarca !
" S' egli entravan neir Area,
Dove campb No& co' suoi parenti,
E con tutte le razze de' viventi,
"Non crediate altrimenti
Che le spezie si fusser propagate,
Che si poteva dir, le son sonate ;
32 PROFESSOR IN PISA [iS89-
" Perch& queste brigate
Non pur mangiavan le starne e gli storni,
Le pecore, le capre e i liocorni,
" Ma in que' quaranta giorni
Asini e buoi morivan tutti quanti,
Orsi, draghi, serpenti e liofanti.
" Hanvi poi tanti e tanti
Cavalier da far prove memorande
Intorno ai piatti, intorno alle vivande,
" Che sarla cosa grande
Dir del Mannelli 1'ingordigia orrenda,
0 del Sertin da quella gran faccenda
" Dir la furia tremenda,
Un rasciugar di piatti, e d'altri vasi
Dell' Ansaldi, del Medici e del Masi,
" Hannovi anco quel Rasi ;
Di questo non occorre far paroia,
Perche ognun sa ch' ei tira ben di gola.
" Or da costor m'invola
Con quel bocchino, e coi leggiadri sguardi
Quel tristo Trafuriel di Carlin Bardi.
" Che venne al quant o tardi,
Essendo stato fino alle tre ore
Non so dal Confessoro o dal Dottore ;
"E vigiuro di cuore
Che mi parea con quello spadaccino
Qualche San Giorgio, o quaiche San Martino.
" Evvi anco un Lupicino,
Che divora, trangugia, anzi tracanna ;
II nome solamente lo condanna."
Early in 1591, Virginia, the eldest of Galileo's
sisters, was married to Benedetto Landucci, son
of the Tuscan ambassador at Rome during the
pontificate of Leo X. Writing to his father on
26th December 1590, this most loving of brothers
says : —
i592] A PITIABLE POSITION 33
11 1 am preparing for Virginia a set of silken bed-
curtains, the silk for which I bought at Lucca, and
have had it woven at little cost, so that, although
the stuff is one and a quarter yards wide, it only
cost me about three carlini the yard. The stuff is
made with selvage, and will be sure to please. I am
now having made the silk fringes for ornamenting
the curtains, and could also have the bedstead made
if desired. I beg you not to speak of this in the
house, as I wish it to be an unexpected surprise. I
will bring them at the Carnival holidays, and, if you
wish, I could also bring enough to make four or five
vests of damask and velvet of an exquisite design."
Not content with this present, which, considering
his scanty means, was more than liberal, he further
bound himself in the marriage contract to provide a
dot, the non-payment of which, as we shall see,
brought on him no end of sordid annoyances — his
ungracious brother-in-law going so far as to threaten
him with prison.
On his return to Florence (middle of 1592)
Galileo's position was truly pitiable. Without
employment, and with no immediate prospect of
obtaining it, the monetary situation must have
appeared to him overwhelming, aggravated as it
was by the death of his father on 2nd July 1591.
Besides his mother, there was a brother, Michel-
angelo, who had received a good musical educa-
tion from his father, but who had not yet been
able to contribute anything towards the household
expenses; and two sisters, Livia and Elena — all
entirely, or almost entirely, depending on him
for their daily wants.
CHAPTER III
GALILEO, PROFESSOR IN PADUA
I592-I6IO
IN our second chapter we saw that Galileo long had
designs on the Mathematical Chair in Padua, which
had been vacant since January 1588, another fact
which shows the little value that was attached to
pure science even in learned Padua.1 Now he again
approached his friend, the Marquis del Monte, on
the subject Del Monte was a distinguished pupil of
the Padua University, had many friends there, and
also a relative who was high-placed in the military
service of the Venetian republic. With letters of
introduction from this influential man, Galileo set
out for Venice towards the end of the summer of
1592, all his worldly goods (as he used afterwards to
tell his friends) being contained in a trunk which
did not weigh loolbs. He passed through Pesaro,
the home of his noble friend and patron, and halted
at Padua, where he was warmly received by
Gianvincenzio Pinelli, a learned man of Genoese
extraction long domiciled at Padua, and an intimate
friend of del Monte. Armed, further, with recom-
mendations from Pinelli, Galileo arrived in Venice
1 See remarks on this subject, p. 10 ante,
i592-i6io] PROFESSOR IN PADUA 35
about ist September, and was met with the alarming
intelligence that a formidable rival was already in
the field, namely, Giovanni Magini, whom we have
before mentioned as the Professor of Mathematics in
Bologna, whose term there was about to expire, and
who was long known to have aspired to the Chair at
Padua. However, with the aid of his friends, del
Monte and Pinelli, and of their friends in Venice,
Galileo had the good fortune to be selected. Being
informed privately of this happy issue, he set out on
2Oth September for Padua, en route for Florence, to
wind up his affairs there, and to obtain the permis-
sion of his sovereign to withdraw from Tuscany.
On 26th September he was gazetted, and as
the terms of the diploma (preserved amongst the
Galilean MSS. in the National Library, Florence)
will serve to show the estimation in which our
philosopher was held, we reproduce it here.
(After preamble.) "Owing to the death of
Signor Moletti, who formerly lectured on Mathe-
matics at Padua, the Chair has been for a long time
vacant, and, being a most important one, it was
thought proper to defer electing any one to fill it till
such time as a fit and capable candidate should
appear. Now there has been found Domino Galileo
Galilei, who lectured at Pisa with very great honour
and success, and who may be styled the first in his
profession, and who, being ready to come at once
to our said University, and there to give the said
lectures, it is proper to accept him. Therefore, the
said Domino Galileo Galilei is hereby appointed
Mathematical Lecturer in our University for four
years certain, and two uncertain (and the last two
are to be at the will and pleasure of our Serenity),
with the yearly salary of 180 florins."
36 PROFESSOR IN PADUA [1592-
The gaining of this coveted post over so formid-
able a rival as Magini was, of course, very gratifying
to the amour propre of Galileo, but it was also very
welcome from the money point of view. The salary
was exceptionally good for the time/ and, owing to
the large number of students who flocked to Padua,
he would be able to add considerably to his income
by private lessons.
The Paduan session opened on ist November,
but, unlike his treatment at Pisa, our new professor
was allowed ample time to settle his affairs in
Florence, and to prepare his inaugural address,
which was to be worthy alike of the occasion and
the man. Accordingly, on 7th December 1592,
Galileo entered on his new duties with a discourse
which is said to have won the greatest admira-
tion, not only for its profound knowledge, but for
its eloquence and elegance of diction. It is thus
referred to, and evidently by one who heard
it, in Tycho Brahms "Astronomiae Instauratae
Mechanica," 1598.
" Interea, Gallilaeus de Gallilaeis Florentinus
Professionem Mathematicam hie adeptus est, qui
suarum lectionum septimo Decembris initium fecit.
Exordium erat splendidum in magna auditorum
frequentia. Datae Patavii 28 Decembris, Anni
For some time after his arrival at Padua, Galileo
was apparently the guest of Pinelli, whose library of,
it is said, 80,000 volumes would be useful in prepar-
1 It was still very much under the salaries attached to the other
chairs. Thus, the Professors of Philosophy and of Civil Law received
annual stipends of 1400 and 1680 florins respectively,
i6io] TREATISES 37
ing his inaugural address. He then appears to
have established himself in a modest house in the
vicinity of the Church of San Giustina, on the Prato
della Valle (now Piazza Vittorio Emmanuele).
Little did he then think as he strolled about the
Prato, then a Grande Place for f&tes and spectacles
of all kinds, that his statue would be one of seventy-
seven which would be erected in years long after
to commemorate great men who had made Padua
illustrious for all time.
During the first few years at Padua, Galileo
displayed an extraordinary and versatile activity.
He wrote a number of treatises, chiefly for the use
of his pupils, among the larger of which may be
mentioned : On Military Architecture, on Fortifica-
tions, on Mechanics, on the Sphere, on Accelerated
Motion, on Gnomonics. All of these attained a
wide circulation in manuscript copies ; some were
not printed until long afterwards, while others, like
the paper on Gnomonics, are unfortunately lost.
Others, again, strayed beyond the pupils and
friends for whom they were intended, and found
their way into the hands of persons who did not
scruple to claim and publish them as their own.
Galileo's treatise on Mechanics (" Delia Scienza
Meccanica"), written in 1594, deals with the powers
of the lever, pulley, and screw, and concludes with
an account of the Archimedian Screw for raising
water, followed by a short fragment " On the Force
of Percussion."
In the introductory remarks Galileo demonstrates
the important principle of Virtual Velocities, which,
according to Professor Jack, marks, with his laws of
38 PROFESSOR IN PADUA [1592-
falling bodies, the greatest advance in mechanical
science since the world began. Here, perhaps, it
will be best described in the popular language of
Professor Jack : —
" It was in connection with his investigations
of motion on a plane that Galileo laid down the
principle that, perhaps, serves best as the basis of
the theory of balancing forces, the principle of what
is called Virtual Velocities. Every one is familiar
with it, in the ordinary maxim, that what is gained
in speed is lost in power. In the board laid across
a fallen tree, on which children see-saw, the lighter
child is put at the extremity of the longer arm.
With a plank 12 feet long, a child 50 Ibs. weight
will be balanced against one 70 Ibs. weight when
the plank rests on the tree 7 feet from the light
child's end, and 5 feet from the heavy one's. When
they swing the amount of swing is proportional to
the distances from the fixed point. If the plank
moves, so that the child at the 7 feet end rises
through 7 inches, the other goes down through 5.
In every case like this, where forces are in equi-
librium on a system, we can imagine a motion given,
every point moving according to the geometrical
circumstances. Let us imagine such a motion.
When two forces act on a system and keep it at
rest, multiply the space through which the point of
application of each force moves, referred to the line
in which the force acts, by the measure of the force.
When there is equilibrium the resulting quantities
are equal and of opposite signs. The one child
weighing 50 Ibs, rises vertically through 7 inches,
and we may call the product 350 inch-lbs. upwards.
The 70 Ibs. child moves in the same time 5 inches
downwards, and the product, which is 350 inch-lbs.
downwards, is equal and opposite to the other. If
there is equilibrium it must always be so ; if it is so
X6io] TREATISE ON THE SPHERE 39
there must be equilibrium. It is to Galileo that
we owe this most fruitful of statical principles. It
can easily be extended to the case when any number
of forces act at any number of points on a body or a
system ; but it was not till a century later that John
Bernouilli could state it in all its generality, or show
how admirably it serves as a sufficient basis for the
whole theory of equilibrium.3'1
The treatise on the Sphere, which was first
published at Rome in 1656 (fourteen years after
Galileo's death), is supposed by some authors to be
apocryphal, as it teaches the Ptolemaic cosmogony,
placing the earth immovable in the centre, and
adducing the usual arguments. But this does not
make the work necessarily apocryphal, for we have
it under his own hand that for some years he taught
the Ptolemaic system in his classes out of compliance
with popular feeling, although at heart he was a
follower of Copernicus.2
In his first letter to Kepler, dated 4th August
1597, and acknowledging the receipt of the latter 's
" Mysterium Cosmographicum," he says : —
" I have as yet read nothing beyond the
preface of your book, from which, however, I
catch a glimpse of your meaning, and feel great
joy on meeting with so powerful an associate
in the pursuit of truth, and, consequently, such
a friend to truth itself; for it is deplorable that
there should be so few who care about truth,
and who do not persist in their perverse mode
of philosophising. But as this is not the fit
time for lamenting the melancholy condition of
1 " Nature" (1879), vol. xxi. p. 40.
a Maestlin, Kepler's master, did the same, while all the time he
was well known to be a Copernican.
40 PROFESSOR IN PADUA [1592-
our times, but for congratulating you on your
elegant discoveries in confirmation of the truth,
I shall only add a promise to peruse your book
dispassionately, and with the conviction that I
shall find in it much to admire.
"This I shall do the more willingly because
many years ago I became a convert to the
opinions of Copernicus,1 and by his theory have
succeeded in explaining many phenomena which
on the contrary hypothesis are altogether in-
explicable. I have arranged many arguments
and confutations of the opposite opinions, which,
however, I have not yet dared to publish,
fearing the fate of our master, Copernicus, who,
although he has earned immortal fame among a
few, yet by an infinite number (for so only can
the number of fools be measured) is hissed
and derided. If there were many such as you
I would venture to publish my speculations, but
since that is not so I shall take time to consider
of it"2
In the early summer of 1593 Galileo con-
tracted an illness, which nearly proved fatal,
and from which he suffered at intervals all
through life. A party of three young men (so
Viviani tells the story), of whom Galileo was
one, "were enjoying at an open window in the
country a current of air which was artificially
cooled by a fall of water. They, unfortunately,
1 See also the "Dialogues on the Two Systems of the World,"
second "Day," where Sagredo tells how he was led in early
life to adopt the Copernican doctrine, and where Galileo evidently
describes his own mental evolution.
a This interesting letter was the beginning of the friendship
of these two great men, which lasted uninterruptedly till 1630, the
date of Kepler's death. There is a still earlier admission in his
letter of soth May 1597, to his friend Professor Mawoni of Pisa.
i6io] A NARROW ESCAPE 41
fell asleep under its influence, and so great was
its effect on Galileo's hitherto robust constitution
that a severe chronic disorder ensued, which
showed itself in acute pains in the body,
accompanied by frequent haemorrhages and loss
of appetite and sleep. The others suffered still
more severely, for one died in a few days, while
the third became deaf and died in a short time
after."
Professor Favaro has been at great pains to
corroborate this strange story, and has suc-
ceeded in giving it a more matter-of-fact appear-
ance. He has identified the place as the Villa
in Costozza, which is not far from Vicenza, and
which then belonged to the Count da Trento.
The Villa still exists, and in one of the rooms
on the first floor he found an opening to a
narrow passage or tunnel which led to a
neighbouring cavern. The air issuing from this
cavern is always cool (Favaro found it to be
52° Fahr.), and, perhaps, sometimes poisonous,
like the Grotto del Cane, near Naples, so
celebrated for its mephitic vapours. . This would
explain the disastrous results of sle'eping under
its influence which befell Galileo and his
companions.1
While carrying on his professorial duties,
giving private lessons, and writing learned tracts,
Galileo was occupying himself profitably in other
ways. Thus it would appear that his skill as
an engineer was often in request by the State,
for which he is said to have designed, or super-
1 Favaro's "Galileo e Suor Maria Celeste," pp. 49-53.
42 PROFESSOR IN PADUA [1592-
intended the construction of, various works and
machines.1 Amongst the latter may here
be noted a machine for raising water, of small
dimensions but of great power, so that one
horse could raise the water and distribute it
through twenty channels. For this the Venetian
republic gave him the exclusive use for twenty
years, under a patent dated i5th September
1594; but, although it was tried with success
in the garden of the Contarini Palace in Venice,
it never came into much use.
About 1596-7 he invented a more profitable
instrument, his Geometrical and Military Compass.
This useful instrument is now called the Sector,
and is to be found in most cases of mathematical
instruments. It consists of two straight rulers
connected by a joint so that they can be set to
any required angle. On one face are four pairs
of lines.
Arithmetical lines, which serve for the division
of lines, the solution of the Rule of Three, the
equalisation of money, the calculation of interest.
Geometrical lines, for reducing proportionally
superficial figures, extracting the square root,
regulating the front and flank formations of
armies, and finding the mean proportional.
Stereometrical lines, for the proportional reduc-
tion of similar solids, the extraction of the cube
root, the finding of two mean proportionals, and for
the transformation of a parallelepiped into a cube.
1 So say Viviani and Gherardini in their biographies of Galileo, but
Professor Favaro, after a diligent search among the archives of Venice,
could find nothing to bear out the statement For this and other
cogent reasons he doubts its accuracy.
1610] GEOMETRICAL COMPASS 43
Metallic lines, for finding the proportional
weights of metals, and other substances, for trans-
forming a given body into one of another material
and of a given weight.
On the other side of the instrument are :
Polygraphic* lines, for describing regular
polygons, and dividing the circumference into
equal parts.
Tetragonical lines, for squaring the circle or
any other regular figure, for reducing several
regular figures to one figure, and for transforming
an irregular rectilineal figure into a regular one.
Joined lines, used in the squaring of the various
portions of the circle and of other figures contained
by parts of the circumference, or by straight and
curved lines together.
There is joined to the compass a quadrant,
which, besides the usual divisions of the astro-
nomical compass, has engraved on it a squadron
of bombardiers, and, in addition, transversal lines,
used for taking the inclination of a scarp of a wall.
From the encouraging reception given to this
invention, orders for which came from all parts
of Europe, Galileo determined to open a work-
shop in his own house, no doubt in order that
the manufacture of this and other scientific
apparatus 1 might proceed uninterruptedly under
his personal supervision, and so be less liable to
piracy. This we gather from an entry in his
Day-book under 5th July 1599.
1 His papers show that large numbers of the Geometrical and
Military Compass, in copper and silver, were manufactured, and that
he was also making magnetic compasses, and various kinds of
drawing instruments.
44 PROFESSOR IN PADUA [1592-
" Messer Marcantonio Mazzoleni, mechanician,
comes to reside in my house to work for me,
and at my cost, on mathematical instruments, I
undertaking to bear the expenses of him, his
wife, and child, and to pay him in addition the
sum of six ducats per annum."
This is one of the instances, before referred to,
where Galileo's manuscripts and ideas got into the
hands of people who were not ashamed to publish
them as their own, and to denounce the author
as an impudent plagiarist. Some years after the
invention, finding that his right to it was being
disputed, Galileo published a description of it and
dedicated the book to his pupil, Prince Cosimo,
son of the Grand Duke of Tuscany.1 This was
speedily followed by another book, the production
of Baldassare Capra, a young Milanese, in which
he claimed the invention as his own, and accused
Galileo of piracy.2 The matter was brought before
the University authorities, and Galileo was able
to show that he had made the invention as early
as 1597, and had explained its construction and
uses to numerous persons in Padua and elsewhere,
amongst them being Capra himself! These state-
ments were supported by depositions of well-
known men, as Gio. Fran. Sagredo, Giacomo
Badovere, Mazzoleni (Galileo's mechanician),
Giacomo Alvise Carnaro, and Fra Paolo Sarpi.
1 " Operazioni del Compasso Geometrico e Militate." The dedica-
tion is dated Padua, loth July 1606. This is his first printed work.
2 This work is entitled "Usus et Fabrica Circini Cujusdam
Proportions, " Padua, March 1607. A modern writer speaks of
Capra as "one of those parasites who live at the expense of the
talent and the renown of others." Chasles : " Galileo, sa Vie et son
Proces," Paris, 1862, p. 20.
i6io] THE CAPRA PLAGIARY 45
The last-mentioned only need be quoted. Writing
from Venice under date 2oth April 1607, he
affirms and attests that he had carefully compared
the two works in dispute, and had found Capra's
to be little more than a Latin translation of
Galileo's Italian. He then goes on : —
" I further affirm that about ten years ago In
Padua Signor Galileo showed me the instrument
(described in his book) and explained its uses ;
and that about two years later, the said Signor
made me a present of one, which I still have in
my possession."
As Capra made no defence, the University
authorities did not take long to decide. Under
date 4th May 1607, they unanimously decreed
that his book was a scandalous plagiary and an
insult to Galileo and the University (of which
Capra was a member) ; that all the copies in
the possession of the author and his publisher, to
the number of 483, be given up to them for sup-
pression " in the way that seems best " ; and that
proceedings be taken against the printer and
publisher.
Galileo afterwards published a full account of
this affair in his " Difesa contro alle Calunnie ed
Imposture di Baldassare Capra." The first part
is taken up with a defence of his views on the
new star of 1604, which Capra had attacked in
another publication — moved thereto, as Viviani
says, " by envy of the universal applause which
accrued to Galileo from his lectures on the
subject"
From the opening passages of Galileo's "II
46 PROFESSOR IN PADUA [1592-
Saggiatore " (1623), it would appear that the real
author of the book which went under Capra's
name was Simon Mayer, a German graduate of
Padua, whom we shall meet with later on arro-
gating to himself the merit of two of Galileo's
astronomical discoveries. On this occasion, as
soon as he found our philosopher intent on
resenting the injury, he hastily quitted Italy,
leaving his friend Capra to bear alone the shame
of the exposure which followed.
In September 1598, the first period of Galileo's
appointment expired, which the Venetian Senate
were in no hurry to renew formally ; not because
of any doubt as to the incumbent's fitness, but
because of the dreaded increase of salary which
was usually expected on re-appointment, and which
all governments like to evade if they can. Galileo
himself had allowed the first term to expire, and
had nearly completed one year of the second,
before taking any steps in the matter. Then,
about the middle of 1599, with the advice and
assistance of Pinelli, Gianfrancesco Sagredo, a
young Venetian of great promise, and other
friends, he formally requested that his appoint-
ment be renewed, on an increased salary, as a
precedent for which he cited the case of Professor
Magini at Bologna, who on re-appointment was
awarded a salary much in excess of that enjoyed
by Galileo at Padua.
The question of augmentation was apparently
long and stoutly opposed on one side, and as
hotly pressed on the other. The Doge, Contarini,
complained that he was pestered on the subject,
,6io] REPUTATION AS A TEACHER 47
not only by Galileo's friends, but by his own
household. " If Galileo,31 he cried, " is not con-
tent with his salary he can resign." Moletti, he
pointed out, had never more than 300 florins, and
it was an understood thing that the Professors
should eke out their incomes by private lessons.
In the end the appointment was renewed, on
28th October 1599, for a further period of six
years, commencing 27th September 1598. The
salary was fixed at 320 florins (about ^70), and
Sagredo was grumblingly bidden to warn his
friend not to expect any further augmentation,
" as the Senate did not choose to make his case
a precedent for every learned and hungry foreigner
who might think fit to press a similar claim."
Galileo's reputation as a teacher was now
widely spread over Europe, and numbers of
young foreigners flocked to Padua to attend his
lectures. Amongst these are noted the Arch-
duke Ferdinand, afterwards Emperor of Germany ;
the Landgrave of Hesse ; the Princes of Alsace
and Mantua ; and a Prince Gustavus of Sweden,
often confounded with the great Gustavus
Adolphus. Our own William Harvey, the dis-
coverer of the circulation of the blood, was a
student at Padua, 1598-1602, and would no doubt
be a frequent attendant.
It is not certain when he moved from his
modest house near the Church of San Giustina;
but towards the end of 1 599 we find him installed
in a large house in the Via Vignali, now Via
Galileo. Here he was able to accommodate
suitably his private pupils, of whom he now
48 PROFESSOR IN PADUA [I592-
had large numbers resident with him, both Italians
and foreigners. His private papers show that he
looked after the catering himself, which must
have been no light matter, seeing that he often
had as many as twenty boarders at a time, some
of whom were accompanied by servants or
followers of some kind. Inclined to be prodigal
by nature, Galileo made nothing out of his
pupils' keep, being content if their contributions
covered the expenses of house-keeping.
With the house went a garden, to which in
1603 he added an adjoining piece of ground
containing a large arbour and vine-trellises. The
care of this garden, the flowers, the fruits, the
vines, was his great delight. He saw to every-
thing and did much himself in the way of weed-
ing, pruning, tying. Indeed, all his life he was
very fond of gardening, which he followed as
much as an education as a recreation and dis-
traction from severer studies. Here he took his
pleasure, sometimes alone, revolving deep things
in philosophy, but more often surrounded by
groups of his friends, or pupils, whom he now
sported with, now charmed with performances on
the lute, which he touched with a master's hand —
" As sweet and musical
As bright Apollo's lute, strung with his hair,"
now conversed, as they strolled along the arbour
and under the spreading vines, on any subject
that presented itself — the germination of seeds,
the nutrition and vegetation of plants, the making
of wines, philosophising all the while "from
grave to gay, from lively to severe." We can
i6io RESIDENT PUPILS 49
imagine how charming and instructive his con-
versations were, for Galileo had the habit of
allowing no natural phenomena, however trivial
in appearance, to escape him, and he found the
advantage of this in his lectures and writings,
as it furnished him with a stock of homely
illustrations to which the daily experience of his
hearers and readers readily assented, and which
he could show to be identical in principle with
the matter in hand. Thus he could always
find—
" Tongues in trees, books in the running brooks,
Sermons in stones, and good in everything."
"We seem to see him now," says Favaro,
writing within gunshot of the sacred garden,
"under the trellis of vines cared by his own
hands, surrounded by loving friends and pupils,
and discoursing with them on divine philosophy ;
or presiding at an evening meal in summer spread
under the grateful shade of trees or arbour ; or
playing the lute, as he was always ready to do
in convivial meetings. Oh ! how the remem-
brances of such evenings passed with Galileo in
his pleasant garden under the vault of our splendid
sky must have impressed themselves on the
memories of the youth of Italy, France, England,
and Germany, who came to Padua to listen to
our great master."1
Among the crowd of noble and learned men,
with whom at this period Galileo had cemented
a friendship which was only to be severed by
death, may be mentioned (besides Pinelli) Fra
Paolo Sarpi of the Order of Servites, Theologian
1 " Galileo e Suor Maria Celeste," p. 73.
D
So PROFESSOR IN PADUA
and Counsellor of the Venetian Republic, and
afterwards known as the Machiavelli of Venice ;
Fra Fulgenzio Micanzio, Sarpi's devoted friend
and colleague ; Fabrizio d'Acquapendente, the
famous surgeon of Padua, who has been called
"the Columbus of the human body," and under
whom our great Harvey studied ; Antonio de
Medici ; General del Monte ; and young Gian-
francesco Sagredo, who developed into "a witty
and eccentric patrician, whose house at Venice
resembled a Noah's ark, containing all manner of
beasts.". Pinelli took an opportunity of his corre-
spondence with Tycho Brah6 to recommend Galileo
"as a man whose friendship would be worth while
cultivating." Tycho addressed a letter to Galileo,
under date 4th May 1600, but the acquaintance went
no farther, and the great Dane died at Prague,
1 3th October 1601.
To the name of William Harvey, whom we
have mentioned above as, probably, a friend of
Galileo, we may now add the names of a few
others of English and Scotch nationality, as,
Robert Fludd, "The Father of the English
Rosicrucians," who was studying in Padua circa
1602 ; Messrs Moore and Willoughby, both of
whom are mentioned by Coryat in his " Crudities,"
the one as a doctor of physic, and the other as
a learned student in the University. Riqhard
Willoughby was one of Galileo's resident pupils,
and evidently did him credit, for amongst the
thousands of armorial bearings, etc., of distin-
guished members of the University which cover
its walls, appears that of Willoughby ; and a still
,610] THE AIR THERMOMETER 51
greater compliment was paid him by the Master
in the presentation of a copy, with an autograph
inscription, of the " Difesa contro. . . . Baldassare
Capra." A little later, Galileo had two Scotch
pupils who were among his most devoted friends.
These were John Wodderborn (or Wedderburn),
whom we shall meet with later on as his
master's champion ; and Thomas Seggett, who
was also a friend of Kepler, and in whose
" Album Amicorum," now in the Vatican library,
Galileo inscribed his name.1 Their coats-of-arms
and memorial tablets are also on the University
walls.2
To this period (1602) may be referred Galileo's
invention of the air thermometer. The date is
uncertain, for while Viviani asserts that the instru-
ment was designed during the first term of his
Professorship at Padua (1592-98), other evidence,
on- which Galileo rested his claim when contested
some years later, will only carry us back to
about 1602, Thus, Castelli, writing to Ferdinando
Cesarini, 2Oth September 1638, says: —
" I remember an experiment which our Signer
Galileo had shown me more than thirty-five years
ago. He took a small glass bottle about the size
of a hen's egg, the neck of which was two palms
1 Under date 13th August 1599. Galileo's signature, followed by
a few verses referring to the telescope and the discovery of Jupiter's
moons, is also in Brinck's album (under year 1614), and, curiously
enough, is next to that of Cardinal Bellarmine. The verses are given
in "Notes and Queries," January 1858, p. 44.
2 Professor Darwin gives the names of one hundred English and
Scotch students to whom memorial tablets are erected. See his
" Monuments to Cambridge Men at the University of Padua."
(Cambridge Antiquarian Society Proceedings^ March 1894.)
PROFESSOR IN PADUA
['592-
long (about 22 inches), and as narrow as
a straw. Having well heated the bulb in his
hand, he inserted its mouth in a vessel containing
a little water, and, withdrawing the heat of his
hand from the bulb, instantly the water rose in
the neck more than a palm above its level in
the vessel. It is thus that he constructed an
instrument for measuring the degrees of heat
and cold."
From this it is plain that the instrument con-
sisted merely of a glass tube ending in a bulb,
the air in which, being partially
expelled by heat, was replaced
by water from a glass vessel into
which the open end of the tube
was plunged. The different de-
grees of temperature would then
be indicated by the expansion or
contraction of the air which re-
mained in the bulb ; so that the
scale would be the reverse of
that of the thermometer now in
use, for the water would stand
at the highest level in the coldest
weather.
So long as the orifice of the
tube remained open, this instrument could not be an
efficient measurer of temperature, for it was impos-
sible to distinguish the expansive and contractive
effects of heat and cold from the effects of varying
atmospheric pressure. It was, in truth, a baro-
meter as well as thermometer, although Galileo
apparently did not recognise its utility as such.
AIR THERMOMETER.
!6io] THERMOMETER PERFECTED 53
Galileo's friend, Sagredo, was the first to divide
the tube into 100 degrees in 1613. He also appears
to have experimented with closed tubes from about
1615 ; but it was not until many years after (1653)
that the practice of hermetically closing the orifice
after exhausting the air was introduced. The
credit of this capital improvement is due to
Leopoldo de Medici, brother of Ferdinando II.,
who adopted the plan of expelling the air by
boiling the spirit and sealing the end of the
tube whilst the contained liquid was in an ex-
panded state, thus depriving the instrument of
its barometrical character and making it a true
thermometer.1
We have said above that Galileo's right to this
invention was contested, as in the case of his
geometrical and military compass, and in others to
which we shall come later on. It was claimed for
Porta, Santorio, and Paolo Sarpi, in Italy ; for
Robert Fludd and Francis Bacon in England ;
and for the Dutchman, Drebbel. But in disproof
of these claims it will be enough to say that the
first mention of the instrument by Porta occurs in
1606, by Santorio in 1612, by Sarpi and Fludd in
1617, by Bacon in 1620, and by Drebbel in 1621.
In 1604 the attention of astronomers was
attracted to a new star which suddenly appeared
with great splendour in the constellation Serpen-
1 About 1611-1612 Galileo substituted spirit of wine for water;
and later still Ferdinando II., a former pupil of Galileo, employed
coloured spirit of wine, and reduced the dimensions of the tube.
Mercury was first used by Lana in 1670. The Fahrenheit scale was
adopted in 1724, that of Reaumur in 1730, and the Centigrade scale
by Celsius in 1742.
54 PEOFESSOR IN PADUA [1592-
tarius. Maestlin, who was one of the first to
notice it, thus describes it : —
" How wonderful is this new star ! I am certain
that I did not see it before 2gth September, nor
indeed, on account of several cloudy nights, had I
a good view till 6th October. Now that it is on
the other side of the sun, instead of surpassing
Jupiter as it did, and almost rivalling Venus, it
scarcely equals the Cor Leonis, and hardly sur-
passes Saturn. It continues, however, to shine
with the same bright and strongly sparkling light,
and changes colour almost every moment, now
tawny, then yellow, presently purple, and red, and,
when it has risen above the vapours, most frequently
white/'
Galileo appears to have noticed the new star
very soon after Maestlin, i.e. on roth October;
and (whether by accident or design is not
known) he chose for the subject of his ordinary
lectures in the session then opening the theory
of the planets. This afforded his auditors the
wished-for opportunity of getting his views on
the new phenomenon, the appearance of which
had given rise to the most bewildering statements.
Some said it was a light in the inferior regions
of space — "the elementary sphere," but they did
not explain how it got there; others, that it was
an old star hitherto unnoticed; others again,
foqnding their opinion on abstruse teleological
grounds, declared that new stars were created
by God from time to time, and that this was
one of them; while, to add to the confusion,
the astrologers deduced from it the wildest
forebodings.
i6io] NEW STAR OF 1604 55
After carefully watching the star for some
time (it lasted eighteen months), Galileo resolved
to expound his views in three extra-ordinary
lectures, which were delivered to the public in
the great hall (Aula Magna) of the University
early in January 1605. In the opening sentences
of the first lecture, which are the only parts
preserved to us, he took occasion to rebuke his
auditors for their general insensibility to the
wonders of creation daily exposed to their view,
in no way less admirable than the new prodigy,
to hear an explanation of which they had hurried
in crowds to his lecture room. As regards the
star itself we know, from references in his other
writings,1 that he demonstrated that it was neither
a meteor, nor yet a body existing from all time,
and only now noticed, but a body which had
recently appeared and would again vanish.
Unlike his contemporaries, Tycho Brah£ and
Kepler, who thought that new stars (and comets)
were temporary conglomerations of a cosmical
vapour filling space; or, as is now thought, the
result of some catastrophe or collision whereby
immense masses of incandescent gases are pro-
duced, Galileo suggested that they might be
products of terrestrial exhalations of extreme
tenuity, at immense distances from the earth,
and reflecting the jsun's rays — an hypothesis which,
as we shall see later on, he also applied to
comets. From the absence of parallax he showed
that the new star could not be, as the current
1 "Difesa contro alle Calunnieed Imposture d Baldassare Capra,''
and " Postille al Libro d' Antonio Rocco."
56 PROFESSOR IN PADUA [1592-
theory held, a mere meteor engendered in our
atmosphere, and nearer to us than the moon, but
that it must be situated among the most remote
heavenly bodies.
This was inconceivable to the Aristotelians,
whose notions of a perfect and unchangeable
heaven, subject neither to growth nor to decay,
were quite at variance with the introduction of
any such new body. It is hard to say whether
Galileo's colleagues, bred in the old philosophy,
were more annoyed at the appearance of the star,
or at his calling attention to it so publicly and
forcibly. Controversy was now unavoidable at
Padua, as a few years before at Pisa, and Galileo
did not shirk it. He boldly threw down the
gauntlet in favour of the Copernican theory, and
repudiated the old systems of Aristotle and Ptolemy,
which up to that time he had taught in his classes.
The Aristotelians put forth one of their best
advocates, Antonio da Montepulciano, to confute
Galileo's views, and the latter replied in the only
way possible — by ridicule. With the aid of some
of his pupils he . wrote and printed an exquisite
squib in the Paduan dialect, entitled, " Dialogo
de Cecco di Ronchitti da Bruzene in Perpuosito
del la Stella Nuova."1
In 1604, when the second term of Galileo's
Professorship expired, he applied for its renewal
with a further increase of salary ; but, as usual, the
Venetian authorities were slow to move. At this
1 Padua, 1605, edited by Girolamo Spinelli. Reprinted with a
modern Italian version in Favaro's edition of Galileo's works,
vol. ii. p. 307.
I
i6io] HISTORIC LECTURE-DESK 57
time Vincenzio Gonzaga, the reigning- Duke of
Mantua, was anxious to attach him to his court
and person, and made some tempting overtures,
but nothing came of them. However, while in
Florence during the summer of 1605, Galileo took
an opportunity of interesting his young pupil
Cosimo, son of the Grand Duke, in his case ; and
at length, and mainly through the influence of
the Tuscan Ambassador at Venice (prompted by
Cosimo), he was reappointed for a third term of
six years, with an augmented salary of 520 florins
(about ^115), by decree of 5th August 1606.
His public lectures were at this time so thronged
that the ordinary class-rooms, large as they were,
were often insufficient to contain his audiences. His
more popular lectures, as, for instance, those on the
new star, were delivered in the Aula Magna, the
great hall of the University, and capable of holding
1000 persons. Even this, according to Drink water,
was not large enough, for " on several occasions he
was obliged to adjourn to the open air."1
The Cattedra (chair or lecture-desk) which then
existed in the Aula Magna, and which Galileo has
made historical, is now preserved as a sacred relic
in the Stanze di Galileo in the University buildings.
It is made of stout rough-planed planks, untrimmed
and unpainted, and held together by nails. The
Cattedra shown in attached drawing is a modern
structure. Around the walls are hung thousands
of coats of arms of professors and students of Padua
who. became distinguished in after life.
1 " Life of Galileo" (Library of Useful Knowledge), London, 1833,
p. 1 6.
58 PROFESSOR IN PADUA [1592-1610
The bust on pedestal shown on the left of the
drawing is that of Galileo, by the sculptor Ferrari.
It was presented by the Archduke Maximilian of
Austria (the ill-starred Emperor of Mexico), and
bore on the pedestal an inscription to that effect.
After the Austrians were driven out of Italy this
inscription was effaced, and replaced by the present
one.
CHAPTER IV
GALILEO, PROFESSOR IN PADUA — (continued)
I592-l6lO
IN 1607 Galileo had been studying the " De
Magnete"1 of Dr William Gilbert of Colchester,
a book which had for him always a great fascina-
tion, and for two reasons — firstly, its arguments
traversed many of the principles of the Aristotelian
School ; and secondly, it contained a number of
original experiments in electricity and magnetism,
coupled with philosophical reflections of a far-reaching
kind, which appealed to his own daring spirit.
Up to Gilbert's time little was known of
magnetism. The attractive power of the load-
stone was known to Aristotle and Pliny, and the
latter appears to have been also acquainted with
its power to communicate this attractive property
to other bodies.
The polarity of the magnet, that is, its power
of taking up a north and south direction when
freely suspended, was known to the Chinese from
a very early period. Thus, in the second century
B.C., we find allusions to "magnetic cars" with
1 " Physiologia Nova de Magnete, Magnetic! sque Corporibus,"
London, 1600. From a letter of Fra Paolo Sarpi, dated nth
September 1602, it would appear that Galileo in that year first became
acquainted with Gilbert's book.
50
60 PROFESSOR IN PADUA [1592-
which ambassadors from distant countries were
provided, in order that they should not miss the
way on their return home. In the fourth century
of our era Chinese captains employed the magnet
to direct their courses across the open seas ; and
it was through these that the knowledge of the
compass was carried to India, and thence to the
eastern shores of Arabia and Africa. The Arabic
designations Zoron and Aphron (south and north),
which Vincent de Beauvais1 gives to the ends of
the magnetic needle, indicate, like many Arabic
names of stars which we still employ, the source
whence Western nations received the elements of
their scientific knowledge.
The application of the compass to navigation,
doubtless, soon led to the discovery of another
property of the magnet, its declination or variation
from the north pole, according to locality. It must
have been known to the Chinese in' the twelfth
century, as it is mentioned by a Chinese philosopher
who wrote about the year mi. And Columbus
made the same discovery on his first voyage to
America in September 1492,
The inclination or dip of the needle was noticed,
but hardly understood, by George Hartmann in
1544 ; it was better described by Fortuni Affaytatus
in 1549, and by Martin Cortes in 1551 ; but it
only became generally known through the labours
of Robert Norman, a nautical instrument maker
of Wapping, who began his experiments in 1576,
and published an account of them in his " Newe
Attractive," 1581.
1 In his " Speculum Naturale," first published in Paris, 1473.
i6io] GALILEO'S ARMATURES 61
Doubtless, owing to his other occupations,
Galileo's researches in magnetism did not take
him far. The main results are given in two letters
to Curzio Picchena, Chief Secretary to the Grand
Duke of Tuscany, dated i6th November and
gth December 1607. From these we learn that
he had made many experiments with loadstones,
which resulted in his devising an armature by
which the portative force of a stone could be con-
siderably increased. He observed that the longer
a stone sustains a weight the more it gains in
strength. He also found that smaller stones were
usually more powerful than larger ones. Thus,
a small stone which he had picked up in Venice
was much more powerful than one of 5 Ibs. belong-
ing to his friend, Sagredo. This latter could
normally sustain a weight of 6^ Ibs, but when
provided with Galileo's armature it was capable
of supporting more than 12 Ibs. By breaking up
large stones and shaping the pieces in a certain
way he was able to make each piece sustain thirty
to forty times the weight borne by the original
stone. The Abbe Castelli tells us in his treatise
on the magnet (circa 1639-40) : —
" I have seen such a loadstone, only 6 ozs. in
weight, armed with iron by the untiring industry of
Signor Galileo, and presented to his Highness the
Grand Duke Ferdinando, which lifts 15 Ibs. of iron
worked into the shape of a sepulchre." l
1 This form was probably suggested by the legend of Mohammed's
coffin suspended in the air by loadstones. Sir Isaac Newton is said
to have had a stone, set in a ring, which weighed only 3 grains, yet
was able to support 746 grains. A Galilean stone and armature are
now shown in the Tribuna di Galileo in Florence.
62 PROFESSOR IN PADUA [1592-
Gilbert was one of the first persons who arrived
at general, though confused, notions on the subject
of gravitation. In his " De Magnete " he explains the
influence of the earth upon the moon by comparing
the former to a huge loadstone ; and in another
work, not, however, published until many years
after his death/ he gives his opinions at greater
length. In this treatise he asserts that the earth
and the moon act upon each other like two mag-
nets, but the influence of the earth must be greater
than that of the moon, on account of its greater
mass. Again, although the influence is magnetic in
it$ nature it does not show itself as in ordinary
magnets, "It is not," he says, "so as to make
the bodies unite like two magnets, but that they
may go on in a continuous course/1 In another
place he ascribes the tides partly to the influence
of the moon.
These speculations of the English philosopher
had a strange fascination for Galileo. In 1608, he
had the idea of recording their importance in a
medal, which he proposed to strike on the occasion
of the marriage of his pupil, Prince Cosimo, and
the Archduchess Madeleine of Austria. Under
the name, Cosmos, he proposed to engrave the
figure of the prince, and a magnet from which
depended several pieces of iron, with the mottoes :
" Vim Facit Amor/' and " Magnus Magnes Cosmos."
In the third " Day " of his Dialogues on the
Ptolemaic and Copernican systems, published in
1 " De Mundo Nostro Sublunari," Amsterdam, 1651. Gilbert died
in 1603, aged 63. Leonard Digges and his son, Thomas, Gilbert's
contemporaries, held the same view.
,6io] NEEDLE TELEGRAPH 63
1632, he utilises his own early magnetic observa-
tions, and warmly acknowledges the merits of
Gilbert's work, declaring that his marvellous
conception of the earth as a great loadstone was
to him a subject of praise, admiration, and envy.
The passage is worth quoting : —
" I extremely praise, admire, and envy this
author. I think him, moreover, worthy of the
greatest praise for the many new and true obser-
vations that he has made, to the disgrace of so
many vain and fabling authors, who write, not from
their own knowledge, but repeat everything they
hear from the foolish vulgar, without attempting to
satisfy themselves of the same by experiment —
perhaps that they may not diminish the size of their
books/'
Here he is evidently tilting at the " Scientific"
writers, numerous in his and the following century,
who filled their books with fables about the all-
embracing powers and virtues of the magnet, and
on which charlatans traded and grew fat. One
such person he appears to have met in Venice, of
whom he gives an amusing account in the same
Dialogues, at the end of the first " Day/' One
of the speakers, Sagredo, commenting on the
remarks of the previous speaker, says : —
"You remind me of one who offered to sell me
a secret art, by which, through the attraction of a
certain magnetic needle, it would be possible to
converse across a space of two or three thousand
miles. And I said to him that I would willingly
become the purchaser, provided only that I might
first make a trial of the art, and that it would be
sufficient for the purpose if I were to place myself
64 PROFESSOR IN PADUA [i592.
in one corner of the room and he in the other. He
replied, that in so short a distance the action would
be scarcely discernible ; whereupon I dismissed the
fellow, saying that it was not convenient for me just
then to travel into Egypt, or Muscovy, for the
purpose of trying the experiment, but that if he
chose to go there himself, I would remain in Venice
and attend to the rest."
During his residence at Padua Galileo was in
the habit of returning to Florence for the long
summer holidays. On these occasions for some
years, and beginning about 1601, he gave instruc-
tions in mathematics to the young prince, Cosimo
(born 1590), there being, apparently, no one in
Florence whom the Grand Duke thought capable
of carrying on this branch of the boy's education.
Galileo, of course, was duly sensible of the honour
done in thus selecting him as the young prince's
mathematical tutor ; and the arrangement was
desirable for other reasons — it added to his income,
always a serious matter ; and it gained him the
esteem and friendship of the reigning family of
Tuscany, which, although not able (as we shall see)
to protect him entirely from misfortunes, was still
strong enough to make his troubles lighter than
they would otherwise have been.
While the Grand Duke was wont to declare
that Galileo was the greatest mathematician in all
Christendom, his wife, the Grand Duchess Cristina,
believed him to be the greatest of astrologers, and
at the commencement of wha? proved to be her
husband's last illness, she begged him to correct his
horoscope! He did so/ and communicated the
i6xo] JUDICIAL ASTROLOGY 65
result in a letter of i6th January 1609, according
to which Ferdinando I. had still many years to
live. Galileo's prognostic was speedily proved to
be false, as the Grand Duke died twenty-two
days after !
Florence, from the earliest period, was noted for
its cultivation of the rites of sacrifice and divination,
and during the thirteenth and fourteenth centuries,
astrology was taught in the Universities of Italy,
and in particular at Padua and Bologna. Even in
the succeeding three centuries, and in spite of
advancing knowledge, judicial astrology still held
sway over the hopes and fears, not only of the vulgar,
but of the highest and best educated classes.1
No wonder, then, if Galileo, more temporum,
dabbled in horoscopes ; but it is not to be supposed
that a mind, which early discarded the trammels of
ancient sciences, and took nothing on trust or mere
authority, could really have believed in them. We
prefer to consider his action in this, and other
instances, in the light of a pious fraud.2
Having brought our account of Galileo's public
career up to the eve (1609) of his immortal discoveries
1 Even grave astronomers and mathematicians were not exceptions.
Thus, to mention only a few, Cardan, the algebraist, starved himself
to death so that his prognostic as to that event should be fulfilled.
Tycho Brahe and Kepler dabbled in the art, and the latter helped to
maintain his family by casting nativities and publishing a yearly
almanac, the prototype of our modern " Moore." Poor Kepler could
not get his salary from the authorities at Prague, and so was driven
to astrology, as the only thing that would pay, and on it he lived for
years. Finally, Francis Bacon and Thomas Browne, typical wise
men of England, thought that there was much truth in a sober and
well-regulated astrology.
2 For more on this subject see Favaro's "Galileo Astrologo
secondo document! editi ed inediti," Trieste, 1881 ; or his '"Galileo e
Suor Maria Celeste," p. 61.
E
66 PROFESSOR IN PADUA [i592-
in astronomy, we must, before proceeding, retrace
our steps and give some account of his private life.
We have seen that by the death of his father, in
1591, he had become the head of the family. This
position, always attaching a grave responsibility to
its possessor, was at this time, and particularly in
the present case, fraught with much anxiety. Not
only had Galileo, on his slender resources, to keep
himself in Padua and provide for the requirements
of the household in Florence, but it was his duty to
see to his brother's setting out in life, and a still
more sacred duty, to find a suitable husband for his
unmarried sister, Livia. In Italy in those days, a
girl's education being finished, two paths were open
— not always for her to choose. One led to the
cloister, the other to the house of a husband. It
had, apparently, been the family intention for Livia
to take the veil, but so great was her aversion to a
convent life, that her brother did not insist, much as
the arrangement would have saved him in trouble
and expense.
Though his sister, Virginia, had been married to
Benedetto Landucci before the father's death, the
burden of providing the dowry had fallen on Galileo,
who, pressed on all sides for money, had been
unable immediately to pay the amount. At length,
in May 1593, not choosing to wait any longer, and
not caring who went short so long as he got his due,
Landucci threatened to proceed to harsh measures —
in fact, to have Galileo arrested for debt the next
time he set foot in Florence ! l
1 " If you come here next month I shall be rejoiced to see you,
only you must not come unprovided with funds, for I hear that
x6io] FAMILY AFFAIRS 67
Livia writing to her brother, ist May 1593, shows
how all looked to him as to a Father Bountiful : —
" As our Lena1 is going to join you in Padua I
could not help sending by her these few lines to tell
you about myself, and, though your lordship may
not care to hear about me, I care to hear about you,
for I have no one in the world but you. So please
be so kind as to answer, that I may have that little
bit of pleasure. Though your lordship writes to
our mother, she never brings me your letters — only
says, 'Your brother sends his love.' She told me
lately your lordship was going to send Michelangelo
to Poland. I was at first extremely grieved at
hearing this, but then I comforted myself by saying :
4 If Galileo thought it was a dangerous place he
would not send him/ for I know that you love him
dearly. Besides that, I heard you were soon coming
here, and it will seem a thousand years till you
arrive! Please do remember to bring me some
stuff to make a dress, for I am in great need of
one."
Galileo had some difficulty in giving his brother
a start in life. He had desired for him some post at
the Grand Ducal court, but there seemed to be no
opening, though his musical talents and elegant
manners had gained for him many friends in Florence.
Early in 1593 he joined Galileo in Padua, in the
hope of obtaining, if not permanent employment as
Benedetto is determined to have his own, and menaces loudly that he
will have you arrested the instant you arrive. He is just the man to
do it, so I warn you, for it would grieve me much if anything of the
kind were to happen."— (Extract from Madam Giulia's letter to Galileo,
dated 29th May 1593.)
1 Nothing is known of this sister. She appears as Elena in the
family genealogy, and is supposed by some biographers to have
married and settled in Padua. Professor Favaro could find nothing
to substantiate this story.
68 PROFESSOR IN PADUA [1592-
a musician, at least some pupils from amongst the
many foreign students of the University. Of the
Polish scheme, to which Livia refers in the above
letter, nothing is known beyond the fact that
Michelangelo did go to Poland, but was soon
back again on his brother's hands. At length, early
in 1600, the offer of the Polish prince (name un-
known) 1 was renewed on very favourable terms, and
the young man set out on his second voyage in
August of that year, provided with an outfit and
money by Galileo. Michelangelo, with his " elegant
manners/' would evidently be in his element there,
for he was to have a place at the prince's table ; be
dressed like the first gentlemen of his court ; have
two servants to wait upon him ; a coach and four ;
200 Hungary ducats yearly (about 300 Italian scudi) ;
and perquisites !
Livia was by this time getting tired of convent life,
and was plaguing her mother to find her a husband.
Madam Giulia did so, and informed Galileo, upon
whom of course would lie the burden of finding the
dot. Replying on yth August 1600, he says : —
" From your letter and that of Mr Piero Sali,
I hear of the proposed match for our Livia, as to
which I do not see how I am to act, for, though
from what Mr Piero says, I esteem it desirable,
yet it is impossible for me to consent to it just at
present The reason is this [here he enters into
details of Michelangelo's Polish engagement, and
goes on], I of course must provide him with money,
and besides, the prince wishes him to bring certain
things ; so that what with these articles and what
he requires for himself, I cannot avoid spending less
1 Probably one of the Radziwil family.
1610] FAMILY AFFAIRS 69
than 200 scudi. Now, you know what expenses I
have had this last year, so that I really cannot do
as I would. On the other hand, Sister Contessa
[Superioress of the Convent St Giuliano] writes
that on all accounts I ought to take Livia away
from the convent, as she hates remaining there.
Now, as she has waited so long, I should like her
to be well and comfortably settled. If I am to
believe Sr. Piero, this Pompeo Baldi [the selected
bridegroom] is a good sort of man, yet hearing that,
including his private income, he has not 100 ducats
yearly, I do not see how a household is to be main-
tained on that sum. Therefore I would, if possible,
have the matter deferred. Michelangelo will, with-
out fail, send me a good sum of money as soon as
he gets to his destination, and with this, joined to
what I can get together, we may take measures for
establishing the child, since she too is determined to
come out and partake of the miseries of this world.
Meanwhile, I wish you would see about taking her
away from St Giuliano and placing her in some
other convent till her turn comes, and persuade her
that she will lose nothing by waiting. Tell her
that there have been queens and great ladies who
have not married till they were old enough to be her
mother. Therefore, pray see her as soon as you
possibly can, and give the enclosed letter to Sister
Contessa. She has been asking me to pay what is
due for Livia's board. Find out the amount, and I
will send it at once."
Depending on his brother's promised help in
meeting Livia's dowry, Galileo made up a new
match between her and a Pisan gentleman, Taddeo
Galletti, on ist January 1601, promising a dot of
1800 ducats, of which 600 ready cash, and a»
trousseau (worth 200), were to be paid down, and the
rest to be paid within five years. But of this 800 he
70 PROFESSOR IN PADUA [1592-
had to borrow 600, relying on his brother's assur-
ances of a speedy remittance from Poland. Vain
hopes! Livia had been married nearly a year,
and Michelangelo had neither repaid the money
advanced for his own outfit, nor contributed to
his sister's dowry. Writing to him 2Oth Novem-
ber 1 60 1, Galileo thus expresses his resentment of
such ungrateful conduct : —
" Though you have sent no answer whatever to
any of the four letters which I have written within
the last ten months, I nevertheless write and repeat
what I have said. I would rather think that all my
letters had missed you, or any other unlikely thing,
than that you meant to be wanting in your duty not
only in answering my letters, but in sending money
to pay the debts which we owe to various persons,
and in particular to Signor Taddeo Galletti, our
brother-in-law. If I had imagined things were
going to turn out in this manner, I would not have
given the child in marriage, or else I would have
given her only such a dowry as I was able to pay
myself without assistance, since I seem to be fated
to bear every burden alone. I beg that you will,
without delay, have a deed drawn out and wit-
nessed by a public notary, in which there shall be
an acknowledgment of your being bound to pay
the said dowry to Signor Taddeo jointly with me.
I insist on this being done without delay, and,
above all, I desire that you will write and give
some news of yourself, for every one is feeling
anxious about you, there having been no word of
your whereabouts since you left Cracow."
Michelangelo never paid a farthing for years,
and then only a small fraction (50 crowns) of what
he owed. In 1605 he was back again in Padua,
i6io] FAMILY AFFAIRS 71
living at Galileo's expense, till the latter succeeded
in getting him a post as music master in the court
of the Duke of Bavaria. That he should spend
his gains upon himself and, when spent, fall back
upon his brother, seemed to him a matter of course.
Selfish as he was conceited, never from first to last
could he be brought to see that, when he had more
than enough for his legitimate expenses, the helping
of relations became at once a sacred duty.
For cool effrontery and heartless cynicism the
following letter of 4th March 1 608, to Galileo, is, we
hope, not often paralleled : —
" I was glad to get your letter, and, though it
was full of complaints, still I am pleased to find that
you do not despise me quite so much as I had
imagined. Now I will answer you about the claims
of our brothers-in-law. My dear brother, if I have
not been able to pay them as I certainly should
have liked to do, I do not see that you can blame me
so much. You complain of my having spent such
a large sum of money on one feast ; I do not deny
that the sum was large, but just consider that it was
on the occasion of my wedding. There were more
than eighty persons present, among whom were
many gentlemen of importance, and among these
there were no less than four ambassadors. Had I
not followed the custom of the country, I should
have been put to shame, so that I was forced to
spend what I did, and indeed could not possibly
have managed with less. You cannot accuse me
of ever having spent such sums of money simply
for my own gratification, never, indeed, have I
thrown money away on anything, but, on the
contrary, have often denied myself what I wanted
in order to save. You say that it does not serve
your turn for me to write and tell you that * God
72 PROFESSOR IN PADUA [1592-
will not be pleased if you keep up a feeling of
rancour against me/ Of course, I know it will not
serve your turn ; I did not write it supposing that
it would help you to get rid of the debt to our two
brothers-in-law. As to that matter, I tell you
shortly that I will do what I can, and, indeed, will
put myself to every inconvenience rather than not
satisfy their claims in part; but as to my finding
1400 crowns, which is the sum still remaining to be
paid, I know that I cannot do it, and never shall,
for I find it scarcely possible to pay the interest.
You should have given our sisters a dowry, not
merely in conformity with your own ideas of what
was right and fitting, but in conformity with the
size of my purse. God knows that if I have not
paid off my share it is because I could not. When
I sent you those 50 crowns, Signor Cosimo lent
me 30 of them, and I have not yet repaid him,
though I must soon, as he writes saying he wants
one of my lutes! By and bye I will borrow
another 50 crowns and send you. I cannot
promise more, since for these last few months I
have been obliged to spend a great deal on my
house. I know you will say that I should have
waited and thought of our sisters before taking a
wife. But, good heavens ! the idea of toiling all
one's life just to put by a few farthings to give one's
sisters ! This joke would be indeed too heavy and
bitter, for I am more than certain that in thirty
years I could not have saved enough to cover this
debt. God help me ! I would do more if I could.
Have a little pity on me and consider ; you cannot
say that I ever had the heart to gratify my own
liking without caring about others. You may say
that my having married is a proof that I care not
for paying my debts as long as I can gratify my
own liking. To this I shall make no answer. God
knows I am thankful to have my wife, and I hope
1610] GALILEO'S CHILDREN 73
He will enable me to carry out my desire in satis-
fying this debt. I shall say no more, but I trust
you will consider me a good brother, for I will do
all I can to send you some assistance, since you say
it is all my fault that you are in such distress. But
excuse me, if I failed hitherto it was because I
could not help it.
" I understand that you are going to send the
case of lutes shortly. I have been expecting its
arrival with some impatience ; for during this Lent
I am in great want of them for playing concerted
music, and to have them quicker I would not mind
paying something more for the carriage."
Galileo must have been more than human not to
feel some resentment at the selfishness displayed in
this rambling epistle, H is anger, however, was short-
lived. In 1610, the brothers had again resumed
their correspondence, and from that time Michel-
angelo never failed, as we shall see, to write whenever
he wanted his brother's assistance. The 50 crowns
mentioned in his letter are probably all that he
ever paid to his long-suffering brother.
As if the worries and burdens of his father's
family were not enough, Galileo must needs add
to them the cares of a family of his own. In 1599,
he entered into amorous relations with a Venetian
lady, Marina Gamba, by whom he had three
children, Virginia, born I3th August 1600; Livia,
born 1 8th August 1601 ; and Vincenzio, born 2ist
August 1606.
CHAPTER V
GALILEO, PROFESSOR IN PADUA — (continued)
I592-I6IO
EARLY in the month of October 1 608, the telescope
was invented in Holland, and, according to all
accounts, its discovery was the result of an accident.
Long ago Epicurus defined the universe and all
that it contains as the result of a fortuitous con-
course of atoms, and so it is very often in the
arts and sciences of man, great discoveries are the
result of the fortuitous juxtaposition of two and
two. In the present case, and as the story goes,
an apprentice, playing with spectacle lenses in the
shop of one Hans Lipperhey, an optician of
Middleburg, noticed that by holding two of them
in a certain position a large and inverted view of
objects was obtained. On hearing of this the
master fixed two glasses in a tube, so that the
weather-cock on a neighbouring church spire could
be seen apparently nearer and upside down. This
toy was shown in his window, where one day the
Marquis Spinola chanced to see it, and entered
the shop to examine it. Struck by the strange
phenomenon it presented, he purchased the instru-
ment, and afterwards gave it to Prince Maurice of
Portrait of Galileo, aged about 40.
[To face p. 74.
i592-x6io] INVENTION OF TELESCOPE 75
Nassau, who thought it might be useful in military
reconnaissances.
Among the Acts of the States-General pre-
served at the Hague, Professor Van Swinden found
some interesting papers relating to this matter.
On 2nd October 1608 the States Assembly took
into consideration a petition of Lipperhey for the
exclusive right of making and selling an instrument
for seeing at a distance. They suggested that the
instrument should be arranged so as to enable one
to look through it with both eyes. A trial was
fixed for the 4th October, and it was resolved that,
if it should be found useful, an engagement should
be entered into with the inventor to make three
such instruments of rock crystal, and that he
should be bound not to divulge the secret to
anybody. The trial on the 4th was apparently
satisfactory, for two days later the Assembly
voted Lipperhey 900 florins. On i5th December
they examined his arrangement of the instrument
" to see with both eyes," and approved it ; but, as
others by this time had a knowledge of the in-
vention, they refused to grant him the exclusive
privilege of making and selling it. They, how-
ever, gave him an order to make, for the use
of the Government, two other instruments " to
see with both eyes," allowing him the same
remuneration as in the first instance.
Of the others referred to above, one was
James Metius of Alkmaer, who claimed the in-
vention in a petition, dated I7th October, or
fifteen days after Lipperhey. In this petition he
declares that the idea occurred to him accidentally
76 PROFESSOR IN PADUA [r592_
while engaged on other experiments, and that he
had now succeeded so far in perfecting his in-
vention "as to make distant objects appear as
distinct by it as by the instrument which had
lately been offered to the States/' Apparently
the instrument of Metius was not so good as he
said, for he was advised to bring it to greater
perfection, when his petition for a privilege would
be taken into consideration.
Very soon a third claimant appeared in the
person of Zacharias Jansen, also an optician and
a near neighbour of Lipperhey. As regards this
claim, the truth would seem to be that Jansen, as
far back as 1590, had really constructed the
microscope ; and that, on hearing of Lipperhey's
invention, he adapted his own instrument from
seeing things near to seeing things at a distance;
and so he was able, with some show of reason, to
claim the invention.1
Leaving this part of the subject, the fact for
us at present is that reports of the invention,
more or less vague, spread slowly over Europe,
and reached our philosopher while on a short
visit to Venice about the middle of June 1609.
As Galileo's independent invention of the tele-
scope, like so many more of his discoveries, has
been denied or belittled by envious detractors in
his own and later times, the story had best be
told in his own words. In a letter from Venice
to his brother-in-law Landucci, dated 29th August
1609, he says : —
1 For more on this subject see Professor Moll's paper in Journal,
Royal Institution^ vol. i. pp. 3 19 and 483.
X6w] EXHIBITION OF TELESCOPE 77
" I write now because I have a piece of news
for you, though whether you will be glad or sorry
to hear it I cannot say, for I have now no hope
of returning to my own country,1 though the oc-
currence which has destroyed that hope has had
results both useful and honourable. You must
know then that about two months ago \i.e. about
June 1609] a ^port was spread here that in
Flanders a spy-glass had been presented to Prince
Maurice, so ingeniously constructed that it made
the most distant objects appear quite near, so
that a man could be seen quite plainly at a
distance of 2 miles. This result seemed to me
so extraordinary that it set me thinking, and as
it appeared to me that it depended upon \ the laws
of perspective, I reflected on the manner of
constructing it, and was at length so entirely
successful that I made a spy-glass which far sur-
passes the report of the Flanders one. As the
news had reached Venice that I had made such
an instrument, six days ago I was summoned
before their Highnesses, the Signoria, and ex-
hibited it to them, to the astonishment of the
whole sdnate. Many of the nobles and senators,
although of a great age, mounted more than once
to the top of the highest church tower in Venice,
in order to see sails and shipping that were so
far off that it was two hours before they were
seen, without my spy-glass, steering full sail into
the harbour; for the effect of my instrument is
such that it makes an object 50 miles off appear
as large as if it were only five.
" Perceiving of what great utility such an
instrument would prove in naval and military
operations, and seeing that his Serenity the Doge
desired to possess it, I resolved on the 24th
1 A design which he had formed earlier in the year. See
p. 1 1 6 infra.
78 PROFESSOR IN PADUA [1592-
inst. to go to the palace and present it as a
free gift. On quitting the presence-chamber I
was commanded to bide awhile in the hall of
the Senate, whereunto the Procurator, Antonio
Prioli, one of the heads of the University of
Padua, came, and, taking me by the hand, said
that the Senate, knowing the way in which I
had served it for seventeen years at Padua, and
being sensible of my courtesy in making it a
present of the spy-glass, had ordered my election
(with my good-will) to the Professorship for life,
with a salary of 1000 florins yearly; and as
there remained yet a year to terminate the
period of my last re-election, they willed that
the increase of salary should date from that
very day.1 Knowing that Fortune's wings are
swift but that those of Hope are drooping [i.e.
the hope of returning and settling in Florence],
I said I was content to abide by his Serenity's
pleasure. Then the illustrious Prioli, embracing
me, said : ' As I command here and can order
what I please (it being my turn this week), I
will that after dinner the Senate assemble, and
that your election be put to the ballot/ which
was done [with few dissentient votes.] So I
am bound here for life, and can only hope
to enjoy a sight of my own country during the
recesses."
1 The decree is dated 2^th August 1609, and the preamble
runs as follows : — " Domino Galileo Galilei having been mathe-
matical lecturer in Padua for seventeen years, to the gain of the
University and to the satisfaction of all ; and having during his
professorship made known to the world divers discoveries and
inventions to his own renown and the common weal; but in
particular having lately invented an instrument by which (knowing
the secrets of perspective) things visible, b(ut most distant, are
brought within easy vision, and which may be made to serve in
many occasions ; now, it is proper that this Council do gratefully
and munificently recognise the labours of those who are employed
for the public benefit. Therefore," etc.
Campanile and Church of San Marco, Venice.
[To face p. i
i6io] ITS INVENTION BY GALILEO 79
In "II Saggiatore," published in 1623,
Galileo enters more fully into the reasonings
which led him to the invention, and defends his
right to consider the telescope as a child of his
brain. He says : —
"What part belongs to me in the invention
of the telescope, and why may I reasonably call
it my son? As I have long ago shown in my
* Sidereus Nuncius/ news arrived at Venice,
where I happened to be at the moment, that
a Dutchman had presented to Count Maurice
of Nassau a glass by means of which one could
see distant things as clearly as if they were
near. With this simple fact I returned to
Padua, and, reflecting on the problem, I found
the solution on the first night after my arrival,
and the next day I made an instrument and
reported the fact to my friends at Venice, with
whom I had been discussing the rumour. In
the next six days I made a more perfect instru-
ment, with which I returned to Venice, and
showed it for more than a month to the wonder
and astonishment of the chiefs of the republic
— a task which caused me no small fatigue.
But perhaps it may be said that no great credit
is due for the making of an instrument, or the
solution of a problem, when one is told before-
hand that the instrument exists, or that the
problem is solvable. It may be said that the
certitude of the existence of such a glass aided
me, and that without this knowledge I would
never have succeeded. To this I reply, the help
which the information gave me consisted in
exciting my thoughts in a particular direction,
and without that, it is possible they may never
have been directed that way; but that such
information made the act of invention easier to
8o PROFESSOR IN PADUA [1592-
me I deny, and I say more — to find the
solution of a definite problem requires a greater
effort of genius than to resolve one not specified ;
for in the latter case hazard, chance, may play
the greater part, while in the former all is the
work of the reasoning and intelligent mind.
Thus, we are certain that the Dutchman, the
first inventor of the telescope, was a simple
spectacle-maker, who, handling by chance different
forms of glasses, looked, also by chance, through
two of them, one convex and the other concave,
held at different distances from the eye ; saw
and noted the unexpected result; and thus found
the instrument. On the other hand, I, on the
simple information of the effect obtained, dis-
covered the same instrument, not by chance,
but by the way of pure reasoning.1 Here are
the steps : the artifice of the instrument depends
either on one glass or on several. It cannot
depend on one, for that must be either convex,
or concave, or plain. The last form neither
augments nor diminishes visible objects ; the
concave diminishes them, the convex increases
them, but both show them blurred and indistinct.
Passing then to the combination of two glasses,
and knowing that glasses with plain surfaces
change nothing, I concluded that the effect could
not be produced by combining a plain glass
with a convex or a concave one ; I was thus
left with the two other kinds of glasses, and
after a few experiments I saw how the effect
sought could be produced. Such was the march
of my discovery, in which I was not assisted in
1 This is exactly what Huygens, writing years afterwards, seems
to deny. "I would place,35 he says, "without hesitation above all
mortals him who by reflection alone, and without the aid of chance,
should arrive at the invention of the telescope." "Dioptrica,"
Leyden,
i6io] HIS FIRST TELESCOPES 81
any way by the knowledge that the conclusion
at which I aimed was a verity.
" But some people believe that the certainty of
the result aimed at affords great help in attaining
it. Let them read history, and they will find that
Archites made a dove that could fly, and that
Archimedes made a mirror that burned objects at
great distances, and many other admirable machines.
Now, by reasoning on these things such people,
doubtless, will be able, with very little trouble and
with great honour and advantage, to tell us how they
were constructed. And even if they do not succeed,
they will be able to certify for their own satisfaction
that that ease of fabrication which they had promised
themselves from the foreknowledge of the result is
very much less than what they had imagined."
Of the first telescope referred to in the above
extracts no further mention is made, so we may
suppose that it was of little value ; but the second,
which he presented to the Doge and is unfortunately
lost, is mentioned with some particulars in his
"Sidereus Nuncius," published at Venice about the
middle of March 1610. It consisted of a leaden
tube, with a plano-concave eye-glass and a plano-
convex object glass, and had a magnifying power of
3 diameters, thus making objects appear three times
nearer, and consequently nine times larger. From
other sources we learn that the tube was about 70
centimetres long and about 45 millimetres diameter.
This instrument was shown for the first time in
public on 2 ist August 1609, from the top of the
campanile of San Marco, when the farthest object
that could be clearly seen was the campanile of the
Church of San Giustina in Padua, distant about
35 kilometres in a straight line.
F
82
PROFESSOR IN PADUA
[1592-
The principle of Galileo's telescope is illustrated
in the adjoining diagram. C is the centre of the
object-glass, and c that of the eye-glass ; the
former being a convex, the latter a concave lens.
The direction of the line cC may be spoken of as
the axis of the telescope. It will be readily under-
stood that if the instrument be adjusted so that its
axis points in the direction of a minute object s',
then, on applying the eye to the eye-glass, that object
appears exactly in the centre of the field of view.
Fig. 6.
THE GALILEAN TELESCOPE.1
The eye placed at E will see the point s; in the
same direction as if the two intervening lenses were
suddenly annihilated. To fully realise the pheno-
menon of vision through the telescope, we must
examine the course of the rays of light which reach
the eye from an object slightly removed from the
axis of the telescope. Such an object is repre-
sented by S in the figure, Rays of light emanate
from this point in all directions ; we are concerned,
however, only with those which strike the object-
glass between P and Q. These rays pass through
both lenses, being refracted each time. The convex
1 For convenience in drawing the breadth of the telescope is
enlarged out of proportion to its length.
i6io] THE GALILEAN TELESCOPE 83
lens bends them inwards, so that they would all, if
subsequently uninterrupted, very nearly meet at
about the point F in the figure. But before reach-
ing this point they are intercepted by concave lens,
which turns their course outwards again. The
final result will, provided the distance cC between
the two lenses be suitably adjusted, be a beam of
parallel rays, as indicated in the figure. To a
beam of parallel (or, it may be, very slightly diver-
gent) rays the human eye is sensible ; so that the
beam of rays represented by pp;, qq', and the space
between them, would on entering the eye render
visible the small luminous object S from which they
originally came. And as the apparent direction of
this object depends entirely on the direction in
which the rays were last travelling before entering
the eye, the object S will be seen in the direction of
the broken line EA, the dotted line ER being
inserted to show the direction in which the same
object would have been visible but for the inter-
vention of the telescope. The effect of this is
that the apparent distance of S and s; from one
another is increased about three times by the use of
the instrument, which we may accordingly say has
a magnifying power of 3 diameters.
In the diagram the objects examined, S and s',
have for obvious reasons been placed near the con-
vex lens. But if the telescope be directed to two
stars, near one another in the heavens, but both of
course at practically infinite distances from the
observer, the phenomena are exactly as described
above, although the concave lens would require to
be pushed slightly into the main tube in order that
84 PROFESSOR IN PADUA [1592-
the rays of light from the stars, after passing down
the telescope, may finally emerge parallel. At the
same time, the change of distance of an object
observed will slightly affect the magnifying power.
On his return to Padua Galileo made his third
telescope, of which he only says that "it made
objects appear more than sixty times larger," which
is equivalent to a magnifying power of about 8
diameters. But in a very few days he had a much
better one, which enlarged four hundred times. With
this he made his first observations on the moon,
which he " brought to a distance of less than 3
semi-diameters of the earth, thus making it appear
about twenty times nearer and four hundred times
larger than when seen by the unaided eye." He
also turned it towards Jupiter, but with no specified
results. To obviate the shaking when held in the
hand, the instrument was firmly fixed on a support.
The lenses were adjustable, the tubes which held
them being capable of being drawn out of, or
pushed into, the main tube. Thus, to see clearly
things not very distant, the glasses should be drawn
apart a little; while for very distant objects they
had to be approached. He found he could grind
large convex lenses more truly than small ones.
He preferred therefore to make his object-glasses
larger than necessary, and to cover a portion of
their surface, leaving open around the centre just
so large a space as he found, on testing, to give
the best results.
While on a short visit to Florence, probably
in October 1609, he had this instrument with him,
and showed it to his late pupil, Cosimo II., now
X6io] TELESCOPIC DISCOVERIES 85
become Grand Duke, "who, to his great surprise
and delight, was able to see that the moon was
a body very similar to the earth."
Very early in January 1610, Galileo had con-
structed a fifth and still more powerful telescope,
" sparing neither labour nor expense/' which showed
objects more than thirty times nearer and nearly
one thousand times larger.1 With this instrument
he not only verified and completed his observations
on the moon, begun the previous autumn with his
fourth telescope, but he also discovered Jupiter's
moons, some of the fixed stars, and contributed
to the solution of that long-standing puzzle to
philosophers — the Milky Way.
Writing to Belisario Vinta, then with the
Tuscan Court at Pisa, 3oth January 1610, Galileo
thus modestly alludes to his first series of dis-
coveries : —
" I am at present staying in Venice for the
purpose of getting printed some observations which
I have made on the celestial bodies by means of
my spy-glass (mio occkiale) and which infinitely
amaze me. Therefore do I give thanks to God,
who has been pleased to make me the first observer
of marvellous things unrevealed to bygone ages.
I had already ascertained that the moon was a
body very similar to the earth, and had shown
1 Galileo arrived at the powers of his glasses by the following
crude method. " Place," he says, " upon a wall at a certain distance
two unequal discs, one of which you will observe with the telescope
and the other with the naked eye. If the disc seen through the
telescope appear equal to the other, the magnifying power of the
instrument is in the proportion of the two discs. If they do not
appear equal the * other J disc must be enlarged or diminished until
they do, and then the magnifying power will be, as before, in the
proportion of the discs."
86 PROFESSOR IN PADUA [1592-
our Serene Master, the Grand Duke, as much,
but imperfectly, not then having such an excellent
spy-glass as I now possess, which, besides showing
the moon most clearly, has revealed to me a
multitude of fixed stars never before seen, being
more than ten times the number of those that can
be seen by the unaided eye. Moreover, I have
ascertained what has always been a matter of con-
troversy among philosophers, namely, the nature
of the Milky Way. But the greatest marvel of
all is the discovery of four new planets. I have
observed their motions proper to themselves and
in relation to each other, and wherein they differ
from the motions of the other planets. These new
bodies move round another very great star, in the
same way as Mercury and Venus, and, perad-
venture, the other known planets, move round the
sun. As soon as my tract is printed, which I
intend sending as an advertisement to all philoso-
phers and mathematicians, I shall send a copy to
his Highness, the Grand Duke, together with an
excellent spy-glass, which will enable him to judge
for himself of the truth of these novelties."
The tract referred to in the above letter is his
" Sidereus Nuncius" (Messenger of the Stars), the
preface of which is dated 4th March 1610, and the
book, doubtless, appeared immediately after, say,
towards the middle of March. In this epoch-
marking treatise he gives the results of his obser-
vations to date, of which we proceed to give a
His observations were first directed to the moon.
The discovery of new spots on its face, added to
those already visible to the naked eye, and observa-
tions on the changes of light on those spots, led him
i6io] LUNAR OBSERVATIONS 87
to the conclusion that the surface of the moon, far
from being smooth and polished, according to the
opinion of the ancients, was rough with deep de-
pressions and high mountains. Those parts which
remained or became brilliant he inferred were land,
like the solid parts of this earth, while those which
remained obscure — the permanent spots — were
water. The illuminated edges of the moon in all its
phases showed themselves perfectly round, without
those indentations which one would expect from the
inequalities of its surface. Galileo explained this
appearance — (i) by supposing that the mountainous
parts, as it were, masked each other, so that at the
distance of the earth the intervening depressions were
not discernible, and (2) by the existence of a lunar
atmosphere of a density such as to reflect the solar
rays while not obstructing the vision. Thus the
reflection of solar light by this atmosphere gave
the appearance of a regular circular contour, only
intensified in the parts most illuminated. From
the appearance of illuminated mountain-tops in
the dark part of the moon at some little distance
from the broken line along which sunrise or
sunset was general, he was able to judge of the
height of some of these mountains. And his calcu-
lation agrees very well with the modern estimate.
The higher mountains were found to rise 4 or 5
miles above the general level — a height which is
seldom exceeded on the earth.
He, of course, remarked the feeble light, so-
called phosphorescent, which, in the first and last
quarters of the moon, makes visible to us that part
of its disc which is no longer illuminated directly by
88 PROFESSOR IN PADUA [iS92.
the sun. After showing that this light1 did not
originate in the moon itself, and was not reflected
there from Venus, he concludes that it can only be
due to the sunlight reflected from the earth to the
moon, and thence reflected back to our eyes.1
After referring for greater details to the work
which he proposed to publish on the system of the
world, he contends, contrary to the received opinion,
that our earth is a moving planet, and that it exceeds
the moon in luminosity, and, therefore, that it is
far from being the sink of impurity hitherto
supposed.
In examining the fixed stars and comparing them
with the planets, Galileo discovered a remarkable
difference. While the planets showed themselves as
discs like little moons, the stars appeared no larger
than they do to the naked eye, bright specks in the
firmament, sending forth twinkling rays. In ex-
planation of this fact he supposes that the telescope
has the effect of stripping the star of the false light
by which it is surrounded when viewed with the
naked eye. This spurious corona is ascribed by him
to the effect of irradiation which generally increases
with the brightness of the field upon which the
luminous object is projected. Thus, at sunset, when
the obscurity of the heavens is tempered by the
twilight, the stars, even of the first magnitude,
appear very minute. So, with respect to Venus,
notwithstanding her usual splendour, she does not
1 Leonardo da Vinci and Maestlin had already arrived at the
same conclusion ,• but da Vinci's writings were certainly not known to
Galileo (see p. 23 ante\ and Maestlin's opinion probably not, as
knowledge in those days did not spread fast, except in special
cases.
!6io] STAR-CLUSTERS 89
exceed a| star of the sixth magnitude on those
occasions when she happens to be, visible at
noon.1
Upon directing his telescope to the more con-
spicuous star-clusters, he was astonished to find
that they contained, besides those already known,
a great number of other stars too faint to be in-
dividually recognised by the naked eye. The
number of the Pleiades, which had been fixed at
seven, now rose to forty, while in the constellation
of Orion, instead of seven he counted eighty stars.
Certain portions of the Milky Way were resolved
into a countless number of minute stars ; and he
inferred that as a whole it derived its singular white-
ness from innumerable other stars which his instru-
ment was not powerful enough to separate*
When Galileo turned \usfourth telescope to the
planets, he saw them as little moons. Jupiter's disc
was of considerable magnitude, but in no other way
did he differ from the other planets. Now, on
7th January 1610, directing his fifth and more
powerful glass towards Jupiter, his attention was at
once drawn to three small but very bright stars that
appeared in his vicinity, two on the east side and
one on the west. He at first imagined them to be
fixed stars, and yet there was something in their
appearance which he thought curious. They were
all disposed in a right line parallel to the plane of
the ecliptic, and were brighter than other stars of the
same magnitude.2 This did not, however, induce
1 He has a great deal more on this subject of irradiation in his
letters to Griemberger on Lunar Mountains ; in his work on " Sun-
Spots," and " II Saggiatore."
2 See attached facsimile of Galileo's notes of these observations.
90 PROFESSOR IN PADUA [IS92.
him to alter his opinion that they were fixed stars,
and therefore he did not note their distances from
each other or from the planet. Happening, by mere
accident, as he says, to examine Jupiter again on
8th January, he was surprised to find that the stars
were now arranged quite differently. They were
all on the west side, and were nearer to each other
than on the previous evening, and at equal distances
apart. The strange fact of the mutual approach of
these stars had as yet no significance for him ; it
only excited his astonishment that the planet should
be seen to the east of them all when on the previous
night it was to the west of two of them. He very
soon began to think that perhaps the motion of
Jupiter might be direct, contrary to the accepted
opinion of astronomers, and that he had got in
advance of the stars. He therefore waited for the
following night with some anxiety, but he was dis-
appointed, for the heavens were enveloped in
clouds. On loth January he could see only two
stars, and they were both on the east side! He
suspected that the third might be concealed behind
the disc of the planet. Those visible appeared as
before in the same right line, and lay in the direction
of the ecliptic. Unable to account for such changes
by the motion of the planet, and being at the same
time fully assured that he always observed the same
stars, his doubts now turned into admiration, and
he concluded that the motions must be referred
to the stars themselves and not to the planet. He
therefore determined to watch them with the closest
attention.
On nth January he again saw only two stars,
Facsimile &U>ichcs uf lupikr's Sotelliitt (from Gulilco's MSS.).
i6io] JUPITER'S SATELLITES 91
still on the east side of Jupiter, but the outer one
was now nearly twice as large as the other,
although on the previous night they were almost
equal. This fact, taken in connection with the
constant change of the relative positions of the
stars and the total disappearance of one of them,
left no doubt on his mind of their real character
He concluded that there are in the heavens three
stars revolving round Jupiter in the same way as
Venus and Mercury revolve round the sun. On
1 2th January he again saw three stars, two on
the east side of Jupiter, and one on the west.
The third began to appear about three o'clock
in the morning, emerging from the eastern limb
of the planet ; it was then very small, and dis-
cernible only with great difficulty. On i3th
January he saw four stars, three of them on
the west side and one on the east. They were
all in a line parallel to the ecliptic, with the
exception of the central one of the western group,
which was a little towards the north. They
were all about the same size, and shone with a
much greater lustre than fixed stars of the same
magnitude. January i4th was cloudy, but next
night he saw all four stars to the west of the
planet, all nearly in the same right line, and
increasing in size and brilliancy, according to their
distance from Jupiter.
And so he continued nightly, up to 2nd March
1610, to make these observations, sixty-six of which
are figured and described in the "Sidereus
Nuncius."
The persistence of the relative distances between
92 PROFESSOR IN PADUA [iS92-
these four bodies and Jupiter in all their changes
left no room for doubt that they accomplished
with him, and in about twelve years, a revolu-
tion around the sun as a centre. Their own
orbits round the planet were unequal in time,
those nearest moving more rapidly than those
more remote; while the most remote of all
appeared to complete its revolution in one-half
month.1
"It is now/' he says in conclusion, "not simply
a case of one body (the moon) revolving around
another body (the earth), while the two together
make a revolution around the sun, as the Coper-
nican doctrine teaches; but we have the case of
four bodies or moons revolving round the planet
Jupiter, as the moon does round the earth, while
they all with Jupiter perform a grand revolution
round the sun in a dozen years."
By the ist of January 1610 Galileo had fitted
up his workshop, so as to be able to make and
grind his own glasses, of which he turned out
large numbers, but of which only a small per-
centage was found to be of any great value.
Thus, by the middle of March, out of one
hundred and more which he had ground "at
great fatigue and expense," only ten were able
1 Two years later, in the opening passages of his " Discourse on
Floating Bodies," he gives the periods of revolution approximately
as follows : — The innermost one, i day 18 hours 30 minutes ; the
second, 3 days 13 hours 20 minutes ; the third, 7 days 4 hours ; and
the fourth or outermost, 16 days 18 hours. The modem figures are
in days, hours, minutes, and seconds, i, 18, 28, 36; 3, 13, 17, 54;
7> 3> 59> 36; and 16, 18, 5, 7, respectively. A fifth satellite was dis-
covered in 1892, whose period is only n hours and 57^ seconds.
Jupiter's belts were discovered by Torricelli, a disciple of Galileo.
i6io] GALILEO'S TELESCOPES 93
to show the newly discovered moons of Jupiter
and the fixed stars.1 The object glasses gave
him the most trouble, as it is easy to understand,
since everything depends on the degree of
accuracy with which this glass brings to a focus
the rays of light passing through it.
The same difficulty was found elsewhere, for
Kepler, in one of his letters about this time, tells
Galileo that it was easy to find good concave
lenses in Germany, but that he found it most
difficult to procure decent convex ones. In fact,
for a long time no instruments at all approaching
Galileo's were to be had in Europe, and he was
consequently besieged with orders from all parts.
Thus, Daniel Antonini, writing from Brussels in
April 1611, complains that in all Flanders no instru-
ment was to be had capable of magnifying more
than five times, and says that he was obliged to
make one himself, which was able to show " fairly
well the inequalities of the moon's surface and the
Medicean stars."2 As late as 1634 a good instru-
ment could not be procured in Paris, Venice, or
Amsterdam ; and even in Holland, the home of
the telescope, down to 1637, there was not one
which could show Jupiter's disc well defined.3
1 Letter to Vinta, igth March 1610. At this time his clever workman
Mazzoleni. was also engaged not only on the geometrical and military
compass, of which many hundreds were made and sold all over
Europe, but on hydrostatic balances, air thermometers, magnets and
magnetic compasses for ships, and various kinds of drawing com-
passes for engineers and architects. He had also added a printing-
press, where his tract on the Geometrical and Military Compass was
set up. See pp. 43-44 ante.
2 I.e. Jupiter's satellites, see p. 96 infra.
3 Galileo continued all these years to grind his own glasses, and
it was not until his eyesight began to fail that he consented to
94
PROFESSOR IN PADUA [1592-
It detracts little from the merit of Galileo's
invention that the modern refracting telescope is
based upon a different combination of lenses than
that which he used, After possessing himself of
one of Galileo's instruments, Kepler designed,
though he did not make, a telescope consisting
of two convex lenses. The difference between the
two systems can be seen by comparing the adjoin-
ing diagram with that of Galileo's telescope already
Fig. 7.
KEPLERIAN TELESCOPE.1
given. Without entering into a detailed description,
it may be well to point out that in Galileo's the
rays of light which travel from the point S and
penetrate to the observers eye do not, on striking
the object-glass, cover the whole of its surface ;
impart his secret to Ippolito Mariani, commonly known as II Tordo,
whom he appointed as his successor in the art. From about 1637,
Francesco Fontana of Naples also began to turn out good glasses of
the Galilean pattern. After Galileo's death Torricelli, having devised
an improved way of grinding and polishing lenses, of which he was
the first to calculate previously the curve, made some instruments of
great perfection. Gradually other Italians took up the art, and
became noted for the excellence of their telescopes, as Viviani,
Severino, and Campani.
1 For convenience in drawing the breadth of the telescope is
enlarged out of proportion to its length.
i6io] KEPLERIAN TELESCOPES 95
and also that (as explained above) these rays,
passing down the tube of the telescope, are not
allowed to come to a focus, but are intercepted by
the eye-glass. In these respects Kepler's system
is different ; and for work at the present day,
although the interval of nearly three centuries has
produced refinements and complications in the
manufacture undreamt of by either Galileo or
Kepler, the modern instrument is essentially a
development of the combination devised by
Kepler. Galileo's arrangement is suitable for low
magnifying powers, and has advantages where
portability is desired ; it survives in the common
field-glass and opera-glass.
It must further be pointed out before forming
an estimate of Galileo's work that he knew nothing
of the reflecting telescope. Finding, as he did, that
a convex-lens as object-glass brought the rays of
light from a distant object to — or, more truly in
his case, towards — a focus, it seems not to have
occurred to him that a concave mirror might serve
the same purpose. The first reflector was designed
by James Gregory, a Scotch mathematician, in
1663, and described in his "Optica Promota"; but
poverty prevented its construction. It was nine
years later that Sir Isaac Newton, acting on
Gregory's suggestions, and influenced also by the
results of his own researches in the theory of light
produced the first reflecting telescope, now pre-
served in the rooms of the Royal Society, London.
At the present day only a comparatively small
number of the world's great telescopes are con-
structed on the reflective system. But for certain
96 PROFESSOR IN PADUA [1592-
departments of astronomical work these have
advantages over the refractor.1
During the Easter recess in Padua, April
1610, Galileo, according to custom, would probably
have visited Florence ; but this time he had an
express invitation from the Court, then at Pisa, to
repair thither for the purpose of explaining to the
Grand Duke his discovery of the four satellites of
Jupiter, which, in honour of the reigning family
of Tuscany, he proposed to call Medicean Stars,
after the four brothers Cosimo II., Francesco, Carlo,
and Lorenzo de Medici. Cosimo II., who all his
life showed a sincere attachment to his old tutor,
asked for and obtained the gift of the instrument
with which this discovery was made ; 1 but Galileo
quickly repented of his generosity. He evidently
could not part with his "old discoverer," as he
affectionately called it in after years ; so, while
always reserving it for the Grand Duke, he kept it
near himself till his death, when it was handed over
to Prince Leopoldo, brother of Ferdinando II.
Of its subsequent history little for certain is
known. It would appear that in Galileo's last
years the instrument was accidentally broken.
Then, in 1675, there is a record in the inventory
of the effects of Cardinal Leopoldo de Medici of a
" broken object-glass with which Galileo discovered
the four new planets"; and in 1677 another record
of its having been set in an ivory frame, for which
1 For much interesting information on the subject of telescopes, see
Grant's " History of Physical Astronomy,'3 London, 1852, chap, xx.,
and article " Telescope," in " Encycl. Brit.," Qth ed.
1 Cosimo made him a return present, in the form of a gold chain
and medal, as a badge of merit, worth about 400 scudi
i6io] GALILEO'S "OLD D I S CO VE RE R" 97
one Vittorio Crosterr, an engraver and carver, was
paid 19^- lire. It is now preserved (together with
two telescopes, said to have been made by Galileo,
and certainly of his time) in the Tribuna di Galileo
in Florence, with many other precious relics of the
period. Accurate measurements of it have been
quite recently made by Professor Roiti of the Uni-
versity of Florence, as follows : — Focal distance,
1.70 metres; diameter .056 metre. One face has
the curvature of a sphere with radius of .935 m£tre,
and the other face is practically plane, having just
a trace of convexity.
CHAPTER VI
GALILEO, PROFESSOR IN PADUA (concluded]
I592-I6IO
THE hundred and more telescopes, which Galileo
had made in the first half of 1610, were distributed
with copies of the "Sidereus Nuncius" amongst
the princes and learned men of Italy, France,
Flanders, and Germany. The best instruments
he reserved for particular friends and patrons,
amongst whom he mentions the Duke of Bavaria,
the Elector of Cologne, Cardinal del Monte, and
the Duke of Urbino, as having " begged" for them.
The Cardinal sent in return a small picture to
which an indulgence was attached ! The Duke of
Bavaria was not behind-hand, but what his present
was is not stated (let us hope it was more sub-
stantial than the Cardinal's) ; while the Elector of
Cologne wrote that the pamphlet was disappoint-
ingly incomplete, since it contained no directions
for the making of the instrument. He therefore
requested Galileo to impart the secret, promising
to recompense him in a princely fashion.
In communicating this request, and evidently
not caring to bear the brunt of the Elector's anger
i592-i6io] POPULAR EXCITEMENT 99
in case of non-compliance, Galileo's brother, Michel-
angelo, wrote, 1 4th April 1610: —
" See if you can gratify the Elector by showing
him how to make the instrument, and if not, write
to him direct in your own way."
Then he peevishly continues : —
"You say not a word about the telescope /
asked you for. If I am not a prince, able to
remunerate you, at least I am your brother, and it
seems very strange to me that you do not care to
gratify me/'
At the French Court the arrival of Galileo's
telescope caused immense excitement, the queen,
Marie de Medici, being particularly interested in
it as the invention of a distinguished fellow-country-
man. It is related that in her eagerness to see the
moon through it, she would not wait till the in-
strument was suitably fixed at the open window,
but fell on her knees on the floor, to the con-
sternation of her suite and the amazement of the
grave Italian in charge of the telescope.
The solicitude of the French Court to gain a
place in the heavens by the side of the Medici
family is very amusing. In a letter of 2Oth April
1610, the great astronomer is begged: —
"In case you discover any other fine star, call
it by the name of the Great Star of France, as well
as the most brilliant of all the earth, and, if it
seems fit to you, call it rather by his proper name,
Henri, than by the family name Bourbon. Thus
you will have an opportunity of doing a thing
due and proper in itself, and, at the same time,
ioo PROFESSOR IN PADUA [,592.
of rendering yourself and your family rich and
powerful for ever."1
As the news of Galileo's marvellous discoveries
spread over Italy, the popular excitement grew
intense. Thus, in Florence, poets chanted the
discoveries and the glory of their fellow-citizen,
and a public f&te was celebrated in his honour.
In Venice, Girolamo Sirturo describes the excite-
ment as amounting to frenzy, and tells an amusing
story of his own experience. With the first tele-
scope which he had succeeded in making, he
ascended the tower of San Marco, in the hope of
trying it unmolested. Unluckily for him, he was
seen by some idlers in the square below, a crowd
soon collected round him, who insisted on taking
possession of the instrument, and, handing it one to
another, detained him for hours till their curiosity
was satisfied. Desirous of obtaining the same
gratification for their friends, they endeavoured to
find out where Sirturo lodged, but he, overhearing
their enquiries, thought it better to quit Venice
early the next morning and pursue his observations
in a less inquisitive neighbourhood.
In the "Sidereus Nuncius" Galileo did not
formally proclaim his discoveries in relation to, and
in support of, the Copernican theory of the world ;
but in his lectures and conversations he made
no secret of his belief. Nor, indeed, was any
specific announcement needed ; his readers could
see for themselves the connection, .and the speedy
result was a tremendous explosion of incredulity
and malice. The Aristotelians were furious, and
1 Henry IV. was assassinated very soon after, on I4th May 1610.
i6w] ATTITUDE OF PERI P ATETI CS 101
even men like Welser of Augsburg, and Clavio of
Rome, both admirers of Galileo, would not credit
his statements until they had learnt better from
observations of their own. The latter, who was
the first mathematician of his day, for months,
down to October 1610, " laughed at the idea of
there being four new planets, to see which they
must first be put inside the telescope. Let Galileo
keep his opinions and welcome. I hold to mine.51
Nor did it mend matters when Galileo offered
10,000 scudi to any one who would construct so
cunning an instrument. Others refused even
to look through the telescope; some, lest they
should see, others convinced they could not
see, things of which Aristotle had made no
mention !
Among other sticklers for conservatism were the
celebrated professors, Cesare Cremonino of Padua,
one of Galileo's colleagues, and Julius Libri of Pisa,
both of whom peremptorily rejected, on a priori
grounds, Galileo's discoveries and the conclusions
he drew from them. Libri died in December 1610,
refusing to look through a telescope, and stigmatis-
ing to the last the " absurdities " of the presump-
tuous Florentine. In communicating the news of
Libri's death to his friend Welser (i;th December),
Galileo expressed the hope that this stiff-necked
opponent of his " absurdities," who would not look
at them from earth, might now perhaps see them
on his way to heaven.
Some passages of Galileo's letter to Kepler of
1 9th August 1610 will best show how these men
of science refused to be convinced.
102 PROFESSOR IN PADUA [i59>
" You are the first and almost the only person,
who, after a cursory investigation, has given entire
credit to my statements. . . . We will not trouble
ourselves about the abuse of the multitude, for
against Jupiter even giants, to say nothing of pig-
mies, fight in vain. Let Jupiter stand in the
heavens and let the sycophants bark at him as they
will. ... In Pisa, Florence, Bologna, Venice and
Padua, many have seen the planets, but all are
silent on the subject and undecided ; for the greater
number recognise neither Jupiter nor Mars, and
scarcely the moon, as a planet . . . What is
to be done? Shall we side with Democritus or
Heraclitus ? I think, my Kepler, we will laugh at
the extraordinary stupidity of the multitude. What
do you say of the leading philosophers here to
whom I have offered a thousand times of my own
accord to show my studies, but who, with the lazy
obstinacy of a serpent who has eaten his fill, have
never consented to look at the planets, or moon, or
telescope ? Verily, just as serpents close their ears,
so do men close their eyes to the light of truth. To
such people philosophy is a kind of book, like the
^Eneid or the Odyssey, where the truth is to be
sought, not in the universe or in nature, but (I
use their own words) by comparing texts ! How
you would laugh if you heard what things the first
philosopher of the faculty at Pisa brought against
me in the presence of the Grand Duke. He tried
hard with logical arguments, as if with magical in-
cantations, to tear down and argue the new planets
out of heaven ! l
As a specimen of the " logical " arguments to
which Galileo alludes in the above extract, this is
1 Ponsard in his drama " Galilee," Paris, 1867, takes off capitally
these proud Aristotelians (Act I. Scenes 3 and 4) ; but in the process
Galileo's history is mostly turned upside down.
i6io] ATTITUDE OF PERIPATETICS 103
what Francesco Sizzi, a Florentine astronomer, says
in his " Dianoia Astronomica" (Venice, 1611.)
''There are seven windows given to animals
in the domicile of the head, through which the
air is admitted to the tabernacle of the body, to
enlighten, to warm, and to nourish it. What
are these parts of the microcosmos? Two nostrils,
two eyes, two ears, and a mouth. So in the
heavens, as in a macrocosmos, there are two
favourable stars, two unpropitious, two luminaries,
and Mercury undecided and indifferent. From
this and many other similarities in nature, such
as the seven metals, etc., which it were tedious
to enumerate, we gather that the number of
planets is necessarily seven. Moreover, these
satellites of Jupiter are invisible to the naked
eye, and therefore can exercise no influence on
the earth, and therefore would be useless, and
therefore do not exist. Besides, the Jews and
other ancient nations, as well as modern
Europeans, have adopted the division of the
week into seven days, and have named them
after the seven planets. Now, if we increase
the number of the planets, this whole and
beautiful system falls to the ground."1
Another opponent deserves to be named, if
only for the impudence of the charge he brings
against Galileo.
"We are not to believe/' says Christmann,
in his " Nodus Gordius," "that nature has
given Jupiter four satellites in order to immortalise
the name of the Medici. These are the dreams
1 Sizzi would not look through the telescope, because he was sure
beforehand he could not see any of the marvels which Galileo pre-
tended to find in the heavens by its aid. In 1618 he was broken on
the wheel in Paris for some political crimes.
104 PROFESSOR IN PADUA [i592.
of idle men who love ludicrous ideas better
than our laborious maintenance of the heavens.
Nature abhors such horrible chaos, and to the
truly wise such vanity is detestable."
In the midst of all this opposition and abuse,
we must not suppose that Galileo was without
friends, and even some converts. Thus, on 7th
May 1 6 10, he was able to inform Secretary
Vinta that even the most exalted persons in
Padua, who had vehemently attacked him, had
at length given up the game, and had acknow-
ledged, coram publico, that they were not only
convinced, but were ready to defend him against
all comers.
The praises of Kepler, then renowned as
the first astronomer in Europe, were, as we
have just seen, a great consolation to him.
Kepler had the " Sidereus Nuncius" at once
reprinted in Prague, with a long and appreciative
preface from himself, and some laudatory verses
from Thomas Seggett, a learned Scotchman, a
former pupil of Galileo, then working with him,1
In the preface, which is in the form of a letter to
Galileo, dated iQth April 1610, Kepler says: —
" I was sitting idle at home thinking of you,
most excellent Galileo, and of your letters, when
the news was brought me of the discovery of
four planets by the help of the double eye-
glass. . . . The authority of Galileo had the
greatest influence on me, earned by the accuracy
of his judgment, and by the excellence of his
1 The oft-quoted exclamation, Galilaee! vicistil is always wrongly
attributed to Kepler. It occurs in Seggett's verses.
i6io] KEPLER'S ATTITUDE 105
understanding. So I immediately fell to thinking
how there could be any addition to the number
of the planets without upsetting my ' Mysterium
Cosmographicum," published thirteen years ago,
and according to which Euclid's five regular
solids do not allow more than six planets round
the sun. I am, however, so far from disbelieving
the existence of the four circumjovial planets,
that I long for a telescope to anticipate you, if
possible, in discovering two round Mars (as the
proportion seems to require), six or eight round
Saturn, and, perhaps, one each round Venus and
Mercury."1
Galileo's detractors must have been hard
pushed for a stick wherewith to strike him when
they took Kepler's preface to be a covert attack.
Certainly Maestlin, Kepler's old master, took it
so, and wrote : —
" In your essay you have plucked Galileo's
feathers well — I mean you have shown him not
to be the inventor of the telescope, not to be
the first to observe the irregularities of the moon's
surface, not to be the first discoverer of more
worlds than the ancients were acquainted with,
etc. One source of exultation was still left him,
but from the apprehension of that Martin Horky
has now entirely delivered me."
1 This is a specimen of the wild notions in which Kepler
revelled. For the same curious reason Huygens, who in 1659
discovered a satellite near Saturn, declared that no more would
be found, since the one near Saturn, Jupiter's four, and the earth's
one, made up the number six, exactly the number of the planets, thus
together making twelve, which is the first perfect number 1 In
Galileo's day Scheiner thought he saw five satellites round Jupiter,
de Rheita counted nine, and others gave him a round dozen!
Jupiter is now known to have five, Saturn eight, besides his rings,
Uranus four, Ne tune one, and Mars two.
106 PROFESSOR IN PADUA [1592-
It is difficult to see where in Kepler's preface
Maestlin found all this, for it is one continued
encomium. Maestlin, however, was not the only
one to misunderstand. The Martin Horky just
mentioned, a young German travelling in Italy,
wrote to Kepler: —
" I will never concede his four new planets
to that Italian from Padua, though I die for
it."
He followed up this declaration by publishing
a book, which is evidently the one referred to by
Maestlin.1 It professes to examine four main
questions touching the alleged planets — (i)
Whether they exist? (2) What are they? (3)
What are they like ? (4) Why they are ? Horky
summarily disposes of the first question by
declaring that he had examined the heavens with
Galileo's own glass, and could see no such thing as
a satellite about Jupiter. As to the second he
declares solemnly that he does not more surely
know that he has a soul in his body, than that
reflected rays are the sole cause of Galileo's
observations. In regard to the third question he
says, rather illogically, that these planets are like
the smallest fly compared with an elephant ; and as
1 " Peregrinatio contra Nuncium Sidereum^ Galileo, by the advice
of Kepler, did not deign to reply, but he found able champions in his
Scotch friend and pupil, John Wedderburn of Padua (p. 51), and in
Antonio Roffeniv a professor in the University of Bologna. Apparently,
our old acquaintance, Professor Magini, was the secret instigator of this
outrage, but, openly, he pretended to be very shocked at Horky's bad
manners. The latter, however, afterwards confessed to Kepler that
Magini and other professors in Bologna were the real offenders. Sizzi
had admitted the same inspiration in the case of his " Dianoia Astro-
nomica," of which we have already spoken.
1610] ATTITUDE OF PERIPATETICS 107
to the fourth he concludes that the only use of them
is to gratify Galileo's vanity and thirst of gold.
Horky sent a copy of this amazing production to
Kepler, and, returning to Prague soon after,
presented himself to the great astronomer. But
the reception was little to his taste, for the burst of
indignation which followed showed him Kepler's
real sentiments. The conclusion is characteristic.
After venting his wrath against "this scum of a
fellow, whose obscurity had given him audacity,"
Kepler, recounting the story to Galileo, says : —
" In the end, Horky begged so hard to be
forgiven that I have taken him again into favour
upon this one condition, to which he has agreed —
that I am to show him Jupiter's satellites, and that
he is to see them, and own they are there."1
After completing his observations on Jupiter,
Galileo turned his glass to the other planets to see
if they, perchance, had attendant moons ; but up
to 25th June 1610, he was unable, with all his
diligence, to discover any. At this he was inclined
to be a little glad and a little sorry — glad because
he would thus be the only one destined by God for
1 See Kepler's letter to Galileo, dated 25th October 1610. As
usual, Galileo's right to the first discovery of Jupiter's satellites was
contested, the claimant being Simon Mayer of Anspach, whom we
have met before in connection with the Capra plagiary (p. 45 ante].
In 1614 he published at Nuremberg his "Mundus Jovialis," in which
he formulates his claims. As to these, it is enough to say with
Humboldt that Kepler, who knew Mayer personally, makes no mention
of his discovery either in the edition of the " Sidereus Nuncius " which
he published in Prague in April 1610, or in his letters to Galileo,
or in those addressed to the Emperor, Rudolph II., in the autumn
of 1610. On the contrary, Kepler always spoke of "the glorious
discovery of the Medicean stars by Galileo." See " Cosmos," vol. ii.
p. 70S-
io8 PROFESSOR IN PADUA [I592-
so great a discovery ; and sorry because he could
not oblige the French Court by finding Henri
Quatre a place in the heavens. However, before
a month elapsed, he made another brilliant
discovery — the ring of Saturn ; only it did not
appear to him as a ring, but like a triple star, of
which the central one (Saturn itself) was three to
four times larger than the laterals, and all three in
a plane parallel to the equinoctial points or ecliptic.
Not wishing to make public the discovery until he
had made further observations in the autumn, when
Saturn would be well above the horizon, and yet
fearing that some one might forestall him, he
announced the discovery in a brief letter, dated
Padua, 3Oth July 1610, to Belisario Vinta at
Florence, but begged him to keep it secret for
a while. As a further precaution he sent to friends
in Italy and Germany a jumble of thirty-seven
letters as follows : —
SMAISMRMILMEPOETALEUMIBVNENUGTTAVIRAS
Kepler and other friends puzzled long over
this string of letters, the former thinking it had
some reference to his favourite planet Mars. At
length Giuliano de Medici, Tuscan ambassador
at the German Court, was charged by the Emperor
Rudolph IL to ask for the solution, to whom
Galileo, replying i3th November 1610, gave the
following startling explanation : —
" Altissimum Planetam Tergeminum Observavi."
"I have observed," he goes on to say, "with
great admiration that Saturn is not a single star
i6xo] SATURN'S RING 109
but three together, which, as it were, touch each
other. They have no relative motion, and
are constituted in this form (see Fig. 8, A), the
middle being much larger than the lateral ones.
If we examine them with a glass of inferior
power, the three stars do not appear very
Fig. 8.
(Facsimiles from Galileo's
(A) (B) (C)
cQo
distinctly. Saturn has an oblong appearance
somewhat like an olive, but by employing a glass
which multiplies the superficies more than 1000
times, the three globes will be seen very distinctly
and almost touching, with only a small dark space
between them.1
" I have already discovered a court for Jupiter,
and now there are two attendants for this old man,
who aid his steps and never leave his side."
The learned world of Italy had not yet had
time to digest the surprising facts announced in
1 The telescope with which Galileo discovered Jupiter's satellites
had, as we have seen, a power of 30, enlarging objects "nearly
loco times." Here, and in other letters of the latter half of 1610,
he speaks of his glass enlarging " more than 1000 times," but without
specifying the power, as in all previous cases. From this, Professor
Favaro concludes that between April and July Galileo had made for
himself a sixth telescope. This may be so, but I think it more likely
that he only improved his fifth, his "old discoverer" (for instance, by
substituting a better eye-glass), thereby increasing its enlarging
power from nearly 1000 to more than 1000. Indeed, in his letter to
Clavio of 1 7th September 1610, he says as much — " Having
ultimately improved my instrument a little more." Galileo never got
beyond this power.
i io PROFESSOR IN PADUA [1592-
the "Sidereus Nuncius," when the asserted triple
nature of Saturn again contravened the prevail-
ing ideas that, by order of Aristotle, there was
nothing new to be found in the heavens. Accord-
ingly, the peripatetics were inclined to discredit
the discovery ; the most they would admit was
that Saturn appeared to be of an oblong shape —
precisely as Galileo said it appeared when viewed
through glasses of less power than his own.
Continuing his observations, Galileo found that
the lateral bodies did not retain the same ap-
parent magnitudes. In fact, they had been gradu-
ally diminishing, although they appeared to be
immovable, both with respect to each other and
to the central body. They continued to grow less
and less during the next two years, and towards
the close of 1612 they vanished altogether! Horri-
fied at this extraordinary phenomenon, and full of
alarm for the consequences to himself when his
Aristotelian opponents should come to hear of
it, he thus wrote to Welser on ist December
1612 : —
" Looking at Saturn within these last few
days, I found it solitary without its accustomed
stars, and, in short, perfectly round and defined
like Jupiter, and such it still remains ! Now what
can be said of so strange a metamorphosis ? Are,
perhaps, the two smaller stars consumed like spots
on the sun? Have they suddenly vanished and
fled? Or has Saturn devoured his own children?
Or was the appearance, indeed, fraud and illusion,
with which the glasses have for so long mocked
me and many others who have observed with
me? Now, perhaps, the time is come to revive
i6io] SATURN'S RING in
the withering hopes of those who, guided by more
profound contemplation, have fathomed all the
fallacies of the new observations, and recognised
their impossibility. I cannot resolve what to say
in a change so strange, so new, so unexpected.
The shortness of time, the unexampled occur-
rence, the weakness of my intellect, the terror of
being mistaken, have greatly confounded me."1
However, he soon plucked up courage, and in
the same letter conjectured that the two attendant
stars would reappear after revolving round the
planet, and that by the summer solstice of 1615,
they would not only be again visible, but be
more luminous, and larger.
Commenting on the above quoted passage,
Arago2 and other modern writers after him con-
clude that Galileo was so discouraged by the
disappearance of the lateral bodies that he made
no further observations on Saturn. But Arago
is most certainly wrong here. Galileo continued
to observe Saturn for many years. By the middle
of 1613, he was able to inform his friends that,
according to his prediction, the lateral stars were
reappearing !
Apparently, no change calling for special com-
ment was noticeable until the summer of 1616,
1 The real reason is now well known. The ring lies in the plane
of Saturn's equator, and we obtain a view of its north or south side
according as the planet at different -parts of his orbit leans his north
pole towards or away from the earth. Accordingly the ring goes
through all its phases once during the twenty-eight years of Saturn's
revolution round the sun ; disappearing twice in that period, at the
time when the planet is so placed that he presents the ring edgeways
to our line of vision.
8 "Astronomic Populaire," Paris, 1857, vol. iv. p. 442.
112 PROFESSOR IN PADUA [1592-
when he announced a new fact relating to
Saturn, which filled his friends with admiration
and pleasure. For considerably more than two
hundred years this new fact remained not only
unexplained, but forgotten. Then Alberi, while
preparing his edition of Galileo's Works, 1842-56,
found amongst his MSS. a paper containing some
calculations belonging to the year 1616, on the
back of which was a pen-and-ink sketch, as shown
in Fig. 8, b}. No explanation of the figure was
to be found, but Alberi concluded that it was
intended to show the form of Saturn's ring as
seen by Galileo in August 1616, and as com-
municated to his friends, as above stated.
Not satisfied with the evidence that the sketch
found by Alberi was really made by Galileo, and
that it belonged to the date assigned, Professor
Favaro has lately instituted a new search, and
with the happiest results. Taking as his starting-
point a letter from Prince Cesi to Galileo of 3rd
September 1616, acknowledging the "new fact"
about Saturn,1 Favaro has been rewarded by
finding the ipsissima verba of Galileo. They
were sent by Prince Cesi to John Faber in
Rome for his information, and by him immediately
passed on, as the latest piece of news, to Cardinal
Federigo Borromeo, amongst whose papers, now
in the Ambrosian Library, Milan, Favaro found
them. Quite recently the learned Professor has
read a paper on this interesting discovery, from
which I quote Galileo's words as follows : —
1 Unfortunately, the year 1616 is one of those in which Galileo's
correspondence, as it has come down to us, is incomplete.
i6io] SATURN'S RING 113
" I cannot rest without signifying to your Ex-
cellency [Prince Cesi] a new and most strange
phenomenon observed by me in the last few
days in Saturn. Its two companions are no
longer two small and perfectly round globes, as
they have hitherto appeared to be, but are now
bodies much larger, and of a form no longer
round, but, as shown in the annexed figure (see
Fig. 8, c), with the two middle parts obscured,
that is to say, two very dark triangular-like spaces
in the middle of the figure and contiguous to the
middle of Saturn's globe, which latter is seen,
as always, perfectly round."1
Towards the end of his life, when Galileo was
blind, and a confirmed invalid from age and ail-
ments, he once more referred to Saturn. Cas-
telli, writing to him from Rome under date 4th
August 1640, said : —
" The other evening, on turning the telescope
towards Saturn, I noticed, to my great amaze-
ment, that he was a single star, distinct and
round, and with two other round stars (one at
each side) lying in the direction from Levante
to Ponente [i.e. nearly east and west], and no
longer in the form of coifs attached to the
central body, such as your first observations
showed them."
Replying on 28th August 1640, Galileo wrote : —
" When first I observed Saturn he was com-
posed of three round stars, situated in a straight
line from Ponente to Levante, of which the
central was much larger than the lateral ones.
Thus I continued to see him for some months.
1 Atti del Real* Istituto Veneto^ February, 1901.
H
ii4 PROFESSOR IN PADUA [i592-
Then, after an interval of some more months,
I again examined him and found him solitary,
z>. the great central star was only to be seen.
Amazed at this result, and supposing it to be
due to some kind of change, I ventured to say
that in five or six months, i.e. at the summer
solstice, the two small lateral stars would reap-
pear. They did, and so I saw them for a long
time after. Then after another interval, during
which Saturn was masked by the sun's rays, I
again observed him, and now saw him with two
mitres, instead of round stars, which gave him
the figure of an olive. I saw the central globe
very distinctly, and two very dark spots in the
middle of the attachment of the mitres, or, as
one may say, the ears. So I observed him for
many years ; and now your Rev, writes (as also
other of my friends) that the mitres are trans-
formed into two small globes. It may be that
in the last three years, during which I have
been unable to make any observations,1 Saturn
may have become once again solitary, and then
later on may have returned to the form in which
I at first observed him. It will be for the future
and for others to make observations, registering
the times of mutation so as to accurately de-
termine their periods — that is, if there will
be any persons curious enough to do what I,
from the same motive (not knowing how to do
better), have done for so long a time."
Thus we see that up to the last, Galileo had
made no announcement as to the precise nature
of Saturn's appendage. He contented himself
with describing what he saw, and, recognising the
incompleteness of his knowledge, and, perhaps,
1 Galileo became totally blind in December 1637,
!6io] HUYGENS' DISCOVERIES 115
the inadequate power of his glasses, he left it
to the future and to others to solve the problem.
This was done by Christian Huygens in 1656.
Working with a refracting telescope with a magni-
fying power of 100 diameters, this celebrated
astronomer not only saw and described the ring
as a ring, but discovered one of Saturn's satellites,
of which eight are now known to exist.
SATURN'S RING AS SEEN BY HUYGENS.
CHAPTER VII
GALILEO QUITS PADUA AND RETURNS TO FLORENCE
l6lO-l6l2
GALILEO'S fame, especially through his telescopic
discoveries, and partly also through the exertions
of his noisy opponents, had long extended beyond
the bounds of Italy. The eyes of all Europe
were directed to the great astronomer of Padua,
and students flocked to him from all quarters.
According to a familiar French proverb, one
must suffer in order to be beautiful, so, to be a
professor with a European reputation demands
some sacrifice, entails some evil, which, under
certain circumstances, may outweigh the good.
It was so in Galileo's case ; lectures and private
lessons of all kinds left him little leisure for his
own studies, and so, after twenty years' professor-
ship at Pisa and Padua, he began to wish for a
post in which he could devote himself entirely to
the completion of various works on mechanics and
astronomy, for which, during all these years, he
had been amassing materials. A letter from Padua
in the spring of 1609, shows his longing for this
salaried leisure. It is not addressed, but from the
context it must have been written to some one
lie
16101612] NEGOTIATES FOR RETURN 117
high in influence, if not in office, at the Court of
Florence, probably to Belisario Vinta, the Grand
Duke's chief Secretary of State.1 This first
attempt, however, had no definite result, so that
a few months later (after the invention of the
telescope) he gratefully accepted, as we saw, the
Chair of Mathematics at Padua for life. But the
invention of the telescope and his consequent dis-
coveries had now given him a world-wide reputa-
tion, and it appeared desirable to the Tuscan
Court to attach to itself so great a man.
The first steps towards this end were taken
when Galileo visited Pisa, about Easter 1610, in
order to show to Cosimo II. his telescopic dis-
coveries, and especially the satellites of Jupiter,
which bore his family name of Medici. Galileo's
case is fully stated in his letter of 7th May 1610,
to Vinta, as follows : —
" I will not hesitate to say, having now laboured
during twenty years, and those the best of my life,
in dealing out (as one may say) in detail, and at
the request of everybody, the little talent which
God has given me, that my wish is to have
sufficient leisure to enable me, before my life
comes to a close, to conclude three great works
which I have in hand, and which may, perhaps,
bring some credit to me and to those who assist
me in the undertaking, besides being a greater
service to students than in the rest of my life I
could do them by personal tuition. Greater leisure
than I have here I doubt if I could get elsewhere,
so long as I am obliged to give public and private
lectures in order to meet the expenses of my family.
1 We do not reproduce it, as its substance is given in a later and
fuller communication quoted infra.
ii8 GALILEO QUITS PADUA [>6io-
Nevertheless, not even the liberty I have here is
sufficient, when I am obliged to spend many and
often the best hours of the day at the call of this
and that man. My salary is 520 florins, which I
am almost certain will be advanced to as many
crowns upon my re-election, and this I can increase,
by receiving pupils and by private lessons, to any
extent I please. My public duties do not occupy
me more than sixty half-hours in the year, and
even then not so strictly but that I may, on
occasion of any pressing matter, contrive to get
some vacant days. The rest of the time is
absolutely at my own disposal ; but as my private
lectures and domestic pupils take up very much
of this spare time, to the hindrance of my own
studies, I wish to be entirely exempt from public
duties, and in a great measure from the others.
Therefore, if I am to return to my native country,
I should wish that leisure and opportunity be
afforded me to complete my works without em-
ploying myself in lecturing. In short, I wish to
gain my bread by my writings, which I would
always dedicate to my Serene Master.
" Of useful and curious secrets I possess so
many that their very abundance does me harm,
for if I had but one I should esteem it greatly,
and, perhaps, through it I might have found that
fortune which as yet I have not met. And,
indeed, I have not sought it. Magna longeque
admirabilia apud me habeo. Many are no good
to me, or I should say, they are only of use to
princes ; for they alone make wars, build fortresses,
and, for their royal pleasure, spend such sums of
money as private gentlemen cannot, any more than
I can.
"The works which I have to finish are chiefly
— (i) two books on the system or structure of the
Universe, an immense work, full of philosophy,
1612] CONTEMPLATED WRITINGS 119
astronomy, and geometry; (2) three books on
local motion, a science entirely new, no one,
ancient or modern, having discovered any of the
many admirable consequences which I demonstrate
in natural and violent motions, so that I may with
reason call it a new science invented by me from
its very first principles ; (3) three books on
mechanics, two on the demonstration of principles,
and one of problems. Although others have
treated this subject, no one either in quantity or
quality has done a quarter of what I am writing
on it. I have also treatises on natural and other
subjects, such as (i) on sound and speech; (2) on
light and colours; (3) on the tides; £4) on the
composition of continuous quantity ; (5) on the
movements of animals ; and others. I have also an
idea of writing some books relating to the military
art, giving not only a model of what a soldier
ought to be, but teaching him with exact rules
everything in the way of mathematics that it is
his duty to know, as castrametation, manoeuvring
battalions, fortifications, sieges, surveying, estima-
tion of distances, knowledge of artillery, uses of
various instruments, etc.
" I also wish to reprint the 'Use of the Geo-
metrical and Military Compass/ which is dedicated
to his Highness, and is no longer to be procured.
This instrument has met with such favour from
the public that no others of the kind are now
made, and I know that up to this several thousands
of mine have been made and sold.
" Then I need not say what an amount of
labour will be required to fix the periods of the
four new planets, a task the more laborious the
more one thinks of it, as they are separated from
one another by very brief intervals, and are all
very similar in size and colour. So that, illustrious
Signor, I must begin to think in what way I can
120 GALILEO QUITS PADUA [1610-
free myself from those employments which so retard
my own studies — particularly those, which another
might fill quite as well as I can. Therefore, I beg
you to bring these considerations to the notice of
his Highness, and acquaint me with his decision.
"As to salary, I shall be quite content with
the sum you named to me at Pisa, feeling it an
honour to be his Highness s servant. I say
nothing as to the amount, being convinced that as
I am to live upon it his Highness would not
wish to deprive me of any of those comforts which
others enjoy, who are less in want of them than
I am. Therefore I say no more on this point.
" Finally, as to the title and pretext by which
I take service, I would wish that to the title of
Mathematician his Highness would be pleased to
add that of Philosopher, as I have studied a greater
number of years in philosophy than months in pure
mathematics. And how far I have profited by it,
and if I can and ought to merit the title, I hope
to be able to show his Highness as often as it is
his pleasure to give me an opportunity of discuss-
ing such subjects with those whose knowledge is
most esteemed." l
1 Some of the treatises named in this letter, like the one on
dialling previously mentioned, and, it is feared, more of Galileo's
papers and correspondence, are now lost, partly through the accidents
of his stormy life, and in transport from place to place, and partly,
as we shall see later on, through the extraordinary negligence and
criminality of custodians. The loss of the essay on Continuous
Quantity is particularly to be regretted, as it would be interesting to
see how far he succeeded in methodising his thoughts on this im-
portant subject. It is to his early disciple Buonaventura Cavalieri
(who refused to publish his book so long as he hoped to see Galileo's
printed) that we owe " The Method of Indivisibles," which is recog-
nised as one of the first germs of Newton's Fluxional Calculus. The
treatises on sound and speech and on light and colours were probably
never completed, but we find fragments of them in later works, as "II
Saggiatore" and the Dialogues of 1632 and 1638. Similarly, of the
movements of animals we have the fragment " Intorno al camminare
del cavallo."
i6i2] QUITTING PADUA A MISTAKE 121
This letter brought the business to a speedy
settlement. On 5th June, Vinta wrote that
Cosimo II. was pleased to nominate him as First
Mathematician of the University of Pisa, with
a yearly salary of 1000 scudi, and without the
obligation of residing at Pisa, or of delivering
lectures. In reply, Galileo declared himself en-
tirely satisfied with the proposed conditions, but
added that he would like to be designated not
only First Mathematician at Pisa, but also Philo-
sopher and Mathematician to the Grand Duke
himself. Accordingly, on i2th July 1610, the
decree summoning him to Florence in this two-
fold capacity was issued.
Notwithstanding the many advantages which
this new post secured to him, it was a bad ex-
change from the free soil of Republican Venice to
the protection (ineffectual as it proved at the crisis
of his life) of a princely house which, although
personally well disposed towards him, could never
shield him as could and would the Republic.
About 1542, the Jesuits had established a school
in Padua, and, increasing gradually in influence,
had shown symptoms of a design to get the
management of public education entirely into their
own hands. After several violent disputes, it
was at length decreed by the Venetian Senate,
in 1591, that no Jesuit should be allowed to give
instruction at Padua in any of the sciences taught in
the University. As years dragged on, the relations
between Rome and Venice became increas-
ingly strained, until at last, in April 1606, Pope
Paul V, took the extreme step of placing the
122 RETURNS TO FLORENCE [1610-
contumacious Republic under an interdict. The
Senate's reply was to expel for ever the Jesuits
from the soil of Venice.1 Since this event, full
liberty of thought and teaching was enjoyed in the
Republic ; whereas, in religious Tuscany, Church
influences were very strong and weighed heavily in
all matters, and particularly in politics and science.
Early in September 1610, Galileo left Padua,
where, eighteen years before, he had found ^ a
ready welcome and an ever-increasing apprecia-
tion, deserting his staunch friends Paolo Sarpi,
Francesco Sagredo, and many others. Indeed,
he seems to have felt himself that he was not
behaving well in this matter, for, in his letter to
Vinta last quoted, he begged that the negotia-
tions be kept secret until all was decided and
therefore irrevocable.2
Although he was received in Florence with
much honour, soon the clouds of envy, malice,
and bigotry, began to form round him, and ulti-
mately, as we shall see, combined, if not to his
destruction, at least to embitter the rest of his
life. Sagredo foresaw this clearly. On his re-
turn from the East in the spring of 1611, he
wrote expressing his regret and disappointment
at not finding Galileo, and his grave doubts as
to the wisdom of the change.
1 Their nocturnal deportation from the city of lagoons is amusingly
told in Galileo's letter of nth May 1606, to his brother Michelangelo.
2 Galileo tried to induce Kepler to apply for his chair in Padua,
but without success. Again in 1617, on the death of Magini, Kepler
was offered the vacant chair in Bologna, which he once more refused.
See Martin's "Galile'e," Paris, 1868, pp. 14 and 194; and for Kepler's
reasons, Drinkwater's " Life of Kepler," in Library of Useful Know-
ledge, p. 38.
1612] THE PHASES OF VENUS 123
" Where," he asks, "will you find the same
liberty as in Venetian territory, and, notwith-
standing all the good qualities of the young ruler
of Tuscany, who can promise with any confidence
that, if not ruined, you will not be persecuted and
tossed on the surging billows of Court life by the
raging storms of envy?"
Within less than a month after his arrival in
Florence, Galileo made another astounding dis-
covery in the heavens — namely, the varying
crescent form of the planet Venus. He announced
this discovery to his correspondent, Giuliano de
Medici at Prague, in an anagram, as in the case
of his observations on Saturn, as follows : —
"Haec immatura a me iam frustra leguntur o y"
and after convincing himself, by three months'
observations, of its correctness, he sent the follow-
ing solution of the riddle on ist January 1611.
" Cynthiae figuras aemulatur mater amorum"
"That is, Venus rivals the appearances of the
moon ; for Venus being now arrived at that part
of her orbit in which she is between the earth
and the sun, and with only a part of her en-
lightened surface turned towards us, the telescope
shows her in a crescent form, like the moon in a
similar position."
Tracing her through the visible portion of
her orbit, Galileo had the satisfaction of seeing
the illuminated part assume successively the forms
appropriate to his hypothesis. It was with reason,
therefore, that he laid stress on the importance of
this observation, which established yet another
i24 RETURNS TO FLORENCE [1610-
fact obnoxious to the Aristotelians, namely, that
a new point of resemblance was here found
between the moon and one of the principal
planets ; for, as it was well known that the moon
was luminous only when exposed to the sun's
rays, so this change of figure in Venus demon-
strated that she, and, therefore, probably all the
other planets, were of themselves not luminous,
but only reflected the sunlight which fell upon
them. And thence he concluded that they must
all revolve round the sun — "a fact which was
surmised by Pythagoras, Copernicus, Kepler, and
their disciples, but which could not be proved by
ocular demonstration, as it now can be in the case
of Venus and Mercury. Kepler and the other
Copernicans may now be proud to have judged
and philosophised correctly, and it may well excite
disgust that they were regarded by the generality
of men of book-learning as having little under-
standing and as not much better than fools.'*
It had always been a formidable objection to
the Copernican theory that Venus and Mercury
did not exhibit the same phases as the Moon,
which they should do if they revolved round the
sun. Copernicus himself had endeavoured to
account for this, by supposing that the sun's rays
passed freely through the body of the planets, and
Galileo took occasion to praise him for not being
deterred from adopting the system (which on the
whole appeared to agree best with the phenomena)
by meeting with some appearances which it did
not enable him to explain.
Another objection, equally embarrassing to the
j6ia] ON MARS AND MERCURY 125
Ptolemaic and Copernican systems, was raised.
Why, it was asked, did not Venus appear four
times as large when nearest to the earth as when
farthest away? Galileo was now able to answer
this also. Venus does not appear four times as
large when she is nearest to the earth, simply
because her illuminated part is not then four
times as large, though her diameter is ; and as
with the naked eye we judge of her size only by
the amount of light, the nearer distance is offset
by the lesser light, so that her size does not
seem to vary.1
Milton, whose Paradise Lost has many allusions
to Galileo and his astronomy, has not suffered this
brilliant discovery to pass unnoticed. After describ-
ing the creation of the sun he adds : —
" Hither, as to their fountain other stars
Repairing, in their golden urns draw light,
And hence the morning planet gilds her horns." 2
Of changes in Mars Galileo could say little for
certain. After observing him carefully for four
months he was seen to vary in size according to
his distance from the sun. Galileo thought that
when the planet was at the middle points of his
orbit he observed changes in the illuminated disc
something like the phases of the Moon and Venus ;
but it is difficult, he adds, with so small an object
to say whether it is always perfectly round.
1 The revolution of Mercury about the Sun which Galileo here
infers, was confirmed as a fact by Kepler's observation of the transit
of Mercury in 1630. Our countryman, Horrox, was the first to observe
a transit of Venus in 1639.
a Book VII. v. 364. For other references, see Book I. v. 286;
III. 565 et seq., 722 et seq.; IV. 589; V. 261, 414 ; VII. 577; VIII.
1-178.
124 RETURNS TO FLORENCE [1610-
fact obnoxious to the Aristotelians, namely, that
a new point of resemblance was here found
between the moon and one of the principal
planets ; for, as it was well known that the moon
was luminous only when exposed to the sun's
rays, so this change of figure in Venus demon*
strated that she, and, therefore, probably all the
other planets, were of themselves not luminous,
but only reflected the sunlight which fell upon
them. And thence he concluded that they must
all revolve round the sun — "a fact which was
surmised by Pythagoras, Copernicus, Kepler, and
their disciples, but which could not be proved by
ocular demonstration, as it now can be in the case
of Venus and Mercury. Kepler and the other
Copernicans may now be proud to have judged
and philosophised correctly, and it may well excite
disgust that they were regarded by the generality
of men of book-learning as having little under-
standing and as not much better than fools."
It had always been a formidable objection to
the Copernican theory that Venus and Mercury
did not exhibit the same phases as the Moon,
which they should do if they revolved round the
sun. Copernicus himself had endeavoured to
account for this, by supposing that the sun's rays
passed freely through the body of the planets, and
Galileo took occasion to praise him for not being
deterred from adopting the system (which on the
whole appeared to agree best with the phenomena)
by meeting with some appearances which it did
not enable him to explain.
Another objection, equally embarrassing to the
1612] ON MARS AND MERCURY 125
Ptolemaic and Copernican systems, was raised.
Why, it was asked, did not Venus appear four
times as large when nearest to the earth as when
farthest away? Galileo was now able to answer
this also. Venus does not appear four times as
large when she is nearest to the earth, simply
because her illuminated part is not then four
times as large, though her diameter is ; and as
with the naked eye we judge of her size only by
the amount of light, the nearer distance is offset
by the lesser light, so that her size does not
seem to vary.1
Milton, whose Paradise Lost has many allusions
to Galileo and his astronomy, has not suffered this
brilliant discovery to pass unnoticed. After describ-
ing the creation of the sun he adds : —
" Hither, as to their fountain other stars
Repairing, in their golden urns draw light,
And hence the morning planet gilds her horns." 2
Of changes in Mars Galileo could say little for
certain. After observing him carefully for four
months he was seen to vary in size according to
his distance from the sun. Galileo thought that
when the planet was at the middle points of his
orbit he observed changes in the illuminated disc
something like the phases of the Moon and Venus;
but it is difficult, he adds, with so small an object
to say whether it is always perfectly round.
1 The revolution of Mercury about the Sun which Galileo here
infers, was confirmed as a fact by Kepler's observation of the transit
of Mercury in 1630. Our countryman, Horrox, was the first to observe
a transit of Venus in 1639.
a Book VII. v. 364. For other references, see Book I. v. 286 ;
III. 565 et seq., 722 et seq.; IV. 589*; V. 261, 4H ; VII. 577; VIIL
1-178.
126 RETURNS TO FLORENCE [1610-
Of Mercury lie also observed little, because
that planet's orbit does not take him far from
the sun, and, in consequence, his small disc is
always so resplendent that not even the best
telescope could deprive him of his factitious rays
(irradiation).1
In consideration of the intense interest, friendly
and otherwise, excited by these epoch-making
discoveries, and the probability of their being
used against him in Rome, Galileo thought it
desirable to go there himself, and acquaint at
first hand the savants and dignitaries of the
Church with his work in the heavens. These
people, he argued, must be first made to see the
facts with their own eyes, so that they may be
able to comprehend and assent to the conclusions
to be drawn from them. Therefore, on I5th
January 1611, he wrote to Vinta (who was then
with the Court at Pisa), informing him of his
design, adducing the above reasons, and request-
ing the necessary leave of absence. His request
was not only granted but the Grand Duke placed
a litter at his disposal, undertook to defray all
expenses, and directed the Tuscan Ambassador
in Rome to lodge him at the Embassy and to
entertain him during the visit. Illness, however,
supervened, so that it was not till 23rd March
1611, that he was able to set out, provided with
many letters of introduction, amongst them one
from Michelangelo the younger (nephew of the
1 For Galileo's observations on Venus, Mercury, and Mars, see his
letters to Castelli, dated soth December 1610, and to Clavio in Rome
under the same date.
i6i2] SECOND VISIT TO ROME 127
great sculptor and painter) to Cardinal Barberini
(afterwards Pope Urban VI I L),
He was received with the greatest distinction
by princes and all the Church dignitaries, who
vied with learned laymen in doing him honour.
Even those who discredited his discoveries and
dreaded their results, were as eager as the true
friends of science to see and hear this wonder of
the age. His first duty was to call on his old
friends, Cardinal del Monte and the Jesuit Father
Clavio, by the latter of whom he was presented
to the leading Jesuits of the Roman College.
After exhibiting on several occasions in the
garden of the Quirinal Palace, belonging to
Cardinal Bandini, all his recent discoveries, or
" celestial novelties " as they were called, a
commission of four scientific members of the
Roman College was appointed, at the request of
Cardinal Bellarmine, to examine and report. As
the result, the commissioners, Fathers Clavio,
Griemberger, Maelcote, and Lembo, were con-
strained to admit what they had long denied
and ridiculed, being now convinced by ocular
proofs of the truth of the facts announced by
Galileo. By this opinion (given on 24th April)
of the Papal experts, his discoveries received to
a certain extent the sanction of the Church.
Attentions of all sorts were now heaped upon
him ; Pope Paul V. granted him a long audience,
and assured him of his unalterable good-will,
which, however, did not remain so, as the sequel
will show. High dignitaries of the Church
followed suit, and were lavish in their admiration ;
128 RETURNS TO FLORENCE [1610-
and the Accademia dei Lincei (founded in 1603
by Prince Cesi), the prototype of our Royal
Society, elected him a member. So that when he
took his departure, on the 4th of June, Galileo
left behind in Rome many sincere friends and
admirers, and some very envious foes.
A letter of 3ist May, from Cardinal del Monte
to Cosimo II., will best show how Galileo's friends
regarded his visit.
"Galileo has, during his stay in Rome, given
great satisfaction, and I think he must have felt
it no less himself, for he had the opportunity of
showing his discoveries so well, that to all clever
and learned men here they seemed no less true
and well-founded than astonishing. Were we
still living under the ancient republic of Rome I
verily believe there would have been a column
on the Capitol erected in his honour/'
Immediately after the publication of the report
of the Bellarmine Commission, Galileo announced
a new discovery in the heavens, namely, dark
spots on the body of the sun, which, towards the
end of April 1611, he showed to several prelates
and savants in Rome.
Describing these phenomena at a later date1
Galileo states that at first he was undecided
whether to explain the ever-changing nature, and
position of the spots by supposing that the sun
revolved on his own axis, or by imagining that
other unknown stars, besides Mercury and Venus,
revolved about the sun, which were visible only
as spots, and invisible at other times on account
1 " Discourse on Floating Bodies," Florence, 1612.
i6i2] SUN-SPOTS 129
of their small distance from him. But further
observation led him to abandon the latter sup-
position and to announce positively1 that the
spots were in actual contact with the body of
the sun, where they were continually appearing
and disappearing, much as clouds about our
earth ; that their figures were very irregular,
some being very dark and others less so ; that
one would often divide into two or three, and at
other times two or three would unite into one ;
and that they all had a common and regular
motion, being carried round with the sun, which
turned on its axis in a little less than a lunar
month,2 and in the same direction as the planets.
These observations were, in their consequences
to Galileo, particularly unfortunate, as in the course
of the controversy in which they entangled him, he
first became personally embroiled with the powerful
Jesuit party, whose influence was one of the chief
causes of his subsequent misfortunes.
A Jesuit father, Christopher Scheiner, Professor
of Mathematics at Ingolstadt, claimed priority in
the discovery of the Sun-spots, asserting that early
in 1611 he first noticed them and showed
them to his pupils. Scheiner stated his case in
three letters over the signature Apelles latens
post tabulam, and addressed to Mark Welser,
Chief Magistrate of Augsburg. In the first
letter dated i2th November 1611, he states
that he made his first observations seven months
previously ; but apparently he then attached no
1 Letter to Prince Cesi, dated i2th May 1612.
2 Modern observations make it vary from 25 to 27 J days.
I
130 RETURNS TO FLORENCE [16x0-
value to them, for, on resuming his work in the
following October, he thought the appearances
arose from some defect in his glasses — an idea
which was only dissipated by these further studies,1
Clearly then, it was only after resuming his observa-
tions (October 1611) that he believed in the actual
existence of the spots, which he then explained
by supposing them to be caused by multitudes of
little planets, revolving round the sun in an orbit
inside Mercury, and producing the appearance of
spots in crossing his disc.
On the publication of Schemer's letters at
Augsburg, Welser, on 6th January 1612, sent a
copy to Galileo requesting to be favoured with his
opinions of the phenomena therein described.
Galileo replied in three letters 2 in which he easily
combated Scheiner on the nature of the spots,
and stated that his own observations dated back
eighteen months.8
1 An amusing incident is related in connection with Schemer's
observations, which shows how the authority of Aristotle held its
ascendency over men's minds even when his dogmas were opposed
to the testimony of the senses. On communicating his discovery to
the Provincial of his Order, the latter replied : " I have read
Aristotle's writings from end to end many times, and I can assure you
I have nowhere found anything similar to what you describe. Go, my
son, and tranquillise yourself ; be assured that what you take for spots
on the sun are the faults of your glasses, or of your eyes." Scheiner
was only permitted to publish his observations anonymously, as
mentioned in the text.
2 The first of which, dated 4th May 1612, is now in the British
Museum in autograph ; the second is dated I4th August, and the
third ist December. All three were published in 1613 under the
title " Istoria e Dimostrazioni delle Macchie Solari."
3 He says this at the beginning of the first letter, which is dated
4th May 1612. This would fix the date at about beginning of
November 1610 ; yet, from Fra Micanzio's letter to Galileo of
27th September 1631, the first observations would appear to go back
i6i2] SUN-SPOTS AND FACULAE 131
In these letters Galileo further stated that the
spots often dispersed like vapours or clouds, which
he supposed them to be ; that they sometimes lasted
only one or two days, and at other times thirty or
forty days ; that they contracted in breadth as
they approached the sun's limb, without diminishing
their length ; that they described circles parallel to
each other; that the rotation of the sun again
brought the same spots into view ; and that they
were never seen to extend to a greater distance
than 30° from the sun's equator.1
Besides the spots, Galileo's telescope disclosed
other interesting appearances on the sun's disc.
Some parts are perceived to be brighter than the
rest of the surface, and hence are called faculae.
These phenomena are described in the third letter
to Welser, where with great acuteness he adduces
them as a proof that the spots are attached to the
surface of the sun, and are not little planets as
Scheiner supposed ; for the telescope frequently
showed spots and faculae travelling across the sun's
disc together ; and, accepting Schemer's supposition
with regard to the former, it would be probable
that the latter also should sometimes appear as
bright spots beyond the sun's limb — a conclusion
which was totally at variance with all his observa-
tions.
These letters were written from the Villa delle
Selve of his friend Filippo Salviati, near Signa
to the time when Galileo was still at Padua, say to August But
writing so long after the event, Micanzio may well be mistaken as to
the date.
1 Appended to the second letter are forty sketches of the spots as
observed from day to day during June, July, and August 1612.
132 RETURNS TO FLORENCE [1610-
(9 fniles from Florence), where Galileo spent much of
his time at this period, and particularly during his
frequent indispositions, as he considered that the
air of the city was prejudicial to his complaints.1
The letters, with Schemer's appended, were
printed at Rome in March 1613, and were dedicated
to Salviati. They were published under the
auspices of the Accademia dei Lincei, " In order,"
as the Academy report sets forth, "to mark its
sense of the merit of the work and the claim of its
author to be regarded as the first discoverer of
Sun-spots/'2
In order to complete our history of the Sun-
spots in so far as Galileo is concerned, we have
left unnoticed other important matters on which
he was at the same time engaged, and to these
we must now return. Soon after his return to
Florence in June 1611, he wrote a pamphlet in
the usual form of a letter, dated ist September
1611, and addressed to Father Griemberger, "on
1 Salviati had ever been one of his wannest friends, and delighted
in drawing round him all the great scientists of the time. He was a
member of the Accademia dei Lincei, and although not an author of
any great work, or of any important discovery, he has yet earned, by
his liberality to science, and by his devotion to Galileo, an honoured
name that will not die. He died 22nd March 1614, and in after years
Galileo raised to his memory a monument more enduring than
marble, by assigning to him the place of honour in the immortal
Dialogues of 1632, where Salviati is the Copernican interlocutor, and
represents, in fact, Galileo himself in the dialogue.
2 The first discovery of Sun-spots has also been claimed for
Thomas Hariot in England, for Simon Mayer in Germany, and for
Johann Fabricius in Holland. The first two claims rest on very
doubtful evidence ; the third is better founded. In fact, Fabricius
was the first to publish the results of his observations in his " De
Maculis in Sole Observatis" (Wittenberg, June 1611), and therefore,
according to modem notions, he has the best claim to priority. For
more, see Grant's " History of Physical Astronomy," pp. 213-15.
i6i3] ON LUNAR MOUNTAINS 133
the Inequalities of the Moon's surface," or lunar
mountains. The moon was with him a stock
subject for observation, the results of which he
communicated from time to time in letters to
(besides Griemberger) Welser, Brengger, Gallan-
zoni, and others. Indeed, his last astronomical
discovery, towards the close of life and just before
he became blind, was connected with the moon.
It had been asserted that, as the full moon
always presented a well-defined outline, whether
when viewed with the naked eye, or through a
telescope, it was impossible that there could exist
any equalities around her circumference. Galileo,
however, maintained that the irradiation of the
moon's light, by obliterating any asperities around
her edge, might effectually conceal the real nature
of that part of her surface. With respect to
irradiation generally, he remarked that it increases
with the brightness of the object. It is from this
cause that the planets near the sun have a greater
irradiation than those that are more remote. So
intense is the irradiation of Mercury, that it is
impossible, even with the most powerful telescope,
to deprive him of his brilliant corona. The same
is true, though in a less degree, with respect to
Mars. On the other hand, Jupiter, and especially
Saturn, being more feebly illuminated by the solar
light, lose their irradiation in the telescope, and
disclose their true figures. With respect to Venus,
when she is near her inferior conjunction, she
resembles the new moon ; but such is the intensity
of her irradiation, that she appears to the naked
eye like any other star. In this position, however,
134 RETURNS TO FLORENCE [1610
as the extent of the illuminated surface, is small, and
the light is at the same time enfeebled by the
obliquity of the surface, it is possible by means of
a telescope to discern the real appearance of the
planet. When, however, she is near her superior
conjunction, she presents a complete hemisphere
of vivid light towards the earth of such intensity
that even the most perfect telescope does not
suffice to destroy her irradiation and reveal to
us her true figure.
Galileo, therefore, contends that since the
effect of irradiation is so great as to conceal from
the unaided eye the immense cavity of Venus
when she assumes the form of a crescent, it is
much more probable that a telescope will fail to
efface the irradiation of the moon enough to dis-
close the small eminences and cavities which may
be situated near the edge of her disc.1
Like all subsequent observers up to the close
of the eighteenth century, Galileo is said to have
believed in the existence of lunar seas and of a
lunar atmosphere ; while on the question of the
existence of lunar inhabitants he is supposed to
have kept an open mind.2 His belief in a lunar
atmosphere may be conceded, but as regards the
1 See p. 88 ante. Also Grant's " History of Physical Astronomy,"
PP- 347-52. In one of the frescoes in the Borghese chapel in S. Maria
Maggiore, Rome (the Virgin with the moon under foot), by Cigoli, the
friend and correspondent of Galileo, the hills and valleys of the moon
are painted as the telescopes of the day (1612) revealed them.
2 As regards the habitation of the planets, however, he was dis-
creetly silent. In a letter to Prince Cesi, 25th January 1613, he says :
" If the question be put to me I will answer neither yes nor no." He
also refers to tr^e subject in the same indeterminate way in his letters
on Sun-spots and in the Dialogues of 1632.
i6ia] MOON NOT HABITABLE 135
other points the very reverse is the fact, as the
following letter shows. Writing to Giacomo Muti
from Rome, on 2 8th February 1616, Galileo
says : —
"A few days ago, when paying my respects to
the illustrious Cardinal Muti, a discussion arose on
the inequalities of the moon's surface. Signor
Alessandro Capoano, in order to disprove the
fact, argued that if the lunar superfecies be unequal
and mountainous, one may say as a consequence
that, since Nature has made our earth mountainous
for the benefit of plants and animals beneficial to
man, so on the moon there must be other plants
and other animals beneficial to other intellectual
creatures. Such a consequence, he said, being
most false, therefore the fact from which it is
drawn must also be false, therefore lunar mountains
do not exist ! l To this I replied : As to the in-
equalities of the moon's surface we have only to
look through a telescope to be convinced of their
existence ; as to the € consequences/ I said, they
are not only not necessary, but absolutely false
and impossible, for I was in a position to prove
that neither men, nor animals, nor plants as on
this earth, nor anything at all like them can exist
on the moon. I said then, and I say now, that I
do not believe that the body of the moon is
composed of earth and water, and wanting these
two elements we must necessarily conclude that it
wants all the other things which without these
elements cannot exist or subsist I added further :
even allowing that the matter of the moon may be
like that of the easfh (a most improbable
supposition), still not one of those things which
1 The work of the peripatetic philosopher Lagalla ("De Phoeno*
menis in Orbe Lunae," Bologna, 1612), enforcing the same arguments,
is reprinted in the later editions of Galileo's works, with his marginal
comments.
136 RETURNS TO FLORENCE [1610-
the earth produces can exist on the moon, since
to their production other things besides earth
and water are necessary — namely, the sun — the
greatest agent in Nature — and the resulting
vicissitudes of heat and cold, and of day and night.
Now, such vicissitudes are on the moon very
different from those on the earth. In the latter
case, to produce a diversity of seasons, the sun
rises and falls more than 47° (in passing from
one tropic to the other); in the former case the
variation is only 5° on each side of the ecliptic.
While, therefore, on the earth the sun in every
24 hours illuminates all parts of its surface, each
half of the moon is alternately in sunshine and
darkness for 15 continuous days of 24 hours.
Now, if our plants and animals were exposed to
ardent sunshine every month for 360 consecutive
hours, and then for a similar time were plunged
in cold and darkness, they could not possibly
preserve themselves, much less produce and
multiply. We must, therefore, conclude that what
would be impossible on our earth under the circum-
stances we have supposed to exist, must be impossible
on the moon where those conditions do exist."
No sooner were these questions of sun-spots
and lunar mountains out of hand than Galileo
became engaged in another protracted discussion,
which resulted in another famous treatise, pub-
lished in Florence in 1612. This is his " Discourse
on Floating Bodies," in which he uses the principle
of virtual velocities from which modern geometers,
and especially Lagrange, have drawn largely, and
by the aid of which he demonstrates the more
important theorems of hydrostatics.1
1 This important principle was first announced in his treatise on
Mechanics, written in 1594. See p. 37 ante.
1612] FLOATING BODIES 137
The question of floating bodies had been dis-
cussed at one of the scientific parties which the
Grand Duke liked to assemble round him, and the
general opinion appearing to be that of Aristotle,
that the floating or sinking of a body depended
principally upon its shape, Galileo undertook to
show its untenableness. Some one in the company
asserted that condensation is the effect of* cold, and
ice was mentioned as an instance. Galileo retorted
that ice is rather water rarefied than water con-
densed, the proof of which is that it always floats
upon water. His opponents rejoined that this
phenomenon was due, not to the lightness of the
ice, but to its incapacity, owing to its flat shape,
to overcome the resistance which the water opposed
to its sinking. Galileo denied this, and asserted
that ice of any shape would float upon water, and
that if a flat piece of ice were forced to the bottom
it would, when left to itself, rise again to the
surface.1
The general character of this remarkable Dis-
course will be understood from the following
passages : —
"The diversity of figure given to any solid
cannot be the cause of its floating or sinking in
water ; so that if a solid made, for instance, into
a sphere sinks or floats, it will likewise sink or
float when made into any other form. The breadth
of the figure may indeed retard its velocity as well
of ascent as of descent, and more and more in
proportion to the breadth and thinness of the said
1 Cardinals Gonzaga and Maffeo Barberini (afterwards Pope
Urban VIII.) were among the guests, and the latter took Galileo's
side in the discussion against the peripatetics led by Gonzaga.
138 RETURNS TO FLORENCE [1610-
figure ; but that it can be reduced to such a form
as to put an end to its motion I hold to be im-
possible. In this I have met with opponents who,
pointing to some experiments, and, in particular,
taking a thin board of ebony and a ball of the
same wood, and showing that the latter sinks, while
the former, if placed lightly on the surface, floats,
hold by the opinion of Aristotle that the cause
of flotation is the breadth of the figure, which
renders it unable to overcome the resistance of
the water to penetration ; whereas in the case of
the ball its form enables it to overcome this re-
sistance, and it readily sinks. I assert, on the
contrary, that there is not any solid of such light-
ness or of such a figure that, being placed on the
water, will not divide and penetrate it ; and if
you examine carefully your thin boards of wood
you will see that they have part of their thickness
under water ; and, moreover, you will see that
shavings of ebony, stone, and metal, when they
float, have not only broken the continuity of the
water, but are with all their thickness under the
surface, and this more and more according to their
specific gravity; so that a thin plate of lead will
be lower than the surface of the surrounding water
by at least twelve times the thickness of the plate,
and a gold plate will dive below the level almost
twenty times its thickness/'
In order to show more clearly the non-resistance
of water to penetration, Galileo then directs a cone
to be made of wood or wax, and asserts that when
it floats, either with its base or its apex in the
water, the solid content of the part immersed will
be the same, although the apex is (by reason of
its shape) better adapted to overcome the resist-
ance of the water to division. The shape, then,
i6i2] FLOATING BODIES 139
cannot be the cause of the buoyancy. Or the
experiment may be varied by mixing the wax with
lead filings till the compound sinks in water, when
it will be found that in any shape the same weight
of cork must be added before it will rise to the
surface. He goes on : —
" This silences not my antagonists, who say that
my experiments import little to them, and that it
is enough for them to have demonstrated in one
instance, and in such manner as pleases them best,
that an ebony ball when put into water sinks to
the bottom, while an ebony board stays to swim
at the top, and the matter being the same, and
the two bodies differing in nothing but in figure,
they affirm that with all perspicuity they have
demonstrated and sensibly manifested what they
undertook. Nevertheless, I believe and think I
can prove that this very experiment proves nothing
against my theory. And first, it is false that the ball
sinks and that the board does not; for the board
will sink too, if you do to both as the words of
our question require ; that is, if you put them both
in the water ; for to be in the water implies to be
placed in the water; and, by Aristotle's own
definition of place, to be placed imports to be
environed by the surface of the ambient body.
But when my antagonists show the floating board
of ebony they put it not into the water, but upon
the water, where, being detained by a certain
impediment (of which more anon), it is surrounded
partly by water, partly by air, which is contrary
to our agreement, for that was that the bodies
should be in the water, and not part in the water,
part in the air. I will not omit another reason,
founded upon experience, and, if I deceive not
myself, conclusive against the notion that figure
and the resistance of the water to penetration have
140 RETURNS TO FLORENCE [1610-
anything to do with the buoyancy of bodies.
Choose a piece of wood or other matter, as for
instance walnut-wood, a ball of which rises from
the bottom of the water to the surface more slowly
than a ball of ebony of the same size sinks, so
that clearly the ball of ebony divides the water
more readily in sinking than does the walnut in
rising. Then, take a board of walnut-wood equal
to and like the floating ebony of one of my anta-
gonists, and if it be true that this latter floats by
reason of the figure being unable to penetrate the
water, the other of walnut- wood, without all question,
if thrust to the bottom ought to stay there, as
having the same impeding figure, and in conse-
quence unable to overcome the said resistance of
the water. But if we find by experience that not
only the thin board, but every other figure of the
same walnut-wood, will return to float, as un-
questionably we shall, then I must desire my
opponents to forbear to attribute the floating of
the ebony to the figure of the board, since the
resistance of the water is the same in rising as in
sinking, and the force of ascension of the walnut-
wood is less than the ebony's force for going to
the bottom.
c< Now, let us return to the thin plate of gold or
silver, or the thin board of ebony, and let us lay it
lightly upon the water, so that it may stay there
without sinking, and carefully observe the effect.
It will appear clearly that the board or plate is
lower than the surface of the water, which rises up
and makes a kind of rampart round it on every side.
But if it have already penetrated and overcome the
continuity of the water, and is of its own nature
heavier than the water, why does it not continue
to sink, but stop and suspend itself in that little
dimple that its weight has made in the water ? My
answer is, because in sinking till its surface is below
x6i2] FLOATING BODIES 141
the water, which rises up in a bank round it, it draws
after and carries along with it the air above it, so
that that which descends is not only the board of
ebony (or metal plate), but a compound of ebony
and air, from which composition results a body no
longer specifically heavier than the water, as was
the ebony or metal alone. But, gentlemen, we
want the same matter; you are to alter nothing
but the shape, and therefore have the goodness to
remove this air. This may be done simply by
washing the upper surface of the board, for the
water having once got between the board and the
air will run together, and the ebony will sink to
the bottom ; and if it does not, you have won the
day. But methinks I hear some of my antagonists
cunningly opposing this, and telling me that they
will not on any account allow their board to be
wetted, because the weight of the water so added,
by making it heavier than it was before, forces it
to the bottom, and that the addition of new weight
is contrary to our agreement.
"To this I answer first, that nobody can
suppose bodies to be put into water without wetting
them, nor do I wish to do more to the board
than you do to the ball. Moreover, it is not true
that the board sinks on account of the weight of
the water added in the washing ; for I will put ten
or twenty drops on the floating board, and so long
as they stand separate it shall not sink ; but if the
board be taken out, and all that water wiped off,
and the whole surface be bathed with a single drop,
and be again put upon the water, there is no
question but it will sink, water running to cover it,
being no longer hindered by the air. In the next
place, it is altogether false that water can in any way
increase the weight of bodies immersed in it, for
water has no weight in water, since it does not sink.
Now, just as he who should say that brass by its
142 RETURNS TO FLORENCE [1610-
own nature sinks, but that when formed into a
kettle it acquires from that figure a virtue of lying
in the water without sinking, would say what is
false, because that is not purely brass which then is
put into the water, but a compound of brass and
air ; so is it neither more nor less false that a thin
plate of brass or ebony swims by virtue of its dilated
and broad figure.
" Some may wonder that I affirm this power to
be in the air of keeping a board or metal plate from
sinking, as if in a certain sense I would attribute
to the air a kind of magnetic virtue for sustaining
heavy bodies with which it is in contact. To satisfy
all these doubts, I have contrived the following
experiment to demonstrate how truly the air does
support these solids ; for I have found, when one of
these bodies (which floats when placed lightly on
the water) is thoroughly bathed and sunk to the
bottom, that, by carrying down to it a little air,
without otherwise touching it in the least, I am able
to raise and carry it back to the top, where it floats
as before. To this effect I take a ball of wax, and
with a little lead make it just heavy enough to sink
very slowly to the bottom, taking care that its
surface be quite smooth and even. This, if put
gently into the water, submerges almost entirely, there
remaining outside only a very little of the top, and,
so long as it is thus joined to the air, the ball floats ;
but if we take away the air, by wetting this top, the
ball sinks to the bottom, and remains there. Now
to make it return to the surface by virtue of the air
which before sustained it, thrust into the water
a glass, with the mouth downwards, which will
carry with it the air it contains ; move this down-
wards towards the ball, until you see that the air
has reached the top of it ; then gently draw the
glass upwards and you will see the ball rise, and
afterwards stay on the top of the water, if you
1612] FLOATING BODIES 143
carefully withdraw the glass without too much
disturbing the water. There is therefore a certain
affinity between the air and other bodies, which
holds them united, so that they separate not without
a kind of violence, just as between water and other
bodies ; for in drawing such bodies wholly out of
the water, we see it follow them, and rise sen-
sibly above the level before it quits them/'
His opponents were in hopeless confusion
between the phenomena of hydrostatic pressure,
which they professed to be discussing, and those of
capillary action which they quoted against Galileo.
With his careful observations to support him,
Galileo would have carried conviction more readily
had he emphasised the distinction between the two
questions, and realised himself that the floating
plate of metal indicated a natural property of
liquids which deserved special investigation.
Having established his theory of buoyancy by
these ingenious experiments, Galileo proceeds to
show what must be the dimensions of a plate of
any substance which will float as the wax does,
assuming in each case that we know the greatest
height at which the rampart of water will stand
round it In like manner he shows that a
pyramidal or conical figure may be made of any
substance in such a way that, by the help of the
air, it shall rest upon the water without wetting
more than its base ; and, furthermore, that we
may form a cone of any substance so that it shall
float (partially submerged) if placed gently on the
surface with its point downwards, whereas no care or
pains will enable it to do so with its base down-
144 RETURNS TO FLORENCE [1610-
wards, owing to the different proportions of air which
in the two positions are in contact with the water.1
As may be gathered from the foregoing ex-
cerpts, the book contains many ingenious experi-
ments and much acute reasoning in support of
the true principles of hydrostatics. Like all his
other works it encountered violent opposition, and
Galileo had, more than once, to enter the field to
repel the counter " arguments " of his opponents.
The first published attack was by Giorgio Coresio,
a professor in Pisa, under the form of a letter to
the Archbishop of Florence. The reply to this was
entrusted to Galileo's valiant disciple and champion,
Benedetto Castelli. The manuscript was submitted
to the Master and revised by him, and was about to
be published when Coresio was dismissed (on its
leaking out that though professedly a Catholic he
really belonged to the Greek Church), and died soon
after. Thereupon, the work was laid aside, on the
principle de mortuis nil nisi bonum. A second attack
was published anonymously, but was well known to
be the work of Arturo d'Elci, head of the University
of Pisa, the same who, as we shall presently see,
forbade any allusions in lectures to the astronomical
discoveries of Galileo. To this Galileo replied in a
long letter, dated 4th January 1613, and addressed
to Tolomeo Nozzolini.2 More elaborate attacks
were next published by Lodovico delle Colombe
1 Galileo took advantage of a second edition of this publication to
record briefly his latest observations on Venus, on Jupiter's moons, and
on the Sun-spots, all of which were, until then, only known to his friends
and correspondents. This edition appeared in August, two months
after the first.
2 Nozzolini had previously defended Galileo's views against the
attacks of d'Elci and Coresio in a letter (22nd September) to Mgr,
Marzimedici. Archbishop of Florence.
x6ia] CONTROVERSY 145
and Vincenzio di Grazia. To these a detailed
and overwhelming answer was printed in the name
of Benedetto Castelli. After pulverising all the
" arguments J> of his opponents, the writer taunt-
ingly bids them remember that he was merely
Galileo's pupil, and thence to conclude how much
more effectually Galileo himself would have con-
futed them had he thought it worth his while.1
It was in reference to this controversy that
Galileo declared that ignorance had been the best
master he ever had, since, in order to be able to
demonstrate to his adversaries the truth of his
conclusions, he had been forced to prove them
by such a variety of experiments as made him-
self doubly confident ; though to satisfy his own
mind alone he had never felt it necessary to
make many.
1 It was not generally known till several years after Galileo's death,
that Castelli's essay was in fact written by the Master himself. It
is entitled "Risposta alle Opposizioni del Colombe e del Grazia,"
Florence, 1615.
K
CHAPTER VIII
GATHERING STORMS FIRST APPEARANCE BEFORE
THE INQUISITION AT ROME RETURN TO FLORENCE
I6l2-l6l7
THE uncompromising boldness with which Galileo
published and supported his opinions had, as we
have seen so often, raised against him a host of
enemies, who each had objections peculiar to him-
self, but who now began to perceive the policy of
uniting their strength in the common cause to
crush, if possible, so strange an innovator. The
Aristotelian professors, the Jesuits, the political
churchmen, and those timid but respectable persons
who at all times dread innovation, whether it be
in religion or in science, all were drawn together
against the philosophical tyrant who threatened
them with the penalties of too much knowledge.
The party of Galileo though weak in numbers
was not without power and influence. He had
trained around him a devoted band who idolised
his genius, and disseminated his views, for many
of his favourite pupils were now professors in the
leading schools of Italy.
No longer able to combat Galileo's hard facts
and powerful arguments by asserting that the
facts were faults in his glasses and instruments
i6i2-i6i7] CRUSADE AGAINST GALILEO 147
devilishly designed, and that his arguments were
vain-glorious and "scientifically" absurd, his op-
ponents now took their stand on theology, and
raised the cry of the Church in danger. On the
simple ground that his astronomical doctrines were
incompatible with Scripture, a great din was raised
and began to make itself heard, especially in
Florence, early in the year 1612.
With the first mutterings of the storm in his
ears, Galileo wrote thus to Prince Cesi on I2th
May in that year: —
" I suspect that this new discovery [the Sun-
Spots] will be the signal for the funeral, or rather
for the last judgment of the pseudo-philosophy —
the funereal signals having already been shown
in the moon, the Medicean stars, Saturn, and
Venus. And I expect now to see the peripatetics
put forth some grand effort to maintain the im-
mutability of the heavens!"
True to her original attitude of hostility,
Galileo's Alma Mater, Pisa, was consistent and
persistent in her opposition to his teachings.
Thus, Father Castelli, who in October 1613, was
called to the Mathematical Chair in that Uni-
versity, told Galileo (6th November 1613) that
he was forbidden to treat in his lectures of the
double motion of the earth, or even to hint at its
probability ! " Of our controversies," he goes on
to say, "not a word whatever, a thing which
astonishes me. Your marvellous discoveries are
scarcely known here even by name!"
Notwithstanding all this commotion in the
schools and amongst the minor churchmen, the
148 GATHERING STORMS [1612-
authorities at Rome had not yet taken the alarm.
On the contrary, we find the Cardinals Maffeo
Barberini (afterwards Pope Urban VIII.) and
Federigo Borromeo thanking Galileo for sending
them his book on the Sun-Spots, and express-
ing their admiration for his researches as described
therein. Similarly, Battista Agucchia, one of the
principal officials of the Papal Court, writing 8th
June 1613, expressed his belief that Galileo's teach-
ings would in time be universally acknowledged.
" Although now they had many opponents,
partly from their novelty and extraordinary char-
acter, and partly from the envy and obstinacy of
those who had from the first maintained the con-
trary opinion."
But amongst his other friends (not in Rome)
there was at least one more discriminating, one
who knew better the men and their spirit — Fra
Paolo Sarpi of Venice. This old and faithful
friend did not share this confidence in the triumph
of truth — " I foresee," said he, " that the ecclesiastical
authorities will change a question of physics and
astronomy into one of theology, and that to my
great grief Galileo, if he wants to live in peace and
escape the charge of heresy, will have to recant."
" The day will come," he continues, "when men of
science will have to deplore the disgrace of Galileo."
Prophetic words, as the sequel will show.1
An accidental circumstance was the spark which
fired the train. One day in December 1613,
1 Griselini, " Del Genio di Paolo Sarpi," Venice, 1785, vol. ii. p. 70.
Professor Favaro, however, doubts their authenticity, and questions
Griselini's authority.
1617] LETTER TO CASTELLI 149
Castelli and other learned men were guests at
the Grand Duke's table at Pisa, where, as usual,
the Tuscan Court was wintering. The conversa-
tion turning on the " satellites of Jupiter,'1 Castelli
took the opportunity of extolling and expatiating
on his master's discoveries, One of the guests,
Boscaglia, Professor of Physics at the University,
and a peripatetic of the purest water, managed to
excite the religious scruples of Cristina, Dowager
Grand Duchess, by telling her that all Galileo's
telescopic discoveries were true, only the deduction
from them of the double motion of the earth must
be wrong, as the Holy Scriptures were clearly
opposed to such a doctrine. Castelli, who had
left the apartment, was recalled to answer this
objection. At first he deprecated bringing the
Bible into the controversy, but as this was un*
availing, he resolutely took the theological stand-
point, and defended the new views of the universe
so well, that many of those present took his side —
the Dowager Duchess standing alone, and Boscaglia
taking no part. Castelli hastened to apprise
Galileo of this incident, and added that it appeared
to him that the Grand Duchess had merely per-
sisted in opposition, in order to draw him out.
— (Letter of i4th December 1613.)
This, then, was the provocation to Galileo's
famous letter of 2ist December 1613 to Castelli,
in which for the first time he engages in theological
discussions, and which, although not intended for
publication, was to be turned to account by his
enemies, and to form the groundwork of his
subsequent trial. The letter is too long to quote
150 GATHERING STORMS [1612-
in full, but the following passages will show the
line of argument pursued.1 He begins by showing
that there is as much difficulty in reconciling the
Ptolemaic as the Copernican system of the world
with the astronomical expressions contained in the
Scriptures, and asserts that (the object of Scripture
not being to teach astronomy) such expressions
are there used as would be intelligible to the vulgar,
and without regard to the true structure of the
universe.2 He then goes on: —
"As the Bible, although dictated by the Holy
Spirit, admits (for the reasons given above) in
many passages of an interpretation other than
the literal one, and as, moreover, we cannot maintain
with certainty that all interpreters are inspired by
God, I think it would be the part of wisdom not to
allow any one to apply passages of Scripture in such
a way as to force them to support as true any
conclusions concerning nature, the contrary of
which may afterwards be revealed by the evidence
of our senses, or by actual demonstration. Who
will set bounds to man's understanding ? Who can
assure us that every thing that can be known in the
world is known already? ... I am inclined to
think that Holy Scripture is intended to convince
1 This letter, with the one from Castelli which called it forth, is
given in full in "Private Life of Galileo," London, 1870, pp. 73-7.
2 When the intrigues against Galileo began in, Florence 1611-12,
he consulted Cardinal Conti as to how far the Scriptures were
favourable to the Aristotelian constitution of the world. Conti
replied, 7th July 1612, that the Scriptures were rather contrary than
favourable to the peripatetic doctrine of the incorruptibility of the
heavens ; but he was not so sure on the question of the motion of the
earth. He thought that this opinion could not be reconciled with
passages in Scripture which attributed motion to the sun and stars
only, except on the assumption that the Scriptures employed a popular
form of expression — a form understandable by the vulgar, but which
was not necessarily and rigorously true to the facts.
x6i7] LETTER TO CASTELLI 151
men of those truths which are necessary for their
salvation, and which being far above man's under-
standing cannot be made credible by any learning,
or by any other means than revelation. But that
the same God who has endowed us with senses,
reason, and understanding, does not permit us to
use them, and desires to acquaint us in another way
with such knowledge as we are in a position to
acquire for ourselves by means of those faculties —
that, it seems to me I am not bound to believe,
especially concerning those sciences about which
the Holy Scriptures contain only small fragments
and varying explanations ; and this is precisely
the case with astronomy, of which there is so little
that the planets are not all enumerated, only the
sun and moon, and once or twice Venus under
the name of Lucifer. This, therefore, being
granted, I think that in discussing natural
phenomena we ought not to begin with texts
from Scripture, but with experiment and de-
monstration, for from the Divine Word Scripture
and Nature do alike proceed. And I can see that
that which experience sets before our eyes con-
cerning natural effects, or which demonstration
proves unto us, ought not upon any account to
be called in question, much less condemned, upon
the testimony of Scriptural texts, which may
(under their mere words) have meanings of a
contrary nature. ..."
The letter concludes with a long discussion of
Joshua's miracle, ending in a reductio ad absurdum.
Castelli, seeing nothing objectionable in this
letter, gave it a wide circulation in written copies.
But not so the enemies of Galileo, who eagerly
seized it as a weapon to be used against him.
They turned his emphatic opinion that the Scrip-
152 GATHERING STORMS [1612-
tures had no business in scientific controversy
into the reproach that he assailed the universal
authority of the Bible, and, referring to his
explanation of Joshua's miracle, they loudly
demanded that the Scriptures must be protected
from the arbitrary interpretations of profane lay-
men.
After some months of underhand agitation,
Father Caccini of the Dominican convent of San
Marco was the first to declare war openly, in a
sermon from the pulpit of Santa Maria Novella
in Florence. Preaching on the fourth Sunday
in Advent (December) 1614, an<i selecting as his
texts chap. x. vers. 12, 13, of Joshua, and chap. i.
ver. n, of Acts, he began with the words:
11 Ye men of Galilee ! why stand ye gazing
up into heaven ?" He asserted that Galileo's
doctrine of the earth's revolution round the
sun was irreconcilable with the holy Catholic
faith, since it contradicted several passages in
Scripture. He reminded his hearers that no one
was permitted to interpret the Bible in any other
sense than that adopted by the Fathers; he as
good as denounced Galileo's teachings as heretical ;
and wound up with a coarse attack on mathe-
maticians in general, whose science he called
an invention of the devil, and who should be
banished from all Christian states, since all
heresies proceeded from them. A preacher at the
Puomo (cathedral), a Jesuit strange to say, replied,
and undertook to show that Copernicus was right ;
that Galileo and his followers were good Catholics ;
and that Caccini and the Dominicans generally were
1617] DENOUNCED TO INQUISITION 153
ignorant fools! As may be imagined, this line
of argument added fuel to the fire, and the result was
a great commotion in Florence. This fierce attack
made Galileo lose patience ; he wished to publicly
resent the insults, but on the advice of friends
he kept quiet, and the storm subsided for a while.
The man who first brought Galileo's affairs
before the Inquisition (or the Holy Office) was
one Father Lorini, a friend of Caccini and a
member of the same convent This man was
Professor of Ecclesiastical History in Florence,
and was from the beginning of 1612 a ringleader
of all the local intrigues against Galileo. A copy
of the letter to Castelli had come into his
hands, and this, after Caccini's fierce sermon, he
sent to the Holy Office in Rome with an un-
signed denunciation, dated 5th February 1615,
and addressed to Cardinal Mellini, President of
the Congregation of the Index. This document
was most artfully drawn up ; too cowardly to
mention Galileo by name, as he knew him to
have friends at the Vatican, he denounces the
Galileists in general, "who maintain agreeably to
the doctrine of this man Ipernic, or whatever
they call him, that the earth moves and the
heavens stand still." "All the fathers," he goes
on, "of this devout convent of San Marco find
many passages in this letter which are suspicious
and presumptuous, as when it says (i) that many
expressions of Holy Scripture are indefinite;
(2) that in discussions about natural phenomena
the lowest place must be assigned to them ;
(3) that the commentators have often been mis-
154 GATHERING STORMS [Mis-
taken in their interpretations ; (4) that the
Scriptures should not be mixed with anything
but matters of religion ; (5) that in nature philo-
sophical and astronomical evidence is of more
value than Holy writ ; arid finally (6) that when
Joshua commanded the sun to stand still we
must only understand that the command was
addressed to the primum mobile, and not to the
sun " ; and so on, and so on.
In consequence of this denunciation the Holy
Office instituted a secret enquiry. As Lorini had
only sent a copy of the letter to Castelli, the
Inquisition took steps to gain possession of the
original, written and signed by Galileo, and wrote
(26th February 1615) to the Archbishop of Pisa
to procure the document "in a skilful manner."
But in this they were foiled ; Castelli no longer
possessed the letter, having returned it to Galileo,
and the latter, on being asked for it again,
supplied only a copy, unsigned and undated, and
which, moreover, he strictly enjoined Castelli not
to let out of his hands. Castelli accordingly read
the letter to Archbishop Bonciani (in presence of
several canons of his cathedral), who concealed
as well as he could his annoyance at the failure
of his scheme. So, Cardinal Mellini had to be
content with Lorini's copy of the incriminated
letter, which was submitted to the Councillor of
the Holy Office for his opinion. His report was
a colourless one : some passages were objectionable,
but, although at first sight they looked ill, they
were capable of being taken in a good sense,
and on the whole the document was not of that
i6i7] INQUISITION TAKES ACTION 155
nature that it could be said to deviate from
Catholic doctrine.
Meanwhile, Caccini, who had been transferred to
Rome, was summoned as one specially well-informed
about Galileo's teachings! His evidence was a
repetition of his sermon, mixed up with all the
tittle-tattle of Florence. After denouncing Galileo
and his works as Godless, he concluded, "at any
rate he is suspicious in religious matters, because
he belongs to a certain Accademia dei Lincei,
and corresponds with the Godless Fra Paolo
Sarpi at Venice, and with many Germans."
Galileo appears to have known nothing ac-
curately of these proceedings. He could only
learn that some Dominican monks were making
use of his letter to Castelli in order to effect
the condemnation of the Copernican doctrines.
Fearing that the copy on which they relied at
Rome might have been tampered with, he sent a
correct copy, on i6th February 1615, to his friend
and old pupil, Mgr. Piero Dini, with a request that
he would forward it to Father Griemberger, and
perhaps also to Cardinal Bellarmine. He added
that he had written to Castelli currente calamo^
and that he had since made many researches
into the matters therein discussed, which he was
embodying in a larger treatise — a copy of which
when finished he would send.1 Mgr. Dini in
reply, and apparently as the result of a con-
ference with Cardinals del Monte and Bellarmine,
urged Galileo to hurry on his writing, but at the
1 This was his celebrated letter or Apology addressed to the
Grand Duchess Cristina.
156 GATHERING STORMS [1612-
same time advised caution, to avoid theology,
and to confine himself to mathematics and physics.
" Write freely," he said, "but be careful to keep
outside the sacristy." Mgr, Ciampoli, another
(Florentine) disciple then residing in Rome, writ-
ing 28th February, conveyed the assurance of
Cardinal Maffeo Barberini that he had Galileo's
interests at heart, and that it would be more
prudent not to go beyond his role of Professor
of Mathematics, as the theologians claimed to
have the sole right of explaining the Scriptures.
Prince Cesi gave him much the same advice,
and added his belief that any deliberate formu-
lation of the, Copernican doctrine would only end
in its prohibition, and the suppression of his book.
This excellent advice unfortunately came too late,
for, as we see, the Inquisition was already moving ;
and even if Galileo had never written his letter
to the Grand Duchess, or had written it in the
way suggested, his enemies already had grounds
enough to go upon.
Although down to the end of June 1615,
Galileo received reassuring letters from Rome,
that there was nothing in progress at which he
need be at all disconcerted, yet, so well did the
Inquisition keep its secret, it was all the time
laying its plans to entrap him.1
Meanwhile, about the middle of 1615, Galileo
1 From 2oth June 1615, to Galileo's visit to Rome in the
following December, but two letters from his Roman friends are
extant, which, considering the anxious period covered, is remarkable.
Von Gebler thinks it probable that Galileo destroyed the corre-
spondence out of regard for his friends. " Galileo and the Roman
Curia," London, 1879, P» 64.
x6i7] LETTER TO GRAND DUCHESS 157
completed his great apologetic treatise in the form
of a letter to the Dowager Grand Duchess Cristina,
in which he defines at great length his position as
a natural philosopher, and as a sincere member of
the Church of Rome. It is, naturally, an amplifica-
tion of his letter to Castelli already quoted, and
need not, therefore, be more fully noticed.1 The
pith of it is contained in the saying of Cardinal
Baronius, which the author quotes : —
"The Holy Spirit intended to teach us in the
Bible how to go to heaven, not how the heavens
go-"
The concluding passages may be quoted as
follows : —
" Again, to command professors of astronomy
that they must themselves see to confuting their
own observations and demonstrations is to ask
the impossible, for it is not only to command
them not to see what they do see, and not to
understand what they do understand, but to seek
for and to find the contrary. I would entreat
these wise and prudent Fathers to consider
diligently the difference between opinionative
and demonstrative doctrines, to the end that
they may assure themselves that it is not in the
power of professors of demonstrative sciences to
change their opinions at pleasure, and adopt first
one side and then the other ; that there is a great
difference between ordering a mathematician, or a
philosopher, as to what opinion to hold, and doing
the same with a merchant, or a lawyer, since
1 Von Gebler gives an excellent rlsunU^ at pp. 64-70 of " Galileo
and the Roman Curia." The Apology and the letter to Castelli were
not published until after the trial of 1633, and then apparently with the
object of showing the learned world how unjust his condemnation was.
158 GATHERING STORMS [i6«-
demonstrated conclusions touching things of nature
and of the heavens cannot be changed with the
same facility as opinions touching what is lawful,
or not, in a contract, bargain, or bill of ex-
change.
" Therefore, let such people apply themselves
to the study of the arguments of Copernicus and
others, and leave the condemning of them as
erroneous and heretical to whom it belongeth.
Yet, as to this latter, they must not hope to find
such rash and precipitate determinations in the
wary Holy Fathers, or in the absolute wisdom of
him who cannot err (the Pope), as those into
which they suffer themselves to be hurried by
some particular affection or interest of their own.
In these, and such like opinions which are not
directly articles of faith, certainly no man doubts
that his Holiness hath always an absolute power
of admitting or condemning them ; but it is not
in the power of any creature to make them to be
true or false, otherwise than as, in fact, they are."
This letter, notwithstanding its moderate and
even deprecating tone, was, of course, a fresh
weapon against him, and his enemies denounced
him more noisily than ever. Ominous reports
began to circulate, but still Galileo could not learn
any thing more definite than that something was
brewing against him, and that the Copernican
theory would probably be interdicted. Thinking
that he could best combat these intrigues by
going to Rome, he set out early in December
1615, provided with cofdial letters from the Grand
Duke to his Ambassador Guicciardini, to Cardinals
del Monte and Orsini, and others. His enemies
spread about that this step did not originate with
1617] THIRD VISIT TO ROME 159
himself, but was the result of a direct citation.
This, however, is abundantly disproved by the
Grand Dukes letters in which he distinctly says
that Galileo goes to Rome of his own accord
(spontaneamente).
His reception by the authorities seemed to be
cordial, but he quickly discovered that a zealous
agitation was going on, not only against his teach-
ings but against himself. However, he was con-
fident that he should very soon destroy the traps
of his enemies, and justify himself in a way that
would bring discredit upon themselves. Judging
from a letter of some days later, 23rd January 1616,
to Secretary Picchena, he had not found his defence
so easy as he anticipated. He says : —
"My business is far more difficult and takes
much longer, owing to untoward circumstances,
than the nature of it would require. I cannot
communicate directly with those persons with whom
I have to negotiate — partly to avoid doing injury
to any of my friends, and partly because they can-
not communicate anything to me without running
the risk of grave censure. So I am compelled
with much pains and caution to seek out third
persons who, without even knowing my object,
may serve as mediators with the principals. . . .
I have also to set down some points in writing,
and to cause that they shall come privately into
the hands of those whom I wish to see them."
At length Galileo succeeded, as he thought,
in freeing himself personally from all accusations
and in refuting the slanders of Caccini and his
confederates. The monk paid him a long visit,
humbly begged pardon for his previous conduct,
160 GATHERING STORMS [1612-
and offered any satisfaction in his power. But
Galileo rightly gauged his sincerity, in a letter to
Picchena of aoth February, in which he says : —
" I perceived not only his great ignorance, but
that he has a mind void of charity and full of
venom."
Lorini excused himself in a still more contemptible
manner. He coolly admitted that he knew nothing
and wanted to know nothing of the merits of the
controversy. He only acted "for the sake of
saying something, lest men should think that the
Dominican Fathers were asleep or dead."
But by adjusting his own difficulties Galileo
had performed only half the task he set himself.
The grander part of it, viz. the preservation of the
Copernican doctrines from the interdict of the
Church, had yet to be accomplished.
" My business, so far as it concerns myself, is
completed. All the exalted personages who have
been conducting it have told me so plainly and
in a most obliging manner, and have assured me
that people are fully convinced of my uprightness
and honour, and of the devilish malice and injustice
of my persecutors. As far, therefore, as this matter
is concerned I might return home without delay ;
but there is a question connected with my case,
which does not concern myself alone, but all those
who during the last eighty years have advocated,
in printed works and private letters, in public
lectures and private conversations, a certain theory
not unknown to your Excellency, on which they
are now proposing to pronounce judgment. In
the hope that my assistance may be of use in this
matter, so far as a knowledge of those truths is
i6i7] ADVOCATES TOLERATION 161
concerned which are proved by the science to
which I have devoted myself, I as a zealous and
Catholic Christian neither can nor ought to with-
hold that assistance which my knowledge affords ;
and this part of the business keeps me fully em-
ployed."— (Letter to Picchena, 6th February 1616).
As illustrating his manner of assisting the
Copernican cause, the following letter from Antonio
Querengo to Cardinal d'Este, 2oth January 1616, is
interesting.
"Your Reverence1 would be delighted with
Galileo if you heard him holding forth, as he often
does, in the midst of fifteen or twenty, all violently
attacking him, sometimes in one house, sometimes
in another. But he is armed after such fashion
that he laughs all of them to scorn ; and even if
the novelty of his opinions prevents entire per-
suasion, at least it convicts of emptiness most of
the arguments with which his adversaries endeavour
to overwhelm him. He was particularly admirable
on Monday last, in the house of Signor Federigo
Ghisilieri ; and what especially pleased me was
that, before replying to the contrary arguments,
he amplified and enforced them with new grounds
of great plausibility, so as to leave his adversaries
in a more ridiculou3 plight when he afterwards
overturned them all."
This entering the lists in the cause of Coperni-
canism was, to say the least, magnanimous, and
Galileo was entitled as no other was to appear
as an advocate; but unfortunately his warm and,
perhaps, too solicitous efforts in the cause had a
1 The title Eminence was pot conferred on Cardinals until twelve
years later. .
Ir
1 62 BEFORE THE INQUISITION [1612-
result precisely opposite to the one he intended.
The fact is, Galileo's too sanguine temperament
deceived him woefully as to the true course of these
transactions, as we shall also find to be the case
in his second and more terrible encounter with the
Holy Office ; for, a few days after he thought his
own affairs so satisfactorily settled that he could
if he chose return to Florence in triumph, a bolt
shot out of the blue which paralysed him, and
spread consternation among his friends. Without
any warning (for such was the manner of the In-
quisition), on i pth February, the Qualifiers, or
official experts, of the Holy Office were called on
for an opinion on the following propositions ex-
tracted from Galileo's work on the Sun-spots :— *-
(1) The sun is the centre of the world, and,
therefore, immovable from its place.
(2) The earth is not the centre of the world,
and is not immovable, but moves, and
also with a diurnal motion.
On the 24th February the Qualifiers reported : —
(1) The first proposition is unanimously de-
clared to be false and absurd philosophi-
cally, and formally heretical, inasmuch
as it expressly contradicts the doctrines
of Holy Scripture in many passages,
both if taken in their literal meaning and
according to the interpretation of the
Holy Fathers and learned theologians.
(2) The second proposition is declared unani-
mously to deserve the like censure (as
the first) in philosophy, and, as regards
its theological aspect, to be at least
erroneous in faith.
1617] BELLARMINE'S ADMONITION 163
On 25th February, Cardinal Mellini reported
this opinion to the Holy Office, and, as the result,
Cardinal Bellarmine was directed "to summon
before him the said Galileo, and admonish him
to abandon the said opinion ; and in case of refusal
the Commissary is to intimate to him, before a
notary and witnesses, a command to abstain alto-
gether from teaching or defending the said opinion,
and even from discussing it ; and if he do not
acquiesce therein he is to be imprisoned."
This admonition was administered on the next
day, as appears from the following minute : —
" Friday, the 26th. At the palace, the usual
residence of the Lord Cardinal Bellarmine, the said
Galileo, having been summoned and brought before
the said Lord Cardinal, was, in presence of the
Most Revd. Michelangelo Seghizzi, of the order
of preachers, Commissary - General of the Holy
Office, warned by the said Lord Cardinal of the
error of the aforesaid opinion and admonished to
abandon it. And immediately thereafter before me
and before witnesses, the Lord Cardinal Bellarmine
being still present, the said Galileo was by the
said Commissary commanded and enjoined, in the
name of his Holiness the Pope, and the whole
Congregation of the Holy Office, to relinquish
altogether the said opinion, that the ' sun is the
centre of the world, and immovable, and that the
earth moves; nor henceforth to hold, teach, or
defend it in any way whatsoever, verbally or in
writing; otherwise proceedings would be taken
against him in the Holy Office; which injunction
the said Galileo acquiesced in and promised to obey.
" Done at Rome, in the palace aforesaid, in the
presence of Badino Nores, of Nicosia, in the
Kingdom of Cyprus, and Augustino Mongardo,
164 BEFORE THE INQUISITION [1612-
from a place in the abbacy of Rose, in the diocese
of Politianeti, inmates of the said Cardinal's house,
witnesses."1
Here the process ended so far as Galileo was
concerned, but it was followed up a few days later
by an edict prohibiting and suspending certain
writings, amongst them the book of Copernicus.
This decree runs as follows : —
"March 3, 1616. The Lord Cardinal Bellar-
mine having reported that Galileo Galilei, mathe-
matician, had, in terms of the order of the Holy
Congregation, been admonished to abandon the
opinion he has hitherto held, and had acquiesced
therein ; and the decree of the Congregation of the
Index having been presented, prohibiting and sus-
pending respectively the writings of Nicolas
Copernicus on 'The Revolutions of the Celestial
Orbs'; of Diego di Zuniga 'On Job'; and of
Paolo Antonio Foscarini, Carmelite friar ; his Holi-
ness has ordered this edict of prohibition and sus-
pension respectively to be published as follows : —
"March 5, 1616 [after preamble]. And
whereas it has also come to the knowledge of the
said Congregation that the Pythagorean doctrine
(which is false and altogether opposed to Holy
Scripture) of the motion of the earth and the
quiescence of the sun, which is also taught by
Nicolas Copernicus in his 'Revolutions of the
Celestial Orbs/ and by Diego di Zuniga in his
book 'On Job/ is now being spread abroad and
accepted by many — as may be seen from a certain
letter of a Carmelite father, wherein he attempts to
show that the aforesaid doctrine is consonant with
1 It should be noted that this minute bears no signature, neither of
Cardinal, Commissary, and witnesses, nor of Galileo.
1617] COPERNICAN DOCTRINE 165
truth and is. not opposed to Holy Scripture.
Therefore, in order that this opinion may not
insinuate itself any further ^ to the prejudice of
Catholic truth, the Holy Congregation has decreed
that the said works of Nicolas Copernicus and
Diego di Zuniga be suspended until they be cor-
rected ; that the book of the Carmelite, Foscarini,
be altogether prohibited and condemned ; and that
all other books in which the same doctrine is taught
be likewise prohibited."1
It should be noted that the book of Copernicus
was only suspended until corrected. These "cor-
rections," which were of the most trivial character,
were carried out under the supervision of Cardinal
Gaetani in 1620, after which it would be allowable
to read the book, and its doctrines could be held by
the faithful, "ex hypotkesi, and without affirming
anything." *
1 The Diego di Zuniga mentioned in this decree was a professor
in Salamanca, who in 1584 adopted the Copernican theory as not
opposed to Scripture. Foscarini's letter of 6th January 1615 was
addressed to the General of his Order, and in it he accepts Galileo's
discoveries as proof of the truth of the Copernican theory. One
passage is worth quoting : —
" Holy Church with its visible head, the Pope, assisted by the
Holy Spirit, cannot err in questions of faith, but it can err in its
judgments of practical questions, in philosophic speculations, and
other matters which are not concerned with our salvation."
This was precisely Galileo's contention throughout all these
polemics.
8 They consisted in the omission of a few passages in the preface,
and in the alteration of certain words in the text, as, notably, the word
" star " when applied to the earth. Also such words as stated or im-
plied that the hypothesis was true were altered so as to make it one of
mathematics pure and simple, and without any pretension to reality.
As no one cared to bring out an edition of Copernicus in this
bowdlerised state, his book remained prohibited in Italy for over
two hundred years. '
166 BEFORE THE INQUISITION [1612-
Galileo remained in Rome for nearly three
months after the promulgation of the decree of 5th
March. His enemies spread the report that he had
been obliged to recant formally and to abjure his
opinions. It would be easy to show his friends
how grossly exaggerated was this report; but in
order the better to confute these calumnies, and
to guard against them in the future, he obtained
a paper from Cardinal Bellarmine, stating the facts
as follows : —
" We, Robert Cardinal Bellarmine, having heard
that it is calumniously reported that Signor Galileo
Galilei has in our hand abjured, and has also been
punished with salutary penance, and being requested
to state the truth as to this, declare that the said
Signor Galileo Galilei has not abjured, either in our
hand or the hand of any other person here in Rome,
or anywhere else, so far as we know, any opinion
or doctrine held by him ; neither has any salutary
penance been imposed upon him, but only the
declaration made by the Holy Father, and pub-
lished by the sacred Congregation of the Index,
has been intimated to him, wherein it is set forth
that the doctrine attributed to Copernicus — that
the earth moves round the sun, and that the sun
is stationary in the centre of the world, and does
not move from east to west — is contrary to the
Holy Scriptures, and therefore cannot be defended
or held.
" In witness whereof we have written and sub-
scribed these presents with our hand this 26th
day of May 1616."
We have been careful to give the principal
documents connected with this momentous process,
for upon them, and especially upon the unsigned
i6i7] ADMONITION EXAMINED 167
minute of 26th February, hinge the charges on
which Galileo was brought before the Inquisition
in 1633, and his defence. Von Gebler and other
critical historians in recent times conclude that the
minute of 26th February is spurious — concocted
by enemies, and placed among the acts of the
case with the hope of being useful at some future
time. Von Gebler says : —
"In common with other critics, we ourselves
had long been of opinion that this note originated
not in 1616 but in 1632, in order to legalise the
trial of Galileo begun in the latter year. But
after repeatedly and very carefully examining the
original papers, preserved among the Papal archives,
we were compelled to acknowledge that the material
nature of the document entirely excludes the sus-
picion of a subsequent fabrication. The note was
not fabricated in 1632, but, probably, in 1616.
With subtle and perfidious calculation a lie was
then entered, which was to have the most mo-
mentous consequences for the great astronomer."1
Von Gebler discusses this question at great
length, but he does not convince us that his
view is the right one. That the document is not
a forgery of the year 1616 seems to us sufficiently
proved by the facts that it lay buried for sixteen
years, its existence not even hinted at, and that
it was only accidentally discovered late in 1632, to
the surprise of every one. Were it a forgery with
a purpose, its authors would be sure to bring it
up in the fierce discussions over the comets of
1618-19, or over Galileo's " II Saggiatore" of 1623,
1 "Galileo and the Roman Curia," p. 90.
168 BEFORE THE INQUISITION [1612-
which contained " heretical" teaching, and which,
as we shall see, was a b&te noire of the Jesuits,
or, finally, immediately after the publication of his
Dialogues early in 1632. That Galileo himself in
after years said it was a forgery — part of a deep-
laid plan to crush him — we can excuse as the
hasty expression of an outraged man writhing
under persecution.
The learned Professor Favaro, who has for the
last twenty-five years made a study of Galileo's
life and works, takes the opposite view to Von
Gebler. He also has very carefully examined
the Vatican MSS., and can come to no other
conclusion than that the document in question is
genuine and bond fide ; that it was drawn up at
the time, and put in its place, as a record of what
actually happened, and with no sort of arriere pensde.
Between these two extreme opinions it seems
to us that a middle view will more nearly corre-
spond with the facts, and with the subsequent
conduct of Galileo and his enemies. We accept
Professor Favaro's view, but with this qualifica-
tion, that the document is true to the letter, but
not to the spirit of the proceedings of 26th
February. To our mind the admonition by the
Cardinal was all that was intended (see documents
above, dated 3rd March and 26th May). The
further interference of the Commissary - General
was due to trSp de zele, or fussiness, on his part,
and may have arisen in this way. Imagine the
case of a culprit brought up for sentence on his
first offence before a magistrate and a fussy or over-
zealous clerk. The culprit, expecting (as we know
i6i7] ADMONITION, ITS REAL EXTENT 169
Galileo did) something very mild, is surprised at
being admonished to abandon his opinions ; he
gives expression to this surprise by word or look
— seems not to comprehend. "What," he then
exclaims, "must I abandon them altogether? Can
I not even dis " " No, no," cuts in the clerk.
"You are commanded to abstain altogether from
teaching or defending, and even from discussing
them in any way whatever, and if you do not
acquiesce you will be imprisoned." The culprit,
amazed, says no more, bows, and retires crestfallen,
noting only the Cardinal's admonition, and disre-
garding the Commissary's remark altogether, or
regarding it as no part of the decision, as merely
a repetition in other and stronger words of the
Cardinal's simple admonition.
That this is the view which Cardinal Bellarmine
and the Holy Office took of the proceedings is clear
from the wording of the documents dated 26th May
and 3rd March, in which the interpolation of the
Commissary-General is ignored ; and that it is the
view which Galileo took, his after conduct will
show. Then, the facts that his writings are not
mentioned in the decree of 5th March, and that
the book of Copernicus is only suspended pending
correction, go to show that the Copernican doctrines
might still be held and discussed in a hypothetical
way, and by Galileo as well as by others. In
fact, it was so understood at the time, and the
trivial alterations afterwards made in the book of
Copernicus (as above stated) confirmed this idea,1
Galileo having taken his admonition was ad-
1 See more on this subject p, 275 infra.
i;o BEFORE THE INQUISITION [1612-
mitted to an audience of the Pope, Paul V., on
nth March, which lasted three-quarters of an
hour. He took occasion to refer to the events
just concluded, and expressed his fears of never-
ending persecution; but Paul V. consoled him
with the assurance that he need have no fear ; that
he was held in so much esteem by himself and the
whole Congregation, that they would not listen to
any calumnies ; and that, as long as he occupied
the chair of St Peter, Galileo might rest assured
that he was safe from all danger,
On the eve of Galileo's departure from Rome,
Cardinal del Monte wrote to the Grand Duke
"to bear witness that he was leaving with the
best reputation, and the approval of all who have
had transactions with him, for it has been made
manifest how unjust have been the calumnies of
his enemies/'1 However, the Grand Duke's
Ambassador, Guicciardini, told a different story,
and, perhaps, a truer one. All along he had tried
to get Galileo recalled to Florence ; his last letter
of 1 3th May may be cited as a specimen of his
previous despatches.
"Galileo," he says, " seems disposed to emulate
the monks in obstinacy, and to contend with
personages whom you cannot attack without ruin
to yourself. It may any moment be heard in
Florence that he has stumbled into some abyss
or other. However, the heat will probably drive
him from Rome before long, and that will be the
best thing that can happen to him."
Cosimo IL, alarmed by these gloomy reports
1 The letter is dated 4th June 1616.
i6i7] ON THE TIDES 171
of his ambassador, at last issued orders for Galileo's
return, and on 23rd May Picchena wrote : —
" You have had enough of monkish persecutions
and ought to know by this what the flavour of them
is. His Highness fears that your longer stay in
Rome may involve you in fresh difficulties, and
would therefore be glad if (as you have so
far come honourably out of the affair) you would
not tease the sleeping dog any more, and would
return here as soon as possible. There are rumours
flying about which we do not like, and the monks
are all powerful. I, your servant, must not fail
to warn you, and to inform you, as in duty bound,
of the wishes of our Master, wherewith I kiss your
hand/'
Galileo complied with this order with the least
possible delay, and set out on his homeward
journey on 4th June 1616.
Amidst all the cares and worries of this visit
Galileo's teeming mind was busy, as always, with
abstruse questions of science. He had not been
many days in Rome when a suggestion from
Cardinal Orsini was enough to start him on a
treatise on the Flux and Reflux of the Tides, written,
as was customary in those days, in the form of a
letter to the Cardinal, and dated 8th January 1616.
We have seen from his letter to Vinta, of 7th May
1610, in which he enumerates his contemplated
works, that a treatise on the Tides was one of
them. Galileo's theory is that the tides are the
visible effects of the terrestrial double movement,
since they are the combined result of (i) the earth's
daily rotation, and (2) the inequality of the absolute
velocities through space of the various parts of the
1/2 RETURN TO FLORENCE [1612-
earth's surface. We now know this to be erroneous,
but it required a farther advance in the science of
motion than had been obtained even at a much
later date to point out its insufficiency.
The problem of the tides had been from the
earliest ages one of the most difficult, and the
solutions advanced by different enquirers show that
it long deserved the name given to it — "the grave
of human curiosity." Some supposed the rise of
the waters to be due to the influx of rivers into the
sea ; others compared the earth to a huge animal,
whose respiration caused the tides ; a third theory
supposed the existence of subterraneous fires which
periodically made the sea to boil up ; while others
again attributed this boiling effect to changes of
temperature in the sun and moon, or to variations
in the amount of their light.
Galileo's ideas on the subject are given at great
length in his treatise, and are developed and re-
inforced in his Dialogues on the Two Systems of
the World, where they occupy the whole of the
fourth "Day."
Almost as soon as he had discovered the moons
of Jupiter in 1610, Galileo began a work the
difficulty and fatigue of which he has himself
indicated by comparing it with the labours of Atlas.
It was a series of observations on the satellites with
a view of drawing up tables so as to be able to
predict all particulars of their situations, relations,
and eclipses ; and thus to have the means of
determining at any hour of the night the longitude
of the place of observation. In the midst of
his numerous occupations and annoyances of all
i6ir] FINDING LONGITUDES 173
sorts, he steadily worked at this laborious
task.1
After six years' observation and calculation of
Jupiter's satellites, and confident of the practica-
bility of his method, Galileo in 1616 opened a
correspondence on the subject with the Court of
Spain.2 The reader will understand how the
satellites were to be used, if their movements
could be so nicely ascertained as to enable
Galileo at Florence to predict the exact times
at which any remarkable configurations, such as
an eclipse, would occur. A mariner, who should
observe the same eclipse and compare the local time
(which he might know by setting his watch by
the sun on the previous noon) with the time
mentioned in the tables, would, from the difference
between the two, have data for calculating his
position. Thus, as the earth rotates through
360° of longitude in 24 hours, or 15° per hour,
the difference between the two times multiplied
1 A ready method of finding longitudes at sea had long been an
object of search with all the maritime powers of Europe. In 1598
the Spanish Government offered a prize of 1000 crowns for the
discovery of such a method. The Dutch followed the example of
Philip III. of Spain ; the French Government followed with a prize of
100,000 livres ; and the French Academy established an annual
prize for those who made the most useful discoveries connected with
the subject. In 1714 the English Parliament appointed a committee
to consider the question, when an Act was passed gran ting ^10,000 for
a method of finding the longitude to a degree, or 60 geographical
miles ; £i 5,000, to 40 miles ; and ^20,000, to 30 miles. At length,
in 1736, the problem was solved in the ship's chronometer of John
Harrison, a village carpenter of Faulby, Yorkshire, which did not vary
two minutes in the course of a year.
2 In 1612 Galileo first announced his method to the Spanish
Government, through the medium of the Tuscan Ambassador, but
no details or explanations were then given.
1/4 RETURN TO FLORENCE [1612-
by 15 will give the degrees of longitude by
which the ship is distant from the meridian of
Florence.
Our moon had already been used for the
same purpose; it changes its position amongst
the stars continuously, and if at specified times
throughout the day that position can be predicted,
it is available as a signal of the exact time at
Florence, or wherever the tables are calculated
for. Using his watch as already explained, the
mariner would then be able to determine his
longitude. But in the beginning of the seven-
teenth century, tables predicting the position of
the moon could only have been very rough.
And its very proximity to the earth is a dis-
advantage; for an observer on the high seas
would get a slightly different view of it from
that expected at Florence, and this apparent
difference in the moon's position amongst the
stars, as seen from the two different places,
would have to be allowed for.
This complication would be avoided if Jupiter
were made use of as a time-recorder instead of
the moon. The great distance of Jupiter, the
frequency of the eclipses (more than 1000 yearly),
and (it was expected) their suddenness, seemed
to promise success to Galileo's method. It was,
however, beset by practical difficulties. First,
there was the difficulty of observing such small
objects as Jupiter's moons from the deck of a
ship ; and secondly and greater, accurate time-
keepers were necessary, but were not available ;
for, although we have just spoken of watches.
i6i7] LONGITUDE METHODS 175
the watches and clocks of those days were not
such as could be relied on even for the few
hours between the time of observing the sun
at noon and the subsequent observation of
Jupiter.
Galileo thoroughly appreciated these difficulties,
and to obviate the first he proposed to use a
binocular telescope with a magnifying power of
10 diameters. This he called the Celatone or
Testiera> as the apparatus resembled a diving-
helmet with telescopes fixed in the apertures for
the eyes.1 He also had made in the arsenal at
Pisa a kind of boat or chair, floating in another
boat filled with water or oil, in which the observer
would be protected from all motion.2 To remedy
the second difficulty he had hopes of utilising his
early observations on the pendulum and applying
it as a measurer of time. But it was many years
1 The above reference to the Celatone is based on a letter of
Galileo to Orso d'Eki, without date but circa June 1617. The
passage is vague and evidently with a purpose, as he wished the
" invention" to be kept secret. Professor Favaro has since drawn my
attention to another of Galileo's letters, dated 6th June 1637, in which
we find the apparatus for the first time clearly described. " I made,"
he says, " for the use of our navy a kind of cap, fitted to the head of
the observer, and supporting a telescope in such a way that it always
points in the same direction as the tree eye, so that an object viewed
by the latter is also seen by the other eye through the telescope. A
similar apparatus could be made and fixed on the shoulders and chest
of the observer, to support a telescope of a power sufficient to show
the satellites of Jupiter, and adjustable as in the case of the Celatone.
When, then, the free eye is turned towards Jupiter the other eye sees
through the telescope not only the planet but its satellites." From
this it is clear that Galileo did not propose a binocular telescope as
has hitherto been supposed, but simply a new way of using an ordinary
one.
2 Galileo's letter to Picchena, 22nd March 1617. In this way he
is said to have made satisfactory observations in the harbour of
Leghorn, while the ship was tossed about by a strong wind.
i;6 RETURN TO FLORENCE [1612-
later before steps were taken to give his ideas a
practical form.
During his visit to Rome (in 1616) Galileo
disclosed his longitude proposals to the Conte
di Lemos, the Spanish Viceroy of Naples, who
had been President of the Council of the Spanish
Indies, and was fully aware of the importance of
the matter. Negotiations were opened with the
Spanish Minister at Rome, and the Grand Duke
of Tuscany, Cosimo II., instructed his ambassador
at Madrid to conduct the business with the
Spanish Court. Galileo entered warmly into
these negotiations, as may be gathered from the
following extract from a letter to the Tuscan
Minister in Spain.
"Your Excellency may well believe that if
this were an undertaking which I could conclude
by myself, I would never have gone about
begging favours from others. But in my study
there are neither seas, nor Indies, nor islands,
ports, shoals, and ships, for which reason I am
compelled to share the enterprise with great
personages, and to fatigue myself to procure the
acceptance of that which ought with eagerness
to be asked of me. But I console myself with
the reflection that I am not singular in this, since
it commonly happens that, with the exception of
a little reputation (and that too often obscured
and blackened by envy), the least part of the
advantage falls to the share of inventors of things
which bring gain (in honours and riches) to
others. However, I will never cease to do
everything in my power to forward this matter.
I am ready to leave here all my comforts,
country, family, friends, and to cross over into
i6i7] LONGITUDE NEGOTIATIONS 177
Spain, to stay as long as I may be wanted in
Seville, or Lisbon, or wherever it may be
convenient, in order to implant the knowledge of
my method, provided only that due assistance
and diligence be not wanting on the part of
those who are to receive it."
But he could not, with all his enthusiasm,
bring the Spanish Court to a decision. His
proposals were discussed in Council, favourable
reports were made to the King, but his Majesty
could not make up his mind to spend money on
experiments which he thought might prove as
fallacious as others that had been tried before
with the same object. The negotiation dragged
on during 1617 and part of 1618 and then
languished, and, although occasionally renewed
during the next ten or twelve years (in 1620,
1629, and 1632), was never brought to a satisfactory
issue.
Galileo's ' disappointment was in some degree
mitigated later on by his own Sovereign taking
up the method for use in the Tuscan Navy. Its
application, however, has proved to be beset with
so many difficulties that the method has fallen
into disuse. The unsteadiness of the observer
at sea cannot be overcome, and is more serious
in an observation of the required nature than in
the measurement of the moon's distance from a
star. Accordingly the method is now one of
historic interest only.
M
CHAPTER IX
GALILEO IN FLORENCE
1617-1624
FOR a long time after his return to Florence in
June 1616, Galileo's health had been very indifferent.
A complication of his old maladies, aggravated by
long fits of hypochondria, left him little time or
taste for work, and sadly interrupted his corre-
spondence. His old friend Sagredo often advised
him to take his ease and be content with the
laurels he had already won. " Philosophise," he
used to say, "comfortably in your bed and
leave the stars alone. Let fools be fools, let the
ignorant plume themselves on their ignorance.
Why should you court martyrdom for the sake of
winning them from their folly? It is not given
to every one to be of the number of the elect. I
believe the universe was made for my service, not
I for the universe. Live as I do and you will be
happy." This, indeed, was the burden of Sagredo's
letters from the time his friend quitted Padua in
1610 up to his own death on 5th March 1620.
But Galileo had not the epicurean temperament
of his friend. Speculation and experiment were as
necessary to him as food and air ; yet from these
178
1617-1624] DESPONDENCY 179
he was now practically debarred by the Papal pro-
hibition of 26th February. How could he resume
his old work, or begin any new one ? The Coperni-
can theory of the world was the basis of all his
work. Its acceptance and application were for-
bidden him, and the general permission to employ
it as a working hypothesis was a mockery. Can
we wonder then at the fits of melancholy which
frequently oppressed him. Yet inaction to a man
of his temperament was intolerable; he must be
doing something ; he was fond of gardening, but
he could not be always digging, and weeding, and
pruning. He must be doing something else; he
could not write for publication, but he could at least
commune with his intimate friends ; and so, for some
years he poured out his thoughts in long private
letters, copies of which were circulated amongst the
learned men of Europe. Unfortunately, few of
these are now extant ; but amongst these few there
is one which deserves notice, as it shows how in-
tolerable the writer felt his position to be. It is
also interesting as a specimen of the keen sarcasm
of which he was a master. During his stay at
Rome, as we have seen, he wrote a treatise on the
tides. Now, on 23rd May 1618, he sent .a copy of
this to the Archduke Leopold of Austria; but as
since it was written the proceedings culminating in
the decree of 5th March 1616 had taken place,
Galileo added the following accompaniment : —
"With this I send a treatise on the causes of
the tides, which I wrote more than two years ago,
at the suggestion of his Reverence Cardinal Orsini
in Rome, and at the time when the theologians
i8o GALILEO IN FLORENCE [1617-
were thinking of prohibiting the book of Copernicus
and the doctrine enunciated therein of the motion
of the earth, which I held to be true until it pleased
those gentlemen to prohibit the work and to declare
that opinion to be false and contrary to Scripture.
Now, knowing as I do that it behoves us to obey
the decisions of the authorities and to believe them,
since they are guided by a higher insight than any
to which my humble mind can of itself attain, I
consider this treatise which I send you merely to
be a poetical conceit or a dream, and desire that
your Highness may take it as such, inasmuch as it
is based on the double motion of the earth, and,
indeed, contains one of the arguments which I have
adduced in confirmation of it. But even poets
sometimes attach a value to one or other of their
fantasies, and I likewise attach some value to this
fancy of mine. Now, having written this treatise
and having shown it to the Cardinal above
mentioned and a few others, I have also let a few
exalted personages have copies, in order that,
in case any one not belonging to our Church should
try to appropriate my curious fancy (as has
happened to me with many of my discoveries),
these personages, being above all suspicion, may be
able to bear witness that it was I who first dreamed
of this chimera. What I now send is but a fugitive
performance. It was written in haste and in the
expectation that the work of Copernicus would not
be condemned as erroneous eighty years after its
publication, I had intended at my convenience and
in quiet to have gone more particularly into this
subject, to have added more proofs, to have
arranged the whole anew, and to have put it into
a better form. But a voice from heaven has
aroused me and dissolved all my confused and
tangled fantasies in mist! May therefore your
Highness graciously accept it, ill-arranged as it is ;
1 624] THE COMETS OF 1618 181
and if Divine love ever grants that I may be in a
position to exert myself a little, your Highness may
expect something more solid and real from me."
In August 1618, three comets appeared in the
heavens, and the brilliant one in the constellation
of the Scorpion — one of the most splendid of
modern times — especially attracted the attention
of astronomers. Although this was visible until
January 1619, Galileo had little opportunity of
observing it, as he was confined to bed nearly the
whole time by severe illness.1 However, we may
suppose with Viviani that he was able to observe a
little, but, certainly, he reflected much, and, as soon
as he was able, he communicated his views to his
friends, amongst others to the above-mentioned
Archduke Leopold, who, being in Florence on a
visit, came to see him.
His views were published about the middle of
1619, through the medium of Mario Guiducci, a
Florentine disciple.2 He did not consider comets to
be really heavenly bodies, analogous to the planets
as was currently supposed, but only atmospheric
phenomena — columns of vapour which rise from the
earth to a great height, far beyond the moon, and be-
come temporarily visible by refraction of the sun's
rays. In fact, he classed comets in the same category
as rainbows and mock suns. Referring to some
proposed parallax measurements of the comets,
1 During great part of the years 1617 and 1618, Galileo was ill or
ailing. In June 1618 he made a pilgrimage to Loreto, "The Mecca
of Christendom," in the hope that a change of air and habits might
free him from the fevers which molested him-
2 "Discorso delle Comete di Mario Guiducci," etc., Florence,
1619.
1 82 GALILEO IN FLORENCE [1617-
he pointed out the difference in this respect
between a fixed object, the distance of which
may be calculated by two angular observations
at a known distance apart, and atmospheric
appearances like rainbows which are simul-
taneously formed in different drops of water
for each spectator, so that two observers in
different places are, in fact, viewing different
objects. He then warns astronomers not to
engage with too much warmth in a discussion
on the distance of comets before they assure
themselves to which of these two classes of
phenomena they are to be referred. The
remark is in itself perfectly just, although the
opinion which occasioned it is now known to
be erroneous ; but it is questionable whether the
few observations which up to that time had been
made upon comets were sufficient to justify the
bitter censures which have been cast on Galileo
on account of it. Indeed, the same opinion was
held for a time by Cassini, the celebrated
astronomer of the Paris Observatory, many years
after Galileo, and when the science was con-
siderably more advanced ; and even Newton
did not consider it beneath notice, for in his
"Principia" he takes pains to show on what
grounds it is untenable.
In the course of Guiducci's essay, some opinions
of the Jesuit father, Orazio Grassi (in a public
discussion on the comets at the Collegio Romano),
were so indiscreetly attacked as to raise the ire
of the whole Jesuit's College at Rome. Grassi,
under the pseudonym of Lotario Sarsi, published
1624] WRITES «IL SAGGIATORE" 183
an onslaught on Galileo's cometary theory in a
book called "The Astronomical and Philosophical
Balance" (1619) — a violent pamphlet full of abuse
of Galileo and his school.1 Friends, like Prince
Cesi, and Mgrs. Ciampoli and Cesarini, now
advised that the master himself should take up
the fight ; but ill-health and caution, owing to the
troubled state of the religious and political horizons,
prevented the appearance of his reply for three
years. At length, in October 1622, he sent the
MS. of this celebrated work, " II Saggiatore *'
(The Assayer), to Mgn Cesarini in Rome, and
for five months it passed from hand to hand
among the members of the Accademia dei Lincei,
who examined it carefully and (with the author's
consent) altered some passages which might
possibly have given a handle to his enemies.
The Papal Imprimatur was granted 2nd February
1623, on the report of Father Niccolo Riccardi,
Examiner, who was formerly a pupil of Galileo,
and of whom we shall hear a great deal in the
sequel. This report was as follows: —
"By command of the Master of the Palace,
I have read the work f II Saggiatore/ and not
only have I detected nothing in it which is contrary
1 The reader will have observed that, so far, hardly one of
Galileo's discoveries, or of his published opinions, whether correct or
incorrect, has wanted antagonists and detractors ; and so we shall
find it to the end. The case is probably unique in history, and rightly
did Byron sing of " The starry Galileo with his Woes," for never was
a man so persecuted for fifty out of the seventy-eight years of his busy
life* A French biographer (Parchappe) justly laments "the loss to
science in the enormous expenditure of energy and time consumed in
defending himself and his teaching against the incredible rage of his
enemies in struggles without end." "Galilee, sa Vie," etc, Paris,
1866, p. 79.
1 84 GALILEO IN FLORENCE [1617-
to good morals, or deviates from the Divine Truth
of our religion, but I have found in it such beautiful
and manifold observations on natural philosophy
that I think our age will not have to boast merely
of having been the inheritor of the labours of
earlier philosophers, but also of having been the
discoverer of many secrets of nature which they
were not able to penetrate, thanks to the subtle
and solid researches of the author whose con-
temporary I think myself happy to be."
While the work was in the press, an event
occurred which seemed likely to produce a change
for the better in Galileo's relations with Rome.
On 8th July 1623, Gregory XV. succumbed to age
and infirmity in the second year of his pontificate ;
and the man, who at the age of fifty-five succeeded
him (elected 8th August 1623), was Cardinal
Maffeo Barberini, now Pope Urban VII L
Galileo placed great hopes for the progress of
science in general, and for, at least, toleration of
the Copernican doctrine, on this election ; and
to all appearances he was justified in doing so.
Not only was Urban VIII. a refreshing contrast
to his immediate predecessors who cared little for
art or science, but, as Cardinal, he had for many
years entertained a great friendship for Galileo,
as many letters of his still extant show. Thus,
writing from Bologna, 5th June 1612, on receipt of
a copy of the work on Floating Bodies, he says : —
"I have received your treatise on various
scientific questions which have been raised during
my stay here, and shall read them with great
pleasure, both to confirm myself in my opinions
i624] URBAN VIII. AND GALILEO 185
which agree with yours, and to enjoy with the rest
of the world the fruits of your rare intellect/'
Another letter of 2Oth April 1613, after the
work on Sun-spots had appeared, may be
quoted : —
1 * Your printed letters to Welser have reached
me, and are very welcome. I shall not fail to
read them with pleasure again and again as they
deserve. This is not a book which will be allowed
to stand idly among others. It is the only one
which can induce me to withdraw for a few hours
from my official duties to devote myself to its
perusal, and to the observation of the planets of
which it treats — if the telescopes we have here
are fit for it. Meanwhile I thank you very much
for your remembrance of me, and beg you not
to forget the high opinion which I entertain for
a mind so extraordinarily gifted as yours."
The Cardinal had not confined himself to mere
assurances of esteem and friendship in his letters,
but had shown them in his acts. Thus, in the
troublous times in 1615-16, his influence with
Pope Paul V. greatly helped Galileo to extricate
himself from his difficulties.
In 1620, Barberini gave another and a really
enthusiastic proof of his regard. He celebrated
Galileo's discoveries in some elegant verses (in
which astronomy was allied with morality) and
sent them with the following letter, dated 2 8th
August : —
"The esteem, which I always entertain for
yourself and for your great merits, has given
occasion to the enclosed verses. If not worthy
1 86 GALILEO IN FLORENCE [1617-
of you they will serve at any rate as a proof of
my affection ; while I purpose to add lustre to
my poetry by coupling it with your renowned
name. Without wasting words in further apologies,
I beg you to receive with favour this small proof
of my great esteem."
After much delay in the printing, "II Saggiatore"
appeared at the end of October 1623, with a
dedication to Pope Urban VIIL, and under the
auspices of the Accademia dei Lincei. This cele-
brated work is a masterpiece of ingenuity, for the
author not only dexterously avoids the snares laid
for him by Father Grass! and his supporters, but
brings defeat and ridicule upon them at every
turn. All this is done in so sparkling a style,
and the reasoning, and counter refutations are
so convincing, that "II Saggiatore" deserves its
reputation as a model of dialectic skill, and an
ornament of classical Italian literature.
The book was a great success, and, of course,
intensified the bitterness of the Jesuitical party;
so much so that the General of the Order forbade,
under severe penalties, the members to speak of
it even among themselves. It is important to
note that the Pope was delighted with it, and
had it read aloud to him at table.
Early in 1625, the book was denounced
anonymously to the Inquisition as a veiled
defence of the Copernican doctrines, and a move-
ment was begun to prohibit it, or, at least, to
have it "corrected"; but the attempt failed, and
only brought discredit upon the agitators. Father
Guevara, General of the Theatines, to whom it
1624] "IL SAGGIATORE" 187
was submitted for examination, reported most
favourably of it, and went so far as to say that,
even if the doctrine of the earth's motion had
been maintained, it would not have appeared
to him a sufficient reason for condemning the
work.
One or two extracts will be interesting. As
a specimen of keen cutting banter the following
is admirable. Sarsi had quoted a story from Suidas
(in support of his argument that motion always
produces heat) to the effect that the Babylonians
used to cook their eggs by whirling them in a
sling. To this Galileo replied : —
" I cannot refrain from marvelling that Sarsi
will persist in proving to me, by authorities, that
which at any moment I can bring to the test of
experiment We examine witnesses in things
which are doubtful, past, and not permanent, but
not in those things which are done in our own
presence. If discussing a difficult problem were
like carrying a weight, since several horses will
carry more sacks of corn than one alone will, I
would agree that many reasoners avail more than
one ; but discoursing is like coursing, and not like
carrying, and one barb by himself will run farther
than a hundred Friesland horses. When Sarsi
brings up such a multitude of authors, it does not
seem to me that he in the least degree strengthens
his own conclusions, but he ennobles the cause of
Signor Mario and myself, by showing that we
reason better than many men of established re-
putation. If Sarsi insists that I must believe,
on Suidas's credit, that the Babylonians cooked
eggs by swiftly whirling them in a sling, I will
believe it ; but I must say, that the cause of such
an effect is very remote from that to which it is.
1 88 GALILEO IN FLORENCE [1617-
attributed, and to find the true cause I shall reason
thus. If an effect does not follow with us which
followed with others at another time, it is because,
in our experiment, something is wanting which was
the cause of the former success ; and if only one
thing is wanting to us, that one thing is the true
cause. Now we have eggs, and slings, and strong
men to whirl them, and yet they will not become
cooked ; nay, if they were hot at first they more
quickly become cold ; and since nothing is wanting
to us but to be Babylonians, it follows that being
Babylonians is the true cause why the eggs became
cooked, and not the friction of the air, which
is what I wish to prove. Is it possible that in
travelling post, Sarsi has never noticed what fresh-
ness is occasioned on the face by the continual
change of air ? and if he has felt it, will he rather
trust the relation by others of what was done two
thousand years ago at Babylon, than what he can
at this moment verify in his own person? I, at
least, will not be so wilfully wrong, and so un-
grateful to nature and to God, that having been
gifted with sense and language I should voluntarily
set less value on such great endowments than
on the fallacies of a fellow-man, and blindly and
blunderingly believe whatever I hear, and barter
the freedom of my intellect for slavery to one as
liable to error as myself."
Our next extract is a good sample of Galileo's
metaphysics, in which may be observed the germ of
a theory closely allied to that which was afterwards
developed by Locke and Berkeley.
" I have now only to fulfil my promise of declar-
ing my opinions on the proposition that motion is
the cause of heat, and to explain in what manner it
appears to me that it may be true. But I must first
i624] GALILEO'S METAPHYSICS 189
make some remarks on that which we call heat,
since I strongly suspect that a notion of it prevails
which is very remote from the truth; for it is be-
lieved that there is a true accident, affection, or
quality, really inherent in the substance by which
we feel ourselves heated. This much I have to say,
that as soon as I form a conception of a material or
corporeal substance, I simultaneously feel the
necessity of conceiving that it has its boundaries,
and is of some shape or other; that, relatively to
others, it is great or small ; that it is in this or that
place, in this or that time ; that it is in motion, or at
rest ; that it touches, or does not touch another body ;
that it is unique, rare, or common ; nor can I, by any
act of the imagination, disjoin it from these qualities ;
but I do not find myself absolutely compelled to
apprehend it as necessarily accompanied by such
conditions as that it must be white or red, bitter or
sweet, sonorous or silent, smelling sweetly or dis-
agreeably ; and if the senses had not pointed out
these qualities, it is probable that language and
imagination alone could never have arrived at them.
Therefore, I am inclined to think that these tastes,
smells, colours, etc., with regard to the object in
which they appear to reside, are nothing more than
mere names, and exist only in the sensitive body ;
insomuch that when the living creature is removed
all these qualities are carried off and annihilated ;
although we have imposed particular names upon
them (different from those other and real accidents),
and would fain persuade ourselves that they truly
and in fact exist. But I do not believe that there
exists anything in external bodies for exciting tastes,
smells, and sounds, but size, shape, quantity, and
motion, swift or slow; and if ears, tongues, and
noses were removed, I am of opinion that shape,
quantity, and motion would remain, but there would
be an end of smells, tastes, and sounds, which,
190 GALILEO IN FLORENCE [1617-
abstractedly from the living creature, I take to be
mere words."
As we are now approaching the great crisis of
Galileo's public life, it will be convenient to pause
and take a glance at his family affairs. We have
seen (p. 73) that he was never married, but that he
had by the Venetian, Marina Gamba, three children
— Virginia, Livia, and Vincenzio. These children
were brought up with the mother in Padua, and in
a separate establishment from that occupied by the
father in Via Vignali.
It would appear that when Galileo quitted Padua
in the autumn of 1610, he took the two girls with
him to Florence, and placed them under the care of
his brother-in-law, Landucci ; Vincenzio, being then
only four years old, was left behind with his mother
until October 1612, when he too was brought to
Florence. Shortly afterwards, Marina married a well-
to-do man in her own sphere, one Giovanni Bartoluzzi.
This step appears to have been taken with Galileo's
approval, judging from the respectful and friendly
tone of the only letter of Bartoluzzi (i7th August
1619) found amongst Galileo's papers. It appears
from this letter, and from two others written by
Liceti, 3ist December 1610, and Pignoria, 25th
January 1613, that Galileo behaved with great
liberality to Marina and her husband.
In March 1610, before his final departure from
Padua, he had the intention of placing his elder
daughter as a boarder in the convent of the Nun-
ziatina, Florence ; but, although all the preliminaries
were settled, the project, for some unknown reason,
1624] DAUGHTERS BECOME NUNS 191
was not carried out. What to do with the girls
was now become a serious question. Their taint
of birth was in painful contrast to the honoured
name of his own noble family, as his mother, in her
frequent and " terrible " tempers, did not fail to
remind him. His means, generally as we have
seen insufficient for his wants and never too large,
did not hold out the hope of being able to make
them independent, or to settle them suitably in
marriage. In these circumstances he resolved,
while they were yet young, and before they could
acquire a taste for the world, to place them both in
a convent for life. In November 1611, he took
steps to carry out this resolution, but met with many
difficulties. He did not wish that the children
should be separated, but there was a strict rule
against sisters taking the veil in the same convent
Then, there was the further difficulty of the girls
being much under the canonical age of full sixteen
— Virginia, the elder, being only eleven. However,
after long negotiations, and finally through the
influence of Cardinal Bandini, the necessary licences
were obtained, and in October 1613 the two girls
were placed in the Convent of San Matteo, Arcetri,
near Florence, as a preparatory step to their novi-
tiate and final profession. In July 1614 they were
entered as novices of the Order. The Mother
Abbess of the time was a sister of the Secretary
Vinta, whose name has often occurred in these
pages. From the first the good Lodovica Vinta
took a kindly interest in the poor children ; and at
her suggestion the feasting usual on taking the veil
was dispensed with. "It would be better," she said,
192 GALILEO IN FLORENCE [1617-
" in every way for the ceremony to take place quietly,
and the money will be far better employed in adding
to the girls' little comforts in the convent than in
regaling friends and relations/' Finally, Virginia
became a professed nun on 4th October 1616,
under the name of Suor Maria Celeste ; and Livia
on 28th October 1617, under the name of Suor
Arcangela ; and here we shall leave them for awhile.
After the death of Filippo Salviati, on 22nd
March 1614, Galileo appears to have given up
the villa near Signa, and to have had no settled
home of his own for the next three years. He
probably had a pied-a-terre in his mother's house,
where, owing to her terrible tempers and his own
frequent illnesses, his lot was not a happy one.
On 1 5th August 1617, he rented the villa of
Lorenzo Segni on the Bellosguardo Hill outside
Florence, and here he lived for the next fourteen
years. Perched upon a hill it commanded most
lovely views of the city and the silvery Arno at
its foot, with the far-famed Fiesole beyond, and
of beautiful country all round.
" From Tuscan Bellosguardo,
Where Galileo stood at nights to take
The vision of the stars, we have found it hard,
Gazing upon the earth and heavens, to make
A choice of beauty."
— ELIZ. B. BROWNING.
Two hundred years after, the villa was for a
time (circa 1810) the residence of another famous
Italian, Ugo Foscolo, the poet and patriot-soldier
of the stirring times in Italy during the Napoleonic
period. In 1835, the then owner, Amerigo degli
i624] SISTER MARIA CELESTE 193
Albizzi, erected on the north-west front of the house
two white marble tablets (each surmounted by a
white marble bust) with long inscriptions com-
memorative of these two great men. The bust
of our philosopher, showing well his peculiar nose,
is the work of the Florentine sculptor Emilio
Demi ; and the inscription is from the pen of
Vincenzio Antinori, then Director of the Museum
of Natural History, Florence.1
For nearly seven years after taking the veil we
lose sight of Galileo's daughters. We left them
as children of sixteen ; we are now to meet them
as women. Sister Arcangela, the younger, we
shall not like ; but Virginia, or Sister Maria
Celeste, as we must henceforth call her, we shall
learn to love. All we know of this charming
personality is told in her letters to her father.
The first is dated loth May 1623, but Professor
Favaro thinks there must have been many previous
ones which are now lost. However this may be,
those that remain, one hundred and twenty-four
in number, show that there was a close intimacy
and affection between father and daughter, and
that these relations grew in intensity with the
daughter's maturing years. If they did not write
they must have often met, for Galileo's house at
Bellosguardo was a pleasant half-hour's walk
along a charming road from the convent of San
1 For the inscription see Albert's ed. of Galileo's works, vol. xv.
p. 394. The house is now known as Villa POmbrellino, and is occupied
by the Russian General, Alexis Zouboflj who kindly allows visitors
to see these interesting memorials. The villa is entered from the
Piazza Bellosguardo, where one sees on a house in front a marble
slab intimating that Garibaldi and Mario lived there.
N
j94 GALILEO IN FLORENCE [1617-
Matteo. In no other way than on the supposition
of a previous intimacy of a close personal kind
can we account for the affection which bursts
forth in the first letter we possess, and overflows
through all of them to the end. This affection
must have been, as indeed we shall see it was,
a great comfort and consolation to Galileo, sorely
tried as he was by frequent illness, by the worries
and ingratitude of all the rest of his family, and
by the persecution of the outside world.
His letters to his daughter, though we know
that she kept them, and was in the habit of
re-reading them during such leisure moments as
her duties left to her, have unfortunately dis-
appeared. It is probable that these letters so
treasured by the daughter were destroyed at her
death, lest the convent should be compromised
by their presence among its archives — an action
which, however much we may regret it, we
cannot blame, as we must remember that when
Maria Celeste died in 1634 her father was a
prisoner of the Inquisition, vehemently suspected
of heresy.
We can, however, generally guess the contents
of these lost letters, by the answers, which, thanks
to her father's loving care, have been preserved
to us. In these, Sister Maria Celeste emerges
from behind the convent grating ; she lifts the
veil which envelops her, and shows us a woman's
heart full of filial tenderness, of self-abasement,
and of interest in some things of that world she
had renounced in her childhood. We see this
heart of hers often pierced with sorrow, and always
i634] SISTER MARIA CELESTE 195
divided between love and fear — love for her father,
and fear of impending evil to him.
Besides the father-worship which glows in every
page, these letters bear evidence throughout of
sound sense and sober judgment, joined to a
simple piety. There is not a trace of mysticism
in them ; there is no mention of minute practices
of devotion ; she does not pass her nights in the
chapel, kneeling on cold stones and expecting
visions ; she goes to bed like a sensible woman,
and takes her seven hours' sleep ; she regrets
sometimes that her constitution should require so
much sleep, but only because she would like
better to sit up and write long letters to her
" Dearest Lord and Father." Of her Heavenly
Father she discourses much ; of the Virgin seldom ;
and we hear of no patron saint. The nuns, she
tells us, have each their patron saint — their Devote
to whom they tell all their little joys and sorrows ;
but she has her father to confide in and therefore
wants no Devoto.
Around this loving and lovable nun the other
sisters stand — a group of shadows with a name
attached to each. Some flit by, once mentioned —
sisters these, but not friends ; a few come before
us more often, Sister Luisa Bocchineri in particular,
who was Maria Celeste's bosom friend, and a sister
of her brother Vincenzio's future wife. Her own
sister Livia appears as little more than a shadow,
and what we see of her inclines us, perhaps, to
some pity, but to little love. Her disposition seems
to have been decidedly selfish, and her sister had
to give up to her a great deal for the sake of peace.
196 GALILEO IN FLORENCE [1617
" As Sister Arcangela's disposition/' she writes,
"is very different from mine, being rather odd and
whimsical, it is better for me to give up to her in
many things, in order to preserve that peace and
unity which accord with the exceeding love we bear
each other."
We further learn that Arcangela was subject
to frequent fits of hypochondria, and that she was
constantly ailing. Indeed, ill-health seemed to be
more the rule than the exception at San Matteo.
Maria Celeste herself was far from being always
well ; sometimes she, sometimes another sister,
sometimes half the convent was down with fever ;
and rheumatism was frequently complained of.
For the next ten years of Galileo's life and
the rest of her own (1623-34), we shall be
constantly in touch with this exquisite woman,
in extracts from her letters, and the more we see
of her the more we shall love her.1
On the election of Cardinal Barberini to the
Papacy as Urban VIIL, Galileo conceived the idea
of going to Rome to offer his congratulations in
person, and to use his influence with the new
Pope to obtain, at least, toleration for the Coperni-
can doctrines, now no longer opposed by the
weighty influence of Cardinal Bellarmine, who had
died two years before. Remembering the warmth
of Barberinis letters while Cardinal, Galileo had
reason to hope from a Pontiff so enlightened at
1 We can only give extracts from a few of these letters. The
reader will find them more fully reported in Mrs Olney^s "Private
Life of Galileo " ; while to those who can read them in the original
we recommend Professor Favaro's u Galileo e Suor Maria Celeste,"
Florence, 1891, where all the letters are given in full.
i624] SISTER MARIA CELESTE 197
least this much ; while as regarded himself, he felt
that he must have permission to teach the new
astronomical doctrines, not merely as hypotheses
but as actual truths, now or never ; and according
as his desire was fulfilled or not, so would his
life-work be complete or incomplete.
Knowing her father to be an object of ani-
mosity in so many quarters, the accession of
Urban VIII. was a cause of great rejoicing to
Maria Celeste, and having been favoured with a
sight of the Pope's letters when Cardinal to
Galileo, she wrote loth August 1623, when re-
turning them, in a strain of eagerness : —
" I cannot describe the pleasure with which I
perused the letters of the illustrious Cardinal, who
is now our Pope, knowing as I do how greatly
he loves and esteems you. I have read the letters
several times, and now send them back as re-
quested, having shown them to no one except
Sister Arcangela, who is also much delighted to
see how greatly you are favoured by such an
exalted personage. May the Lord give you
health to fulfil your desire of visiting his Holi-
ness, so that you may enjoy a still greater measure
of his favour. Seeing how many promises he
makes in these letters, we hope that you will easily
get something to help our brother.1 I imagine that
by this time you will have written a beautiful letter
to his Holiness to congratulate him, and as I feel
1 Vincenzio. Nothing is known of the youth of Galileo's son. In
the first years after his arrival in Florence in 1612, he probably lodged
with his uncle, Landucci, at least during his father's frequent absences.
On 25th June 1619, he was legitimated by Grand-Ducal decree, and
not long before the time of Maria Celeste's writing, he was sent to
Pisa, under the care of Father Castelli, to study law.
198 GALILEO IN FLORENCE [1617-
curious about it, I should like very much (if you do
not object) to see a copy/'
Poor simple soul ! She had not perceived the
distance between her father, Philosopher and First
Mathematician to a Grand Duke, and Maffeo Bar-
berini, the Pope of Rome. Her father must have
written at once to enlighten her on the degrees
of comparison, for, in her reply of three days
later, she confesses her ignorance with touching
humility : —
" From your beloved letter I see how little
knowledge of the world I must possess to have
thought as I did that you would write immediately
to such a personage — to one who is, in fact, the
head of Christendom. I therefore thank you
for the hint you have given me, and feel sure
that your love for me will induce you to excuse
my ignorance as well as many other faults that I
possess. I trust that always warned and reproved
by you I may gain in knowledge and discretion.
" Since we are not able to see you in con-
sequence of your lingering indisposition, we must
patiently resign ourselves to the Lord's will, Who
permits all things for our good.
" I put by carefully the letters you write me
daily, and when not engaged with my duties I
read them over and over again. This is the
greatest pleasure I have ; and you may think how
glad I am to read the letters you receive from
persons who, besides being excellent in them-
selves, have you in esteem/'
A few days after, the convent steward, who
had been sent with a message to the villa at
Bellosguardo, brought back the alarming news
1624] GALILEO ILL 199
that Galileo was ill, and in Florence. Fearing
that the illness might be more serious than usual,
she packed off the steward again to the city to
see him, and learn from himself the state of his
health. She says in the affectionate little note
of which the steward was bearer, that she never
regrets being a nun, except when her dear father
is ill, because then she would like to be with
him. Galileo's illness seems to have been serious,
for four days later (aist August) we find her
writing again, and sending as an excuse a few
biscuits baked in a mould representing a fish.
The truth is, as she confesses in her note, she
wants the steward to see her father, and learn
his condition from his own lips, evidently placing
little reliance on messages given by those around
him. On 28th August she wrote again, expressing
her grief at hearing that there was no improve-
ment. She sent him a little present of four
plums with the hope that, as they were not in
as great perfection as she could wish, he would
take the will for the deed. She then goes on to
say : —
" Please remember that when you get an
answer from those gentlemen in Rome, you have
promised me a sight of it. I say nothing of the
other letters you promised to send me, as I sup-
pose they are at the villa at Bellosguardo."
By the end of August, Galileo, though still far
from well, was able to resume his correspondence,
and on returning to his villa he sent her the letters
she wished to see, also some thread and other
trifles that she wanted.
200 GALILEO IN FLORENCE [1617-
Feeiing his time and strength unequal to the
literary demands upon them, he now seems to have
begun to utilise his daughter's clear handwriting
when he wished to have copies of particular letters
or papers. Thus, in a note of this period, returning
such a paper, she hopes that he will think the copy
well done, as then, perhaps, he will let her copy
some more, reminding him that to be occupied in
his service is her great pleasure and contentment.
With improving health, Galileo began to think
it was time to prepare for his journey to Rome, and
he wrote to some of his friends to sound them on
the project To Prince Cesi he wrote, 9th October
1623:—
** I have in my head plans of no small impor-
tance for the learned world, and perhaps can never
hope for so wonderful a combination of circum-
stances as the present to ensure their success, at
least so far as I am able to conduce to it."
Prince Cesi replied : —
" Under the auspices of this most excellent,
learned, and benignant Pontiff", science must flourish.
. . . Your arrival will be welcome to his Holiness.
He asked me if you were coming, and when, and,
in short, seems to love and esteem you more than
ever."
Tommaso Rinuccini, to whom Galileo also
wrote, replying 2Oth October, said : —
" I swear to you that nothing pleased his
Holiness so much as the mention of your name.
After I had been speaking of you for some time,
I told him that you had an ardent desire to come
1624] PROPOSED VISIT TO ROME 201
and kiss his toe, if his Holiness would permit it, to
which he replied that it would give him great
pleasure if it were not inconvenient to you, and if
the journey would not be injurious to your health,
for great men like you, he said, must spare them-
selves so that they may live as long as possible."
Mgr. Ciampoli and other friends also wrote in
the same confident strain.
These replies, as gratifying as reassuring,
Galileo appears to have sent to Maria Celeste for
her perusal, as in her letters of October (1623)
she refers to them. Amongst a great deal about
Arcangela's illnesses, and repairs that she had
been making to her father's linen, and her brother's
collars she writes (2Oth October) :
" I return the letters you sent me to read.
They are so beautiful that my desire to see more
of them is greatly increased."
Again, on 2gth October, she writes : —
" I leave you to imagine how pleased I am to
read the letters you constantly send me. Only to
see how your love for me prompts you to let me
know fully what favours you receive from these
gentlemen is enough to fill me with joy. Never-
theless, I feel it a little hard to hear that you intend
leaving home so soon, because I shall have to do
without you, and for a long time too, if I am not
mistaken. Your lordship may believe that I am
speaking the truth when I say that except you
there is not a creature who gives me any comfort.
But I will not grieve at your departure because
of this, for that would be to complain when you
had cause for rejoicing. Therefore, I too will
202 GALILEO IN FLORENCE [1617-
rejoice, and continue to pray God to give you
health to make a prosperous journey, so that you
may return satisfied, and live long and happily.
Although I know it is not necessary for me to
do so, yet I recommend our poor brother to your
kindness, and I entreat you to forgive him his
fault in consideration of his youth, and which,
seeing it is the first, merits pardon. I do beg and
entreat you to take him to Rome with you, where
opportunities will not be wanting to give him
that assistance which paternal duty and your
natural kindness will prompt you to seek out/'
Vincenzio was then seventeen. What the
escapade was which brought him into disgrace
we are not told. And, unfortunately, this was
not the only time that his sister had to intercede
for him. In disposition this young man would seem
to have resembled his uncle, Michelangelo. Years
brought him no discretion. Wayward, selfish, idle,
with a great capacity for spending money he had
not earned, this only son was a constant thorn in
his father's side. Castelli, who looked after him
at Pisa with paternal solicitude, even to the buy-
ing of his shoes and stockings, had to complain
of his mulish obstinacy. A fault confessed was
half atoned for, the good Father thought, and he
strove hard to bring him to confession, assuring
him that no punishment should follow. " But he
is as hard as a stone, and one would think he was
struck dumb by enchantment. As for me I am
in utter despair about him."
Maria Celeste had been busy working at her
father's new set of dinner-napkins which had been
cut too short, and must have pieces added ; and
i624] FAMILY AFFAIRS 203
not having heard from him for nearly a month,
she was getting very anxious, On 2ist November
she wrote : —
" I cannot rest any longer without news, both
for the infinite love I bear you, and for fear lest
this sudden cold, which generally disagrees so
much with you, should have caused a return of
your old pains and other complaints. I therefore
send the man, who takes the letter purposely,
to hear how you are and also when you expect
to set out on your journey, ... As I have no
bedroom of my own, Sister Diamante kindly
allows me to share hers, depriving herself of the
company of her own sister for my sake. But
the room is so bitterly cold that, with my head
in the state in which it is at present, I do not
know how I shall remain, unless you can help
me by lending me a set of those white bed-hangings
which you will not want now.
" Moreover, I beg you to be so kind as to send
me that book of yours which has just been
published [* II Saggiatore '], so that I may read
it, for I have a great desire to see it.
" These few cakes I send are some I made a
few days ago, intending to give them to you when
you came to bid us adieu. As now your departure
is not so near as we feared, I send them lest they
should get dry.
" Sister Arcangela is still under medical treat-
ment and is much tried by the remedies. I am
not well myself, but being so accustomed to ill-
health I do not think much of it.
"P.S. — You can send us any collars that want
getting up."
CHAPTER X
FOURTH VISIT TO ROME RETURN TO FLORENCE
1624-1629
LONG delayed, first by illness and then by bad
weather, whole tracts of country being under
water, Galileo at length set out for Rome ist
April 1624. Reaching Acquasparta on 5th April,
he stayed a fortnight with his friend Prince Cesi,
and arrived in Rome on the 23rd, provided with a
warm letter of recommendation from the Grand
Duchess Cristina to her son Cardinal de Medici.
From Acquasparta he wrote to his daughter,
telling her of the flattering reception he had met
with from Prince Cesi, who was able to assure him
that his presence in Rome was anxiously awaited
" by great personages." On the other hand he was
grieved to hear of the sudden death of Mgr.
Cesarini, a warm friend whom he had both loved
and honoured. This event, as Maria Celeste
reminds her father (26th April), "gives food
for reflection on the vanity and fallacy of all earthly
hopes"; but she timidly adds, " I would not have
you think that I write only to sermonise you, there-
fore I will say no more."
All the world of Rome was aware of the favour
1624-1629] RESULT OF VISIT TO ROME 205
in which the Pope held Galileo. His old friends,
therefore, received him with greater delight than
ever, and his enemies dared only to clench their
fists behind his back. His letters express the great
satisfaction which his reception afforded him ; but
as regarded the object which was nearest his heart
he was not so satisfied. Within six weeks he had
had six long interviews with Urban VIII., had
always been most affably received, and was allowed
to bring forward all his arguments in support of
the Copernican theory ; but all to no purpose ; the
Pope listened to his arguments, but would not grant
his earnest entreaties for, at least, a passive tolera-
tion of the new doctrines.
As soon as the Pope's attitude became known,
Galileo's clerical friends had to be cautious, and
avoided as far as possible all reference to the pro-
hibited doctrines. One of these, Father Niccolo
Riccardi, at once took his seat on the fence.
" As to the truth or falsity of the theory/' wrote
Galileo to Cesi on 8th June, "he accepts neither
Ptolemy nor Copernicus, but quiets his soul in a very
speedy manner. He sets angels to work at moving
the heavenly bodies, and these make them go as they
do go (however that may be) without the slightest
difficulty or entanglement! Certainly this ought to
be enough for us ! "
Finding that his efforts to get the decree of
5th March 1616 revoked were of no avail, Galileo
resolved with a heavy heart to return home, after
a six weeks' stay in Rome. On the eve of his
departure, the Pope loaded him with favours which
must have seemed to him like mockeries. His
206 FOURTH VISIT TO ROME [1624-
Holiness promised him a pension for his son,1 and
three days after sent a picture for himself; then
two medals — one of gold and one of silver, and
quite a number of Agnus Dei ! Not content with
these marks of favour, he addressed an official letter
(Breve) to the Grand Duke, 8th June, in which, to
the no small chagrin of Galileo's enemies, his
Holiness not only did full justice to our philo-
sopher's services to science, "the fame of which
will shine on earth so long as Jupiter and his
satellites shine in heaven," but laid special stress on
his religious sentiments : —
" We have," he said, " observed in him not only
literary distinction, but love of religion, and all
good qualities worthy of the Papal favour. When
he came to congratulate us on our accession we
embraced him affectionately and listened with
pleasure to his learned demonstrations, which add
fresh renown to Florentine eloquence. We desire
that he should not return to his native country
without receiving from our generosity manifold
proofs of our favour. And that you may fully
understand to what extent he is dear to us, we
give this honourable testimony to his virtue and
piety. And, further, we assure you that we shall
thank you for any kindness that you can show
him ; and by imitating, or even surpassing, our
fatherly liberality, you will add to our gratification/1
Fruitless as was his journey to Rome as re-
1 The pension of 60 crowns was granted on 2Oth March 1627, but
owing to the religious exercises attached to it, Vincenzio would not
accept it It was then transferred to a nephew, but as he proved un-
worthy, it was finally settled on Galileo himself, on I2th February 1630,
with an increase of 40 crowns, but with the condition that, as it was
derived from ecclesiastical benefices, he should adopt the tonsure — to
which he is said to have consented. He drew the pension thus
strangely obtained to the end of his life.
1629] INVENTION OF MICROSCOPE 207
garded the grand object of his life — the emancipa-
tion of the Copernican theory — Galileo was yet able
to do something for the advancement of science.
He improved, if he did not invent, the microscope.
The principle of the telescope and the micro-
scope is to the mathematical optician one and the
same. The former is merely made to collect
parallel rays from distant objects; the latter,
diverging rays from near objects. The invention
of the one, therefore, could hardly fail to follow
immediately upon the other ; and accordingly we
learn that, very soon after inventing the telescope,
Galileo adapted it for the examination of small
objects. John Wedderburn, a Scotch student at
Padua, in a defence of his master (published in
1610) against the calumnies of Martin Horky (see
p. 1 06 ante), states that he heard Galileo describe
in what manner he perfectly distinguishes with
his telescope the organs of motion and of the
senses of the smaller animals, especially in a
certain insect, which has each eye covered by a
rather thick membrane, which, perforated with
seven holes, like the visor of a warrior, allows it
sight
" Here hast thou," he continues, "a new proof
that the glass concentrating its rays enlarges the
object. In other animals of the same size, and
even smaller, some of which have, nevertheless,
brighter eyes, these appear only double, with their
eyebrows and the other adjacent parts."
In 1614, the Frenchman Tarde, Canon of the
Cathedral of Sarlat (Dordogne), was travelling in
Italy, and on arriving at Florence called on Galileo,
208 FOURTH VISIT TO ROME [1624-
whom he found ill in bed. Amongst other reports
of this meeting Tarde says : —
''Galileo told me that the tube of a telescope
for observing the stars is no more than 2 feet
in length ; but to see well objects, which are very
near, and which on account of their small size
are hardly visible to the naked eye, the tube must
have two or three lengths. He tells me that with
this long tube he has seen flies which look as big
as a lamb, are covered all over with hair, and
have very pointed nails, by means of which they
keep themselves up and walk on glass, although
hanging feet upwards, by inserting the points of
their nails in the pores of the glass."1
In "II Saggiatoren there is a further reference
to a telescope arranged so that one can see very
near objects very distinctly, even to the most
minute particles ; and, finally, Viviani, in his " Vita
dl Galileo," and in the laudatory inscriptions which
he placed on the front of his house in Florence2
in 1693, records as a fact that Galileo presented
a microscope to the King of Poland in 1612.
All this goes to show that he was well acquainted
with the uses of his invention qua microscope,
and that he did not dwell upon them, or pursue
them to greater length, is, no doubt, because his
thoughts were wholly absorbed on its perfection
as a telescope, and on the glorious field of astro-
nomical discovery which it laid open to him.
Certain it is, that for many years he gave the
1 See Favaro's " Di Giovanni Tarde e di Una Sua Visita a Galileo "
{Bulkttino di Bibliografia e di Storia delle Sdenze Matematiche e
Fisickt) Rome, July 1887). A diagram of a microscope is reproduced
from a contemporary MS. in the National Library, Florence.
* Now No. 9 Vk San Antonino, formerly Via dell7 Amore.
1629] INVENTION OF MICROSCOPE 209
matter little attention — not until his visit to Rome
of which we are now speaking, and when he
found the microscope discussed as a novelty which
nobody could understand.
We have seen in our account of the invention
of the telescope that Jansen, the optician of
Middleburg, invented a form of microscope about
1590, in which objects were seen inverted. One
of these instruments he presented to the Archduke
Charles Albert of Austria, who in turn gave it to
Cornelius Drebbel, a Dutchman, then living in
London. For many years after, the instrument
was practically forgotten; but about 1621, Drebbel
appears to have resumed its manufacture in
London.
In the following year Jacob Kuffler, a relative
of Drebbel, brought a specimen to Rome, a present
from M. de Peiresc of Paris to one of the Cardinals.
From the letter which accompanied it, dated 7th
June 1622, we take the following passage: —
"Your Lordship will receive the present letter
from the hand of Signor G. Kuffler of Cologne.
He will be able to show you an occhiale or telescope
of a new invention (different from that of Galileo),
with which he shows a flea as large as a cricket,
and almost of the same shape, with its two arms
and the other smaller legs, head, and almost all
the body, covered with crusts or scales, like crickets
or small shrimps. The little insects which generate
in cheese become as large as flies, and are so dis-
tinctly discerned that one sees them to have very
long legs, a pointed head, and every part of the
body quite distinct,"
Unfortunately, Kuffler died before he had time
230 FOURTH VISIT TO ROME [1624-
to explain the management of the instrument, and
so it remained a mystery. Two years later, after
many accidents and delays, two other specimens
arrived, also sent by de Peiresc with brief in-
structions as to their use. Apparently one was
little more than a magnifying glass, which it was
easy to understand ; but of the other and larger,
consisting of two glasses, nobody in Rome could
make anything, " although they had the help of
mathematicians/1
It was at this moment that Galileo arrived.
The instrument was shown to him, and, as may
be imagined, a very brief study told him not only
how to use it but how to improve upon it. He
at once told his friends that he had himself made
a somewhat similar instrument many years pre-
viously, " which magnifies things as much as
50,000 times, so that one sees a fly as large
as a hen." He quickly made some specimens,
showing objects erect, which he sent to his
friends, and soon his microscopes were in as
great request as his telescopes. Amongst others,
he sent one to Prince Cesi, on 23rd September
1624, with the following interesting letter : —
" I send your Excellency a little spy-glass
(occhialino) 1 for observing at close quarters the
smallest objects, which I hope will afford you the
same interest and pleasure that it does to myself.
I delayed sending it because my first specimens
were imperfect by reason of the difficulty in
1 Galileo usually called the telescope occhicde or cannocchiale ;
and now he calls the microscope occhialino. The name telescope was
first suggested by Demisiani in 1612, and microscope by Giovanni
Faber in £pril 1625.
i629] GALILEO'S MICROSCOPES 211
fashioning the lenses. The object is placed on
a movable circle (at the base of the instrument)
which can be turned in such a way as to show
successive portions, a single pose being unable
to show more than a small part of the whole.
As the distance between the lens and the object
must be precisely adjusted in order to see things
that are in relief, it is necessary to bring the glass
nearer to or farther from the object, according to
the parts to be examined. Therefore the little
tube is made adjustable on its stand or guide.
The instrument should be used in a strong light,
or even in full sunlight, so as to illuminate the
object as much as possible.
" I have examined with the greatest delight
a large number of animals, amongst which the
bug is most horrible, the gnat and the moth very
beautiful I have also been able to discover
how the fly and other little animals are able to
walk on window panes and ceilings feet upwards.
But your Excellency will now have the opportunity
of observing thousands of other details of the most
curious kind, of which I shall be glad to have an
account In short, one may contemplate endlessly
the grandeur of Nature, how subtilely she works,
and with what unspeakable diligence.
" JP.S. — The little tube is in two pieces, so that
you may lengthen it or shorten it at pleasure." l
Soon after his return to Florence, Galileo began
to draw up a reply to an attack on the Copernican
theory which had been addressed to him in 1616
by Francesco Ingoli, then a lawyer at Ravenna,
and afterwards secretary of the Propaganda in
Rome. Coming at the time of his first encounter
1 The only relic of these instruments now in existence is pre-
served in the Tribuna di Galileo, Florence. The lenses are
missing.
212 RETURN TO FLORENCE [1624-
with the Inquisition, Galileo wisely refrained from
answering it then. In 1618 an answer was pub-
lished from the pen of that other Corypheus of
science, Kepler, in his " Epitome of the Copernican
Astronomy/'1 but Ingoli did not consider himself
beaten, and rejoined in a letter addressed to a
high official of the Papal Court. Now, after the
lapse of eight years, Galileo thought that, protected
by the favour of Urban VII L, he might himself
venture on a reply ; for although there was no
hope of a public revocation of the decree of 5th
March 1616, he thought, and his correspondents in
Rome were of the same opinion, that the prohibi-
tion would not be rigidly enforced against him.
In this defence of the Copernican theory, he
professes to be actuated by a double motive. On
the one hand he wishes to show that, as he had
given currency to it before it was condemned by
ecclesiastical authority, he had not been the
expounder of an improbable or unreasonable
theory. On the other hand he wishes to prove
to the Protestant Copernicans in Germany that
the views of their great countryman had not
been rejected in Catholic Italy from a disbelief
of their probability, but " from reverence for
Holy Scripture, as well as zeal for religion and
our holy faith." After this strange introduction,
and an assurance that he had no intention of
representing the forbidden doctrine as true, he
proceeds with vigour to refute all Ingoli's
objections.
1 This work was placed on the Index Expurgatorius, loth ,March
1619. Galileo had to smuggle a copy into Italy.
1629] POPE AND COPERNICANISM 213
In spite of his diplomatic preface, his friends
in Rome, aware of the watchfulness of his
enemies, advised him not to publish. Galileo
wisely gave heed to their warnings, and so the
work was only circulated in MS. copies. How-
ever, several passages from it were brought under
the notice of the Pope by Mgr. Ciampoli, and we
learn from a letter of the latter to Galileo, 28th
December 1625, that his Holiness highly approved
them,1 This to Galileo and his friends was a
hopeful sign. Another was the failure of the
agitation undertaken (as already mentioned) in
the same year against "II Saggiatore." Father
Grass! ventured, under pretext of a rejoinder to
that work, to publish a fresh attack on its author
full of spiteful personalities and " arguments'* of
the most absurd kind Apparently Grassi, member
though he was of the powerful Collegio Romano,
could not find a publisher for this work (" Ratio
Ponderum Librae ") in Rome, and had to bring it
out in Paris in 1626, a circumstance which Galileo
interpreted as another encouraging sign of the
times. Again, in 1624 in a conversation on the
subject with the Pope, the Cardinal Zollern
(prompted by Galileo) represented that all the
heretics of Europe considered the truth of the
Copernican doctrine to be beyond doubt, and that,
therefore, it would be necessary to be very circum-
spect in coming to any resolution upon it, to which
his Holiness replied that the Church had not con-
1 In this work Galileo announced that he was preparing a treatise
on the Flux and Reflux of the Tides, based on the hypothesis of the
double movement of the earth.
214 RETURN TO FLORENCE [1624-
demned it ; nor was it to be condemned as heretical,
but only as rash ; and he added, that there was no
fear of any one undertaking to prove that it must
necessarily be true. These and other indications
tended to confirm Galileo in the opinion that, under
the pontificate of Urban VI I L, the advocates of
Copernicanism had little to fear, provided that
the defence was so circumspectly handled as not
to outrage the oft -mentioned decree of 5th
March 1616.
On this assumption (unfortunately a mistaken
one, as we shall see) he now, 1626, resolved to
carry out the great work which he had long
projected, and which, from the vast and varied
knowledge it displayed, and from its sparkling
and incisive style, was to meet with greater
success than had ever been attained by any
scientific work. This was his " Dialogue on
the Two Principal Systems of the World."
During the next four years, 1626-29, Galileo
was almost entirely engaged on the preparation
of this great work. His official duties as
Philosopher and First Mathematician to the
Grand Duke did not take up much of his time,
and his scientific correspondence was not con-
siderable 1 ; but his work was sadly interrupted
by frequently recurring illnesses, and as much so
by family troubles of all sorts which sorely tried
his patience.
1 During this period he appears to have written one mathematical
treatise bearing the curious title, " On the Estimation of the Value of
a Horse." Here may also be noted, though the date is uncertain, his
solution of a problem in chances (Sopra le scoperte de i dadi). This
was many years before Pascal and Fermat wrote on the same subject
1629] BEGINS HIS DIALOGUES 215
From the paucity of his daughter's letters
during 1625-26, it is certain he often went to see
her at the convent. In one written in December
1625 she sends her " dearest Lord and Father"
two baked pears, a winter rose from the convent
garden, and one of her (frequent) little sermons
on the care of his health ; in another she sends
Christmas greetings, and more collars and cuffs
for "our Vincenzio." Sister Arcangela (who is
often ill) is better, but still in bed. In a third
little note she fears that Vincenzio is angry with
her because she delayed sending the new collars
he was in want of. Of this young man we learn
that he was still pursuing his studies at Pisa,
and spending more money than his father could
afford, Galileo wrote to Castelli (2 7th December
1625).
"For the future he is to be content with
three crowns a month for pocket-money. With
this he can buy plaster figures, pens, paper, or
anything he likes, and he may consider himself
lucky to have as many crowns as I, at his age,
had groats."
During the Carnival season of 1626, Galileo,
relieved from attendance on the young Grand
Duke,1 remained closeted at Bellosguardo, ab-
sorbed in his Dialogues. Maria Celeste had
not seen or heard from him for some time ; the
Carnival passed and Lent came, but no Galileo.
Then she gave vent to her disappointment in
1 Cosimo II., Galileo's old pupil and good friend, died in 1621.
As his heir was then only ten years old, the government was carried
on by Cosimo's mother jointly with his widow until 1627, when the
son assumed power as Ferdinando II.
216 RETURN TO FLORENCE [1624-
words ; she is afraid that, in spite of all his past
kindness, his love for his daughters must be on
the wane, since he has left off coining. This
apparently brought him to the convent, and
with him came, as a peace-offering, a basket of
eatables, rosemary, and citrons. After this,
evidently, he was regular in his visits, for only
two letters are extant belonging to this period.
In the spring of 1627, Maria Celeste was
herself really ill Self-denying and uncomplain-
ing though she was, the coarse convent food
was so unsuitable, that at length she asked for
a little money to procure such comforts as were
necessary to her recovery, The bread was bad,
the wine sour, and the beef uneatable ; therefore,
if there happens to be a tough old hen in the
poultry-yard of the villa, she begs she may have
it to make herself some broth.
To the distractions caused by his own chronic
ill-health, his daughters' frequent illnesses, and the
not very satisfactory reports of his son's conduct
at Pisa, were now to be added the worries of
his invertebrate brother Michelangelo and his
tribe of children.
Since the death of their mother (loth August
1620), the brothers communicated but little, if at
all We have seen that Galileo had no reason
to be pleased with his brother's behaviour in
money matters ; and as long as Michelangelo
could rub on without his brother's aid, he had no
inducement to write. Now, however, it seems to
have occurred to him that, after years of a
great career, the friend of popes and princes
1629] FAMILY AFFAIRS 217
must be full of riches as well as of honours ;
the honours might be kept, but as regarded the
riches, they ought to be divided amongst the
noble family of the Galilei, of which he, Michel-
angelo, was one, and as good as his brother,
though (of course), through no fault of his own,
he was less fortunate. If long ago his brother
chose to cripple himself for years in order to
pay Michelangelo's share as well as his own of
their sisters' dowries, that was Galileo's own
affair ; besides it was many years ago and could
not now absolve him from the duty of paying a
share of his brother's expenses in the bringing-up
of a numerous family (only seven !).
The letter proposing this arrangement is
delicious. Writing to Galileo, 5th May 1627, he
proposes sending his wife Anna Chiara to act as
his brother's housekeeper.
"This arrangement," he says, " would be
good for both of us. Your house would be well
and faithfully governed, and I should be partly
relieved from an expense which I do not know
how to meet, for Chiara would take some of the
children with her, who would be an amusement
for you and a comfort for her. I do not suppose
that you would feel the expense of one or two
mouths more. At any rate they will not cost
you more than those you have about you now,
who are not so near akin, and probably not so
much in need of help."
In reply Galileo offered to take his brother
and his whole family and maintain them "till
Michelangelo should succeed in procuring suitable
2i8 RETURN TO FLORENCE [1624-
employnient in Florence. Accordingly, in Sep-
tember, they came to Bellosguardo, a party of
eight — the whole tribe, except the eldest daughter
left behind with an aunt, who, It is to be hoped,
duly appreciated the privilege of supporting her.
Early in January 1628, Galileo sent the eldest
boy, Vincenzio (nineteen years old) to Rome to
study music, and Castelli, who was now settled
there as Mathematician to the Pope, kindly took
charge of him.
Worn out with mental labour, sleeplessness,
and the daily worries of a wild tribe of nephews
and nieces, Galileo fell seriously ill again in
February 1628, and thinking that the end was
near he recalled his son from Pisa, and sent for
his brother-in-law Landucci to be reconciled with
him.1
On hearing of his convalescence, Michelangelo,
who had returned to Munich only a few days
before Galileo fell ill, wrote (5th April 1628),
expressing his joy not so much for his brother's
recovery, but "from what I know of our brother-
in-law, I tremble to think what would have become
of poor Chiara if you had died! " " I think now/'
he goes on to say, "that with your good leave
I shall have all my family back, for I do not wish
them to be in danger of suffering unkind treatment
one of these days. Meanwhile, I beg that you will
1 Their relations were never cordial. Besides the old and long,
standing quarrel over the payment of the dowry, Galileo had other
grievances. Thus, in 1621 Landucci, thinking his merits not properly
valued in Florence, quitted his country for a lengthened period and
left his wife and family on Galileo's hands. See Favaro's " Galileo e
Suor Maria Celeste," pp. 146 and 159.
1629] FAMILY AFFAIRS 219
see to it that your servants pay Chiara proper
respect and obedience, as I could on no account
suffer her to be maltreated."
The nephew, Vincenzio, had not been many
months in Rome when Galileo began to receive re-
ports of his misconduct Son of his father, vanity,
idleness, and impertinence were the least of his fail-
ings, and all Castelli's fatherly exhortations were lost
upon him. The pension of 60 crowns which Urban
VIII. had promised to settle on Galileo's own son
was, on his refusal to fulfil the necessary conditions,
to be transferred to this nephew, on the same terms,
but, wrote Castelli : —
" He has little devotion ; my words enter at one
ear and go out at the other. He wants to buy a
diamond ring, and declares that he is neither monk
nor nun, and will have none of my sermons. He is
obstinate, impudent, and dissolute, and the insolence
of his demeanour is such that I think he must be
mad as well as vicious."
While Castelli was writing in this strain,
Michelangelo was asking .Galileo to pay his son's
debts, and complaining that there was no one
in all Rome capable of instructing him in the
lute.
" Now the dear child will forget all the music he
has learnt at Munich."
" If you really mean," he continues in his letter
of 8th June, "that there is no remedy to this
disorder except my taking the children back again,
I must do it, even if I go to Florence on foot
What my troubles are nobody knows. You may
say that you too have your own troubles ; I believe
220 RETURN TO FLORENCE [1624-
you, and I should think that seeing the ruin of
these unhappy children should not be the least of
them."
He whines about his poverty and the expenses
of a house, yet he would not economise by giving it
up, because, forsooth, " the discomfort of lodgings
would be unbearable." Wines In beer-drinking
Munich were a luxury and dear, yet he must have
good wine "for his health's sake."
When at last Vincenzio had been sent away
from Rome for his misdeeds, Michelangelo re-
quested his brother to keep the young man till he
came himself, as he intended to relieve him of the
burden of maintaining his family. Galileo had
meanwhile endeavoured to procure a page's place
for a younger nephew, Alberto, in the Grand
Duke's household, but the father objected that
" dear Albertino's " tender age (he was born in
1617) made it more proper that he should be
served than that he should serve others. It would
please him better if his Highness would confer a
pension on the boy so that he may stay at home
and learn to play on the lute ! As for Vincenzio,
his conduct was incomprehensible to the father.
" But/' he says, " I know he did not learn his
wicked ways from me or any one else belonging to
him. It must have been the fault of his wet-
nurse!"
Michelangelo went to Florence in September
1628, and took his family back to Munich, although
he had not the wherewith to maintain them, and
greatly against the wishes of his brother who was
willing to keep them at Bellosguardo. This step
i629] FAMILY AFFAIRS 221
caused our long-suffering philosopher to lose all
patience with a man who would only allow himself
to be helped in his own way. They parted never
to meet again, or even to correspond, for
Michelangelo died on 3rd January 1631.
From a letter of Maria Celeste, while these
unpleasant matters were tormenting her father, we
learn that she too was ill and miserable, jealous,
perhaps, of the presence of aunt and cousins in her
father's house.
"I believe," she wrote 4th March 1628, "that
it is possible for paternal love to diminish in con-
sequence of children's ill-behaviour ; and this belief
is confirmed by some signs which seem to tell me
that your affection for us is not so cordial as it was.
Besides which, though you are well now, you never,
never write me a line. For more than a month I
have suffered day and night from headache, and
can get no relief.
" I send a letter for Vincenzio, just to remind
him of our existence which I think he must have
forgotten, seeing that he never writes us a single
line."1
This last illness of her father caused Maria
Celeste the deepest anxiety. Unable to see for
herself, she sent the convent steward on one
pretext or another to himself see her father
and bring her word. The man must have been
devoted to this sweet Sister, else we think he
would have objected to so many long walks to
Bellosguardo, the bearer of such trifles as a
1 He was at home from Pisa for the Easter vacation. As he had
forgotten his sisters7 existence we may be sure he was well supplied
with collars.
222 RETURN TO FLORENCE [1624-
baked quince or a couple of pears, a winter rose,
a preserved citron, or a phial of cinnamon water.
In one of the affectionate little notes of this
period (24th March 1628), she says: —
"Only in one respect does cloister life weigh
heavily on me, namely, that it prevents my
attending on you personally. My thoughts are
always with you and I long to have news of
you daily. As you were not able to see the
steward the day before yesterday, I send him
again to-day with these two pieces of preserved
citron as an excuse."
In June 1628, after six years' study of law at
Pisa, Galileo's son, then twenty-two years old,
took his Doctor's degree, from which, as we
know, Galileo himself was debarred more than
thirty years before, on account of the expense.
His education finished, it was the father's wish
that he should seek employment in some branch
of the Civil Service of Tuscany, but Vincenzio
preferred living an idle life at home, under
pretence of aiding his father in his scientific
and literary work.
During the summer and autumn of 1628,
Galileo's health was so indifferent as to put a
stop to all exertion, and, consequently, to his visits
to the convent distant over two miles across a hilly
road. What little strength he had was reserved
for his scientific correspondence and the composition
of his Dialogues. But, although Maria Celeste
knew this, she was anxious all the same. On loth
December she wrote: —
"You may think from my long silence that
1629] FAMILY AFFAIRS £3%
I had forgotten you, just as I might imagine
that you had forgotten the road to our abode,
from the length of time that has elapsed since
you came this way. However, as I know that
the reason of my silence is that I have not an
hour at present that I can call my own, so I
think in your case that not forgetfulness but
press of business keeps you from coming to see
us. It is some comfort, meanwhile, to have
Vincenzio's visits, as we thus get news of you
on which we can rely."
A daughter of Geri Bocchineri of Prato,
Major-domo of the Grand Duke, was Maria
Celestes best friend in the convent, and is
frequently mentioned in her letters as Sister
Luisa. Shortly after Vincenzio's return home
from Pisa he paid his addresses to a sister of
this lady, Sestilia Bocchineri, and was accepted.
This news greatly delighted Maria Celeste, and,
on 4th January 1629, she writes to know when
and how she should congratulate the bride, and
as regards a wedding present : " As I have not
the means to do as my mind prompts, I must
take advantage of your kind offer of help."
Maria Celeste's satisfaction at the match was
increased by her first interview with the bride.1
She thought she perceived in her such signs of
affection for her father as augured well for the
comfort of his declining years. Writing on 22nd
March, she says : —
** Both my sister and I were much pleased
with her affable manner and good looks. But
1 The marriage took place at Prato on 29th January 1629,
Galileo was present at the ceremony.
224 RETURN TO FLORENCE [1624-
what gave me the greatest joy was to see that
she was fond of you, since from that we may
judge that she will not be wanting in such
loving attention as it would be our delight to
render you were it permitted. . . .
" If you could manage to send back the clock
on Saturday evening, the Sister, whose duty it
is to call us to matins, will be greatly obliged."
From a later letter we learn that the clock,
which had been sent first to one and then to
another with no improvement, was going well
now that Galileo had put it to rights. Some
months later it got out of order again, and
Vincenzio tried his hand at repairing it, but now
(2 ist January 1630), it goes worse than ever.
Yet, perhaps, its not going is more her fault
than Vincenzio's, or, perhaps, it is because the
cord is bad, or, perhaps — she doesn't know, but
anyhow she sends it to her father, for mended
the clock must be, and that quickly too, else
these nuns will let her have no peace.
As evidence of Galileo's delightful faculty of
turning his hand to everything, and of the odd jobs
he was called on to do for the poor nuns of San
Matteo, the following passage from Maria Celeste's
letter of loth September 1630 is interesting : —
11 Now that the weather is getting cooler
Sister Arcangela and I, with those of the nuns
whom we love best, have planned to work
together in my cell which is large; but the
window is high, and wants 'glazing1 in order
that we may see a little better. I should like
to send you the panels (or shutters) to glaze
them with waxed linen, which even if old will
1629] THREATENED LOSS 225
do very well. But I wish to know first what
you think — not that I doubt your willingness,
but because it is a piece of work fitter for a
carpenter than for a philosopher."
The common window of that period was no
more than an opening in the wall fitted with a
shutter in which was a hole (or holes) to let in
light when the shutter was closed in very hot
and very cold weathers.
Towards the end of 1629, Galileo found himself
face to face with yet another trouble which might
have proved to be serious. He was menaced either
with deprivation of his salary as Extraordinary
Professor at Pisa, or with the loss of that leisure
which had been the determining influence in his
quitting Padua in 1610, and which he was now as
anxious as ever to enjoy. Some ill-wishers at Pisa
raised the question whether it was in the power of the
Grand Duke to assign a salary out of the University
funds to one who neither lectured nor resided there.
This scruple had slept for nineteen years, so it is
probable that those who now raised it reckoned on
finding in young Ferdinando II. a less firm sup-
porter of Galileo than his father Cosimo II. had
been. But the matter did not proceed so far ; the
theologians and jurists, to whom the question was
referred, decided that the Grand Duke had the
power, but to put the matter beyond all further
dispute, his Highness appointed Galileo to an
equivalent post in the magistracy of the University,
so that he was left undisturbed in the stipend and
leisure which were now more than ever necessary
in his old age and shattered health.
CHAPTER XI
COMPLETION AND CONTENTS OF THE DIALOGUE ON
THE TWO PRINCIPAL SYSTEMS OF THE WORLD
THE PTOLEMAIC AND THE COPERNICAN
1630-1632
By the beginning of the year 1630, Galileo had
completed his Dialogues, with the exception of an
introduction or preface, an index, and a few finishing
strokes here and there. In announcing this fact to
his friends, he informed Prince Cesi that he intended
going to Rome to see to the printing of the book — a
step of which the Prince highly approved. The
state of affairs at Rome just then seemed very
favourable for this enterprise. Galileo's devoted
disciple Castelli had been called from Pisa in 1624
to be mathematician to the Pope, and enjoyed great
consideration with the Barberini family. This life-
long friend also approved the design, and informed
our philosopher (6th February) that Father Niccolo
Riccardi, another old pupil and now chief censor of
the press, had promised his assistance.1
Another letter of i6th March contained equally
encouraging news. According to this, the celebrated
Dominican monk, Tommaso Campanella, had just
told the Pope that, a short time before, he had tried
1 He was officially known as Master of the Sacred Palace.
226
1630-1632] COMPLETES DIALOGUES 227
to convert some German nobles to the Catholic
faith ; that they were favourably disposed until they
heard of the prohibition of the Copernican theory,
when they indignantly declined to have anything
more to say to him. To this Urban replied ; " It
never was our intention, and if it had depended
upon us that decree would not have been passed."
In other letters Ciampoli and Castelli urged their
old master to set out at once for the Papal residence,
" where they were longing for him more than for a
lady-love." In the face of these fresh indications of
an altered, or, at least, tolerant attitude towards
science, we cannot be surprised at Galileo concluding
that under Urban VI I L an infringement of the
decree of 1616, in the spirit if not in the letter, such
as his Dialogues undoubtedly were, would give no
offence at the Vatican.
While his friends were thus urging him to set
out, his daughter, knowing how frail he was, con-
templated the journey with anxiety. In her letter
of 1 4th March, she hopes he will come to see them
before he goes. Then, after saying how busy she
is, and reminding him of his promise to send her
what we now call " A Polite Letter- Writer/' comes
the housewifely P.S. — "If you want any collars
washed please send them; and eat these fresh
eggs for love of me." Maria Celeste is clearly the
"scholared" one of the convent. She writes letters
for the poor nuns ; helps the Mother Abbess in her
official correspondence, and concocts petitions and
begging letters to " people of quality, such as
Governors, Workmen,1 and such-like personages."
i, may also mean administrators.
228 COMPLETION OF DIALOGUES [1630-
For many days she goes on hoping to see her
father, but he is absorbed in the final revision of
his book, and has no time to go to San Matteo
— even to wish his daughters the customary Easter
greetings. Maria Celeste could not refrain from
an affectionate remonstrance ; she knows he is im-
mersed in study, but she does not wish him to
shorten his precious life for the sake of fame. He
must take care of his health for his own sake,
and for his children's sake.
On 1 2th April, he found time to pay the long-
wished-for visit, and he was made to promise
another, which was to be a kind of family gather-
ing in the convent parlour, where the two sisters
would entertain their father, brother, and sister-
in-law at a dinner (to be provided by Galileo).
Wishing, dear soul, that the banquet should be
worthy of the occasion, and fearing that her father
in his scientific abstraction would send unsuitable
things, she reminds him that she does not want
either lemons or rosemary, but something more
substantial, in particular a flask of his good wine,
two cream cheeses, and some dish that will do
to come after the roast.
The Mother Abbess could not let pass such an
opportunity of detailing the needs of the convent,
and enlisting Galileo's good offices towards pro-
curing some relief from Rome ; and she had as
little hesitation in preferring the request as doubt
of its being granted Why not? Maria Celeste
was loved by her father who could refuse her
nothing, Galileo himself was the Pope's friend,
and surely he could obtain alms for her at Rome,
i63a] TAKES MS, TO ROME 229
as easily as mend the convent clock ; lend her
money when hard pressed ; and give them wine
and fruits and other eatables from his cellar and
garden.
Filled with hope and with his MS. complete,
Galileo at length set out on ist May in a Court
litter, and travelling fast arrived in Rome on the
evening of the 3rd. Furnished with a letter of
introduction from the Grand DukeJs chief secretary,
Andrea Cioli, to the Tuscan ambassador, Francesco
Niccolini, he was most hospitably received by that
gentleman and lodged in the Embassy, where he
quickly gained the friendship of the ambassador
and his wife, which as we shall soon see was to
be so useful to him.
Soon after his arrival he had a long audience
of the Pope, and wrote on i8th May to Florence
in high spirits : " His Holiness has begun to treat
my affairs in a way that permits me to hope for
a favourable result/' Nevertheless, the result was
anything but favourable; indeed, the toleration,
to say nothing of the recognition, of the Copernican
theory so ardently hoped for was as far off as
even Urban VIII. would not object to the publi-
cation, but certain conditions would have to be
fulfilled. The title of the book, " Dialogues on the
Flux and Reflux of the Tides/' was misleading
and would have to be altered. The subject being
really a discussion of the relative merits of the
Copernican and Ptolemaic systems, this would
have to be indicated in the title. The subject,
moreover, would have to be treated from a purely
hypothetical standpoint, and this fact must be
230 COMPLETION OF DIALOGUES [1630-
clearly set forth in a preface or introduction.
Then, the book must conclude with an argument
which the Pope communicated to Galileo in 1624*
and which his Holiness considered unanswerable.
As great importance will attach itself to this argu-
ment in the sequel, we beg our readers to note it
carefully. It is as follows : God is all-powerful ;
all things are therefore possible to Him ; ergo the
tides cannot be adduced as a necessary proof of
the double motion of the earth without limiting
God's omnipotence — which is absurd.
Rather than forego the publication of a work
towards which he had laboured and thought for
over thirty years, Galileo consented to these con-
ditions. Doubtless, he felt that such minds as
were capable of following his reasoning in favour
of Copernicanism would no more be prejudiced by
the hypothetical warning in the introduction than
by the unanswerable argument of the conclusion.
Meanwhile, the MS. was submitted to Father
Riccardi, the Papal censor, and by him passed
on to his assistant Father Raffaele Visconti, who
carefully went through it, altered many passages,
and finally approved the work thus revised. By
this time the middle of June had arrived, and
Galileo was anxious to leave Rome before the
great heat set in. Riccardi read over the MS.
once more and then granted his permission for
the printing of the work in Rome. Thus, by
the end of June 1630, Galileo was back in Florence
1 When Galileo's theory of the tides was being discussed in Rome.
Doubtless, his Holiness brought forward his argument again at the
recent interview.
1632] IMPRIMATUR: THE PLAGUE 231
with his MS. duly revised and corrected, and
with the ecclesiastical Imprimatur for its publica-
tion in Rome, on the understanding that a
preface and conclusion were added in accordance
with the Papal wishes. But events were now
at hand which long delayed Galileo's ardent
desire to see his work speedily given to the
world, and which involved complications after-
wards taken advantage of by his watchful
enemies.
Soon after his return from Rome, Galileo wrote
to his daughter, and from her reply of 2ist June,
we learn that he was ill again : —
"Just as I was thinking of sending you a
long lamentation because of your never coming
near us, I received your most loving letter which
shut my mouth completely. We were truly
grieved to hear of your being ill ; but really,
after making a journey at this time of the year,
and with the plague everywhere, I do not see
how it could be otherwise. I am astonished to
hear of your going into Florence every day.
Pray take a few days' rest ; do not even come to
see us. We would prefer you kept well to the
pleasure of your company/'
The plague, already rife within the city walls,
now began to spread to the suburbs. Even the
fashionable Bellosguardo, whose reputation for
salubrity equalled the beauty of its situation, was
not spared. One of Galileo's own household, a
glass-blower, was taken off early in October ;
and soon after, his son Vincenzio, seized by a
panic, fled with his wife to Prato, leaving his
invalid father alone, and his seven-months'-old
232 COMPLETION OF DIALOGUES [1630-
baby out at nurse in the neighbourhood of the
villa!
On 1 8th October, Maria Celeste wrote : —
" I am troubled beyond measure at the thought
of your distress, and am horrified at the sudden
death of your poor glass-blower. I entreat you
to omit no possible precaution against the present
danger. I believe that you have by you all the
remedies and preventives that are required, so- I
will not repeat. Yet I would entreat you, with
all reverence and confidence, to procure one more
remedy — the best of all, to wit, the grace of God,
by means of true contrition and penitence. This
is without doubt the most efficacious remedy both
for soul and body. For, if in order to avoid this
sickness it is necessary to be always of good
cheer, what greater joy can we have in this world
than the possession of a good and serene
conscience ? . . . I pray your Lordship to accept
these few words prompted by the deepest
affection.
" I wish also to acquaint you with the frame
of mind in which I find myself at present. I am
desirous of passing away to the next life, for
every day I see more clearly the vanity and misery
of this present one. There I would hope that
my prayers for your Lordship would have greater
efficacy."
Ten days later, 28th October, she asks if her
brother has really fled to Prato.
"I was thinking,1' she continues, "I would
write to give him a piece of my mind, and advise
him not to go, or, at any rate, not to leave the
household so inconveniently situated. His going
away in this manner really is exceedingly strange
i632] FAMILY AFFAIRS 233
at this present juncture, as there is no saying
what may happen. However, fearing to make
matters worse, I did not put my intention into
effect. I have the assurance that Almighty God
will supply you by His providence where men
fail you."
From her next letters we infer that Vincenzio
as still away, leaving his aged father with a
scanty household. His idleness all along had
been a cause of great pain to Galileo. With no
energy to help himself, and too conceited to accept
any appointment not commensurate with his ideas
of his own importance, he preferred to live an
ignoble life at his father's expense. On 2nd
November, Maria Celeste tries to console her
father in a long, prattling, and most touching
letter. She entreats him sweetly not to brood
over his loneliness, not to be too angry at
Vincenzio's cowardly and ungrateful conduct, but
to fix his thoughts on heaven : —
<f I pray you," she continues, "not to take
the knife of these crosses and tribulations by the
wrong end, but rather take it by the haft and use
it to cut through all the imperfections which you
may discover in yourself, that being thus freed
from all impediments you may, as with a lynx-
like eye by which you have penetrated the heavens,
penetrate in like manner the things of this lower
world, and so come to know the vanity and fallacy
of all earthly things. ... I pray your Lordship
pardon me if my chattering becomes wearisome.
You incite me to it by telling me you are pleased
to have my letters. I look upon you as my patron
saint (to speak according to our custom here) to
234 COMPLETION OF DIALOGUES [1630-
whom I tell all my joys and griefs, and finding
you always ready to listen I ask, not indeed for
everything I want, for that would be too much,
but just for what I find most needful Now the
cold weather is coming and I shall be quite
benumbed if you do not send me a counterpane,
for the one I am using at present is not mine,
and the person to whom it belongs wants it
back. The one you gave me, as well as the
woollen one, I have given to Sister Arcangela.
She prefers sleeping alone, and I am quite willing
she should do so. But in consequence I have
only a serge coverlet for myself. So I entreat
my most beloved Devoto, who I know well cannot
bear that I should want for anything. ... I send
you two pots of electuary as a preservative against
the plague. The one without a label consists of
dried figs, walnuts, rue, and salt, mixed with honey.
A piece of the size of a walnut is to be taken
in the morning fasting, with a little good wine.
They say its efficacy is truly wonderful. The
contents of the other pot are to be taken in the
same way.
' ' You said in your letter that you had sent me
the telescope, but you have forgotten to do so,
therefore I remind you of it ; 1 also of the basket in
which I sent you the quinces, as I want to send
some more if I can meet with any."
Galileo appears to have promised his daughters a
visit in the beginning of December, but the tramon-
tana (the cold wind from the Apennines) was
blowing hard, and the old man dared not face it.
In consequence, Maria Celeste sends one of her little
notes (isth December) and some of the never-
1 She uses the word occkiale^ but Professor Favaro thinks she
meant occhialino or microscope, which no doubt Galileo intended for
her amusement.
x632] FAMILY AFFAIRS 235
failing preserved citron. She also asks for the
wherewithal to make a few Christmas presents ;
some stuff to make a door-curtain ; and a few trifles,
such as reels, sulphur matches, wicks, and tags. If
not in the house he was not to send out for them,
she would prefer to go without them, to running the
risk of the messenger bringing back the plague from
the city.
In a letter of i8th February 1631, Maria Celeste
says : — " I am quite confused at hearing that you
keep all my letters. I fear that your great love for
me makes you think them more perfect than they
are." This little fact shows very clearly the esteem
in which he held her. He had, no doubt, been pour-
ing out his tortured soul to her. Stung by his son's
misconduct, by his brother's selfish waywardness,
and by the little consideration of other relatives, it
must have been a comfort to him to turn to the
only one of his family whose life was a mingled
hymn of gratitude for his kindness and of prayers
for his welfare. It must have helped to soothe his
aching heart to know that there was one being in
the world who would not misunderstand his motives
and actions, and whose sympathies were his in joy
and in sadness.
Early in the summer of 1631, feeling age and
infirmity creeping surely over him, he began to
think of a change of residence from Bellosguardo to
the neighbourhood of the convent, where he would
be able to enjoy more often his daughter's society.
Maria Celeste's letters show how eager she was to
hear of a house which would combine vicinity to the
convent with a good situation, and a rent suitable to
236 COMPLETION OF DIALOGUES [1630-
her father's much-drained purse. House-hunting
in the neighbourhood of Florence was not then the
easy work it is nowadays, such villas as existed
being mostly occupied by their owners. Vincenzio,
who appears to have got over his sulks and fear of
the plague, was back again with his father, and
helped in search for a house. Maria Celeste heard
of two or three, but there was something against
them all, and it was not until August that she
heard of one which she considered suitable in every
way. Writing on the I2th, she says : —
" I am so anxious to have you in the neighbour-
hood that I am constantly enquiring if there is any
place near here to let. I have just heard of a villa be-
longing to Signor Esau Martellini which is situated
on the Piano de Giullari, and bounds our garden.
I write at once to tell you that you may see if it be
to your liking. I should be glad indeed if it were,
as then I should not be obliged to remain so long
without news of you as is the case at present"
Shortly afterwards, Dame Piera (Galileo's old
housekeeper) going to the convent with a basket of
provisions, rejoiced the daughter's heart by telling
her that there was every prospect of the villa Mar-
tellini being taken. As Maria Celeste's last letter
addressed to Bellosguardo is dated 3oth August, it
would seem that very soon after, Galileo took up his
abode in the village of Arcetri in Martellini's villa,
then called " II Giojello" (the jewel), and now known
as Villa Galileo. There, not five minutes' walk
from the convent (indeed the grounds of the two
houses adjoined) he was able to have daily inter-
course with his daughters, and Maria Celeste no
1632] MOVES TO ARCETRI 237
longer found difficulty in procuring a messenger if
necessary to send affectionate enquiries about his
health, or little presents from the still-room and
pharmacy.
" Nearer we hail
Thy sunny slope, Arcetri, sung of old
For its green wine ; dearer to me — to most,
As dwelt on by that great astronomer,
Seven years a prisoner at the city-gate,
Let in but in his grave clothes. Sacred be
His villa (justly was it -called the Gem ! )
Sacred the lawn, where many a cypress threw
Its length of shadow, while he watched the stars !
Sacred the vineyard, where, while yet his sight
Glimmered, at blush of morn he dressed his vines,
Chanting aloud in gaiety of heart
Some verse of Ariosto ! "
— ROGERS' Italy.
Arcetri is full of memories of the great Florentine
philosopher. On the road front of his villa is a
white marble slab with a long inscription placed
there in November 1788, by Gio. Battista Nelli,1
and commemorating the fact that Galileo lived
there from the Kalends of November 1631 to the
Ides of January 1642. Over the inscription is a
bust with the words : " This effigy of the divine
Galileo was erected in 1843 by Anton: Filippo
Marchioni." 2
On the way back to town, soon after leaving
Arcetri, one comes to the picturesque old Torre del
Gallo, from the tower of which one gets a glorious
1 One of his biographers— "Vita e Commercio Letterario di
Galileo Galilei," Lausanne, 1793. For inscription, see Alberi's
edition, vol. xv. p. 395.
* On the front of a house opposite to the entrance to the villa is an
old sun-dial said to be the work of Galileo,
238 COMPLETION OF DIALOGUES [1630-
view of the surrounding country, extending from
the wooded heights of Vallombrosa on the east, to
the distant Carrara mountains on the west; and
from Certosa and away along the Roman road to
the south, to the heights of old Fiesole on the north,
with the Val d'Arno and Florence in between.
" Of all the fairest cities of the earth
None is so fair as Florence."
-—ROGERS' Italy.
A chamber in the tower is arranged as a
Galilean Museum, and is full of relics of the
philosopher and his contemporaries, as portraits,
busts, engravings, autographs, and medals ; instru-
ments of various kinds, as telescopes, thermometers,
hour-glass, etc. Amongst the paintings we would
particularly direct the visitor's attention to those of
Galileo before the Inquisition ; Galileo, blind and
in bed, dictating to his son and his last disciples
Viviani and Torricelli ; and portraits of the two
latter.1
It is popularly supposed that Galileo used
the Torre del Gallo as an observatory. There
seems, however, to be no ground for this belief;
but that he sometimes came here to enjoy the
grand panorama displayed from the top is likely
enough*
Not far from the Torre del Gallo, and still on
the way to Florence, one comes to the Piazza degli
UganellL Here the great painter Sustermans
1 Quite recently the Torre del Galio has changed hands, and the
Galilean relics, etc., have been dispersed.
The Torre del Gallo, Arcetri, Florence.
{To face /. 238.
i632] OBSTACLES TO PRINTING 239
lived, and here in 1635 he painted his celebrated
portrait of Galileo. A photographic copy of this
is reproduced as the frontispiece to this volume.
This picture, which is thought by experts to be
Sustermans' chef cfceuvre, has a history. It was
sent by Galileo as a present to his friend and .cor-
respondent, Elia Diodati of Paris. Twenty years
later, and as a special favour, it was returned to the
Grand Duke; and later still it was placed in the
Uffizi Collection by Cardinal Leopoldo de Medici —
" In order to show to all two marvels of nature, in
the person of him who is represented, and in the art
of the painter/*1
All this time, from soon after his return from
Rome, Galileo was tormented with the obstacles
and delays which he encountered in the printing of
his Dialogues. It would detain us too long and be
little profitable to set out these complications in
detail ; but they are so well summarised by Galileo
himself in a letter of /th March 1631, to Chief
Secretary Cioli, that we venture to reproduce it as
follows : —
" As your Lordship knows, I went to Rome for
the purpose of getting permission to publish my
Dialogues, and to this end I put them in the hands
of the Master of the Sacred Palace, who committed
them to the care of his colleague, Father Raffaele
1 Sustermans was born in Antwerp 1597, settled in Florence
and there died in 1681. There is another portrait of Galileo in the
Pitti Palace Collection (No. 106, Hall of Mars), which has been
attributed to Sustermans, but is now supposed to be the work of one
of his pupils. See on this disputed point Favaro's "Document!
Inediti per la Storia dei Manoscritti Galileiani," Rome, 1886, pp. 102-3
and 109.
240 COMPLETION OF DIALOGUES [1630
Visconti, that he may examine them with the
greatest attention, and note any doubtful matter or
any conceit of imagination requiring correction,
which (at my own request also) he did most
thoroughly. And when I entreated the Rev.
Master to grant me the required licence, his
Reverence signified his wish to read the whole
MS. through once more. This was done, after
which he returned the book with the licence signed
with his own hand; whereupon I, having been in
Rome for two months, returned to Florence, in-
tending to send back the book (as soon as I had
added the dedication or preface, the conclusion, and
a few other necessary things) to the illustrious
Prince Cesi, President of the Lyncean Academy,
who had always superintended the printing of my
works. But owing to the death of this Prince
[on 2nd August 1630] and the interruption of
communications [by the plague], I was hindered
from printing the work in Rome, and decided on
having it done here. I had arranged matters with
an able printer and publisher, and had procured the
licence of the Rev. Vicar, and of the Inquisitor, and
also of the illustrious Signor Niccolo Antella. I
informed the Rev. Master of the Palace of all that
had taken place, and of the impediments in the way
of the printing in Rome. Whereupon he informed
me, through our Ambassador, that he wished to
have another look at the book, and that I was to
send him a copy. On this I came to you, as you
know, to ask if it were possible to send such a large
volume to Rome with security, and you replied
certainly not, and that letters were hardly safe.
On this I wrote again, stating the impediments, and
offering to send the preface and the end of the
book, to which the superior authorities might add if
they saw fit, or take away, or add notes of explana-
tion ; for I myself do not refuse to call these
i633] OBSTACLES TO PRINTING 241
thoughts of mine chimeras, dreams, paralogisms,
and vain imaginations, submitting the whole to the
absolute wisdom of my superiors. As to the further
revision of the body of the work, I suggested it
might be done here by some person named by the
Rev. Father. He was content that it should be
so, and accordingly I sent him the preface and the
end, and he authorised Father Jacinto Stefani,
Counsellor of the Inquisition in Florence, to revise
the work. This he did with the greatest care,
observing even the minutest points which neither
to him nor to my most malignant adversary could
five the slightest umbrage.1 Indeed, the Rev.
ather declared that the reading of my book
had drawn tears from him more than once, when
he saw with what humility and reverent submission
I deferred to the authority of my superiors. And
he declares, as do all who have read the book, that
I ought to be entreated to publish it, instead of
being hindered in so many ways, of which I need not
here adduce examples.
" Weeks and months ago I heard from Father
Castelli that he had often met the Rev. Master
who had given him to understand that he was
going to send back the preface and the end,
arranged to his entire satisfaction ; but this has not
yet been done.2 The papers have been thrown
aside into some corner, and my life is wasting away,
and I am in continual trouble. I went into town
1 " The reviser here, finding nothing to alter, but in order to show
that he had gone carefully through the MS., contented himself with
substituting some words for others, as for instance, in several places,
'universe1 for ' nature,1 { quality' for Attribute,' 'sublime spirit' for
* divine spirit » — excusing himself to me by saying he foresaw that I
should have to do with fierce foes and bitter persecutors, as indeed
has come to pass."— Galileo to Elia Diodati, I5th January 1633.
2 Evidently some intrigue was afoot in Rome to stifle the book.
Castelli wrote 24th August 1630, recommending for many most
weighty reasons, which he did not wish just then to put on paper,
that the work be printed in Florence, and as quickly as possible.
Q
242 COMPLETION OF DIALOGUES [1630
yesterday at my Serene Master's command, to see
the designs for the facade of the Cathedral, and also
wishing to avail myself of his kindness, so that,
taking counsel with your Excellency, some means
may be found for making the Rev. Master explain
himself — as that the Ambassador be instructed to
signify his HIghness's desire for a termination of
this weary business, and to let him know what sort
of man his Highness has for a servant. But so ex-
ceedingly troubled was I that I could neither speak to
his Highness nor look at the designs. Just now a
messenger from Court has come to know how I
am, and truly I am in such a state that I should
not have risen from my bed had I not wished so
particularly to tell your Lordship of this business,
and to beg you to do for me that which I was
unable to do yesterday, and to take the matter into
your own hands, so that I may, while life yet
remains, see what result I may expect from all my
long and heavy labours. I send this by the hand
of the Court messenger, and shall await your reply
through Signor Geri Bocchineri. And since his
Highness is so anxious to learn the state of my
health I beg you to tell him that I should be pretty
well in body, were I not so afflicted in mind."1
The ambassador, Niccolini, was instructed to
act in accordance with Galileo's wishes, and after
1 In this letter Galileo refers incidentally to one of the few occa-
sions on which his advice was sought in the public service, so far as
we know from documentary evidence. Another occasion occurred a
short tim'e previously, namely, a disastrous inundation of the river
Bisenzio. His report, in which he recommended the canalisation of
the river, is dated i6th January 1631, and addressed to Raflaello
Staccoli, the Auditor-General of Tuscany. On the 22nd July of the
same year, he addressed another report to the Grand Duke on the
proposed canalisation of the Arno. For some interesting information
on these subjects, see Napier's "Florentine History," London, 1847,
vol. vi pp. 393-448.
1632] OBSTACLES REMOVED 243
more months of vexatious objections and delays,
and not until, as Niccolini says, "formally pulled
by the hair," Riccardi sent back the preface
and end, now quite In order, to the censor in
Florence. In his covering letter of lyth July
1631, he says : —
" Conformably to the orders of our Lord (the
Pope) respecting Signor Galileo's book, besides
what I wrote to your Reverence concerning the
body of the work, I send you the preface, with
liberty to the author to alter or embellish as to
the wording, so as the substance is preserved.
The end may be treated in the same way."
By early autumn, and after a second Revision
of the whole work by Father Stefani in accordance
with precise instructions from Rome, all the con-
ditions of the censorship were finally complied
with, and permission to print the book in Florence
was issued in due form of Imprimatur. In all
these annoying hindrances Galileo had a foretaste
of the persecution which was to be his lot for the
rest of his life.
We shall devote the rest of this chapter
to giving an idea of the plan and style of the
work, and a rdsumt of its contents. The book,
which is dedicated to Ferdinando II., bears the
following title, unusually long in an age of long
titles : — " Dialogue of Galileo Galilei, Lyncean,
Mathematician Extraordinary of the University
of Pisa, Philosopher and First Mathematician
of the Most Serene Grand Duke of Tuscany ;
where in meetings of four days are discussed
the Two Principal Systems of the World, in-
244 CONTEXTS OF DIALOGUES [1630-
determmately proposing the Philosophical and
Natural arguments, as well on one side as on
the other." It is written in Italian, and in a
style adapted not for the learned alone, but
intelligible and attractive to every one of ordinary
education. His reason for writing in Italian
instead of in Latin — the usual vehicle fo
philosophical subjects — is characteristic.
"I write in Italian," he says, " because I wish
every one to be able to read what I say. I see
young men brought together indiscriminately to
study to become physicians, philosophers, etc.,
who although furnished, as Ruzzante might say,1
with a decent set of brains, yet being unable to
understand things written in gibberish, assume
that in these crabbed folios there must be some
grand hocus pocus of logic and philosophy much
too high up for them to jump at. I want such
people to know that as Nature has given eyes to
them just as well as to philosophers for the purpose
of seeing her works, so she has given them brains
for examining and understanding them."
The dialogue is carried on by three inter-
locutors, two of whom adduce the scientific
reasons for the double motion of the earth,
while the third honestly tries to defend the
opinions of the Ptolemaic and Aristotelian
schools. Galileo gave to the defenders of the
Copernican doctrine the names of two of his
warmest friends, both long dead — Filippo Salviati
of Florence (died 1614), and Gio Francesco
1 Ruzzante, whose real name was Angelo Beolco, was a Paduan
(1502-1542), and the writer of racy stories and ridiculous incidents in
the Paduan dialect
j632] PLAN OF THE WORK 245
Sagredo of Venice (died 1620). Salviati is the
special advocate of the Copernican doctrines ;
Sagredo is witty, impartial, and open to con-
viction, a half convert, but an acute and ingenious
one. To him are allotted the objections which
seem to have some real force, as well as lively
illustrations and digressions which would be
inconsistent with the gravity of Salviati's
character. Simplicio, a name borrowed from
the noted Sicilian commentator of Aristotle who
wrote in the sixth century,1 is of course a con-
firmed Ptolemaist and Aristotelian, and produces
successively all the scientific arguments of the
peripatetic school ; and as these fail to convince,
he has recourse to all the arts of sophistry.
Placed between the wit and the philosopher,
it may be guessed that his case fares badly, in
fact, he is chaffed and confuted at every turn,
so that no unbiassed reader can fail to perceive
the superiority of the modern theory; and as
Galileo puts into the mouth of Simplicio not
only every possible argument in favour of his
case, but also every possible objection to the
other side, this superiority is made to appear
all the more striking.2
The condition that the Copernican doctrine is
only to be treated as an hypothesis is ostensibly
1 Miss Clerke (verbo Galileo, " Encyc. Brit") says that this choice of
name was " doubtless instigated by a sarcastic regard to the double
meaning of the word"; but there seem to be no grounds for the
suggestion. Indeed, Galileo says distinctly in his preface that the
name was suggested by that of Aristotle's commentator. The name is
used again in his " Dialogues on the New Sciences," published in 1638.
2 A favourite method, see p. 161 ante.
246 CONTENTS OF DIALOGUES [1630
coxnpiied with, If Salviati or Sagredo show the
untenableaess of some Ptolemaic axiom, or add
a stone to the Copernican structure, a remark
is interpolated by one or other to weaken the
effect. When, for instance, it is said that the
final decision in the controversy rests neither
with mathematics and physics, nor with logic
and philosophy, but with "a higher insight";
or when Salviati repeatedly asserts that he does
not wish to maintain the Copernican doctrines as
true, and uses the qualifying word " possible,"
or speaks of them as " fantasies" and "most
vain chimeras/' the reader cannot fail to see
that these reservations, which always occur
at critical moments, are made with the purpose
of appeasing the censors.
When we remember its history we cannot be
surprised that the preface or introduction has no
logical agreement with the contents of the
Dialogue. It is addressed "To the Discreet
Reader," and runs as follows : —
"Some years ago a salutary edict was
promulgated at Rome, which, in order to obviate
the perilous scandals of the present age, enjoined
an opportune silence on the Pythagorean opinion
of the earth's motion. Some were not wanting
who rashly asserted that this decree originated,
not in a judicious examination, but in ill-
informed passion ; and complaints were heard that
counsellors totally inexperienced in astronomical
observations ought not by hasty prohibitions to
clip the wings of speculative minds. My zeal
could not keep silence when I heard these rash
lamentations, and I thought it proper, as being
i632] FLAN OF THE WORK 247
fully informed with regard to that most prudent
edict, to appear publicly as a witness of the actual
truth. I happened at that time to be in Rome ;
I was admitted to the audiences, and enjoyed the
approbation of the most eminent prelates of that
Court; nor did the publication of the aforesaid
decree occur without my receiving some prior
intimation of it Wherefore it is my intention
in this present work to show to foreign nations
that L- much of this matter is known in Italy
(and particularly in Rome) as ultramontane
diligence can ever have formed any notion of,
and (collecting together all my own speculations
on the Copernican system) to show them that
the knowledge of all these preceded the Roman
censures, and that from this country proceed not
only dogmas for the salvation of the soul, but
also ingenious discoveries for the gratification of
the understanding. With this object I have
taken up in the dialogue the Copernican side of
the question, treating it as a pure mathematical
hypothesis, and endeavouring in every artificial
manner to represent it as having the advantage,
not over the opinion of the stability of the earth
absolutely, but over it as taught and defended
by some who profess to be peripatetics, but
retain only the name, and are content, without
improvement, to worship shadows, not philoso-
phising with their own reason, but only from
the recollection of four principles imperfectly
understood."1
The conclusion agrees no better than the
preface with the body of the work. At the end
of the fourth day, which is almost wholly taken
up with the question of the tides, comes naturally
1 It will be noted that this preface is in much the same style as
the introduction to his Ingoli letter. See p. 2*2 ante.
248 CONTEXTS OF DIALOGUES [1630-
the Popes 4< unanswerable " argument of 1624
(p. 230 ante). Salviati treats it accordingly : —
"It is," he says, "an admirable and truly
angelic argument, and perfectly in accord with that
which, coming from God Himself, permits us to
discuss the constitution of the world — doubtless
with the view of preventing (by exercising them)
the diminution and enfeeblement of our intellectual
faculties, while withholding from us the power of
fully comprehending the works of His hands. May
this exercise (permitted and ordained by God) en-
able us to see and admire His greatness, which is
all the more necessary since we shall never be able
to penetrate the depths of His infinite wisdom. "
Sagredo then says : —
" Let this reflection be a fitting conclusion to
our four days' discussion. And now, if Salviati
desires some repose, our curiosity will concede the
delay, but only on condition that at his earliest
convenience he will satisfy us as to the problems
reserved for future meetings. For myself, I am
extremely anxious to hear his exposition of the
elements of the new* science of local motions,
natural and violent, as elaborated by him."
As regards the contents of the Dialogues, we
can only give an outline. Salviati opens the
conference by defining its object, which is to
examine all the physical arguments evoked for
and against their opinions by the defenders of
Aristotle and Ptolemy on the one hand, and of
the Copernican doctrine on the other.
No discussion could be undertaken without first
enquiring into Aristotelian doctrines, which formed
the basis of current theory. In a few words those
i63a] FIRST "DAY" 249
amounted to a statement, that whereas things
earthly are imperfect and full of change, things
heavenly are eternal, unchangeable, and perfect.
Salviati proves that this statement, in the spirit in
which it was usual to accept it, was in reality un-
tenable. The telescope showed him imperfections
on the sun's surface, which was contrary to the be-
lief that that body was unchangeable and free from
blemish. He lays no great stress on the instance
of comets (whose real nature Galileo never under-
stood), but quotes the recent new stars (of 1572
and 1604) as instances of further change in the
heavens. He thus prepares the way for a still
wider departure from Aristotelian theory ; he insists
that the time has come to consider the nature of
the world de novo, respectfully suggesting that
Aristotle, had he the opportunities which the in-
vention of the telescope afforded, would himself
have been the first to realise the inadequacy of
his dogmas on this subject.
Salviati proceeds to poi«it out certain resem-
blances between the earth and moon and the
more distant heavenly bodies. It is shown that
the moon only shines in virtue of the sunshine
falling on her. The idea that the earth might
similarly appear luminous to any inhabitant — could
one be imagined to exist — on the moon is less
familiar, and less readily accepted. And yet the
visibility of the moon during a total eclipse of
the sun, and the appearance " of the old moon in
the arms of the new" (as we now speak of it),
are more probably due to reflected earth-light than
to any other cause. This is discussed at some
250 CONTENTS OF DIALOGUES [1630
length, and the phenomena of Venus's phases
(revealed by the telescope) are shown to be
similar to those of the moon, and may be ex-
plained as due to the same cause. Venus then,
like the moon, owes her brilliance to sunlight
falling on her. The same probably applies to
Mercury and Mars. The obvious inference seems
to be that all of these heavenly bodies are not
so unlike the earth as men had always been
taught to believe. Points of resemblance there
certainly are, and there may be many more, which
the distance of the planets alone prevents us
from discovering. Salviati refers to the common
spherical form of earth, sun, moon, and planets,
suggesting the existence of a common cause for
that shape. The passage is striking enough to
quote : —
" Just as from the mutual and universal tendency
of the parts of the earth to form a whole, it
follows that they all meet together with equal in-
clination, and, that they may unite as closely as
possible, they assume the spherical form, and so
we ought to believe that the moon, the sun,
and other mundane bodies are also of a round
figure, if for no other reason than from a common
instinct and natural concourse of their component
parts ; whence, if by accident any one should be
violently separated from its whole, it is reasonable
to believe that spontaneously and of its natural
instinct it would return*"1
\ Here follow some remarks which show that the idea of universal
gravitation hovered round Galileo's mind without fully entering it.
He perceived the analogy between the power which holds the moon
in the neighbourhood of the earth, and compels Jupiter's satellites to
circulate round their primary, and that attractive power which the
earth exercises on bodies at its surface ; but he failed to conceive the
1632] SECOND "DAY" 251
Having laid stress on the resemblance of earth
and planets as a probable theory, SalviatI proposes
for them all a similar motion round the sun— one
of the two main points of the new Copernican
doctrines. He shows how by this hypothesis the
apparent paths of the planets can all be explained.
And the simplicity of his explanation as contrasted
with the Ptolemaic system appeals to common-
sense, in a way which in itself almost carries
conviction. A glance through a telescope turned
towards Jupiter shows a family of small bodies
circling round a great planet; here one could see
on a small scale the very thing that Copernicus
had described as going on in the case of planets
and sun on a much larger scale, the sun being
in the latter case the central body which corre-
sponded with Jupiter in the other,
On the second "Day" the discussion passes
on to the other chief point in the Copernican
hypothesis, that the daily motion of the stars is
only apparent, being due to a real daily rotation
of the earth on its polar axis. Various objections
are brought against this. The opponents of the
earth's diurnal motion maintained that, if that
motion were real, a stone dropped from the top
of a tower would not fall at its foot. In the same
way it was stated that a stone dropped from
the masthead of a ship would fall near the stern,
in consequence of the ship's velocity. But, strange
as it seemed to Simplicio, it is nevertheless true
combination of central force with initial velocity, and was disposed to
connect the revolutions of the planets with the axial rotation of the
sun — a notion which tended more towards Descartes' theory of vortices
than towards Newton's theory of gravitation.
252 CONTENTS OF DIALOGUES [1630-
that the stone falls at the foot of the mast, the
ship's motion, provided it be uniform, having no
power to disturb its fall In a variety of forms
the argument is brought forward, that if the earth
be really rotating we on its surface ought to be
sensible of the fact, either by our direct power of
feeling, or else by irregularities in the motion of
the things about us. There is a single reply to
all such contentions, viz., all bodies on or near
the earth's surface share the earth's motion, even
the lower parts of the atmosphere being carried
on by it, and, therefore, as all such things have a
common motion, their relations to one another
are just as if the motion did not exist. " Motion is
so far motion (and as motion it operateth) by how
far it hath relation to things which want motion ;
but in those things which all equally partake
thereof it hath nothing to do, and is as if it
never were." Salviati justifies this contention by
a forcible illustration. A ship is out for many
months on an ocean voyage, touching at various
ports, and sailing now east, now west. Fix the
attention on a single bale of cargo, packed tight
in the hold ; and, though the ship may have been
tossed about in all directions by winds and waves,
we are justified in saying that that particular bale
of cargo has not moved during the long journey
from port to port. Let the mate go down into
the hold and disturb that bale from its place by
one inch, and it has had in relation to the rest
of the cargo a greater motion than it acquired
during all the time that ship and cargo were
voyaging together ; the disturbances that were
1632] THIRD "DAY" 253
common to all had no visible effect inside the
hold.
No objections to the hypothesis of the earth's
rotation being found tenable, it is shown by Salviati
how much more simple is the real motion proposed
than the supposition that the universe revolves
daily round a fixed earth. " To make the universe
revolve/1 he says, " in order to maintain the immo-
bility of the earth is as little reasonable as to
require, in order to see Venice from the top of
the Campanile, that the whole panorama should
move round the spectator instead of his simply
moving his head."
The primitive notion of the stars as fixed in
a crystal sphere had been long overthrown. And,
supposing accordingly that the stars were distinct
and independent bodies, it was difficult to imagine
laws controlling their motion about a fixed earth
that should result in revolutions timed uniformly
for all and at the same time of enormous rapidity.
Salviati makes the improbable to be practically
impossible by referring to the phenomenon now
known as the "precession of the equinoxes," in
virtue of which the direction of the earth's axis
in space moves slowly, completing a revolution
in about 26,000 years. The system of stellar
motions that would be necessary to account for
this would be inconceivably complex.
A great part of the third "Day" is devoted
to the question of stellar parallax. In this lay
one of the most serious difficulties of the Coperni-
can theory. If it was true that the earth swept
round the sun in a circular orbit some two hundred
254 CONTENTS OF DIALOGUES [1630
millions of miles in diameter, then it must follow
that at one time of the year we should get an
entirely different view of the arrangement of the
stars from that obtained six months earlier or later
when the earth was at the opposite point of its
orbit. The nearer stars should in fact undergo
displacements in their apparent positions relative
to those more distant The answer to this was
that these displacements probably did take place,
but were too minute to be detected. But this
answer, though strictly true, implied that the
distances of even the nearest stars were great
beyond all comprehension ; and this in turn implied
that the visible size of the stars indicated a real
size of inconceivable dimensions. The latter diffi-
culty was reduced by Salviati's assertion that the
visible size of a star was an optical illusion ; the
telescope showed the stars to be sharp points, in
contrast to the planets which, though small to the
eye, really did possess visible dimensions. But
the former difficulty remained, and nearly two
centuries passed before Bessel made the first rough
measurement of a stellar parallax. His method
was essentially that suggested in the dialogue
by Salviati; though the results obtained indicated
for the star 61 Cygni, a distance which would
probably have astonished even Galileo himself.1
With the difficulties of stellar parallax still
uppermost in his mind, Simplicio looks at the
utilitarian side of the question, and remarks : —
" All this is very well, and it is not to be
1 More recent measurements fix the distance of this star at about
400,000 times that of the sun.
1632] THIRD "DAY" 255
denied that the heavens may surpass in extent
the capacity of our imaginations, nor that God
might have created them a thousand times larger
than they are. But we ought not to admit
anything to be created in vain, or useless in the
universe. Now we see this beautiful arrangement
of the planets disposed round the earth at distances
proportioned to the effects they are to produce
upon us for our benefit. To what purpose, then,
should such a vast vacancy be afterwards inter-
posed between the orbit of Saturn and the starry
spheres, containing not a single star, and altogether
useless and unprofitable? to what end? and for
whose use and advantage ? "
SALVIATI : " Methinks we arrogate too much to
ourselves, Simplicio, when we assume that the
care of us alone is the adequate and sufficient
work and limit beyond which the Divine wisdom
and power do nothing and dispose of nothing.
I feel confident that nothing is omitted by God's
providence which concerns the government of
human affairs ; but that there may not be other
things in the universe dependent on His supreme
power, I cannot, with what power of reasoning
I possess, bring myself to believe. So that when
I am told of the uselessness of an immense space
interposed between the orbits of the planets and
the fixed stars, I reply that there is temerity in
attempting by feeble reason to judge the works
of God, and in calling vain and superfluous every
part of the universe which is no use to us."1
SAGREDO: "Say rather that we have no means
of knowing what is of use to us. I hold it to be
one of the greatest pieces of arrogance and folly
that can be in this world to say, because I know
1 It is in the course of this discussion that Galileo says, "The
space Comprised between Saturn and the fixed stars is, perhaps,
occupied by invisible planets." The discovery of Uranus and Neptune
has confirmed this conjecture.
256 CONTENTS OF DIALOGUES [1630-
not what use Jupiter and Saturn are to me, that
therefore these planets are superfluous. Nay
more, that there are no such bodies in existence.
To understand what effect is worked upon us by
this or that heavenly body (since you will have
it that all their uses must have a reference to
us) it would be necessary to remove it for a while,
and then the effect which I find no longer pro-
duced on me, I may say depended on that body.
Besides, who will dare to say that the space (called
too vast and useless) between Saturn and the fixed
stars is void of other bodies belonging to the
universe? Must it be so because we do not see
them? Then, the four Medicean planets and the
companions of Saturn came into the heavens when
we began to see them, and not before! And by
the same rule the innumerable host of fixed stars
did not exist before men saw them. The nebulae,
which the telescope shows us to be constellations
of bright and beautiful stars, were, till the telescope
was discovered, only white flakes! Oh, presump-
tuous! rather, oh rash ignorance of man." l
Towards the end of the third "Day," reference
is made to an annual rotation of the earth about
an axis perpendicular to the plane of its motion.
In ancient and mediaeval times a simple state of
revolution of the earth round the sun would have
implied a revolution in which the same side of
the earth was always turned to the sun ; the
1 Compare this with the "arguments" of Galileo's peripatetic
opponents: — "Animals that are capable of motion have joints and
limbs ; the earth has neither joints nor limbs, therefore it does not
move. The planets, the sun, and the fixed stars are all of one
substance, that is to say, of the substance of stars ; therefore they
either move together or stand still together. It is to the last degree
unseemly to place among the celestial bodies, which are divine and
pure, the earth, which is a sewer of filth." "Difesa di Scipione
Chiaramonti," Florence, 1633.
i632] THIRD "DAY" 257
moon, according to this description, was said to
revolve simply round the earth without any rotation
of her own, which is not the way in which her
motion would be described at the present day.
Accordingly, in stating the earth to have a revolu-
tion round the sun combined with a rotation about
an axis, Copernicus would have implied that that
axis continuously changed its position in space
so as to be always in the same direction relatively
to the sun. To indicate that as a matter of fact
the position of the axis with regard to the sun
varied, but remained the same with regard to space,
Copernicus had to combine with his two chief
motions a third one of annual rotation.
This third rotation was therefore a complication
only introduced by confusion in geometrical
thought. That the actual state of things is quite
simple is illustrated by Salviati by a reference
to the motion of a ball floating in a basin of
water. If the basin be held in the hand, the
ball floating at or near the centre, and the
experimenter turn round steadily on his feet,
holding the basin in front of him, the ball
remains in a position which is unaltered with
reference to the walls and furniture of the room ;
although with reference to the man supporting the
basin, it might be said to have spun once com-
pletely round. And so with regard to the annual
rotation spoken of by Copernicus, Salviati says :
"What other is the earth than a globe librated
in tenuous and yielding air? That which you
think to be a revolution in itself, you will find
to be a not moving at all, but a continuing to
R
258 CONTENTS OF DIALOGUES [1630-
be altogether immovable in respect of all that is
immovable."
It is here that he speaks so approvingly of
the labours of his great English contemporary,
William Gilbert of Colchester.1 He explains
Gilbert's theory of the earth as a huge magnet,
and develops it, mentioning incidentally some
observations and experiments of his own on
magnetic phenomena — notably on the increased
power of magnets when suitably provided with
armatures.
The attractive and repulsive properties of
magnets reminded Simplicio that in considering
the causes of natural phenomena, some effects
are attributed to sympathy which is an agreement
and mutual appetency between things having the
same qualities, while other effects are due to
antipathy when things naturally repel and abhor
each other.
"And thus/' cuts in the wag, Sagredo, "with
these two words they are able to give a reason
for a great number of effects which we see, not
without admiration, to be produced in nature.
But it strikes me that this mode of philosophising
is not unlike the style in which one of my friends
used to paint. On his canvas he would write
with chalk: here a fountain with Diana ahd her
nymphs; here some harriers; in this corner a
huntsman with a stag's head; the rest may be
a landscape of wood and . mountain ; and what
remains to be done may be put in by the colour-
1 " I glorify," says Salviati, " I admire, and I envy this great author
his marvellous conception of the earth as a magnet." Quite at the
end of this " Day " Gilbert and his opinions are again referred to. See
p.
i633] FOURTH "DAY" 259
man. Thus he flattered himself that he had
painted the story of Acta&on, having contributed
nothing towards it beyond the names!"
The fourth "Day" of the Dialogue is devoted
entirely to an examination of the cause of the
tides, and is a development and extension of
his letter on the same subject to Cardinal Orsini,
1616. It is a singular circumstance that the
argument, upon which Galileo mainly relied as
furnishing a physical demonstration of the truth
of the Copernican theory, rested on a misconcep-
tion. The ebb and flow of the tides, he said,
are a visible effect of the terrestrial double move-
ment, since they are the combined result of (i)
the earth's daily rotation, and (2) the inequality
of the absolute velocities of the various parts of
the earth's surface in its revolution round the
sun. To this notion he attached capital importance,
and he ridiculed Kepler's suggestion (which,
however, was nearer the truth) that the attraction
of the moon was in some way concerned in the
phenomenon. That the influence of the moon was
paramount had indeed been recognised in ancient
times, but a scientific explanation in detail was
not to be expected until the law of universal
gravitation had been fully realised.
This last part of the dialogue is therefore of
little value, and may be passed over in considering
the discussions of the first three "Days." The
chief work of the dialogue was to establish the
Copernican theory; which, first promulgated in
the days when human vision was unaided, had
been found by Galileo to be supported by all
260 CONTENTS OF DIALOGUES
evidence that could be gathered by means of his
new invention. The problem — if it may be still
said to exist — takes a slightly different form at
the present day. So far are we now from the
pre- Copernican theory of a fixed earth, that we
look upon no single object in the whole universe as
fixed. The sun itself has its motion amongst
the other visible stars ; the present direction and
rate of that motion are roughly known. Accord-
ingly, the alternative which offered itself to the
controversialists of Galileo's day, that either the
sun or the earth was stationary, does not concern
us ; both of the bodies are moving. They move,
however, in such a way that the motion of the
sun is sensibly uniform, while the earth and the
other planets can only be reasonably spoken of
as travelling around him while he with his family
of satellites is advancing through space.
With this understanding as to what is meant
when we speak of the sun, though not stationary,
being the centre of the planets' motions, it need
scarcely be mentioned that the Copernican theory
has acquired, since the days of Newton, an enormous
mass of evidence, which in a work of the present
type it would be out of place to discuss. But
whereas Copernicus and Galileo made it a question
practically for common-sense to choose between
the simple and the geometrically complex,
dynamical evidence has now made any alternative
to the simple explanation not only difficult but
altogether beyond comprehension ; the main points
of the Copernican doctrines are proved as
absolutely as anything in science can be proved.
i632] VALUE OF THE DIALOGUES 261
This beautiful volume now so forgotten, of
which we feel we have given an inadequate idea,
is not simply a treatise on astronomical and
physical science — a powerful plea for Copernicanism
in a country and at a time when all science was
" vehemently suspected"; it is a book worthy
of Socrates — a book which ought to be studied
by those who love free observation and experiment,
free discussion and circulation of ideas — in a word,
freedom of thought, as the first essential to the
progress of science and of our common humanity.
In the words of Professor Play fair : —
"One forms a very imperfect idea of Galileo
from considering the discoveries and inventions only,
numerous and splendid as they are, of which he was
the author. It is by following his reasonings and
by pursuing the train of his thoughts in his own
elegant though somewhat diffuse exposition of them
that we become acquainted with the fertility of his
genius — with the sagacity, penetration, and com-
prehensiveness of his mind. The service which he
rendered to real knowledge is to be estimated, not
only from the truths which he discovered, but from
the errors which he detected — not merely from the
sound principles which he established, but from the
pernicious idols which he overthrew. The Dialogues
on the Two Systems are written with such singular
felicity that one reads them at the present day,
when the truths contained in them are known and
admitted, with all the delight of novelty, and feels
one's self carried back to the period when the
telescope was first directed to the heavens, and
when the earth's motion with its train of consequences
was proved for the first time. Of all the writers
who have lived in an age which was only emerging
from ignorance and barbarism, Galileo has most
262 CONTENTS OF DIALOGUES [1630-1632
entirely the tone of true philosophy, and is most
free from the contamination of the time in taste,
sentiment, and opinion/'1
* "Playfair's Dissertation," Supp. "Ency. Brit," 7th Ed. The
Dialogues occupy the whole of vol. i. in Albert's edition of the Works
of Galileo, 1842-56, and two- thirds of vol. vii. of Favaro's edition. An
English translation was brought out by Thomas Salusbury in 1661.
CHAPTER XII
PUBLICATION OF THE DIALOGUES — GALILEO AND THE
INQUISITION
1632-1633
BY the beginning of January 1632, the printing of
the Dialogues was so far advanced, that on the 3rd
Galileo was able to inform his friend Cesare Marsili
at Bologna that the work would be ready in ten
or twelve days. It did not, however, appear till
February. On the 22nd of that month Galileo
presented copies to the Grand Duke (his former
pupil) to whom the work was dedicated, and to
other members of the Medici family. Next day he
sent thirty-two copies to Marsili ; and had a number
handsomely bound for friends and patrons in Rome,
but they could not be despatched, owing to the con-
tinued prevalence of the plague. Indeed, it was
not till May that two unbound copies reached the
Eternal City. One of these came into the hands of
Cardinal Francesco Barberini (the Pope's nephew),
who lent it to Castelli. . The latter writing to
Galileo, 29th May, expressed his admiration for the
work which surpassed all his expectations.1 Shortly
afterwards, Cohte Filippo Magalotti, Galileo's friend
1 In a previous letter, 26th September 1631, the good Father vowed
that when the book appeared he would read no others than it and his
Breviary.
264 PUBLICATION OF DIALOGUES [1632-
and, from his relationship to the Barberini family
an influential personage, imported eight copies, and,
at the author's request, presented one each to
Cardinal Antonio Barberini, the Pope's brother;
Niccolini, the Tuscan Ambassador ; Father Riccardi
the Press Censor ; Mgr. Serristori, Counsellor of the
Inquisition or Holy Office; and the Jesuit Father,
Leon Santi.
While these copies were being eagerly read in
Rome, and passed from hand to hand, the book had
been circulating in all parts of Italy, in spite of the
obstacles to communication caused by the plague.
The applause with which it was received by all men
of independent minds was tremendous ; but in this
paean of praise there was one solitary note of
warning — a note which would probably have been
unheeded even if it came in time. Paolo Aproino,
having read a MS. copy which Galileo had sent to
Micanzio at Venice, begged his friend to write and
advise the author to pause ere he printed a book
containing such startling doctrines. Micanzio thought
it better that Aproino should himself write, which he
did on 1 3th March — a month too late. Aproino s
advice was to send MS. copies to the public libraries
in the capitals of Europe, with permission for copies
to be made by those who might wish to have them.
This would prevent the dissemination of his revolu-
tionary doctrines amongst the ignorant and ill-
disposed who would only use them as a weapon for
his destruction, while as to the enlightened and
unprejudiced, no one would grudge the expense of a
written copy of such a precious work.
Great as was the applause on the one side, so on
i633] RECEPTION OF DIALOGUES 265
the other side was the consternation which the book
created among the followers of the old school of
thought. The educated world of Italy was then
divided into two hostile camps — that of Aristotle
and Ptolemy on the one side ; and that of Coper-
nicus, Galileo, and Kepler on the other. In the
first were to be found blind worship of authority,
and unquestioning adherence to ancient doctrine ;
in the second, freedom of thought, research, recog-
nition of demonstrated truths — in a word, progress.
As was to be expected, the first-named party was
the most numerous and noisy, and it was reinforced
by all those who opposed the innovators from
interested motives. Foremost amongst these were
the members of the Order of Jesus. They claimed
for themselves the monopoly of instruction, and the
first rank in the learned world, and were jealous of
all intruders. Galileo was therefore in every way
inconvenient to these people. Besides, had he not
measured swords with distinguished members of the
Order, as Fathers Scheiner and Grassi and (unfor-
givable offence) had he not worsted them? And
now his Dialogues appeared in which some old
sores are re-opened ; this revolutionary book must
be suppressed at all costs, and with it its detested
author.
Father Riccardi, the censor, was the first to
announce the coming battle. One day early in
August he remarked to Conte Magalotti, "the
Jesuits will now persecute Galileo with the utmost
bitterness."1 It is important to establish this fact
Scheiner in a conversation with Torricelli would
* Letter, Magalotti to Guiducci, ;th August 1632.
266 PUBLICATION OF DIALOGUES [1632-
say little about the Dialogues, he found the digres-
sions tedious (and no wonder, for some of them
referred to himself), he did not wish to say much
on the subject, but, he significantly added, "Galileo
has treated me very badly." x Then Scheiner himself,
writing to Gassendi of Paris, 23rd February 1633,
says : —
"In these Dialogues the author has made null
all my mathematical researches, and has laid violent
hands on my ' Rosa Ursina,' on my discovery of the
annual movement of the Sun-spots, and of that of
the sun himself. I am preparing to defend myself
and the truth."2
Before the date of his conversation with
Magalotti just mentioned, it came to the ears of
Riccardi, that some " ill-disposed persons7' were
trying to discover something in the book which
could form the basis of an accusation against its
author; they found something on the engraved
title-page ! The words " Dialogo di Galileo Galilei,
Linceo, al Ser™. Ferd. II Gran. Duca di Toscana"
are printed on the field of a pavilion, with the
five palle or balls, the armorial bearings of the
Medici, and surmounted by the Grand Ducal crown.
Below, on the shore of a sea stand three persons
disputing — Aristotle, Ptolemy, and Copernicus, the
two latter having their names printed on the edge
1 Letter, Torricelli to Galileo, nth September 1632.
s " The Rosa Ursina " was published in 1630, and was a fierce
attack on Galileo personally. No direct answer was made, but in
several passages in the Dialogues the book received some hard
knocks, as Scheiner intimates in the above extract This Jesuit, if not
the leader of the new crusade against Galileo, was certainly one of
the foremost and most relentless of his enemies. For further proof of
the complicity of the Jesuits, see pp. 284 and 342 infra.
Title-Page of Dialogue of 1632.
{To face p. 266,
1633] DENOUNCED BY JESUITS 267
of their mantles. At their feet is the device of
three dolphins, surrounded by a narrow band,
bearing a motto and the monogram ^B — the whole
being the business sign of the printer, G. B. Landini.
This title-page was impugned as not having been
submitted for ecclesiastical approval, and particularly
they expatiated, with more malice than wit, upon
the meaning of the three dolphins* device; it re-
minded them so much of the three bees of the
Papal arms ! It was a great relief to Riccardi's
mind when Magalotti pointed out that the same
device appeared on nearly all the works which
issued from the Landini press at Florence, where
also this book was printed.
This shot, then, had not taken effect, and the
" ill-disposed persons " had to find some other mode
of attack. They now brought against the author
the two-fold charge (i) that the preface was printed
in different type from the rest of the book, which
was true, but was simply a necessity of the printer ; I
and (2) that some weighty arguments against the
Copernican theory, which the Holy Father had
brought forward in conversation with Galileo in
1624, were not in the printed book, although it
was a condition that they should be. This charge
was not true, for the " weighty arguments " were in
reality only one, and this, as we have seen, was
duly introduced at the end of the work, where it
1 After receiving the Imprimatur for Rome, and foreseeing no
further difficulty, Galileo had begun to set up his book, and by i6th
August 1631 about one-third of the volume was in print. Hence the
preface, which went to press later, had to be printed on a separate
sheet, and in different type.
268 PUBLICATION OF DIALOGUES [1632-
was appropriately put into the mouth of Simplicio,
who gave it as an argument which he had from " a
very eminent and learned personage " (p. 248 ante}.
Foiled again, the assailants now fastened on
the very natural circumstance that the " weighty
argument" was placed in the mouth of Simplicio,
the defender of Ptolemy. Knowing the Pope's
weaknesses, vanity, arrogance, and ambition,1
they made him believe that by Simplicio — the
simpleton — no other was intended than Urban
VIII. himself! One would have thought this
impossible with this shrewd old man (seeing the
friendly relations which up to this had subsisted
between him and Galileo), but it is beyond all doubt
that it was so, and it put his Holiness in a terrible
rage. While in this condition they easily per-
suaded him that the Copernican doctrine ran
counter to the dogmas of the Catholic faith, and
after this it was not difficult for them to show that
the Dialogues, which were a defence of that
doctrine under a flimsy veil, would do incalculable
injury to the Church. Having thus worked on the
Pope's fears, they easily persuaded him that in this
work Galileo had again, though under concealment,
dared to interpret the Scriptures ; he was therefore
rebellious ; and he was further deceitful in that he
obtained the Imprimatur by cunning devices.
1 He wished to be thought another Leo X. So vain was he that
he caused documents to be forged proving his family to be one of the
oldest and most noble of the Florentine stock. He is noted in history
for three things : (i) excommunication of all who took snuff in churches,
1624 j (2) persecution of Galileo, 1632-42 ; and (3) the foolish
campaign against the Duchy of Castro, "Guerra di Castro,"
1642-3.
1 633] PLAN OF CAMPAIGN 269
Although the safety of the Church and the
vindication of its decrees were the ostensible
reasons for the subsequent proceedings against
Galileo, it would not be far from the truth to say
that revenge for an assumed personal insult was the
primary and determining factor.1 Without this
personal motive the storm may have blown over as
other and equally threatening ones had previously
done. Urban VIII. and many of the high
dignitaries of the Church were, if anything,
Copernicans (they certainly were not Ptolemaists,
and hardly even peripatetics),2 while others were
indifferent and cared little one way or the other.
As regards the Pope himself, we have seen his
letter of soth April 1613, to Galileo, praising so
highly the book on Sun-spots — the very work on
which the prohibition of 1616 was based. We
have also seen how delighted he was with " II
Saggiatore" and the " Reply to Ingoli," in both of
which the Copernican theory is defended ; and,
finally, we have Urban's own statements (i) that
the Copernican doctrine is not heretical, but only
rash, and (2) that if it rested with him, the decree
of 1616 would never have been issued. All this
seems to show that, if the question of a personal
insult had not arisen, the Dialogues might have
weathered the storm, or, at the worst, been put on
the Index, as was the book of Copernicus in 1616,
" until corrected."
While these things were passing secretly at
1 See Galileo's letter to Micanzio, dated 26th July 1636, where he
says the making game of the Pope, as his Holiness had been
persuaded, was the primary cause of all his troubles.
2 See Alberi, vol. xvL p. 326.
2/o THE INQUISITION [1632-
Rome, Galileo in Florence gave himself up to
unmixed delight at the great success of his book.
His friends, such as Castelli, Cavalieri, Micanzio,
Campanella, and others, expressed in letters their
unbounded admiration. Thus, Micanzio, writing
on 3rd July, says : —
"I had hardly time to devour your book when
it was taken from me and lent from one to another.
To-day, no sooner do I get it back by main force,
than I am obliged to send it to the Commissary
Antonini at Verona, one of our cleverest men, and
one who admires you above all the literati of the
age."
Not one of all his friends who praised the book
so highly had any foreboding that it was soon to
bring its grey-headed author before the bar of the
Inquisition, and least of all Galileo himself. He,
of course, expected the usual opposition from his
" scientific " opponents, and was prepared to meet
it ; but he considered himself secure from anything
like conflict with the ecclesiastical authorities.
One day, about the middle of August, the first
thunder-clap broke over Galileo. His publisher
Landini received instructions, though for the time
only provisional, forbidding the further sale of the
Dialogues.1 The second clap, which followed in a
few days, was the news of the appointment of a
special commission at Rome by order of the Pope,
and under the presidency of his nephew, Cardinal F.
Barberini, to examine the book and report. It was
composed of Jesuits, Dominicans, and Theatins,
1 It appears this step was taken on the report of the Jesuit Father
Inchofer, one of the counsellors of the Inquisition.
i633] SALE OF BOOK INTERDICTED 271
" not one of whom had any knowledge of mathe-
matics, or familiarity with abstruse speculations/1
all endeavours of Niccolini and others to get friends
of Galileo, such as Castelli and Campanella, put on
the board being vetoed by the Pope.1 Galileo now
appealed to his Sovereign for protection, and, on
24th August, the chief Secretary Cioli wrote to
Niccolini that the Grand Duke was greatly
surprised to learn that a book which had been laid
before the supreme authorities at Rome by the
author in person ; had been carefully read there
again and again, as well as afterwards at Florence ;
had, at the author's request, been altered by these
authorities "as seemed good to them" ; and finally
had received the Imprimatur for Rome and
Florence, should now, after two years, be considered
suspicious, and be prohibited. His Highness was
of opinion that this opposition must be directed
against the person of the author rather than against
his book, so often and so carefully read and revised
by the proper authorities. In order, then, to inform
himself of the merits or demerits of his servant, his
Highness desires that that which is granted in all
disputes and before all tribunals should be permitted
to the accused, viz., to defend himself against his
accusers. The Grand Duke, therefore, requests
that the accusations may be sent to Florence, so
that the author, who stands firmly on his innocence,
may see and answer them.2
On the same day on which this despatch left
1 See letters of Campanella to Galileo, dated 3ist August and
25th September 1632,
2 The original draft of this despatch, much of which is in Galileo's
handwriting, is now in the National Library, Florence.
272 THE INQUISITION [1632-
Florence a mandate was issued from Rome, con-
firming the provisional prohibition of the Dialogues,
and ordering Landini to send all copies in stock
to Rome. He replied that the edition had been
sold out, and, consequently, he had no copies to
send.
On receipt of the Grand Duke's orders, Nicco-
lini hastened to carry them out, but met with
more opposition than either he or his master had
expected. The Pope received him in such a way
that he thought the world must be going to pieces,
and at the first mention of Galileo's name the
Holy Father interrupted him bluntly : " Your
Galileo has dared to meddle with things that he
should have left alone — in fact, with the most im-
portant and dangerous subjects that can be stirred
up in these days." On the Ambassador remarking
that the book was published with the approbation
of the Church, the Pope angrily replied that both
Galileo and his secretary, Ciampoli, had deceived
him on that matter. The censor, Riccardi, had
also deceived him, "but," he added, "the latter
had been himself deceived, for he had been in-
duced by fair speeches to approve the book, and
by more fair speeches to allow it to be printed in
Florence." Thinking to save the book from con-
demnation, Niccolini hinted that it was dedi-
cated to the Grand Duke. " What of that ? " was
the reply, "I have prohibited books which bear
my own name on the title-page." The Pope
added, "in charging a special commission to ex-
amine the book, instead of handing the affair at
once to the Inquisition, I have followed a course
x633] COMMISSION APPOINTED 273
best for Galileo's interests — he who did not fear
to make game of me." Niccolini then begged
that the accused may know the charges against
him and have an opportunity of justifying him-
self, to which Urban curtly answered : '* Galileo
knows well enough in what way he has trans-
gressed. In these matters of the Holy Office
nothing is ever done but to pronounce judgment,
and then summon to recant"1
Two letters from Magalotti, who was usually
well informed, arrived at the same time as this
despatch, both dated 4th September, one to
Mario Guiducci, the other to Galileo. Magalotti's
news was on the whole reassuring. From the
opinions of persons present at the sittings of
the commission, he thought he could say that
matters would not, go so far as condemnation of
the Copernican doctrine " by supreme authority."2
He thought with Riccardi that they would not
entirely prohibit the Dialogues, but only " correct"
them, so as to sustain the decree of 1616. He
advised (as Niccolini also had done) the utmost
patience and circumspection, and to confer with
Cardinal F. Barberini rather than with the Pope
himself, "for reasons which it is not necessary to
detail"
The special commission, after a month's session,
1 Letter, Niccolini to Cioli, $th September 1632. Here the Holy
Father shows his hand, Galileo dared to make game of him. The
poison had taken effect
2 It never did, in fact, come to this ; for the "supreme authority"
is the Pope speaking ex Cathedra^ or an (Ecumenical Council. The
proceedings of 1616 were not endorsed by "supreme authority,"
and we shall find this to be the case in the present proceeding's
also.
S
274 THE INQUISITION [1632-
submitted a long report to the Pope. The docu-
ment begins with a statement of the course of the
negotiations for the printing of the Dialogues, and
then come three indictments against the author : —
1. Galileo had transgressed orders in deviat-
ing from the hypothetical standpoint, by maintain-
ing decidedly that the earth moves and that the
sun is stationary.
2. He has erroneously ascribed the phenomena
of the tides to the stability of the sun and the
motion of the earth, which are not true.
3. He has been deceitfully silent about the
command laid upon him in 1616, viz., to re-
linquish altogether the opinion that the sun is
the centre of the world and immovable and that
the earth moves, nor henceforth to hold, teach,
or defend it in any way whatsoever, verbally or in
writing.
Then follows the remark : "It now remains to
be considered what proceedings are to be taken
against the person of the author, and against his
printed book." The rest of the document is taken
up with an elaboration of the charges against
Galileo, and a fuller account of the negotiations
for the Imprimatur. These need not detain us;
but in a final clause, Galileo is specifically charged
with having transgressed the order of the Holy
Office to relinquish (etc., as per charge (3) above).
This, then, was his chief offence; the others
"could be corrected if the book was thought to
be of any value " ; but to deliberately and deceitfully
transgress commands, that, evidently, could not be
" corrected" or condoned.
r633] REPORT OF COMMISSION 275
Here for the first time the minute of 26th
February 1616 is mentioned, as to which Niccolini
has something of importance in his despatch of nth
September to Cioli. Reporting an interview with
the Master of the Sacred Palace, he says that
Riccardi, after advising patience and caution, re-
peated the old stock complaints, that the Dialogues
imperilled the faith, that the author did not confine
himself strictly to mathematics, but brought under
discussion religion and the Scriptures [which is not
true], and that the Papal orders as to the preface,
end, and hypothetical treatment had not been com-
plied with — an extraordinary assertion for one who
had himself certified that they had been complied
with. He then confided to the Ambassador as a
profound secret "that it had been discovered in the
books of the Holy Office that sixteen years ago (it
having been heard that Galileo entertained that
opinion, and disseminated it in Florence) he was
summoned to Rome, and forbidden by Cardinal
Bellarmine, in the name of the Pope and the Holy
Office, to hold that opinion. And this alone is
enough to ruin him entirely/1 Evidently the paper
here hinted at is the minute of 26th February 1616.
It will, therefore, be desirable to pause for a
moment, and read again our remarks on p. 166,
for our account so far of these new proceedings
brings out a point there discussed, which we wish
to emphasise, viz. that the minute is not true to
the spirit of the proceedings. We have seen that
the Pope knew all about the process of 1616 — in
fact, as Cardinal Maffeo Barberini, was an unwilling
party to it. If Galileo was then commanded to
276 THE INQUISITION
relinquish altogether his opinion, and henceforth
not to hold, teach, or defend it in any way what-
soever, verbally or in writing, why did Urban VIII.
discuss this same opinion with him in 1624? why
did he openly approve "II Saggiatore" and the
tl Reply to Ingoli " ? and why in 1630, when Galileo
took his Dialogues to Rome, was he not met with
a non-possumus, and referred back at once to this
rigid prohibition ? Clearly, because this rigid pro-
hibition had for him no existence — had no right to
exist, for he knew it was not intended that Galileo
should be forbidden to hold, teach, or defend his
opinion in any way whatsoever, verbally or in
writing, except in case he refused to be bound by
Cardinal Bellarmine's simple admonition — a con*
tingency which did not arise. The minute, there-
fore, is not true to the spirit of the proceedings,
and should properly be treated as non-existent. It
is, moreover, of no value in law in that it bears
no signatures. To base, then, a charge against
Galileo on such a worthless paper convicts his
persecutors of ultra vires, and shows their de-
termination to punish him at any price, even at
the cost of a judicial crime.1
Now let us return to our narrative. A few days
1 The steps of these new proceedings are also against the theory
of a forgery with ulterior designs. Were it so, why, during the long
and vexatious negotiations about the Imprimatur^ did not the forgers
appeal to it at once, as a bar to granting a licence ? Why, immediately
on the appearance of the book, did they not accuse Galileo of break-
ing his solemn promise, and call down upon his head the penalty for
disobedience with which the document threatened him ? Why have
recourse for months to trumpery charges and ignoble stratagems,
when they could have played this trump card ? Clearly, because its
existence was not known to them until the first week in September
1632, when its discovery was a surprise to all, friends and foes alike.
i633] SUMMONED TO ROME 277
after Niccolini's interview with Riccardi, on the
1 5th September, the Pope sent word to the
Tuscan Ambassador that Galileo's affairs would
be handed over to the Inquisition. At the same
time the strictest secrecy as to this step was
enjoined on both the Grand Duke and Niccolini,
with a hint that otherwise they would be pro-
ceeded against, according to the statutes of the
Holy Office. Niccolini, astounded by this inti-
mation, hastened to the Pope to avert, if possible,
the danger of a trial, but his pleadings were in
vain. Urban was good enough to say that Galileo
was still his friend, but his opinions had been
condemned sixteen years before, and were in the
highest degree pernicious to the Church. On
23rd September the following order was issued: —
"His Holiness charges the Inquisitor at Florence
to inform Galileo, in the name of the Holy Office,
that he is to appear in the course of the month
of October, in Rome, before the Commissary-
General. He must obtain a promise from Galileo
to obey this order, which the Inquisitor is to de-
liver in the presence of a notary and witnesses,
but in such a way that Galileo shall know nothing
of their presence, so that if he refuse to obey
they may bear witness to his contumacy/'
This order, which was delivered to Galileo on
ist October, and with which he consented in
writing to comply, fairly overwhelmed him, for,
from the secrecy maintained in Rome, he was
wholly unprepared for any such measure. Scarcely
recovered from a complaint in the eyes which had
lasted several months, suffering otherwise in health,
278 THE INQUISITION [1632-
and at an advanced age, he was now to go to
Rome in the midst of the plague (which had
broken out afresh) to appear before the terrible
Inquisition. No wonder that he was dismayed,
and that in spite of his promise "willingly to
obey the order in the course of this month,
October," he made every effort to evade it His
deep depression is evident from a long and
pitiable letter, of i3th October, to Cardinal
Francesco Barberini (the Pope's nephew), sent
through the hands of Niccolini : —
" That my Dialogues recently published should
find adversaries was not to be doubted, as your
Eminence no doubt foresaw, It is in general the
lot of all opinions which in one way or another run
counter to the accepted doctrines. From the recep-
tion of my other works I expected as much, but
what I did not expect was that the hate of one or
two of my enemies (furious at seeing the lustre of
their works tarnished by mine) would be able so to
influence my superiors as to make them believe that
my works are unworthy of the light of day, and
should be stifled. The prohibition of the printing
and sale of my Dialogues has been a cruel blow to
me, but I am consoled by the knowledge of the
extreme purity of my conscience, and by the feeling
that I shall have no difficulty in justifying my
intentions.
" I will not conceal from your Eminence that the
injunction to present myself without delay before
the tribunal of the Holy Office has afflicted me
profoundly. It is impossible to think without
bitterness that the fruits of my labours and studies
for so many years (which gave to my name in the
scientific world a certain tclai) should now be
branded as criminal. All this depresses me to such
i633] GALILEO'S DEPRESSION 279
an extent as to make me curse the time I have
devoted to these labours — yes, I regret having
given to the world so much of my results. I feel
even the desire to suppress, to destroy for ever, to
commit to the flames, what remains in my hands.
Thus I should satisfy the burning hate of my
enemies. These are some of the thoughts which
afflict me, and increase the burden of my seventy
years ; they aggravate my numerous physical
sufferings, and cause me persistent insomnia.
When to these is added a journey, rendered
more painful and dangerous by sundry causes, I
am almost certain that I shall not reach the end
alive. The desire to live, common to all men,
makes me implore the intercession of your
Eminence, encouraged thereto by the kindness
of heart which distinguishes you, and of which
I as well as others have been the recipient. I
beg you, then, to represent to the Holy Father my
present pitiable situation. . . .
"Whether it be necessary to receive my
justification in writing, or by viv& voce, I would
point out that there are here in Florence the
Inquisitor, the Archbishop, and other learned
functionaries of the Church, who would be able,
it seems to me, to decide graver causes than mine,
and before whom I am ready to appear. It is
hardly likely that in a book, which has been
carefully examined by the censors, with full power
to omit, to add here, to correct there, there should
still remain errors so grave that their correction,
or the punishment due to them, should be beyond
the power of the local authorities." l
Before taking action the Ambassador consulted
1 By the same post Michelangelo, the younger, wrote to the same
Cardinal, entreating him, out of consideration for the philosopher's
age and infirmities, to try all means to have his affairs settled in
Florence. See letter dated I2th October.
280 THE INQUISITION [1632-
Castelli (whom the Grand Duke had appointed as
his counsel in this affair) as to the advisability of
delivering Galileo's letter to the Cardinal. It was
decided to do so, and Niccolini reported that it was
received in a very friendly way, with assurances of
his Eminence's kindly disposition towards the
writer. The letter was discussed by the Holy
Office on nth November, in presence of the Pope;
but his Holiness would not grant the prayer, and
ordered that the writer must be compelled to come
to Rome. Niccolini was unwearied in trying to
get the affair settled in Florence, but to no purpose.
The Pope had seen Galileo's letter of I3th October,
but the journey to Rome could not be dispensed
with. "Your Holiness," exclaimed Niccolini, " in-
curs the danger, considering Galileo's age, of his
being tried neither in Rome nor in Florence,
for I solemnly assure your Holiness that he may
die on the way under all these difficulties and
anxieties/' " He can come very slowly/' replied the
Pope, " in a litter, with every comfort, but he really
must be tried here in person. And may God
forgive him for having been so deluded as to in-
volve himself once more in these difficulties, after
having been extricated by me from his first
difficulties in 1616, when I was Cardinal." Much
discomfited and with profound sorrow, Niccolini
communicated this decision to Galileo in a letter on
1 3th November, and in a despatch to Cioli of the
same date.
A few days later, igth November, Galileo was
summoned before the Inquisitor at Florence, in
accordance with the Papal orders, and was charged
i633] SAD STATE OF HEALTH 281
to comply with the mandate to go to Rome in the
presence of a notary and two witnesses — a respite
of one month being allowed. The appointed time
had nearly arrived and no preparations had been
made for starting. The Inquisitor sent his vicar to
see Galileo and reported the result in a letter to
Rome on i8th December: —
"My vicar found Galileo in bed ; he was quite
ready to set out, but in these times he had no heart
for it ; besides, just now, owing to a sudden attack
of illness he was not in a condition to travel. He
has sent me the enclosed medical certificate, so that
I have not failed to do my duty,"
The certificate, dated i/th December, gives an
idea of the physical sufferings of this much-tried
man, and is signed by three doctors : —
"We, the undersigned physicians, certify that
we have examined Signer Galileo Galilei and find
that his pulse intermits every three or four beats,
from which we conclude that his vital powers are
affected, and at his great age much weakened. To
the above are to be ascribed frequent attacks of
giddiness, hypochondriacal melancholy, weakness of
the stomach, sleeplessness, and flying pains about
the body, to which others also can testify. We
have also observed a serious hernia with rupture of
the peritoneum. All these symptoms are worthy of
notice, as under the least aggravation they might
become dangerous to life."
Little importance seems to have been attached
to this certificate at Rome. Niccolini (26th
December) fears that the ecclesiastical authorities
at Florence will be ordered to take extreme
282 THE INQUISITION [1632-
measures. Castelli (2 5th December) urges his old
and revered master to set out. But in this, as
in all his letters of this period, he shows that
he had no idea of the real nature of the pro-
ceedings going on. Knowing of no crime
committed by his master against the Holy Office,
he urged him to set out, because he had the
idea that Galileo's persecutors desired nothing
better than that he should refuse, in order that
they may decry him as an obstinate rebel against
Holy Church.
On 3oth December the fears of Niccolini
were realised. On that day a Papal order was
issued to the Inquisitor at Florence, stating that
neither his Holiness, nor the Congregation of
the Holy Office, could or would tolerate further
evasions. It must, therefore, be proved that
Galileo's state was really such that he could not
come to Rome without danger to his life. A
commissioner with a physician would be sent to
Florence, who would see Galileo and make a
true and trustworthy report on his condition,
and if he were in a state to travel the commissioner
must bring him a prisoner in chains. If out of
consideration for his health, or other danger to
life, his coming must be postponed, then as soon
as he had recovered, or the danger was over,
he was to be brought a prisoner in irons. The
commissioner and physician would travel at Galileo's
expense, because he had not obeyed the command
to appear when his condition would have per-
mitted it.
To avert these extreme measures the Grand
1633] POPE THREATENS CHAINS 283
Duke caused Galileo to be informed (nth January
1633) that it was at last necessary to obey the
orders of the supreme authorities at Rome, and
in order that he might perform the journey more
comfortably Grand-ducal litters and a trustworthy
guide would be placed at his disposal ; he would
also be lodged in Rome in the house of the
Grand Duke's Ambassador. The pitiful impotence
of an Italian ruler of that day in face of the
Roman Church is painfully obvious in this decision.
The Sovereign does not dare to protect his subject
— more, his old and respected tutor, and the
greatest philosopher of whom Italy could boast —
but gives him up to the dreaded Inquisition, as
if he were an alien malefactor. The Venetian
republic was the only State in Italy that would
have asserted its independence (as it had often
done before), and would have refused to hand
over one of its officials to the Roman power.
Indeed, when these proceedings began, Francesco
Morosini of Venice offered to reinstate Galileo
in his old chair at Padua on any conditions that
he chose to make, and to print his Dialogues in
Venice, Galileo was now suffering a bitter penalty
for the mistake of 1610 in deserting Padua.1
2Oth January 1633 was the day fixed for
Galileo's departure. On the I5th he addressed
a long letter to his friend Elia Diodati of Paris,
a celebrated jurist and advocate. It begins with
1 This old friend of Galileo was a power in Venice. Francesco
Morosini, the son, was the famous Captain-General of the Republic
arid conqueror of the Morea in the war against the Turks 1684^94 ;
hence his name in history, II Peloponesiaco, He was elected Doge
in 1688, and died fighting at Nauplia in 1694, aged seventy-six.
284 THE INQUISITION [1632-
comments on the astronomical treatises of Morin
and Fromond which Diodati had sent him. He
then goes on to speak of his own unhappy
circumstances.
" Many years ago when the stir about Copernicus
was beginning, I wrote a letter [to the Grand-
Duchess Cristina], in which, supported by the
authority of numerous Fathers of the Church,
I showed what an abuse it was to appeal so
much to Holy Scripture in questions of natural
science. As soon as I am in less trouble I will
send you a copy. I say in less trouble, because
I am just now going to Rome, whither I have
been summoned by the Holy Office, which has
already prohibited the circulation of my Dialogues.
I hear from well-informed persons that the Jesuit
Fathers have insinuated in the highest quarters
that my book is more execrable and injurious to
the Church than the writings of Luther and
Calvin. . . .
"My publisher is disconsolate, the prohibition
of the book has caused him a loss of more than
2000 scudi, for the sale of the first edition and
a second twice as large was assured. As for
myself, in the midst of so many afflictions and
embarrassments that which afflicts me most is
the thought that I must renounce my other works —
especially my work on Motion — or at most, that
I cannot hope to see them appear during my
lifetime/'
On 2Oth January, this man of woes set out on
his terrifying journey in a Grand-ducal litter. How
different the circumstances from those of the
same journey eight years before! Prince Cesi,
his entertainer at Acquasparta, was dead ; his own
health, never good for many years past, was now
1633] JOURNEY TO ROME 285
a chronic cause of suffering ; and his eyesight
had begun to fail. Not only was the time of
year unfavourable (January — February being the
season when the biting tramontana is most
frequent), but the country through which he had
to pass was bleak and inhospitable, and its in-
habitants, always wild as the winds that howl
across its wastes, were now made more wild and
desperate by the ravages of the plague. At the
frontier post, Ponte Centino, he was obliged to
halt twenty days on account of quarantine. From
each halting place the poor old man had written
to his daughter, the one soul on earth to whom
he knew he could turn for sympathy and consola-
tion, and she, sweet consolatrix, what can she
say in reply? After expressing her grief at his
being detained so long in a wretched habitation,
deprived of every comfort, she entreats him "to
keep up his spirits, and to put his whole trust in
God, who never forsakes those who trust in Him."
What else could she say ? although at the moment
she knew that some of God's ministers on earth
were intent on his persecution for the greater
honour and glory of His kingdom.
On the afternoon of i3th February Galileo
arrived in Rome and was warmly received at
the Tuscan Embassy. On the next day Niccolini
informed the Grand Duke of his arrival, and that
next morning he would introduce him to Cardinal
F. Barberini, and beg that he be permitted to
remain at the Embassy instead of being locked up
in the prison of the Holy Office. This favour was
at once granted provisionally, and afterwards
286 THE INQUISITION [1632-
officially confirmed, with injunctions to keep in-
doors, and to see no one until further orders.
Beyond this, and to Galileo's surprise, no official
notice was taken of his presence for some time.
Writing to Cioli on igth February, he says : —
"As to the situation of my affairs I can tell
you nothing. However, to judge by what has
passed, it appears to me, as well as to the
Ambassador and his staff, that the storm which
menaces me is a little calmed — at least in appear-
ance, so that I do not give way to discourage-
ment, as if shipwreck were inevitable, and all
hope of reaching port were gone — the more so as
following the instructions of my master, Ariosto :
' I make sail with modesty
Amidst the raging billows.7
"I keep to the house, not thinking it proper
to go out as if I wished to show myself. Up
to the present no official steps have been taken.
One of "the members of the Congregation has
called on me twice, conversing in the most agree-
able manner, and giving me an opportunity to
explain myself, and to show my submission, always
sincere, to the Church — to which, as far as I could
see, he listened with satisfaction. If his visits, as
may be supposed, were made with the knowledge
or even by order of the Congregation, I may con-
sider them as the beginning of a milder treatment,
far removed from the cords, chains, and dungeons,
with ^ which I was menaced. I find another con-
solation in the kindly sentiments towards me ex-
pressed by many influential personages. As it
appears to^ me easier to confirm the latter in their
good opinions than to convert those who are un-
favourable, I think, with the Ambassador, that
letters from our august master to Cardinals Scaglia
i633] HOPES AND FEARS 287
and Bentivoglio l would be very useful, and if you
agree with us I beg that you will obtain me this
favour."
The member of the Congregation here referred
to was Mgr. Serristori. Niccolini thought that
the object of his visits was to discover the present
sentiments and defensive arguments of the dreaded
dialectician, and was inclined to think that they
boded well.
" I think," he writes, " I have succeeded some-
what in cheering up the good old man by what
I have told him of the steps being taken in his
favour. But he constantly expresses his wonder
at all this persecution."2
The same cheerful confidence is expressed in
Galileo's letter of 25th February, to Bocchineri: —
"The Ambassador thinks he perceives each
day a diminution in the irritation against me, and
so does Father Castelli, who is for me a zealous
and indefatigable advocate. We learn, in short,
that the many and serious accusations against me
are reduced to one, and that the others have been
allowed to drop. Of that one I shall be able
to clear myself without much trouble, when the
grounds of my defence have been heard. Little
by little I am bringing these to the ears of some
of the higher officials, who can neither refuse
absolutely to listen to my explanations, nor to
leave them entirely without reply. S6 we con-
clude that in the end a favourable issue may be
hoped for.
" I keep strictly t6 the house which appears
to me and my friends to be the correct thing.
The Cardinal Barberini has given me the same
1 Bentivoglio was a pupil and disciple of Galileo in Padua.
2 Despatch to Cioli, I9th February 1633.
288 THE INQUISITION [r632-
counsel, not ex officio but, as he says, as a friend.
As I have already told you, not a word official
has yet come from the tribunal. One of the
counsellors, my friend and protector for many
years, has visited me a couple of times and
furnished me an occasion to explain myself freely
on several points, and to show him some papers
drawn up by me for this case, with which he
declared himself satisfied.1 We suppose, not with-
out reason, that these visits have been made with
the knowledge, and, perhaps, even by order of the
superior authorities, with the object, perhaps, of
getting some general information. If so, they could
not have adopted a better course in my interests.
" The deprivation of exercise for the last forty
days begins to be prejudicial to me, for as you
know I find exercise necessary for my health. My
digestion especially is troubled ; viscous matters
accumulate ; and for the last three days painful
twitchings in the limbs have prevented my sleeping.
I hope that a severe ^dietetic regimen will effect
a cure. Some days ago I told you how useful
would be letters from his Highness to Cardinals
Bentivoglio and Scaglia, who, as I am privately
informed, are well disposed towards me. If we
find in the Congregation one or two members
ready and resolute to defend innocence and the
truth, we may hope that their voices will suffice
to impose silence on those inipiically inclined.
Therefore I beg you to procure these letters
through the medium of Signor Cioli.
UP-S. — Please communicate this letter to my
daughters and Vincenzio."
Niccolini's despatch to Cioli of two days later
1 For what was probably Galileo's line of defence at this time, see
Favaro's "Nuovi Contributi alia Storia del Processo di Galileo"
(Atti del R. Istituto Veneto, 1894-95), an admirable piece of con-
structive evidence.
i633] CHARGES AGAINST GALILEO 289
(2 yth February) explains the nature of this chief
accusation : —
" Although I am unable to say precisely what
stage Galileo's affairs have reached, or what may
happen next, as far as I can learn the main difficulty
consists in this — these gentlemen maintain that in
1616 he was commanded neither to discuss the
question of the earth's motion, nor to converse
about it. He says, on the contrary, that these
were not the terms of the injunction, which were
that that doctrine was not to be held or defended.
He considers that he has the means of justifying
himself, insomuch as it does not at all appear from
his book that he does hold or defend the doctrine ;
or that he regards it as a settled question, as he
merely adduces the reasons kino inde. The other
charges appear to be of less importance and easier
to get over."1
On the same day the Ambassador in a long
audience officially announced Galileo's arrival, and
expressed the hope that his Holiness would now
be convinced of his reverence for things spiritual,
especially in reference to the matter in hand. The
Pope replied that he had shown Galileo a special
and unusual favour in allowing him to stay at the
Ambassador's house instead of remitting him to
prison. Niccolini suitably acknowledged the great
favour, and then went on to urge that in considera-
tion of Galileo's age and bad health the trial may
be hastened Urban replied that the proceedings
of the Holy Office were usually tedious, and he
really did not know whether so speedy a termina-
tion could be looked for. They were still engaged
with the preliminaries.
1 See remarks on this point, p. 274 ante.
T
290 THE INQUISITION [1632-
As to the nature of these preliminaries nothing
certain could be learnt, but Galileo continued to
hope for the best. In a letter to Geri Bocchineri
(5th March), after acknowledging receipt of the
letters for Cardinals Bentivoglio and Scaglia which
had, as he thought, a good effect, he goes on to
say : —
"As to my affair, it goes on silently as from
the first day. If one can judge by rare signs,
the accusations have lost much of their gravity,
and already some have been entirely dropped by
reason of their evident insignificance, which is a
good presage for those that remain/*
A fortnight later, on igth March, he wrote
in a similar strain to Cioli : —
"The same silence continues to be observed
in my affair, and nothing more can be ascertained
than what the Ambassador has picked up here
and there, and which is sufficiently vague. My
indefatigable defender, Benedetto Castelli, has also
been secretly informed, but in the same general
terms, that the proceedings have taken a slightly
more favourable turn, thanks to the letters of
his Highness. Therefore, as the Ambassador
will tell you, the same intervention with the
other Cardinals, members of the Congregation,
would be of great utility, the two to whom letters
have already been addressed having expressed
themselves in this sense. I pray you then to
obtain for me from his Highness this additional
favour."
In spite of the gravity of the situation, it
would seem that Galileo was careful to write to
his daughter in such a strain as to calm her
i633] WEEKS OF WEARY SUSPENSE 291
anxiety throughout this weary time. Therefore,
on 1 3th March, she writes back: —
"As matters are going on so favourably I
will not mind though your return be delayed, for
indeed my being disappointed is a small thing,
if staying where you are redounds to your
reputation and advantage ; and what makes me
still more easy is to hear how honourably you
are treated by those excellent gentlemen, and in
particular by her Excellency the Ambassadress.
I am well now because my mind is at rest.
Nevertheless I do not cease praying for you."
On the same day (i3th March) on which
Maria Celeste was thus hopefully writing, Niccolini
had an audience of the Pope, in which he was
informed that it would be necessary to summon
Galileo to the Holy Office on the eve of the
trial. It was the usage and could not be
departed from. Again, the Ambassador pleaded
the accused's bad health, great age, and the
willingness he had shown to submit to any
penalties ; but Urban replied it would not do to
order otherwise. He regretted that Galileo "who
had been his friend, with whom he had often
held confidential intercourse, and eaten at the
same table," should be subjected to these annoy-
ances, but it was in the interests of religion.
Notwithstanding this intimation, days and
weeks passed, and yet Galileo w&s not summoned
before the Inquisition. All this time, as we see
from his letters, he was entertaining confident
hopes of some favourable issue ; but, as a matter
of fact, there were no grounds for this belief.
292 THE INQUISITION [1632-
Neither he nor his indefatigable friends, Castelli
and Niccolini, could learn anything definite. The
members of the Congregation, who alone could
have given information, kept the secrets of the
Holy Office very closely, as indeed they were
bound to do under the severest penalties to
themselves. Thus the month of March passed
by ; April was come, and with it the storm
which had been so long threatening.
On the yth, Niccolini went to Cardinal
Barberini by invitation, and was informed, on
behalf of the Pope and the Congregation, that
Galileo must appear before the Holy Office, and,
as it was not known whether the case could be
settled at a single sitting, it might be necessary
to detain him. Once more the Ambassador urged
consideration for his age and health (he had
again been ill and confined- to bed), and begged
the Cardinal to consider whether it would not be
possible for him to return every evening to sleep
at the Embassy. To these appeals his Eminence
replied that such a permission was not to be
expected. He promised, however, that every
comfort would be afforded him in the buildings
of the Holy Office ; that he would neither, as
was customary with accused persons, be treated
as a prisoner, nor be placed in a cell; but he
would have good rooms, and, perhaps, his doors
would not even be locked. Niccolini reported
this notification to Cioli on pth April, adding the
following interesting details : —
"This morning I also had a conversation with
i633] SUBMISSION RESOLVED ON 293
his Holiness, who again gave vent to his
displeasure that Galileo should have discussed
this subject which appears to him to be very
serious, and of great moment to religion. Signor
Galileo thinks, nevertheless, that, he can defend
his statements on good grounds; but I have
warned him to refrain from doing so, in order
not to prolong the proceedings, and to submit
to what shall be prescribed to him to believe
respecting the motion of the earth.1 He has
fallen into the deepest dejection, and since
yesterday has sunk so low that I am in great
concern for his life. I shall beg that a servant
may be allowed him, and as much comfort as
the place will admit of. Meanwhile, we are all
doing our best to console him and to help him
through our recommendations to the most friendly
disposed members of the Congregation; for truly
he deserves every possible kindness that can be
shown him. I cannot describe to you the grief
of the whole house, for every one here loves him
exceedingly/'
From this, then, we learn that up to 8th April
Galileo was still intending to defend himself and
his opinions, and that it was only on the earnest
entreaty of the Ambassador that he gave up all
idea of opposition, and resolved upon entire
submission.
1 In a previous despatch of I9th February, he says : " I have
advised Galileo to be always ready to obey and to submit to whatever
was ordered, for this was the only way to allay the irritation of one
who was so incensed, and who treated this affair as a personal one."
Clearly, this "one" was no other than Urban VIII.
CHAPTER XIII
GALILEO AND THE INQUISITION (continued}
1632-1633
ON 1 2th April 1633, Galileo appeared for his
first examination before the Commissary- General
of the Inquisition, Father Firenzuola, and the
Procurator-Fiscal, Father Sincero. In all his
answers he is actuated by one idea — that of
shortening the proceedings and averting severe
measures by submissive acquiescence. According
to the rules of the Holy Office, an oath is
administered to the accused that he will speak
the truth, and he is then asked whether he knows
or conjectures the reason of his citation. Galileo
replied that he supposed he had been summoned
to give an account of his last book. After being
asked if he acknowledged the work shown him,
" Dialogo di Galileo Galilei, Linceo," as his, and
his reply in the affirmative, the examiners led
him back to his visit to Rome in 1616, and to
what then happened in the matter of the pro-
hibition. His answers show that he only knew
of Cardinal Bellarmine*s admonition, as recorded
in his certificate of 26th May 1616. That a
"command" in more stringent terms was issued
294
1632-1633] FIRST EXAMINATION 295
to him (as the Inquisitor asserts) he is not
aware, but, true to his resolve of submissiveness,
he says again and again : " It may be so, but I
do not remember it." He is then told that this
" command " was to the effect that he must not
hold, defend, or teach, in any way whatever,
verbally or in writing, the doctrines of Copernicus.
Galileo, who hears for the first time the exact
terms of this further injunction "not to teach
in any way whatever, verbally or in writing/' is
amazed, but is still submissive. "It may be,"
he answers, ".that this injunction was also there,
but I do not remember it." He then appeals
again to Cardinal Bellarmine's certificate, " in
which," he says, " there is no mention of this
further injunction which has just been made
known to me."
After trying by every artifice to get from him
an admission that this further injunction was laid
upon him, and after his declaring for the fifth time
that he did not remember any " command" beyond
the admonition of Cardinal Bellarmine, the In-
quisitor asked whether he had received any per-
mission to print his Dialogues, and if in the
negotiations he had mentioned the " command"
aforesaid. He replied : "I did not say anything
about it when I asked for the Imprimatur. I did
not think it necessary to say anything, because I did
not consider that in writing the book I was acting
contrary to, far less disobeying, the command * not
to hold or defend ' the aforesaid opinions. I have
neither maintained nor defended the opinion that
the earth moves and that the sun is stationary, but
296 THE INQUISITION [1632-
have demonstrated the opposite, and shown that
the arguments of Copernicus are weak and incon-
clusive/' With this answer the first sitting of
this memorable trial closed. Silence on matters
connected with the proceedings having been im-
posed on oath, Galileo was led to his apartments in
the private quarters of the Procurator- Fiscal, where
he received kind and considerate treatment. Writing
to Bocchineri on i6th April, he says : —
"Contrary to custom, three large and comfort-
able rooms have been assigned to me, with permission
to walk about in the spacious corridors. My health
is good, for which, next to God, I have to thank the
great care of the Ambassador and his wife, who have
a watchful eye for all comforts — far more than I
require."
A servant was allowed to remain with him,
Niccolini was permitted to send in his meals, and no
obstacle was opposed to his free correspondence
with the kind Ambassador.
In their treatment of Galileo personally (unprece-
dented for its considerateness), throughout the whole
of these proceedings, the Inquisition did homage
to his genius. Since the establishment in 1215 of
this dreadful tribunal, no prisoner had ever been
treated with such leniency ; for princes, prelates, and
noblemen, all had been consigned to the secret dun-
geons from the very commencement of their trial.
The Pope himself in an interview with Niccolini (re-
ported in his despatch to Cioli, 27th February 1633)
said, apropos of this point, that Galileo was treated
as a privileged person, and reminded the Am-
bassador that in the recent case of a gentleman of
i633] REMITTED TO PRISON 297
the princely house of Gonzaga far different measures
had been taken, that he had been not only carried
to Rome by officers of the Inquisition, but was kept
closely imprisoned for a long time before judgment
was pronounced.
On 1 5th April, three days after the first examin-
ation, three counsellors of the Holy Office, Oregius,
Inchofer, and Pasqualigus, delivered their opinions
on the case. Oregius declared that in the Dialogues
the doctrine that the earth moves and that the sun
is stationary is held and defended. Inchofer
declared that Qalileo not only taught and defended
that doctrine, but was himself suspiciously inclined
to it, and even held it to this day. Pasqualigus was
of opinion that by the publication of his Dialogues
Galileo had infringed the order of 1616 in respect to
teaching and defending, and it was very suspicious
that he held the prohibited doctrine.
On hearing of her father's imprisonment Maria
Celeste wrote in deep distress, 2oth April : —
" I have just been informed by Signor Bocchineri
of your being imprisoned in the Holy Office. At
this, though on the one hand it grieves me much,
feeling sure that you are anxious and uneasy and,
perhaps, without bodily comfort, yet on the other
hand, considering that it must have come to this
before the business could be terminated, and con-
sidering also the benignancy with which you have
personally been treated, and (above all) the righteous-
ness of your cause and your innocence in this parti-
cular matter, I feel comforted, and hope for a
prosperous ending with the help of Almighty God,
to Whom I cry without ceasing, recommending you
to His care, with the greatest love and confidence.
Only be of good cheer. Do not give way to grief,
298 THE INQUISITION [1632-
for fear of the effect it would have on your health.
Turn your thoughts to God, and put your trust in
Him who like a loving Father never forsakes those
who trust in Him unceasingly.
"My dearest Lord and father, I have written
instantly on learning this news of you, that you
might know how I sympathise with you in your
distress. Perhaps, when you know this it will not
be quite so hard to bean I have mentioned the
news to no creature in this house, choosing to make
my joy and gladness common to all, but to keep my
troubles to myself. Consequently, every one is
looking forward joyfully to seeing you back again.
And who knows ? Perhaps, even while I am writing
the crisis may be passed, and you may be relieved
of all anxiety. May it be the Lord's will, in whose
keeping I leave you."
Fearing that during Galileo's detention within
the walls of the Holy Office, his letters to his
daughter might be delayed if not detained, Caterina
Niccolini (the Ambassador's wife) with sweet
thoughtfulness wrote to Maria Celeste telling her
what she knew of the situation, but still presenting
the bright side (as Galileo himself had been doing)
lest the poor nun should be too much distressed
It would appear from more than one of Maria
Celeste's letters that the father had spoken so
much to the Ambassadress about his daughter as to
make her Excellency wish for a personal acquaint-
ance, and she signified her intention of paying the
Sister a visit on her return to Florence. From a
letter written to her father some time later, we learn
that Maria Celeste was expecting Signora Caterina
with a mixture of pleasure and trepidation.
After the first hearing of his case on I2th April,
1633] EXTRA-JUDICIAL PRESSURE 299
weeks passed and no further open step was taken in
the trial ; meanwhile, the prolonged deprivation of
exercise in the open air which had been so essential
to his health, combined with mental agitation, threw
the old man on a sick bed. Writing on 23rd April
to Geri Bocchineri he says : —
" I am writing in bed to which I have been con-
fined for sixteen hours with severe pains in my
loins, which according to my experience will last as
much longer. A little while ago I had a visit from the
Commissary and the Fiscal who conduct the enquiry.
They have promised and intimated it as their settled
intention to terminate the case as soon as I am able
to get up again, encouraging me repeatedly to keep
up my spirits. I place more confidence in these
promises than in the hopes held out to me before,
which as experience has shown were founded rather
upon surmises than real knowledge. I have always
hoped that my innocence and uprightness would be
brought to light, and I now hope it more than ever.
" Please send this on to my daughters and
Vincenzio, as usual."
The second examination was fixed for 28th
April, and the course it now took had up to recent
years puzzled all students of this famous trial
While at the close of his first examination we
have seen Galileo deny having defended the
Copernican doctrine, and assert that he had done
just the opposite, now at this second hearing and
almost without waiting for the Inquisitor's questions,
he makes a declaration which, roundabout though
it is, contains a penitent confession that he had
defended those doctrines. The cause of this
change is explained by a letter from one of
300 THE INQUISITION [1632-
Galileo's judges, the Commissary - General
Firenzuola (who was then with the Pope in the
Castle of Gandolfo), to Cardinal Francesco
Barberini, and dated 28th April.1 This interest-
ing letter (slightly condensed) runs as follows : —
"In compliance with the commands of his
Holiness I yesterday informed the Congregation
of the state of Galileo's case. Their Eminences
approved of what has been done thus far, and took
into consideration various difficulties with regard to
the manner of pursuing the case, and of bringing it
to an end. More especially as Galileo has in his
examination denied what is plainly evident in his
book; and in consequence of this denial there
would result the necessity for greater rigour of
procedure, and less regard to the other con-
siderations belonging to the business. Finally, I
suggested that the Congregation should grant me
permission to treat extra-judicially with Galileo in
order to render him sensible of his error, and bring
him to a confession of the same ; and upon my
indicating the grounds upon which I made the
suggestion, permission was granted me. That no
time might be lost I entered into discourse with
Galileo yesterday afternoon, and, after many argu-
ments and rejoinders had passed between us, by
God's grace I attained my object, for I brought him
to a full sense of his error, so that he is willing to
confess it judicially. He requested, however, a
little time in order to consider the form in which he
might most fittingly make the confession. I trust his
Holiness and your Eminence will be satisfied that
in this way the affair will be settled without
difficulty ; the Court will maintain its reputation ;
it will be possible to deal leniently with the culprit ;
1 First published in Heralisi's "Urbano VII I. e Galileo : Memorie
Storiche," Rome, 1875, pp. 197-8.
1633] SECOND EXAMINATION 301
and, whatever the decision arrived at, he will
recognise the favour shown him, with all the
other consequences of satisfaction herein desired,
To-day I think of examining him in order to obtain
the said confession, and, having as I hope received
it, it will only remain to me further to question him
with regard to his intention, and to impose the
prohibitions upon him ; and that done he might
have the house [Niccolini's] assigned as a prison, as
hinted to me by your Eminence."
The second examination did not take place on
28th April as Firenzuola proposed, perhaps on
account of Galileo's indisposition. On 3Oth April
the Court again assembled, the usual oath to speak
the truth was administered, and Galileo was re-
quested to state what he had to say. He then
began the following melancholy confession : —
" In the course of some days' continuous and
attentive reflection oft the interrogations put to me
on the 1 2th of the present month, and in particular
as to whether sixteen years ago an injunction was
intimated to me by order of the Holy Office for-
bidding me to hold, defend, or teach, in any manner,
the opinion that had just been condemned — of the
motion of the earth and the stability of the sun — it
occurred to me to reperuse my printed Dialogues
(which for three years I had not seen), in order
carefully to note whethe^, contrary to my most
sincere intention, there had by any inadvertence
fallen from my pea anything from which a reader or
the authorities might infer not only some taint of
disobedience on my part, but also other particulars
which might induce the belief that I had con-
travened the orders of Holy Church. And being
by the kind permission of th^ authorities at liberty
to send about my servant, I sitffceeded in procuring
302 THE INQUISITION [1632-
a copy of my book, and having procured it I applied
myself with the utmost diligence to its perusal and
to a most minute consideration thereof. And,
owing to my not having seen it for so long, it
presented itself to me as if it were a new writing
and by another author. I freely confess that in
several places it seemed to me set forth in such a
form that a reader ignorant of my real purpose
might have had reason to suppose that the argu-
ments adduced on the false side, and which it was
my intention to refute, were so expressed as to be
calculated rather to compel conviction by their
cogency than to be easy of refutation. Two
arguments there are in particular — the one taken
from the Sun-spots, the other from the ebb and
flow of the tide — which in truth come to the ear of
the reader with far greater show of force and power
than ought to have been imparted to them by one
who regarded them as inconclusive and who in-
tended to refute them ; as, indeed, I truly and
sincerely held and do hold them to be inconclusive
and admitting of refutation. And as excuse to
myself for having fallen into an error so foreign to
my intention, not contenting myself merely with
saying that when a man recites the arguments of
the opposite side with the object of refuting them,
he should, especially if writing in the form of
dialogue, state them in their strictest form, and
should not cloak them to the disadvantage of his
opponent. Not contenting myself with saying
this, I now see I was misled by that natural com-
placency which every man feels with regard to his
own subtleties and in showing himself more skilful
than the generality of men in devising, even in
favour of false propositions, ingenious and plausible
arguments. However, although with Cicero avidior
sim gloriae quam satis est, if I had now to set
forth the same reasonings, without doubt I should
1633] EXTRAORDINARY CONFESSION 303
so weaken them that they should not be able
to make an apparent show of force of which they
are really and essentially devoid. My error then
has been — and I confess it — one of vainglorious
ambition and of pure ignorance and inadvertence.
"This is what occurs to me to say with refer-
ence to this particular, and what suggested itself
to me during the reperusal of my book/'
After making this humiliating declaration,
Galileo was allowed to withdraw, and no questions
were put to him ; but he must have concluded from
this silence or other sign that he had not gone far
enough in the denial of his inmost convictions ;
perhaps, this penitent acknowledgment of error and
vain-glory was not sufficient, and the Inquisitors
would be conciliated by the resolution to publicly
correct his error — whatever prompted the impulse
he returned at once to the Court and spoke as
follows : —
" And in confirmation of my assertion, that I
have not held and do not hold as true the opinion
which has been condemned, if there shall be granted
to me, as I desire, means and time to make a clearer
demonstration thereof, I am ready to do so ; and
there is a favourable opportunity for this, seeing
that in the work the interlocutors agree to meet
again after a certain time, to discuss several distinct
problems of nature connected with the matter dis-
cussed at their meetings. As this affords me an
opportunity of adding one or two other 'days/ I
promise to take up the arguments already adduced
in favour of the said opinion, which is false and has
been condemned, and to confute them in such most
effectual manner as by the blessing of God will
be possible to me. I pray, therefore, this sacred
304 THE INQUISITION [,632-
tribunal to aid me in this good resolution, and to
enable me to put it into effect."
On the evening of the day on which the second
hearing took place, joth April 1633, Galileo was
permitted to return to the Tuscan Embassy, on
oath not to leave it, not to hold intercourse with
any but the inmates of the house, to present him-
self before the Holy Office when summoned, and to
maintain the strktest silence on the subject of the
trial. At this wholly unexpected favour, Niccolini
and his household were, as we may imagine, filled
with delight, and tvot less, we may be sure, was
the rejoicittg* at San Matteo, when Galileo's letter
arrived with th* goad news. Replying on ;th
May, Mark Celeste *ly$ :—
" The kty that your last dear le&fer brought
me, and ttte ttttiftg' to read k over and over to
the nuhs, Who Jtiade «fuite a jubilee on hearing
its contents, ptft fne into such an excited state,
that at last I girt a set etc headache. I do not
say this to fepnsieh you, but to show how I take
to heart all your dbnceras. And though I am not
more strofcfly ^fefcted by What happens to you
than a daufnter oigfht to be» yet I dare to say that
the love arid rfcteneftce I bft&r my dearest Lord
and father 46 surpaifc by a £bod deal that of the
generality rf.ckugfetifrS; and I know that in like
manner ne ejtcdt mdMk parent* in his love of me,
his dattjjfhter, I ^N^ Ifcitty thffeks to our gracious
God for thfe tffcfcieifcs ftfu ha^fc hitherto received.
You justly &f mil ouf fhercies come fVom Him ;
and though you considfet' these ftow received as
an ansWfcf to «!jf praytete, yet tmly they count
for little df AOtMlf. But God knows how dearly
I love yoc* tod ife He h*r» me/'
RELEASED ON PAROLE 305
A week later, I4th May, she writes again: —
" You will have heard already what joy and
comfort your last letter gave ITU*. As I was
obliged to give it to Signor Geri that Vincenzio
might see it, I made a copy which Signor Rondi-
nelli will take into Florence to read to some of his
friends, who he knew would be extremely glad to
hear the particulars."
After a long detailed account of her steward-
ship in the management of his property, she
goes on : —
" I wonder at Vincenzio never having written
to you, and I glory in having been beforehand
with him in writing constantly, notwithstanding
that I too have sometimes found time wanting.
To-day, I have written this at four different times,
having had constant interruptions frtffa the phar-
macy [of which she was kegper], atl& also from
the toothache, which has been troublesome for
many days past/'
For once Maria Celeste sfcfcma to be unjust
to her brother. Vincenzio did not write, it is
true, but the reason was that fear of th6 plague
had interrupted all communication between the
healthy and the infected districts. He htd not
long before condescended to accggt an appoint-
ment as clerk at Poppi, chief town «f the Cfc«en-
tino, a district to which the scotn|fe had not
penetrated. Vincenzio does not apptar to fcfcve
held this appointment very long, f« we learn
that, owing to his inefficiency and carelessness, he
was requested to send in his resignation, or suffer
dismissal. Writing to Galileo cm this subject,
Bocchineri says : —
u
3o6 THE INQUISITION [,632-
" I wish you would write and tell him to mind
his business, and not waste his time over his new
invention — a tuning-fork or some such thing —
which might serve well enough to employ him
after business hours, but which ought not to be
the principal occupation of the day/'
Poor Galileo !
On loth May, Galileo was summoned for the
third time before the Inquisition, where the Com-
missary - General, Firenzuola, informed him that
eight days were allowed in which to prepare a
defence if he wished to do so; but Galileo at
once handed in a paper, from which we may con-
clude that it was written to order, and under the
same extra-judicial pressure as made him write
his humiliating confession of 3Oth April. The
greater part of this document is taken up with
an explanation why he had not mentioned the
prohibition of 1616 when applying for the Im-
primatur in 1630 — which explanation amounts to
a formal admission that on 26th February 1616
he was not only commanded not to hold or
defend the Copernican doctrine, but not to teach
it in any way whatsoever. Coming then to the
last paragraph he says : —
"Lastly, it remains for me to pray you to
take into consideration my pitiable state of bodily
indisposition, to which at the age of seventy years,
I have been reduced by ten months of constant
mental anxiety, and the fatigue of a long and
toilsome journey at the most inclement season,
together with the loss of the greater part of the
years of which, from my previous condition of
health, I had the prospect. I am encouraged to
i633] THIRD EXAMINATION 307
ask this indulgence by the clemency and good-
ness of the most eminent lords, my judges,
and hope that they will be pleased to remit what
may appear good to their entire justice, and to
consider my sufferings as adequate punishment"
This touching appeal to the mercy of his judges
cannot be read without feelings of the profoundest
pity for the crushed old man, who in the evening
of a glorious life was thus compelled to deny his
inmost convictions, and to sue cravenly for that
pity which was not to be shown him.
After his paper had been received, and the
same obligations imposed on him on oath as after
the second hearing, he was allowed to return to
the Embassy. The nearer the time approached
when his illusions were to be dispelled, the more
sanguine was the intelligence he sent to his
friends. A favour granted just at the last, on
the urgent solicitation of Niccolini, and unheard
of in the annals of the Inquisition, might have
encouraged these confident hopes. He was per-
mitted to take the air in the gardens of the Villa
Medici on the Pincio, to which, however, he was
always conveyed in a closed carriage, as he must
not be seen in the streets ! Niccolini did not share
in these hopes of his guest After an audience
of the Pope and Cardinal Barberini, he wrote
to Cioli (22nd May) : —
" I very much fear that the book will be pro-
hibited, unless it is averted by Galileo's being-
charged (as I suggested) to write an apology.
Some salutary penance will also be imposed, as
they maintain that he has transgressed the com-
308 THE INQUISITION [1632-
mand given to him by Cardinal Bellarmine in
1616. I have not yet told Galileo all this,
because I want to prepare him for it by degrees,
in order not to distress him."
A lull now took place in the proceedings —
the preparation for the great catastrophe that
was to crush Galileo and fill the educated world
with horror. Sultry silence reigned for four
weeks, and no one, not even Niccolini, could
learn anything. Indeed, the thunderbolt had
fallen before the fact was known outside the
Holy Office. Galileo's fate had been sealed at
a private meeting of the Congregation, i6th June
1633, at which the Pope presided. It was
decreed to try Galileo as to his intention, under
threat of torture, and if this failed he was then
to be called upon to recant before a plenary
assembly of the Holy Office; to be condemned
to imprisonment at their pleasure; and to be
ordered in future not to discuss in writing or
speaking the opinion that the earth moves and
that the sun is stationary, nor even the contrary
opinion, under pain of further punishment as a
relapsed heretic. Further, the work "Dialogo di
Galileo Galilei, Linceo," was to be prohibited.1
And, in order to make this known everywhere,
copiesv of the sentence were to be sent to all
Papal envoys and to all Inquisitors into heretical
crimes, and especially to the Inquisitor in Florence,
who were to read it publicly to all professors of
mathematics summoned for the purpose.
1 From the Vatican MSS. it was apparently first intended to
publicly burn the book, but after the decree was drafted, the words
Cremandum fere were erased and prohibendum fore inserted.
x633] AWFUL PAUSE: SILENCE 309
Two days after these proceedings had been
determined on, the Pope received Niccolini, who
once more came to beg for a speedy termination
of the trial, the long suspense of which was
torturing to him only in a less degree than it
was to Galileo himself. Urban coolly replied
that it had already been terminated, and that
within the next few days Galileo would be
summoned to hear his sentence. The Ambas-
sador, aghast at this unexpected answer, implored
the Pope to mollify any severity that the judges
might, perhaps, have" thought necessary, and added
that the great complaisance hitherto shown to
his Sovereign's wishes in the matter was fully
appreciated, and that the Grand Duke was only
waiting the end of the business to express his
gratitude in person. The Pope replied that his
Highness need not take this trouble, that he had
readily granted every amelioration possible; but
as to Galileo's opinions they could do no less than
prohibit them as erroneous and contrary to
Holy Scripture, and as to his person, he would,
according to usage, fee imprisoned for a time,
because he had transgressed the mandate issued
to him in 1616. " However," added Urban,
"after the publication of the sentence we will
see you again and we will consult together so
that he may suffer as little distress as possible."
The same day, i8th June, Niccolini reported
this audience to Cioli, and remarked at the end
that he had simply informed Galileo of the
approaching end of the trial and of the prohibi-
tion of his book, but had said nothing about the
310 THE INQUISITION [1632-
personal punishment, in order not to trouble him
too much at once. The Pope had also enjoined
this course, " because, perhaps, in the course of
the proceedings things might take a better turn/'
The drama now rapidly proceeded to a climax.
On the evening of 2Oth June 1633, Galileo was
warned to appear before the Inquisition on the
following morning, when, as we know from the
programme of i6th June, he was to be questioned
under threats of torture about his "intention"
that is, as to his real convictions.
On the morning of the 2ist, Galileo appeared
before his judges. After he had taken the usual
oath and had answered in the negative the query
whether he had any statement to make, the
examiner asked three separate questions, slightly
varied but all to the effect whether he has held
and holds the opinion that the sun is the centre
of the world, and that the earth is not the
centre, but moves, and with a diurnal motion.
To these Galileo suitably replied in the negative.
" I do not hold," he says, in reply to the last
query, " and have not held this opinion of
Copernicus since the command was given me
that I must abandon it. For the rest I am here
in your hands, do with me as you please. J1
Being once more bidden to speak the truth,
otherwise recourse would be had to torture, the
terrified old man answered with the resignation
of despair, "I am here to obey. I have not
held this opinion since the decision was pro-
nounced, as I have stated."
In the protocol of the trial the concluding
1633] FOURTH EXAMINATION 311
sentence follows immediately after Galileo's answer,
"And as nothing further could then be done
in execution of the decree [of i6th June] his
signature was obtained to his depositions, and he
was sent back to his place," that is, to some
place in the buildings of the Holy Office, where
he was detained till 24th June.1
We have no information as to the treatment
he received this time. Was he put into the
apartments he had occupied before, or was he
confined in a prisoner's cell? From the con-
siderate treatment in outward things which
Galileo met with during his trial, we may,
perhaps, conclude that he was not thrown into
the dungeons of the Inquisition as so many
historians are fond of repeating. Neither is
there, as we shall presently see, the slightest
foundation for another vulgar error — that he was
actually put to the torture.
3 Despatch, Niccolini to Cioli, 26th June 1633.
CHAPTER XIV
SENTENCE OF THE INQUISITION AND GALILEO'S
ABJURATION EXILED TO SIENA
1633
ON Wednesday, 22nd June 1633, in the forenoon,
Galileo was conducted to the large hall used
for melancholy proceedings of this kind in
the Dominican Convent of Santa Maria sopra
Minerva, where in the presence of his judges
and a large assemblage of cardinals and prelates
of the Church his sentence was read to him as
follows r1 —
" We, the undersigned,
Gasparo of Santa Croce in Gerusalemme, Borgia,
Fra Felice Centino of S. Anastasia, called Ascoli,
Guido of Santa Maria del Popolo, Bentivoglio,
Fra Desiderio Scaglia of S. Carlo, called Cremona,
Fra Antonio Barberini, called S. Onofrio,3
Laudivio Zacchia of S. Pietro in Vincoli, called San-Sisto,
Berlingero of San Agostino, Gessi,
Fabrizio of S. Lorenzo in Pane e Perna, Verospi,
Francesco of S. Lorenzo in Damaso, Barberini,8
Martino of Santa Maria Nuova, Ginetti,
"by the grace of God, Cardinals of the Holy
1 Jean-Jacques Bouchard writing from Rome to Micanzio, 29th
June 1633, says " he was conducted as a criminal in penitential garb."
2 Pope's brother. 3 pope>s nephew.
1633] SENTENCE 313
Roman Church, Inquisitors General throughout
the whole Christian Republic, Special Deputies
of the Holy Apostolical Chair against heretical
depravity :
" Whereas you, Galileo, son of the late
Vincenzio Galilei, of Florence, aged 70 years,
were denounced, in 1615, to this Holy Office,
for holding as true a false doctrine taught by
many, namely, that the sun is immovable in the
centre of the world, and that the earth moves,
and also with a diurnal motion ; also, for having
pupils whom you instructed in the same opinions ;
also, for maintaining a correspondence on the
same with some German mathematicians ; also
for publishing certain letters on the sun-spots, in
which you developed the same doctrine as true ;
also for answering the objections which were
continually produced from the Holy Scriptures,
by glozing the said Scriptures according to your
own meaning; and whereas thereupon was pro-
duced the copy of a writing, in form of a letter,
professedly written by you to a person formerly
your pupil, in which, following the hypothesis of
Copernicus, you include several propositions
contrary to the true sense and authority of the
Holy Scriptures ; therefore (this Holy Tribunal
being desirous of providing against the disorder
and mischief which were thence proceeding and
increasing to the detriment of the Holy Faith)
by the desire of his Holiness and of the Most
Eminent Lords, Cardinals of this supreme and
universal Inquisition, the two propositions of the
stability of the sun, and the motion of the earth,
were qualified by the Theological Qualifiers as
follows ;
" i. The proposition that the sun is in the
centre of the world and immovable from its
place is absurd, philosophically false, and formally
3H THE INQUISITION [1633
heretical ; because it is expressly contrary to
the Holy Scriptures.
"2. The proposition that the earth is not
the centre of the world, nor immovable, but that
it moves, and also with a diurnal motion, is also
absurd, philosophically false, and, theologically
considered, at least erroneous in faith.
" But whereas, being pleased at that time to
deal mildly with you, it was decreed in the Holy
Congregation, held before his Holiness on the
twenty -fifth day of February 1616, that his
Eminence the Lord Cardinal Bellarmine- should
enjoin you to give up altogether the said false
doctrine ; and if you should refuse, that you should
be ordered by the Commissary of the Holy Office
to relinquish it, not to teach it to others, nor
to defend it ; and in default of acquiescence,
that you should be imprisoned ; and whereas in
execution of this decree, on the following day,
at the Palace, in presence of his Eminence the
said Lord Cardinal Bellarmine, after you had been
mildly admonished by the said Lord Cardinal,
you were commanded by the Commissary of the
Holy Office, before a notary and witnesses, to
relinquish altogether the said false opinion,
and, in future, neither to defend nor teach it in
any manner, neither verbally nor in writing,
and upon your promising obedience you were
dismissed.
" And, in order that so pernicious a doctrine
might be altogether rooted out, nor insinuate
itself further to the heavy detriment of the
Catholic truth, a decree emanated from the Holy
Congregation of the Index prohibiting the books
which treat of this doctrine, declaring it false,
and altogether contrary to the Holy and Divine
Scripture.
"And whereas a book has since appeared
1633] SENTENCE 315
published at Florence last year, the title of which
showed that you were the author, which title is
'The Dialogue of Galileo Galilei, on the two
principal Systems of the World — the Ptolemaic
and Copernican ' ; and whereas the Holy Con-
gregation has heard that, in consequence of
printing the said book, the false opinion of the
earth's motion and stability of the sun is daily
gaining ground, the said book has been taken
into careful consideration, and in it has been
detected a glaring violation of the said order,
which had been intimated to you ; inasmuch as
in this book you have defended the said opinion,
already, and in your presence, condemned ;
although, in the same book, you labour with
many circumlocutions to induce the belief that
it is left by you undecided and merely probable ;
which is equally a very grave error, since an
opinion can in no way be probable which has
been already declared and finally determined
contrary jo the Divine Scripture. Therefore, by
Our order, you have been cited to this Holy
Office, where, on your examination upon oath,
you have acknowledged the said book as written
and printed by you. You also confessed that you
began to write the said book ten or twelve
years ago, after the order aforesaid had been
given. Also, that you had demanded licence to
publish it, without signifying to those who granted
you this permission that you had been commanded
not to hold, defend, or teach, the said doctrine
in any manner. You also confessed that the
style of thfc said book was, in many places, so
composed that the reader might think the argu-
ments adduced on the false side to be so
worded as more effectually to compel ^conviction
than to be easily refutable, alleging, in excuse,
that you had thus run into an error, foreign
3r6 THE INQUISITION [1633
(as you say) to your intention, from writing in
the form of a dialogue, and in consequence of
the natural complacency which every one feels
with regard to his own subtleties, and in showing
himself more skilful than the generality of mankind
in contriving, even in favour of false propositions,
ingenious and plausible arguments.
" And, upon a convenient time being given
you for making your defence, you produced a
certificate in the handwriting of his Eminence
the Lord Cardinal Bellarmine, procured, as you
said, by yourself, that you might defend yourself
against the calumnies of your enemies, who
reported that you had abjured your opinions,
and had been punished by the Holy Office ; in
which certificate it is declared that you had not
abjured nor had been punished, but merely that
the declaration made by his Holiness, and pro-
mulgated by the Holy Congregation of the Index,
had been announced to you, which declares that
the opinion of the motion of the earth and stability
of the sun is contrary to the Holy Scriptures,
and, therefore, cannot be held or defended. Where-
fore, since no mention is there made of two articles
of the order, to wit, the order ' not to teach ' and
*in any manner/ you argued that we ought to
believe that, in the lapse of fourteen or sixteen
years, they had escaped your memory, and that
this was also the reason why you were silent as
to the order when you sought permission to
publish your book, and that this is said by you,
not to excuse your error, but that it may be
attributed to vain-glorious ambition rather than
to malice. But this very certificate, produced
on your behalf, has greatly aggravated your
offence, since it is therein declared that the said
opinion is contrary to the Holy Scriptures, and
yet you have dared to treat of it, and to argue
1633] SENTENCE 317
that it is probable. Nor is there Vmy extenuation
in the licence artfully and cunningly extorted by
you, since you did not intimate the command
imposed upon you. But whereas it appeared to
Us that you had not disclosed the whole truth
with regard to your intention, We thought it
necessary to proceed to the rigorous examination
of you, in which (without any prejudice to what
you had confessed, and which is above detailed
against you, with regard to your said intention)
you answered like a good Catholic.1
"Therefore, having seen and maturely con-
sidered the merits of your cause, with your said
confessions and excuses, and everything else which
ought to be seen and considered, We have come
to the underwritten final sentence against you :
" Invoking, therefore, the most holy name of
our Lord Jesus Christ, and of His Most Glorious
Virgin Mother, Mary, We pronounce this Our
final sentence, which, sitting in council and
judgment with the Reverend Masters of Sacred
Theology and Doctors of both Laws, Our Assessors,
We put forth in this writing in regard to the
matters and controversies between the Magnificent
Carlo Sincero, Doctor of both Laws, Fiscal Proctor
of the Holy Office, of the one part, and you,
Galileo Galilei, defendant, tried and confessed
as above, of the other part, We pronounce, judge,
and declare, that you, the said Galileo, by reason of
these things which have been detailed in the course
of this writing, and which, as above, you have
confessed, have rendered yourself vehemently
suspected by this Holy Office of heresy, that is of
having believed and held the doctrine (which is
false and contrary to the Holy and Divine
1 The phrase is vague and purposely so, for clearly, even the
, threat of torture could not extort from Galileo the wished-for avowal
of his "intention," that is of his still holding- the condemned opinion.
See Martin's "GalileV PP- 129-31.
318 THE INQUISITION [1633
Scriptures), that the sun is the centre of the world,
and that it does not move from east to west, and that
the earth does move, and is not the centre of the
world ; also, that an opinion can be held and
supported as probable, after it has been declared
and finally decreed contrary to the Holy Scripture,
and, consequently, that you have incurred all the
censures and penalties enjoined and promulgated in
the sacred canons and other general and particular
constitutions against delinquents of this description.
From which it is Our pleasure that you be absolved,
provided that with a sincere heart and unfeigned
faith, in Our presence, you abjure, curse, and
detest, the said errors and heresies, and every
other error and heresy, contrary to the Catholic
and Apostolic Church of Rome, in the form now
shown to you.
" But that your grievous and pernicious error
and transgression may not go altogether un-
punished, and that you may be made more cautious
in future, and may be a warning to others to
abstain from delinquencies of this sort, We decree
that the book ' Dialogues of Galileo Galilei ' be
prohibited by a public edict, and We condemn
you to the formal prison of this Holy Office for
a period determinable at Our pleasure ; and by
way of salutary penance, We order you during the
next three years to recite, once a week, the seven
penitential psalms, reserving to Ourselves the
power of moderating, commuting, or taking off,
the whole or part of the said punishment or
penance.1
1 Accordingly, the work was placed on the Index Expurgatorius,
and for more than a hundred years after, it was not allowed to be
printed in Italy, and then (1744) the editot had to state expressly in
an introduction that the theory of the double motion of the earth must
be regarded only as a mathematical hypothesis to facilitate the ex-
planation of certain natural phenomena. He had also to prefix the
sentence of the Holy Office and Galileo's recantation, as well as
i633] ABJURATION 319
"And so We say, pronounce, and by Our
sentence declare, decree, and reserve, in this and in
every other better form and manner, which lawfully
We may and can use. So We, the subscribing
Cardinals, pronounce.
' FELIX, Cardinal di Ascoli.
'GuiDO, Cardinal Bentivoglio.
c DESIDERIO, Cardinal di Cremona.
{ ANTONIO, Cardinal S. Onofrio.
£BERLINGERO, Cardinal Gessi.
6 FABRIZIO, Cardinal Verospi.
* MARTINO, Cardinal Ginetti."
In conformity with the foregoing sentence,
Galileo was made to kneel before the Inquisition,
and make the following abjuration : —
" I, Galileo Galilei, son of the late Vincenzio
Galilei of Florence, aged seventy years, being
brought personally to judgment, and kneeling
before you, Most Eminent and Most Reverend
Lords Cardinals, General Inquisitors of the
Universal Christian Republic against heretical
depravity, having before my eyes the Holy Gospels
which I touch with my own hands, swear that I
have always believed, and, with the help of God,
will in future believe, every article which the Holy
Catholic and Apostolic Church of Rome holds,
teaches, and preaches. But because I have been
Calmet's essay "On the System of the Universe of the Ancient
Hebrews," in which the passages of Scripture relating to the order of
the world are supposed to be interpreted in true Catholic fashion.
But see p. 427 infra.
After many attempts in the next eighty years to have the decree of
5th March 1616 (prohibiting all books which teach the Copernican
doctrine) expunged, it was finally resolved, nth September 1822,
" that the printing and publication of works treating of the motion of
the earth and the stability of the sun, in accordance with the opinion
of modern astronomers, is permitted in Rome." Accordingly, in the
next edition of the Index, published in 1835, Galileo's name, Kepler's,
and those mentioned in the decree of 5th March 1616, were expunged.
320 THE INQUISITION [1633
enjoined, by this Holy Office, altogether to abandon
the false opinion which maintains that the sun is
the centre and immovable, and forbidden to hold,
defend, or teach, the said false doctrine in any
manner ; and because, after it had been signified to
me that the said doctrine is repugnant to the Holy
Scripture, I have written and printed a book, in
which I treat of the same condemned doctrine, and
adduce reasons with great force in support of the
same, without giving any solution, and therefor have
been judged grievously suspected of heresy ; that is
to say, that I held and believed that the sun is the
centre of the world and immovable, and that the
earth is not the centre and movable, I am willing
to remove from the minds of your Eminences,
and of every Catholic Christian, this vehement
suspicion rightly entertained towards me, therefore,
with a sincere heart and unfeigned faith, I abjure,
curse, and detest the said errors and heresies, and
generally every other error and sect contrary to the
said Holy Church ; and I swear that I will never
more in future say, or assert anything, verbally or
in writing, which may give rise to a similar sus-
picion of me ; but that if I shall know any heretic,
or any one suspected of heresy, I will denounce
him to this Holy Office, or to the Inquisitor and
Ordinary of the place in which I may be. I swear,
moreover, and promise that I will fulfil and observe
fully all the penances which have been or shall be
laid on me by this Holy Office. But if it shall
happen that I violate any of my said promises,
oaths, and protestations (which God avert ! ), I
subject myself to all the pains and punishments
which have been decreed and promulgated by the
sacred canons and other general and particular
constitutions against delinquents of this description.
So, may God help me, and His Holy Gospels,
which I touch with my own hands, I, the above
i633] DID THE JUDGES AGREE? 321
named Galileo Galilei, have abjured, sworn,
promised, and bound myself as above ; and, in
witness thereof, with my own hand have subscribed
this present writing of my abjuration, which I have
recited word for word.
"At Rome, in the Convent of Minerva, 22nd
June 1633, I» Galileo Galilei, have abjured as above
with my own hand." l
A notable circumstance connected with these
papers is that, whereas the names of ten Cardinals
appear in the preamble of the sentence, only seven
subscribed it The three who did not sign deserve
to be specifically mentioned ; they were Gasparo
Borgia, Laudivio Zacchia, and Francesco Barberini,
the Pope's nephew. Why did these Cardinals
abstain from signing ? Were they absent accident-
ally, or on purpose ? Or did they dissent and refuse
to sign ? We shall probably never know ; but
bearing in mind the many instances of Francesco
Barberini's good offices in Galileo's behalf, we shall
not be far wrong, I think, if we conclude that they
did not sign because they did not approve the sen-
tence. Another of the ten, Cardinal Bentivoglio,
1 The Vatican MSS. relating to Galileo's trial have a curious
history of their own. They were carried away in 1809 by order of
Napoleon to Paris, where they remained until his first abdication.
Just before the Hundred Days, the King, Louis XVI 1 1., wishing to
inspect them, ordered them to be sent to his private apartments. In
the hasty flight which soon afterwards followed, the MSS. were
forgotten, and disappeared in an unaccountable way. After some
years they were restored to Pope Gregory XVI., in an equally
mysterious manner, and were finally replaced in the Vatican Library
by Pope Pius IX,, in 1848. A French translation, begun by
Napoleon's orders, was brought down to 3oth April 1633, when, no
doubt, the Emperor's abdication prevented its completion. For more
on this subject, see Favaro's "Document! del Processo di Galileo,"
Venice, 1902.
X
322 THE INQUISITION [l633
although he signed, is said to have done his
best to prevent the decision arrived at ; which
is likely enough, seeing that he studied under
Galileo in Padua, and was always reckoned as
one of his disciples,1 We may, then, suppose
that at least four of the ten judges were against
the sentence, which, if true, is another indica-
tion of the determination of Urban VIII. to
punish his quondam friend for calling him a
simpleton.2
It is also noteworthy that not one of the decrees
or orders relating to this trial is ratified by the
Pope. They all begin with the words Sanctissimus
mandavit, but bear no Papal signature. This is
equally the case in the proceedings of 1616 as in
those of 1633. This fact is made much of by
apologists of the Church of Rome. They argue
that from the absence of the Pope's signature the
Church cannot be held responsible. Galileo, they
1 See his " Memorie," Venice, 1648, p. 123 ; also p. 288 ante, where
Galileo says that Cardinals Bentivoglio and Scaglia were well
disposed towards him. The Pope told Niccolini on i8th June that
the Cardinals were unanimous " in intending to impose a penance."
But were they unanimous in all other matters ? It is well to note (as
Professor Favaro points out) that his Holiness was not always sincere
in his communications to Niccolini,
2 Since the above was written, I^have received a letter from Pro-
fessor Favaro in which he says :— "The omission of the signatures has
not the significance hitherto ascribed to it. The three Cardinals were
not present, but there can be little doubt that, notwithstanding their
good disposition towards Galileo personally (a feeling which was
shared by others on the bench), they were assenting parties. Cardinal
Borgia was at the time Spanish Ambassador to Rome, his relations
with the Pope and the Barberini faction were strained, and he seldom
if ever attended the sittings of the Holy Office. Cardinal Barberini,
as we learn from one of Niccolini's despatches, never attended the
Wednesday sittings. Cardinal Zacchia's absence was probably acci-
dental, perhaps on account of ill-health."
i633] SUBTERFUGE OF APOLOGISTS 323
say, was persecuted, not by the Pope, Urban VIII.,
the infallible vicar of Christ, but by the man, Maffeo
Barberini, and his tools the Cardinals. Granted :
but suppose a man be persecuted by the police in
the name of, and to the knowledge of, the higher
powers, are these higher powers to get off scot-free,
because they did not put their hand and seal to the
documents authorising the acts of their subordinates ?
However, since the apologists admit the persecution,
we leave them to derive what comfort they can from
their casuistical argument.1
For a long time it was a popular error that
Galileo was subjected to torture.2 The assertion is
based on the mention in the sentence of a rigorous
examination under which Galileo answered as
became a good Catholic ; and in support it is
pointed out that after this time he was afflicted
(in addition to his other maladies) with hernia, which
was said-to be the usual consequence of "torture by
the cord." Now, as regards the latter it is enough
to say that hernia was an old complaint, and is
certified to by the Florentine physicians in their
certificate of i7th December 1632, already quoted
in these pages. As regards the rigorous exa-
mination, all histories of the Inquisition show that
this formula consisted of five stages which had to
be strictly followed : (i) threat in Court that extreme
measures would be resorted to ; (2) taking the
1 For an excellent review^showing the injustice and illegality of
these proceedings, see Von Getter's " Galileo and the Roman Curia,"
pp. 234-42, or Martin's " Galile'e,' chap, vii., where the whole affair is
exhaustively discussed from a different standpoint.
2 The fable is not dead yet, even amongst educated people. The
latest repetition of it occurs in an article in the Fortnightly Review
for .March 1902.
324 THE INQUISITION [X633
accused into the torture chamber, renewing the
threat, and showing him the instruments of torture ;
(3) undressing and binding ; (4) laying him on the
rack; and (5) actual torture (territio realis\ Now,
a close study of the proceedings clearly shows that
it was not necessary to go beyond the first stage, for
the compliance of the accused saved his judges
from the ineffable disgrace of the crowning infamy.
The difference to a man of Galileo's genius, years,
and infirmities, was little if anything. The whole
period of the trial, from his first citation to Rome on
ist October 1632 to the closing scene on 22nd
June 1633, was one continued infliction of moral
torture. The repeated denials of his inmost con-
victions, and the final abjuration on bended knees,
must have wrung his soul as severely as physical
torture could have wrung the muscles and tendons
of his body.
Another error which early biographers were fond
of repeating, but of which a moment's reflection
would have shown the absurdity, was that Galileo
on rising from his knees after reciting the abjur-
ation muttered Eppur si muove (it moves, never-
theless). Some writers, doubtless to make the
story more vraisemblable, provide a friend to
whom the words are whispered. But consider for
a moment the situation : an old man of seventy
years, suffering in body, and distressed in mind by
the accumulated anguish of a ten months' trial,
alone and without support in the midst of that stern
assembly of Inquisitors. Is it likely that at such a
moment he would have muttered or uttered these
words? He must have known that the slightest
1633] EPPUR SI MUOVE 325
indication by words or gesture of such a state of
mind would have consigned him for life to the
deepest dungeons of the Inquisition, if to no
worse.1
While the older writers go to one extreme and
say that Galileo was tortured, thrown into a dungeon
for years, or for the rest of his life, was in physical
fact a martyr, some recent ones go to the other ex-
treme, and say he had no claim to much sympathy,
brought his troubles on himself by want of tact and
temper, was, in fact, as little of a martyr as it was
possible to be. Others, again, blame him for not
" seeing this thing through." Brewster, for example,
compares him to the Christian martyr, and finds him
sadly degenerate. " Had Galileo," he says, "but
added the courage of the martyr to the wisdom of
the sage ; had he carried the glance of his indignant
eye round the circle of his judges ; had he lifted his
hands to Heaven, and called on the living God to
witness the truth and immutability of his opinions,
the bigotry of his enemies would have been dis-
armed, and science would have enjoyed a memorable
triumph." Perhaps ; but perhaps on the other hand,
his judges, instead of being cowed by the glance of
his eye, would have delivered him to the stake, as
they did Giordano Bruno earlier in the century
(1600), and Marc' Antonio de Dominis only eight
years before.2 Revealed truth may require its
martyrs, at least so Tertullian tells us — the blood
1 The earliest mention of "Eppur si muove" occurs in "Querelles
Litt&raires," by L'Abbe* Irailh, Paris, 1761, vol. iii. p. 49.
3 De Dominis died in prison (1624) in the course of his trial, but
his body was burned with his books by sentence of the Inquisition —
pour encourager les autres^ I suppose.
326 THE INQUISITION [1633
of the martyrs is the seed of the Church; but
scientific truth certainly requires none,/W£ Brewster,
for, as the Koran (strange authority) teaches, "the
ink of the scholar and the blood of the martyr are
of equal value in the eye of Heaven. " Much as
Galileo did for science, he would probably have
done more were his life less stormy. From his
entry into public life in 1589 to his death in 1642,
he was seldom free from polemics. For over fifty
years he was the knight militant of science, and
almost alone did successful battle with the hosts of
Churchmen and Aristotelians who attacked him on
all sides — one man against a world of bigotry and
ignorance. If, then, once and only once, when face
to face with the terrors of the Inquisition, he, like
Peter, denied his Master, no honest man, knowing
all the circumstances, will be in a hurry to blame
him.
After this sorrowful drama had been concluded,
Galileo was led back to the buildings of the Holy
Office. And now that he and the Copernican
system had been condemned with all the terrify-
ing forms of the Inquisition, Urban 's wounded
vanity was soothed, and he was pleased to give
the word for a little mercy. Galileo was not, as
the sentence prescribed, to be detained in the prison
of the Holy Office, but was banished to the villa
of the Grand Duke of Tuscany at Trinita dei
Monti, which, by Papal orders dated 23rd June,
he was to consider as a prison. Thither, where,
many years before, he had shown the moons of
Jupiter and other " Celestial Novelties" to wonder-
ing cardinals, he was now conducted by the
i633] PUBLICATION OF SENTENCE 327
ever-faithful Niccolini on the evening of 24th
June.
From Niccolini Js letter to Cioli of 26th June
we learn that while Galileo took the prohibition
of his book (for which his friend had prepared
him) with tolerable composure, the wholly un-
expected proceedings against himself personally
affected him terribly. He sank into a deep de-
pression from which the Ambassador did his best
to rouse him, but with little success for a time.
In accordance with the decree of i6th June
1633, copies of the sentence and abjuration were
despatched to all Papal Nuncios, all Inquisitors,
and many Universities, Italian and Foreign. In
Padua and Florence especially, the means of publi-
cation were calculated with a refinement of cruelty.
In Padua the local Inquisitor read both documents
to the professors of philosophy and mathematics,
and to the students convened for the purpose in
the University library. A search was made for
copies of the condemned book, and if none were
found the Inquisitor could at least boast of one
voluntary surrender. The peripatetic Fortunio
Liceti gave up his copy — a presentation one by
the author! In Florence the Inquisitor read the
sentence and abjuration publicly in the church
of Santa Croce, notices to attend having been
previously served on all professors, and on all
others who were known to be friends and ad-
herents of Galileo. Thus Aggiunti, Guiducci,
Arrighetti, and many others who loved the great
master were made to participate in his humiliation.1
1 See Guiducci's letter to Galileo, dated 27th August 1633,
328 THE INQUISITION [1633
But the cup of Papal wrath was not emptied
on Galileo's head alone. All who had befriended
him, or had any part in the licensing of his
Dialogues, were punished in some way. Ciampoli,
in December 1632, was deprived of his office of
Secretary of the Papal Briefs and was (practically)
exiled as Governor of Montalto, where he remained
as long as he lived — Galileo's faithful disciple to
the last Early in April 1633 Galileo was deprived
of the valuable advocacy of the devoted Castelli,
who was sent away on some pretext, and was not
recalled until the middle of 1635, when "At last
he had again been permitted to kiss his Holiness's
toe.JJ The Inquisitor in Florence was severely repri-
manded, and Riccardi, the Censor, was dismissed in
disgrace and deprived of all offices during Urban's
lifetime.
The inconsistency of these proceedings will
be noted in the latter cases. These people are
punished for granting that very licence which
Galileo was charged with, and condemned for,
having surreptitiously obtained from them by con-
cealing circumstances with which they were not
bound to be acquainted. Riccardi, in exculpation
of his conduct, produced a letter from Ciampoli,
in which it was said that his Holiness (in whose
presence the letter professed to be written) ordered
the licence to be given ; but the Pope only replied
that this was a Ciampolism ; that his Secretary and
Galileo had circumvented him ; that he had already
dismissed Ciampoli, and that Riccardi must prepare
to follow him.
On the news of Galileo's condemnation reaching
i633] CONSTERNATION OF FRIENDS 329
his daughter, Maria Celeste wrote (on 2nd
July) :_
"The news of your fresh trouble has pierced
my soul with grief — all the more that it came upon
me quite unexpectedly. Not having had a letter
from you this week, I feared something must have
happened, and importuned Signor Geri to tell me.
What I hear from him of the resolution they have
taken concerning you and your book gives me
extremest pain, not having expected such a result.
Dearest Lord and father, now is the time for the
exercise of that wisdom with which God has en-
dowed you. Thus, you will bear these blows with
that fortitude of soul which religion, your age, and
your profession, alike demand."
Receiving no news direct from Galileo for some
days after the promulgation of the sentence in
Florence, Geri Bocchineri and Niccol6 Aggiunti,
fearing a descent on the villa at Arcetri by the
familiars of the Inquisition, requested the keys of
the house from Maria Celeste that they might do
what Galileo had told them might be necessary
to his safety should certain contingencies arise.
Writing on I3th July, she tells her father: —
"They feared you were in trouble, and seeing
how exceedingly anxious they were oil your account,
it seemed to me right and n'ecessary to prevent any
accident, therefore I gave them the keys and per-
mission to do as they thought fit"
The author of the " Private Life of Galileo"
thinks the work here hinted at was the burning of
such writings in Galileo's library as might be used
to further incriminate him.
330 EXILED TO SIENA [1633
"It is probable," the author says, "that much
which was precious was destroyed on this occasion ;
and this may fully account for the disappearance
of those incompleted writings of which mention
is made in his correspondence, but of which no
trace remains " (p. 263).
It is highly probable that as a matter of pre-
caution Galileo's friends took away for safe hiding
certain of his papers ; but that anything was actually
destroyed I doubt. With the exception of those
early treatises (some of which may never have
been written), noted on p. 120, no important paper
of his is missing, and there is no perceptible break
in his correspondence, except that already noted
for the year of his third visit to Rome in I6I6.1
Galileo, after his first great anguish had some-
what subsided, felt that he must quit Rome and
its hateful memories, and so addressed a pitiable
letter to the Pope.
" Most Holy Father," he says, " Galileo Galilei
humbly begs your Holiness to exchange the place
assigned to him for his prison near Rome for some
other in ^ Florence, which may appear suitable to
your Holiness, in consideration of his poor health,
and also because he is expecting a siste^ [in law]
with eight children from Germany, to whom no
one can afford help and protection so well as
himself.2 He will receive any disposition of your
Holiness as a great favour."
But at the Vatican it was thought that to
allow Galileo to return at once to Florence
1 See p. 156 ante, and the Bibliography at end.
2 A pretext, see " Galileo e Suor Maria Celeste," p. 188.
1633] QUITS ROME ON PAROLE 331
would be a superfluity of indulgence. "We
must proceed gently/' said his Holiness, "and
only rehabilitate him by degrees/' Still Urban
was moved to some compassion, and on 3oth
June allowed the poor old man to retire to
Siena, to the house of his former pupil Arch-
bishop Ascanio Piccolomini, where he was to
remain under the orders of the Archbishop, and
on no account to leave the town without per-
mission from Rome. Galileo was informed of
this decision on 2nd July, and early on the 6th
he shook the dust of Rome from off his feet
Niccolini, reporting his departure to Cioli (on
loth July), says: "Signor Galileo set out early
on Wednesday in good health for Siena, and
writes to me from Viterbo that he had performed
four miles on foot, the weather being very cool."
Galileo reached Siena safely on 9th July,
and was warmly received by Piccolomini ; but
neither his devoted kindness, not the stimulating
converse with an old friend, the learned Alessandro
Marsili, then residing at Siena, could make him
forget that he was a prisoner of the Inquisition.
On 23rd July 1633, he wrote to Cioli : —
" To-day I address myself to you, oppressed
by the ennui of a captivity of more than six
months — a captivity made more painful by the
chagrin and the anxiety of the preceding year,
and by all the dangers and all the bodily sufferings
which have followed in their train. My misfortunes
are commiserated by all the world, except by
those who have judged me deserving of this
punishment — but of this another time.
"The duration of my captivity is entirely at
332 EXILED TO SIENA [1633
the pleasure of his Holiness. On the intervention
of the Ambassador Niccolini, the Pope assigned
me, instead of the prison of the Holy Office,
the Villa de Medici, Trinita dei Monti, where I
remained some days. Again, on the Ambassador's
intercession, I was sent to the Archiepiscopal
Palace here, where for fifteen days I have
experienced the greatest kindness from the
excellent Archbishop. But, apart from the wish
that I have to return to my home and to be at
liberty, this liberty is really essential to me.
Therefore, I beg you to move his Highness to
solicit the favour of my liberty from his Holiness,
or through Cardinal Barberini. You might point
out that the house of the Grand Duke has been
for a long time deprived of my services, and insist
on attaching to this circumstance more importance
than it merits/'
After all his bitter disillusions we see that
his hopefulness had not yet abandoned him. The
Grand Duke very kindly consented to exert once
more what influence he possessed with the Pope,
and instructed his ambassador accordingly; but
Niccolini represented that the moment was not
opportune, and recommended that action should be
deferred for a few months. Meanwhile the good
Archbishop did all that love for his venerated
guest could suggest to make his house as little
like a prison as possible, rather "an earthly
paradise," as Maria Celeste wished her father
to consider it; but for a long time these efforts
had little effect The cruel edict condemning
him to perpetual silence on a subject which was
one of the mainsprings of his life was a serpent's
sting which could not be readily forgotten ; his
i633] NEW SCIENTIFIC PROJECTS 333
soul was lacerated, and he fell into frequent fits
of utter despondency, in which he accused his
friends of having forgotten him. In one of these
moments of bitterness he wrote to his daughter —
"my name is erased from the book of the living."
"Nay," came Maria Celeste's soothing reply, "say
not that your name is struck out de libro
viventium, for it is not so, neither in the greater
part of the world, nor in your own country.
Indeed, it seems to me that if for a brief moment
your name and fame were clouded they are now
restored to greater brightness ; at saying which
I am much astonished with myself, for I know
that generally nemo propheta acceptus in patria
sua. I am afraid that if I go on quoting Latin
I shall fall into some barbarism, so I shall stop.
But, indeed, you are loved and esteemed here
more than ever."
As the weary months rolled on, Galileo became
a little resigned to his situation at Siena, and
even began to occupy himself with another of
his great works (indeed the greatest), namely
" Dialoghi delle Nuove Scienze" (or, Dialogues on
The New Sciences), the writing of which he spoke
of as far back as 1610, in his letter to Vinta. His
interest in other scientific matters was as keen as
ever. Thus, writing (27th September) to Andrea
Arrighetti, a young Florentine disciple who had
sent him some mathematical problems, he says : —
"The pleasure with which I read and re-read
your demonstrations was greater than my astonish-
ment, since the pleasure was proportionate to
the sagacity of which you give proof in your
334 EXILED TO SIENA [1633
argumentation, while the astonishment was little,
because I remembered I had under my eyes a
work of Signor Andrea Arrighetti.
"The last theorem held" me for a moment
in meditation and in doubt, as much owing to
the unusual formula as to fatigue of memory,
which lets escape impressions as soon as formed.
Let this be a lesson to you, and encourage you
to exercise the mind while you are young.
" As regards myself, I can say that my relations
with my kind and honoured host bring me much
consolation, and in the midst of so many sad
subjects for meditation they give a new direction
to my thoughts. But more than any other
consolation, the knowledge that you and my other
friends retain for me your old affection makes my
grief less heavy/'
Galileo's detention at Siena would, perhaps, have
been borne more easily did he not know that his
loved and loving daughter, in spite of her resigna-
tion, was consuming her poor heart with longing to
see him once more. " When you were in Rome I
said to myself, if he were but at Siena ! Now you
are at Siena, I say, would he were at Arcetri ! But
God's will be done!" Her life was one continual
prayer for him. Yet, while ever thinking of his
spiritual welfare, she did not neglect his worldly
affairs. In her letters of this period she tells him
of the fruit and the wine which have been sold ;
of the incoming and outgoing of his money ; that
the vines had been injured by hail; that thieves
had been over the garden wall ; that his mule was
behaving badly and would carry no one now her
master was away; that a storm had damaged the
roof, an.d thrown down and smashed a large vase ;
1633] SISTER MARIA CELESTE 335
that the plums were few; and that the wind had
carried away the pears; and so on. With the
money from the sale of some lemons she had had
three masses said for her father's special benefit.
Finally: " there are two pigeons/5 she says, "in
the dovecot waiting for you to come and eat them ;
there are beans in the garden waiting for you to
gather them ; and your tower is lamenting your
long absence."
As soon as the quarantine regulations were
relaxed, Maria Celeste sent the boy Geppo on the
mule to Siena to bring back news of her father,
how he was looking, etc. The poor old man seems
to have asked her to remember him in her prayers,
for on Geppo's return she wrote (3rd October) : —
" It seems to me a thousand years till I see you
back again safe and well. I would not have you
doubt that all this time I have never ceased from
commending you to God with my whole heart, for,
indeed, I feel too anxious for your spiritual and
bodily health ever to have neglected praying for
you. To give you a proof I will tell you that
as a great favour I had a copy of your sentence
shown to me, and though on the one hand it
grieved me to read it, yet on the other hand I
was glad, because I found out a way of being
of some slight use to you, namely, by taking on
myself that part of the sentence which orders you
to recite the seven Penitential Psalms once a week.
I began to do this a while ago, and it gives me
much pleasure — first, because I am persuaded that
prayer in obedience to Holy Church must be effi-
cacious ; secondly, in order to save you the trouble
of remembering it. If I had been able to do
more, most willingly would I have entered a straiter
336 EXILED TO SIENA [1633
prison than the one I live in now, if by so doing
I could set you at liberty."
At length, the weariness and sickness of heart
caused by hope deferred began to tell on this sweet
nun. Worn by continual ill-health, by anxiety for
her father, by nightly watchings in the convent
infirmary, and daily occupations in the stillroom
and pharmacy, she would appear to have felt a
presentiment of her approaching dissolution. She
strove gently to prepare her father, telling him
it was for him to live long to the service and the
glory of the God who had endowed him with such
a wondrous intellect, and to the comfort of many
who would feel his loss. As for herself, she could
neither do much for the glory of God, nor be of
much use to any one, and her living or dying would
make little difference.
In November 1633, thinking the time favour-
able, Niccolini began to agitate for Galileo's pardon,
but the Pope was not disposed to go so far, and
pretended there would be a difficulty in getting
the Congregation of the Holy Office to consent to
such a course — a patent evasion, as the decision
rested solely and entirely with himself. Niccolini,
however, persisted in his efforts, and went to
Cardinal Barberini and other members of the
Congregation to enlist their good .offices. At
length, on 1st December, the question of Galileo's
pardon, or rather release from personal restraints,
came before the Congregation — the Pope pre-
siding— and, though recommended by Cardinal
Barberini, it was refused; but Galileo was per-
i633] RETIRES TO ARCETRI 337
mitted to retire to his villa at Arcetri, where
he was to remain till further orders, and where
he might receive his friends and relations, but
not too many at a time, if he wished to avoid
suspicion.
While Niccolini's letter of 3rd December, con-
taining this piece of good news, was on its way
to Siena, Galileo was writing thus to Bocchineri
in Florence (gth December) : —
" For the last four days I have suffered from
violent pains in the limbs which are more persistent
than ordinary. I fear greatly that this climate (much
more rigorous in winter than that of Florence) is
the principal cause of these ailments ; and I foresee
that I shall be very seriously crippled if obliged
to remain here much longer. I await a decision
from Rome, but I have little hope of its being
favourable."
For once Galileo despaired, and at the wrong
moment! The same day Niccolini's letter of 3rd
December arrived, and a few days afterwards he
set out for Arcetri.
CHAPTER XV
GALILEO AT ARCETRI : COMPLETES HIS DIALOGUES
ON THE TWO NEW SCIENCES
1634-1636
ON returning to his villa, II Giojello, after nearly
a year's absence, Galileo's first care was to visit
his daughters in the neighbouring convent of San
Matteo ; and afterwards, and when permitted to
do so by the local Inquisitor, this was his greatest
pleasure. But alas ! this man of sorrows was soon
to taste again the cup of affliction. When Maria
Celeste heard that her father's prison had been
changed to Arcetri, and that he may be expected
in a few days, she hardly had strength enough
to be glad.
" I do not think," she wrote on 3rd December,
" that I shall live to see that hour. Yet may God
grant it if it be for the best."
Her prayer was granted and hardly more.
Before she lay down, weary and prematurely old,
in her narrow bed in the little convent chapel,
she was able to embrace her dearest Lord and
father. What passed between those two sorely-
tried and loving souls in the last few and suffering
1634-1636] DEATH OF MARIA CELESTE 339
weeks of the daughter's life it would be profanity
to attempt to describe, even if we knew.
Sister Maria Celeste died on 2nd April 1634,
in her 34th year, having been born on 1 3th August
1600. The rest that we know of her will best
be given in the words of her heart-broken father.
Writing to his friend, Elia Diodati, Paris, on 25th
July 1634, he says: —
" I hope that when you hear of my past and
present misfortunes, and my anxiety about those
perhaps still to come, it will serve as an excuse to
you and my other friends and patrons in Paris ; to
you for my long delay in answering your letter, and
to them for my entire silence. According to the
sentence pronounced on me by the Holy Office,
I was condemned to imprisonment during the
pleasure of his Holiness, who was pleased,
however, to assign the palace and gardens of
the Grand Duke near the Trinita dei Monti as
my place of imprisonment As this was in June
of last year, and I had been given to understand
that if I asked for a full pardon after the lapse of
that and the following month I should receive it,
I asked, meanwhile, to avoid having to spend the
whole summer and, perhaps, part of the autumn
there, to be allowed, on account of the climate, to
go to Siena, where the Archbishop's house was
assigned to me as a residence. I stayed there
five months, when this durance was exchanged for
banishment to this little villa, a mile from Florence,
with a strict injunction not to go to the city, and
neither to receive the visits of many friends at once,
nor to invite any.
"Here, then, I was living, keeping perfectly
quiet, and paying frequent visits to a neighbouring
convent where two daughters of mine were living as
340 GALILEO AT ARCETRI [1634-
nuns. I was very fond of them, especially of the
elder who possessed extraordinary mental gifts,
combined with rare goodness of heart; and she
was very much attached to me. During my
absence, which she considered very perilous for
me, she fell into a profound melancholy which
undermined her health, and she was at last attacked
by a violent dysentery of which she died after six
days' illness, just thirty-three years of age, leaving
me in the deepest grief."
Galileo was so overwhelmed by her death that
it seemed to him as if he were destined speedily to
follow her. "I hear her constantly calling me,"
he wrote to Geri Bocchineri on 27th April In
the rest of this letter we have a sad picture of the
old man's desolation. From some alarming bodily
symptoms, and his daughter's call resounding in his
ears, he believed himself to be dying.
"I am going to write to you," he says, "about
my health which is very bad. I suffer much more
from the rupture than has been the case before.
My pulse intermits, and I have often violent palpi-
tation of the heart. Then, the most profound
melancholy has come over me ; I have no appetite
and loathe myself; in short I feel myself perpetually
called by my beloved daughter.
" Under these circumstances I do not think it
advisable that Vincenzio should set out on a journey
now ; as events might occur at any time which
might make his presence desirable ; for, besides
what I have mentioned, continued sleeplessness
alarms me not a little. I tell you this that you
may tell him if you think fit — not because I wish to
disturb his plans, but because it seems to me that
he ought to know. You, who can speak more
firmly to him than I can, will say enough to make
1636] SAVAGE MANDATE FROM ROME ^341
him take the course which is most advisable. He
has been asking for his allowance, 25 crowns;
I enclose it to you to forward to him, as I do not
want to say a single word, for him to turn and twist
at his pleasure."1
As we see from the letter just quoted, Galileo
was at this time suffering much from one of his
many complaints (hernia). On its recurrence
earlier in the year, he sought permission
through the Tuscan Ambassador to move into
Florence for the sake of the regular medical
treatment which his case required, and which
he could not well have at the villa outside the
city. As if to dye his tragic fate still darker, he
received the answer to this petition at the same
moment that the physician told him of the ap-
proaching death of Maria Celeste. In the letter to
Diodati above quoted, he says : —
" My grief at this terrible news was increased
by another calamity. On returning home from the
convent with the doctor who visited my sick
daughter shortly before her death, and who had
just told me that her situation was desperate, and
that she would hardly survive till the next day (as
indeed it proved), I found the Inquisitor's vicar
here, who informed me of a mandate from the Holy
Office that I must in future abstain from asking
permission to return to Florence, or they would
take me back to Rome, and put me in the actual
prison of the Holy Office.2 From this answer it
1 Vagabond still, Vincenzio was at this time living in Florence in
a house which his father had settled on him in the Via della Costa,
and close to the Porta San Giorgio.
2 This savage mandate was dictated by the Pope at a meeting
held on 23rd March.
342 GALILEO AT ARCETRI [1634-
seems to me that in all probability my present
prison will only be exchanged for that narrow and
long-enduring one which awaits us all."
He then goes on to give his correspondent
some interesting information which allows us to
see a little behind the scenes of this terrible
drama : —
" From this and other circumstances which it
would take too long to describe, it will be seen that
the fury of my powerful persecutors continually
increases. They have, at length, chosen to reveal
themselves to me. Thus, about two months ago
when a dear friend of mine at Rome was speaking
of my affairs to Father Cristoforo Griemberger,
mathematician at the Collegia Romano, this Jesuit
uttered the following precise words : 'If Galileo
had only known how to retain the favour of the
fathers of this college he would have stood in
renown before the world, he would have been
spared all his misfortunes, and could have written
what he pleased about everything — even about the
motion of the earth/ From this you will see,
honoured Sir, that it is not this opinion or that
which has brought and still brings about my
calamities, but my being in disgrace with the
Jesuits . . . . * Add to all this other troubles
and many bodily infirmities which, without
mentioning my age (more than seventy years),
so overwhelm me that the least fatigue
exhausts me and makes me ill. For all these
reasons my friends must be indulgent and re-
member that that which at first sight seems to
be negligence is in reality only powerlessness.
"But you, honoured Sir, who more than any
other have wished me well, you will keep me in the
affection of all my friends in Paris, especially of
1636] ALL THE WORK OF JESUITS 343
Signer Gassendi whom I love and venerate so
much. Please communicate to him the contents of
this letter, and tell him also that I have received the
dissertation of Signor Martius Hortensius [on the
double motion of the earth], and that I have read it
with the very greatest interest. If it please God to
deliver me from a part of the evils which I endure
at this moment, I shall not fail to answer his amiable
letter.
" Berigard and Chiaramonti,1 professors at Pisa,
have written long works against me — the latter in
his own defence ; the former against his wish, as he
says, but at the instigation of one who may be
useful to him ! A certain Jesuit father has printed
at Rome that the opinion of the motion of the earth
is of all heresies the most abominable, the most per-
nicious, the most scandalous ; and that one may
maintain in professorial chairs, in society, in public
discussions, and in books, any and every argument
against the principal articles of faith, against the
immortality of the soul, against the creation, against
the Incarnation, against everything, with one ex-
ception only — the dogma of the immobility of the
earth ! The title of this production is ' Melchioris
Inchofer a Societate Jesu Tractatus Syllepticus.' 2 It
1 This man was one of the most bigoted defenders of the old
philosophy, and, as Montucla says, spent a long life in nothing but
retarding as far as he was able the progress of science. He was one of
the Commission appointed in 1632 to get up the case against Galileo.
(See also footnote, p. 256 ante.)
2 This work was lauded by his brother Jesuits "as differing so
entirely from the pruriency of the Pythagorean writings." Quoting
the first verse of Genesis as an argument that the earth was created
after the heavens, he says the question is reduced to a purely geo-
metrical problem. In the formation of a sphere does the centre or the
circumference come first ? If the latter, the consequence is inevitable,
the earth is in the centre of the universe ! The title-page of this book
is decorated with an emblematical figure, representing the earth in a
triangle j and in the three corners, grasping the globe with their fore
feet, are the three bees of the Pope's arms, with the .motto, "ffis fixa
quiescit " (fixed by these it is at rest).
344 GALILEO AT ARCETRI [1634-
is from Rome also that Antonio Rocco writes in
defence of the peripatetic philosophy, and with such
little consideration fpr me. He acknowledges, him-
self, that he knows nothing of mathematics or
astronomy. He has, in fact, not the least notion
of the subjects on which he writes.1
" If God wills, I hope to publish my works on
Motion, and other researches — all more important
than those which have already appeared. This
letter will reach you through my relative Roberto
Galilei, to whom you might read it, as I have
written to him only very briefly. ..."
Full of labour and of sorrow his life had been,
and full of labour and sorrow it was to continue to
the end. Though crushed by grief for his
daughter's death, the habits of industry acquired
in youth, and maintained through life, could not be
laid aside in old age. Work to his teeming mind
was more than a consolation, it was a necessity.
Thus it is that but a few months after Maria
Celeste's death, we find him rousing himself, and
eagerly at work again on his new Dialogues,
wishing, as he told Diodati, that the world should
see the last of his labours before his time of depar-
ture came. But, as he wrote, thoughts crowded
thick and fast upon him, so that his work increased
while each day lessened his span of life. "My
restless brain goes grinding on," he wrote to
Micanzio on igth November 1634, '('m a way that
causes great waste of time, since the thought, which
comes last into my head in respect of some novelty,
drives out all that had been there before." He also
1 For a list of anti-Copernican works published between 1632 and
the time of Newton, 1668, see Martin's " Galilee," note B.
1656] ADVOCACY OF FRIENDS 345
resumed his extensive correspondence with scientific
friends. Unfortunately, few of his letters of this and
the following year have come down to us, so that we
can only infer the subjects from the answers of his
correspondents.
While the prisoner of Arcetri was thus fulfilling
his great mission, his friends took every opportunity
of trying to obtain, at least, some extension of
his liberty. Niccolini, Comte de Noailles (French
Ambassador), and Niccolo de Peiresc (in letters
from Paris), all interceded again and again with the
Pope, but all to no purpose. His Holiness had soft
words for all of them, but nothing was done.1
How deep was the undercurrent of bitterness in
Galileo's heart when stirred by the remembrance of
the Jesuits* machinations, his " wretched enemies,"
as he calls them, his correspondence of this period
sufficiently shows. We give some extracts from
his letter to Niccol6 de Peiresc, 2ist February
1635. After warm thanks for the noble though
fruitless efforts of his friend, he goes on : —
" I have said, my Lord, that I hope for no
alleviation, and this is because I have committed no
wrong.2 If I had erred I might hope to obtain
grace and pardon, since the transgressions of the
subject are. the means by which the prince finds
occasion for the exercise of mercy and indulgence.
Wherefore, when a man is wrongly condemned to
punishment, it becomes necessary for his judges to
1 De Noailles was formerly a private resident pupil of Galileo at
Padua, and de Peiresc was a friend of Phrelli at whose house Galileo
often met him.
8 " Forgiveness to the injured does belong,
But they ne'er pardon who have done the wrong."
— DRYDEN, Conquest of Granada.
346 THE NEW SCIENCES [1634-
use the greater severity in order to cover their own
misapplication of the law. . . , Could all the frauds,
the calumnies, the stratagems, the deceits, which
were made use of at Rome eighteen years ago for
the purpose of imposing on the supreme authority —
could all these, I say, be brought to light, their only
effect would be to enhance the purity and upright-
ness of my intentions. But you, having read my
works, will have seen how they justify my assertion
of sincerity, and you will have understood the true
cause for which, under the mask of religion, I have
been persecuted, and which now continually assails
me and crosses my path, so that no help can come
to me from without ; nor can I undertake my own
defence, all the Inquisitors having received ex-
press orders neither to allow the reprinting of my
published works, nor to grant a licence for any
fresh work I may wish to publish. Thus I am not
only reduced to silence towards those who strive to
distort my opinions, and so to make my ignorance
(as they call it) manifest, but I must also bear the
insults, the contempt, and the bitter taunts of men
more ignorant than myself, without being able to
utter a word in my own defence. "
The Dialogues on The Two New Sciences (i.e.
on Cohesion and Resistance to fracture, and on
Uniform, accelerated, and projectile motion) were
completed by the summer of 1636, and then arose
the question of their publication. After his con-
demnation in 1633, the Holy Office placed his name
in the list of authors whose writings edita et edenda
were strictly forbidden, and so rigorously was
this rule enforced, that Micanzio was not permitted
to reprint the " Discourse on Floating Bodies,"
which did not in any way relate to the Copernican
doctrines. Galileo tried Germany, and sent the
1636] OBSTACLES TO PUBLICATION 347
MS. to his friend Giovanni Pieroni in Vienna, only
to find that all books printed there must first
be sanctioned by the Jesuits, amongst whom at
the moment Galileo's old antagonist, Father
Scheiner, happened to be quartered. So Vienna
would not do. Through the intervention of
Cardinal Dietrichstein, Pieroni then got permission
to print at Olmutz, with the approbation of a
Dominican father, so that the business may be
kept secret from Scheiner and his party. But
very soon after, the Cardinal died, and, besides,
Pieroni was not pleased with the Olmutz press,
so the MS. was brought back to Vienna. A new
approbation was procured (Scheiner having gone
meanwhile into Silesia) and the work was on
the point of being sent to the press when the
dreaded Scheiner reappeared. Pieroni next took
the MS. to Prague, where Cardinal Harrach
offered him the use of the University press ; but
here again difficulties cropped up. Meanwhile
Galileo, wearied with these delays, opened negotia-
tions with Louis Elzevir through Micanzio in
Venice, and, finally, the work appeared at
Amsterdam in 1638.
It is clear from Galileo's correspondence that
this edition was printed with his full concurrence,
although, in order to obviate trouble with Rome,
he pretended that it was pirated from a MS.
copy which he had sent to Comte de Noailles,
tb whom the work is dedicated.
Rightly did Galileo, in his letter to Vinta of
7th May 1610, call his work in mechanics a new
science invented by him from its very first
348 THE NEW SCIENCES [1634-
principles. That this is no exaggeration is shown
by the following passage from the " M^canique
Analytique" of Lagrange, the great Italian
Mathematician, and an undoubted authority on
the subject : —
" Dynamics is the science of forces accelerated
or retarded, and of the various movements which
these forces can produce. This science is due
entirely to the moderns, and Galileo is the one
who laid its foundations. Before him philosophers
considered the forces which act on bodies in a
state of equilibrium only; and, although they
could only attribute in a vague way the accelera-
tion of heavy bodies, and the curvilinear move-
ment of projectiles, to the constant action of
gravity, nobody had yet succeeded in determining
the laws of these daily phenomena on the basis
of a cause so simple. Galileo made the first
important steps, and thereby opened a way, new
and immense, to the advancement of mechanics
as a science.
" These discoveries did not bring to him
while living as much celebrity as those which
he had made in the heavens ; but to-day his
work in mechanics forms the most solid and
the most real part of the glory of this great
man. The discovery of Jupiter's satellites, of
the phases of Venus, of the Sun-spots, etc., required
only a telescope and assiduity; but it required
an extraordinary genius to unravel the laws of
nature in phenomena which one has always
under the eye, but the explanation of which,
nevertheless, had always baffled the researches
of philosophers."
The Dialogue is carried on between the same
speakers, Salviati, Sagredo, and Simplicio, as in
1636] NATURE'S HORROR OF A VACUUM 349
the " Dialogues on the Two Principal Systems
of the World " (1632). The first two of the
four Dialogues published in his lifetime are
concerned with the " Resistance of Solids against
Fraction/' and the " Cause of Coherence in
Solids." The ostensible object of the first
discussion was scarcely reached, while the second
contains little beyond an analysis of formulae
concerning the strength of beams. Their scientific
value lies in the incidental experiments and obser-
vations on motion through resisting media.
The discussion opens with a short examination
of the current belief that models built on exactly
similar designs but on different scales were of
strength in proportion to their linear dimensions.
After exposing the error, Salviati enquires what
is the nature of the force that holds up the lower
part of a rod suspended from above. No complete
explanation is forthcoming; but that suggested
depends upon Nature's repugnance to the vacuum
momentarily produced by the sudden separation
of two flat surfaces. This leads to an experiment
proposed by Salviati for measuring what he speaks
of as the force of a vacuum.
This experiment occasions a remark from
Sagredo that he had observed that a pump would
not work when the water in the cistern had sunk
35 feet below the valve; that he thought the
pump was injured, and sent for the maker, who
assured him that no pump of that construction
would lift water from so great a depth. This
story is usually told as if Galileo had said jokingly
that Nature's horror of a vacuum does not ex-
350 THE NEW SCIENCES [1634-
tend beyond 35 feet.1 He evidently shared the
common notion of suction, for he compares the
column of water to a metal rod suspended from
its upper end, which may be lengthened till it
breaks by its own weight. It is remarkable
that he failed to observe how simply this pheno-
menon may be explained by a reference to the
weight of the atmosphere — a fact with which
he was well acquainted, and, indeed, goes on
in this dialogue to describe an experiment for
determining the weight of air as compared with
water.2
After a rather lengthy digression on the motion
of a rolling circular hoop, in which Galileo brings
forward some truths probably new at the time,
but not essential to the main subject of the present
dialogues, we come to more important matter
in the discussion of motion through resisting
media. This is introduced by some vague
suggestions as to the nature of the action of
heat on solid bodies, leading on to a short
reference to light phenomena, which, Salviati
insists, imply motion through a medium of some
kind.
This statement introduces Aristotle's theory
that bodies move with velocities proportional to
their weights and inversely proportional to the
densities of the media through which they are
1 The first appearance of the story in this form has been traced
to Pascal's "Traitez de Tequilibre des Liqueurs" (preface), Paris,
1663.
a Galileo'? way of determining the specific gravity of the air
was first described in his letter to Gio. Battista Baliani, dated
I2th March 1613, now in the Brera Library, Milan.
1636] LAWS OF FALLING BODIES 351
moving. This proposition is examined in a strict
scientific method. Heavy bodies of different
weights are dropped in air to test the truth of
the first part of the statement ; and afterwards
the motion of bodies rising or falling in liquids
is considered ; the result being to Substitute for
Aristotle's hasty assumption that law of the motion
of falling bodies which is historically the founda-
tion of the science of dynamics.
Two stones are dropped in air ; their weights
are respectively eight and four units. Aristotle's
theory requires that the first shall travel with
twice the velocity of the second; that, in fact, if
the second have four, then, the first will have
eight degrees of velocity. Salviati states that this
does not agree with experiment; but he further
reduces the dictum to an absurdity by considering
the effect of fastening the two stones together.
Common-sense would have it that the result would
be a hurrying of the slower and a delaying of the
faster traveller, producing a mean velocity of some-
where between four and eight velocity-units.
Actual experiment would show that, according
to the manner of fastening and the shape and
distribution of weight in the stones, it might be
possible to obtain a velocity slightly in excess of
that of the heavier stone when falling alone. But
neither common-sense nor experiment agrees with
Aristotle's statement, according to which the
compound body, now containing twelve units of
weight, ought to travel with twelve units of velocity.
So far, indeed, is Aristotle from the truth that
Salviati asserts that if a stone weighing twenty
352 THE NEW SCIENCES [1634-
pounds and another weighing two pounds be
dropped simultaneously from a tower 50 or 100
yards high, they will reach the earth at the very
same moment.
"And I would not have you do as some are
wont, who fasten upon some saying of mine that
may want a hair's breadth of the truth, and under
this hair seek to hide another man's blunder as big
as a cable. Aristotle says that an iron ball weigh-
ing 100 Ibs. will fall through a space of 100
yards while a weight of one pound is falling
through a space of one yard. / say they will
reach the ground together. They find the greater
weight to anticipate the lesser by two inches, and
under these two inches they seek to hide Aristotle's
99 yards ! "
So Galileo satisfied himself that the current
belief was wide of the truth ; and that it was more
nearly correct to say that heavy bodies, dropped
through the air, fell with the same increasing
velocities, whatever their weights, provided only
those weights were sufficient to overcome with
ease the air's resistance to their motion. He
proceeds to examine the motion of bodies sinking
or rising in water and other liquids ; and he brings
forward a group of experimental facts which, viewed
in the light of Aristotle's statement, form a mass of
contradiction. Putting this antiquated theory aside,
Salviati enquires what is meant by the rising of
some bodies in a medium, and shows that only
those bodies rise which are lighter than the
medium. The rising of an inflated bladder in the
air suggests that the atmosphere must have
weight. Simplicio's assertion that it is on the
1636] LAWS OF FALLING BODIES 353
contrary the bladder in this case that has levity is
trivial, and is immediately disproved. Continuing
his line of argument, Salviati points out that the
question of rising or falling depends on the gravity
of the medium as compared with that of the moving
body ; further, that when the motion of the body,
either upwards or downwards, has once commenced,
the different media offer different resistances to the
motion, the heavier media, such as quicksilver and
water, interfering more than air with the motion of
a body ; and we are thus led to the following
summing-up by Salviati.
"We have found the difference of velocities in
movables of different gravities to be more and
more as the media are more and more resisting ;
thus, in a medium of quicksilver, gold does not only
sink to the bottom more swiftly than lead, but it is
the only thing that will sink in it, all other metals
and stones moving upwards therein and floating on
its surface. Whereas between balls of gold, lead,
brass, or any other heavy matter, the inequality of
their motion in the air shall be almost wholly
insensible, so that, indeed, a ball of gold falling from
a height of 100 yards in the end of its fall does not
outstrip one of wax by four inches."
And then comes Galileo's bold, but justifiable
deduction : —
"This being so, I have thought that if the
resistance of the media be wholly taken away, all
matter would descend with equal velocity."
This fundamental law once stated is amplified
later on in the Dialogue, when Salviati explains
that :—
354 THE NEW SCIENCES [1634-
" A heavy body has by nature an intrinsic force
or principle of moving towards the common centre
of heavy things (the centre of the earth) with a
motion continually accelerated in such manner that
in equal times there are always equal additions of
velocity. This is to be understood as holding true
only when all accidental and external impediments
are removed, amongst which is one that we cannot
obviate, namely, the resistance of the medium.
This opposes itself more or less according as it
opens slowly or speedily to make way for the
moving body, which, being continually accelerated,
encounters a continually increasing resistance in the
medium, until at last the velocity reaches that
degree and the resistance that power that they
balance each other. All further acceleration is then
prevented, and the movable continues for ever after
with a uniform and equable motion."
The description of the motion of a falling body
in the first Dialogue is followed by a reference to the
oscillation of a pendulum ; and this in turn leads to
a digression, in which Galileo quotes a number of
interesting experiments on sound. These it will be
best for the present to pass over, as also the con-
tents of the second Dialogue. The more important
work in dynamics is resumed in the third and fourth
Dialogues, on <{ Local Motion" and " Motion of
Projectiles," the outline of which must be indicated
in a few words.
No new physical facts of importance are quoted ;
these two Dialogues are mainly concerned with
theorems and formulae deduced mathematically
from the phenomena explained in the first Dialogue.
The discussion of uniform motion, however, involves
a more emphatic statement than before of the prin-
1636] ACCELERATED MOTION 355
ciple of inertia — that a body projected along a
smooth horizontal plane would, if all resistances and
external impediments were removed, continue to
move uniformly along that horizontal plane for ever.
Generalised, this statement would be equivalent to
Newton's first law of motion. From the definition
of uniform motion as that of a body which moves in
one direction so as to cover equal spaces in equal
intervals of time, Salviati proceeds to deduce the
elementary formulae, which his two listeners readily
accept.
The definition of uniformly accelerated motion,
however, at once introduces a difficulty. Salviati
gives the correct description of it as that of a body
which moves in such a manner that in equal intervals
of time it receives equal increments of velocity. An
alternative is suggested by Sagredo, and Simplicio —
sympathising as usual with Sagredo's untenable pro-
positions— is of course " of the number of those who
allow that a descending body vires acquirit eundo " ;
in fact, that the increments of velocity should be
specified in relation to ? the space rather than the
time through which the body has travelled. They
first appeared to think that the two statements would
be equivalent and that theirs took the more direct
form. It is pointed out by Salviati that the two are
inconsistent, and he rightly conjectures that a direct
reference of acceleration to the space described rather
than to the time of travelling would lead to hopeless
complications. He proceeds, accordingly, from his
own definition to deduce formulae connecting all
these variable quantities — time of motion, velocity
acquired, and space described — with one another.
3$6 THE NEW SCIENCES [1634-
An interesting application of the results obtained
follows. He examines the times of descent down
differently inclined planes, assuming as a postulate
that the velocity acquired by a body falling down an
inclined plane was the same for all planes of the
same height. This fact he had verified by careful
experiments, although he was unable at the time to
account for it.1 After the inclined plane comes an
investigation of " lines of quickest descent " — a
group of interesting problems, though not of
essential importance in the development of the
science of dynamics. Here he shows that the
descent of bodies along an arc of a circle of legs
than 90° is shorter than the time occupied by the
same bodies in traversing the chord of the arc —
"which at first sight would seem to be a paradox,
the arc being longer than its chord/'
This investigation completed, the way is prepared
for the subject of the fourth Dialogue. Sagredo,
anticipating mathematical difficulties, begs for some
preliminary instruction in the properties of the
parabola, after which Salviafei turns to the spbject of
projectiles, and lays down the law of the independ-
ence of the horizontal and vertical motions. A body
projected horizontally would (but for its weight
and " external impediments " which we suppose
removed) continue to move ; and Salviati contends
that as the effect of gravity acting by itself would
be entirely downwards, gravity acting on the hori-
1 Viviani relates that soon after he joined Galileo, he drew his
master's attention to this flaw in the argument. The same night, as
Galileo lay in bed, sleepless through indisposition, he discovered the
necessary mathematical demonstration. It was introduced into the
subsequent editions of the Dialogues, Sixth " Day."
PROJECTILE MOTION
357
zontally projected body can neither increase nor
diminish the rate at which it travels horizontally.
Therefore, whatever be the shape of the path or the
real direction of motion at any moment, the horizontal
part of the motion is uniform, and the distance
travelled horizontally may, therefore, be taken as a
measure of the time that has elapsed since motion
began.
Salviati proves that on this assumption the path
described has geometrical properties which identify
it with the curve known as the parabola. His
demonstration is essentially that now given in
works on elementary dynamics ; the present account
of the dialogues would, however, be incomplete with-
out a quotation of the proof in Galileo's form.
MOTION OF PROJECTILE.
BCD
Fig. 9.
" Let A B represent a horizontal line or plane
placed on high, on which let a body be carried
with an equable motion from A towards B ; and
the support of the plane being taken away at B,
let the natural motion downwards due to the body's
weight come upon it in the direction of the perpen-
dicular B N. Moreover, let the straight line B E
(a prolongation of A B) represent the flow or
358 THE NEW SCIENCES [1634-
measure of the time, on which let any number
of equal parts B C, C D, D E, be marked, and
from the points C, D, E, let lines be drawn parallel
to B N. In the first of these let any part C I
be taken, and let D F be taken four times as great
as C I ; EH nine times as great, and so on. Now,
if we suppose that whilst by its uniform horizontal
motion the body moves from B to C, it also
descends by its weight through C I, and at the
end of the time denoted by B C it will be at I.
In the time B D, double of B C, it will have fallen
four times as far ; for in the first part of this treatise
it has been shown that the spaces fallen through
by a heavy body vary as the squares of the times.
Similarly, at the end of the time B E, or three
times B C, it will have fallen through E H, and
will be at H. Now, it is plain that the points I,
F, H, are in the same parabolical curve B, I,
F, H."
It only remains to verify whether the parabola
as defined geometrically is actually the path of the
moving body. This, as Salviati states, is true
under certain conditions. Firstly, the path tra-
versed must be of small dimensions as compared
with the dimensions of the earth"; this is necessary
in order that the horizontal direction and the
direction of gravity may be the same throughout
the motion. And secondly, the resistance of the
air so far modifies the motion, that the true
parabola is only possible on the supposition
that motion takes place in vacuo ; the resist-
ance of the air, however, is reduced to a
minimum if we examine the motion of a heavy
body of small dimensions travelling with only a
moderate velocity.
1636] PARABOLIC MOTION 359
After demonstrating the parabolic nature of the
path, Galileo enquires into certain points of interest
with regard to it, and gives proofs of many of the
elementary propositions which in modern text-books
are associated with parabolic motion. He also
draws up a table giving the position and dimensions
of the parabola described with any given direc-
tion of projection ; finding by this means what
he would have been unable to give a strict
mathematical proof of — that the range on a hori-
zontal plane is greatest when the angle of
elevation is 45°.
The discussion of parabolic motion occupies the
remainder of the Dialogue. Only one passage
needs special mention. A bullet fired horizontally
travels fast, yet not instantaneously; however
rapidly it moves it takes time to travel even
a short distance ; therefore gravity will draw it
downwards, though ever so slightly, below the
horizontal line which was its original direction. If
.one. would hit a mark, it is, therefore, useless to
fire straight at it. Sagredo had noticed this, and
remarks also on what it appeared to him might
be an allied phenomenon — that a rope hanging
between two points at the same height cannot be
drawn absolutely straight however tightly it may be
pulled. Salviati shows that this is due to the
weight of the rope, just as the drop of the
bullet is due to its weight He continues "as
follows : —
" Besides, I must tell you that which at the
same time will both amaze and delight you; 'tis
this, that the rope, thus stretched more or less,
360 THE NEW SCIENCES [1634-
bends itself into lines very nearly parabolical. And
the likeness is such, that if on a plane surface per-
pendicular to the horizon you describe a parabolic
line, and turn it upside down, and to the extremities
of the base of the described parabola you hold a
chain or cord, by slackening it more or less you'll
see it bend and fit itself to the same parabola.
And this fitting shall be so much the more exact
by how much the described parabola is less curved,
i.e., more distended ; so that in parabolas described
at elevations less than 45 °, the chain agrees with
them almost to a hair."
Galileo has sometimes been accused of having
stated the curve of the suspended chain actually
to be a parabola. From the passage quoted it is
clear that the charge is unfounded. The catenary
resembles the parabola ; and, as Galileo justly
remarks, the resemblance is very striking if the
string is so far taut that the depth of the lowest
point is less than a quarter of the distance between
the two extremities. Galileo's theory of dynamics,
which we have traced briefly, constitutes the more
important part of the Dialogues on the <c Two
New Sciences."1
In order to preserve continuity, no reference has
been made to the subject of the second Dialogue.
It is an investigation of the strength of beams —
an amplification of his researches on the same
1 "In solving the problems of falling bodies and of projectiles,
Galileo was essentially applying the principles of the Differential or
Fluxional or Indivisible Calculus. If pure mathematics had attracted
him as strongly as its application to physks, he would have thought
these problems out, and would have founded the Fluxional Calculus,
which is the glory of Nvewton and of Leibnitz." Professor Jack in
" Nature," vol. xxi. p, 58. See note, p, 120 ante.
1636] STRENGTH OF BEAMS 361
subject, dating back to 1609. Beyond Aristotle's
remark that long beams are weak because they
are at once the weight, the lever, and the fulcrum,
nothing appears to have been written on the
subject before Galileo took it up. In this he under-
takes a problem which is far more intricate than
he realised. A beam is fastened into a stone wall
at one end and at the other supports a heavy
weight; Galileo enquires into the strength of the
beam to resist a snapping tendency. He assumes
the point at which the fracture will take place to
be close to the support. He further assumes that
just before the moment of fracture the two parts
of the beam will be holding together by means
of a uniform force distributed uniformly over the
section, as if the solid were equivalent " to a bundle
of fibres/5 which were all strained equally in the
direction of their length at the moment of snapping ;
and this although the fracture is assumed to begin
at the top, the lowest fibre being the last to give
way.
The curvature of a beam subject to any system
of strains is a subject into which, before the days
of Newton, it was impossible to enquire. And
even in the simpler problem considered by Galileo,
he makes assumptions which require justifying.
Still, the discussion is interesting as the first serious
attempt to examine this difficult statical problem.
The formulae obtained, if they are wanting in detail,
prove that, however vague Galileo's ideas of force,
he fully realised the mathematical fact underlying the
theory of models — that if two frameworks are built
on exactly the same plans but on different scales,
362 THE NEW SCIENCES [1634-
their strengths are not of necessity proportional
to their dimensions.
On the subject of light, Galileo has left very
little in theory; his best work in this field was
the invention of the telescope with which his name
is universally associated.
A suggestion in the first Dialogue that, perhaps,
heat dissolves bodies by insinuating itself between
their minute particles brings on the subject of
light ; on which Sagredo enquires whether we are
to take for granted that the effect of light does or
does not require time. Simplicio is ready with an
answer, that the discharge of artillery proves the
transmission of light to be instantaneous ; to which
Sagredo cautiously replies, that nothing can be
gathered from that experiment except that light
travels more swiftly than sound ; nor can we draw
any decisive conclusion from the rising of the sun.
"Who can assure us that he is not in the horizon
before his rays reach our sight?" Salviati then
mentions an experiment by which he endeavoured
to examine this question. Two observers are each
to be furnished with a lantern ; as soon as the
first shades his light, the second is to uncover his,
and this is to be repeated at a short distance till
the observers are perfect in the practice. The same
thing is then to be tried at the distance of several
miles, and if the first observer perceive any delay
between shading his own light and the appearance
of his companion's, it is to be attributed to the
time taken by the light in traversing twice the
distance between them. He allows that he could
discover no perceptible interval at the distance of
i636] VELOCITY OF LIGHT 363
a mile, at which he had tried the experiment, but
recommends that with the help of a telescope it
should be tried at much greater distances.1
The only other subject remaining to be noticed
is the application of the theory of the pendulum
to musical concords and dissonances, which are
explained, in the same manner as by Kepler in
his " Harmonice Mundi," to result from the
concurrence or opposition of vibrations of the
air striking upon the drum of the ear. It is
shown that these vibrations may be made mani-
fest by rubbing the finger round a glass set in a
large vessel of water; "and if by pressure the
note is suddenly made to rise to the octave above,
every one of the undulations, which will be seen
regularly spreading round the glass, will suddenly
split into two, proving that the vibrations that
occasion the octave are double those belonging
to the simple note." Galileo then describes a
method he discovered by accident of measuring
the length of these waves more accurately than
can be done in the agitated water. He was
scraping a brass plate with an iron chisel, to take
out some spots, and moving the tool rapidly upon
the plate, he occasionally heard a hissing and
whistling sound, and whenever this occurred, and
then only, he observed the light dust on the plate
1 This was done some years later by the Florentine Accademia
del Cimento, with the result that as the observers became more
expert the interval became shorter, so that there was no reason to
suppose that there was any interval at all. In shorty light seemed
to them to travel instantaneously. Roemer, the JDanish astronomer,
first calculated in 1675 the velocity of light, and found it to be about
200,000 miles per second, a close approximation to the modern figure,
viz. 186,000.
364 THE NEW SCIENCES [1634-
to arrange itself in a long row of small parallel
streaks equidistant from each other. In repeated
experiments he produced different tones by scraping
with greater or less velocity, and remarked that
the streaks produced by the acute sounds stood
closer together than those from the low notes.
Among the sounds produced were two, which by
comparison with a viol he ascertained to differ
by an exact fifth; and measuring the spaces oc-
cupied by the streaks in both experiments, he
found thirty of the one equal to forty-five of the
other, which is exactly the known proportion of
the lengths of strings of the same material which
sound a fifth to each other.1
Salviati also remarks that if the material be
not the same, as for instance if it be required to
sound an octave to a note on catgut on a wire
of the same length, the weight of the wire must
be made four times as great, and so on for other
intervals. "The immediate cause of the musical
pitch is neither the length, the tension, nor the
thickness, but the proportion of the numbers of
the undulations of the air which strike upon the
drum of the ear, and make it vibrate in the same
intervals of time, Hence we may gather a
plausible reason for the different sensations oc-
casioned in us by different couples of sounds, of
which we hear some with great pleasure, some
with less, and call them accordingly concords, more
or less perfect; whilst some excite in us great
1 This beautiful experiment has been largely used in modern
times by Chladni, Savart, and Wheatstone, with very interesting
results.
1636] CONCORDS AND DISCORDS 365
dissatisfaction, and are called discords. The dis-
agreeable sensation belonging to the latter,
probably, arises from the disorderly manner in
which the vibrations strike the drum of the ear;
so that, for instance, a very harsh discord would
be produced by sounding together two strings of
which the lengths are to each other as the side
and diagonal of a square, which is the discord of
the false fifth. On the contrary, agreeable concords
will result from these strings of which the numbers
of vibrations made in the same time are com-
mensurable, for then the cartilage of the drum
does not undergo the incessant torture of a
double inflexion which results from discordant
percussions." The sense of pleasure in musical
harmony involves questions which have yet to be
answered. But Galileo's suggestion above has in
it that degree of precision which distinguishes all
his thought from that of the vague theorists of
his day.
Something similar may be exhibited to the eye
by hanging up pendulums of different lengths.
"If these be proportioned so that the times of
their vibrations correspond with those of the
musical concords, the eye will observe with
pleasure their crossings and inter-crossings re-
curring at appreciable intervals ; but if the times
of vibration be incommensurate, the eye will soon
be wearied in following them."
No sooner was the MS. of these Dialogues
out of his hands (summer of 1636) than Galileo's
ever busy brain began to form new projects.
"If I live," he wrote on isth July 1636, to
366 THE NEW SCIENCES [1634-
Bernegger of Strasburg,1 " I intend to put in order
a series of natural and mathematical problems which
I think will be as curious as they are novel."
These were left unfinished, and now form the
fifth and sixth Dialogues which were added to a
later edition by Viviani after Galileo's death. The
fragment of the fifth is on the subject of Euclid's
definition of ratio (Book V. props. 5 and 7), and
was intended to form a part of the third Dialogue,
and to follow the first proposition on equable
motion. The sixth Dialogue was intended to
embody Galileo's researches on the force of
Percussion, on which he was employed at the
time of his death.
" In the last days of his life," says Viviani, " and
amid much physical suffering, his mind was con-
stantly occupied with mechanical and mathematical
problems. He had the idea of composing two
other Dialogues to be added to the four already
published. In the first he intended to insert many
new demonstrations and reflections on various
passages in the first four Dialogues, besides the
solution of many problems in Aristotle's physics.
In the second he proposed to discuss, treating it
geometrically, an entirely new science, viz. the
wondrous force of percussion, which he claimed to
have discovered, and which, he said, exceeded by
a long way his speculations on the same subject
formerly published " ("Vita di Galileo/' 1654).
In these Dialogues in which Galileo recapitu-
lates the results of his early mechanical researches
1 The editor of the Latin edition of his Dialogues of 1632, which
was brought out by the Elzevirs in 1635. The translation was really
by Diodati of Paris, to whom Galileo had sent a copy of the work as
first printed in Italian.
i636] LAWS OF MOTION 367
at Pisa and Padua, and of his life-long meditations,
he does not formulate in definite laws the inter-
dependence of force and motion. This was done
for the first time by Newton at the beginning of
his "Principia" (1687), and hence they are rightly
called " Newton's Laws of Motion"; but in justice
to Galileo it must be admitted that he not only
prepared the way for Newton, but supplied him
with much of his materials. Thus, the first law as
stated by Newton — that a body will continue in a
state of rest, or of uniform motion in a straight line,
until it is compelled to change its state from some
force impressed upon it — is a generalisation of
Galileo's theory of uniform motion. Since all the
motions that we see taking place on the surface of
the earth .soon come to an end, we are led to
suppose that continuous movements, such, for
instance, as those of the celestial bodies, can only be
maintained by a perpetual consumption and a
perpetual application of force, and hence it was
inferred that rest is the natural condition of things.
We make, then, a very great advance when we
comprehend that a body is equally indifferent to
motion as to rest, and that it equally perseveres in
either state until disturbing forces are applied.
Such forces in the case of ordinary terrestrial
movements are friction and the resistance of the
air ; but where no such impediments exist, move-
ment must be perpetual, as is the case with the
heavenly bodies which are moving in a void, or
something approaching it.
The second law — that every change of motion is
in proportion to the force that makes the change,
368 THE NEW SCIENCES [1634-
and in the direction of that straight line in which
the disturbing force is impressed — is involved in his
theory of projectiles. Before Galileo's time it was
a commonly received axiom that a body could not
be affected by more than one force at a time, and it
was therefore supposed that a cannon-ball, or other
projectile, moves forward in a straight line until the
force which impelled it is exhausted, when it falls
vertically to the ground. Galileo's writings in the
fourth Dialogue and elsewhere show the fallacy of
this axiom, since he demonstrates that the path of
the projectile, being the result of a combination of a
uniform transverse motion and a uniformly acceler-
ated vertical motion, must, apart from the resistance
of the air, be a parabola.1 The establishment of
this principle of the composition of forces supplied a
conclusive answer to the most formidable of the
arguments against the rotation of the earth, and,
accordingly, we find it triumphantly brought forward
by Galileo in the second " Day " of his Dialogues of
1632.
The distinction between mass and weight was,
however, not noticed, and, consequently, he failed to
grasp that acceleration, which in the case of motion
under gravity he so closely examined, might be
made a means of measuring the magnitude of the
force producing the motion. How far he was from
this discovery may be gathered from a remark by
Salviati incidental to the main argument, to the
effect that when different bodies are falling freely
1 In a vacuum it would be an ellipse. In fact, a projectile is a
minute satellite of the earth, and in vacua it would accurately obey all
Kepler's laws.
1636] LAWS OF EQUILIBRIUM 369
towards the earth's centre, "the difference of their
gravities has nothing to do with their velocities."
Correct as this may be in the spirit in which it was
meant, it shows that Galileo was yet far from
anticipating in all its generality Newton's second
law.
Of the third of the laws of motion — when a body
exerts force on another, that other reacts with equal
force ; action and reaction are always equal and in
opposite directions — we find traces in many of
Galileo's researches, as in his theory of the inclined
plane, and in his definition of momentum. It is
also adumbrated in his " Delia Scienza Meccanica"
(1594), and in his latest ideas on percussion, which
he was dictating to his disciples, Viviani and
Torricelli, when seized with his last and fatal
illness. But that he was familiar with the
relation between the blow on one body and the
reacting blow on the other or striking body cannot
be maintained. There is no precise statement to
justify such a supposition. Indeed, Galileo's ideas
of force, as they have come down to us, are so
vague that a statement, at the same time precise
and general, cannot be expected.
Galileo's services were hardly less conspicuous
in the statical than in the dynamical division of
mechanics. He gave the first direct and entirely
satisfactory demonstration of equilibrium on an in-
clined plane. In order to demonstrate this he
imagined the weight and the sustaining power to be
applied to the ends of a bent lever whose arms
were of equal length and perpendicular to the
vertical and slant sides of the plane ; then reducing
2 A
370 THE NEW SCIENCES [1634-
the lever to a straight one, between the lines of
direction of the weight and power, it was easy to
prove that the forces in equilibria on the plane were
also in equilibria on the lever, and were to one
another as the length to the height of the plane.
By establishing the theory of " virtual velo-
cities/' he laid down the fundamental principle
which in the opinion of Lagrange contains the
general expression of the laws of equilibrium. And
as regards that still obscure subject, molecular
cohesion, he brought it for the first time within the
range of mechanical theory.
As we have quoted Professor Playfair's apprecia-
tion of the Dialogues of 1632, to make up for
the shortcomings of our own rhumt, so with these
still more admirable ones of 1638, we conclude with
an extract which indicates the enduring value
of Galileo's work in mechanics. Robert Grant,
the distinguished astronomer, and author of the
" History of Physical Astronomy/' says : —
" The astronomical discoveries of Galileo,
although remarkable for their brilliancy, derive their
chief value from the support they lent to the
Copernican theory, and the influence they exerted
in overthrowing the false system of philosophy
which then prevailed. But it is in his important
researches relative to mechanical science that the
genius of this great philosopher is most apparent.
The science of motion could not, indeed, be said to
have existed before his time, for the sole knowledge
on this subject consisted of a few unintelligible
maxims scattered, through the works of Aristotle.
It required no common degree of penetration to
expose the errors which lurked amid the sophisms
of the illustrious Stagirite ; but a genius of a higher
1636] VALUE OF THE WORK 371
order still was necessary to establish the clear and
immutable laws of nature, in the room of the un-
meaning subtleties of the schools, The sagacity
and skill which Galileo displays in resolving the
phenomena of motion into their constituent
elements, and hence deriving the original principles
involved in them, will ever assure to him a dis-
tinguished place among those who have extended
the domains of science. It is, perhaps, impossible,
in the present advanced state of mechanical philo-
sophy, to form a just estimate of the difficulties
which then interposed towards a precise and
luminous view of the fundamental principles of
motion. It is universally admitted that those
phenomena which come under the daily observa-
tion of mankind, and which, on that account, do
not possess any salient features on which the
imagination can repose, are generally those which
are most liable to elude the enquiries of ordinary
minds. The principles which Galileo established
by his sagacious researches had the effect of ele-
vating mechanical science to the dignity of one
of the most important subjects which can concern
the attention of mankind. They were essential
elements in the train of investigation which con-
ducted Newton to the sublime discovery of
Universal Gravitation ; and, in fact, they con-
stitute the basis upon which the vast super-
structure of the physico-mathematical sciences has
been reared." (Introduction, p. n.)1
1 Montucla ("Histoire des Math&natiques," Paris, 1758, vol. ii.
p. 191) says : " I dare to assert that if any one merits the name of
precursor to Newton it is Galileo and not Descartes." See also
Professor Jack's lecture on " Galileo and the Application of Mathe-
matics to Physics," " Nature," vol xxi. pp. 40, 58.
CHAPTER XVI
GALILEO AT ARCETRI HIS LAST WORKS
1636-1641
AFTER completing his " Dialogues on the Two
New Sciences" (summer 1636), Galileo resumed
his plan for determining longitudes by means
of Jupiter's satellites, of which we have already
said something in our Chapter VI I L The
negotiations there described were resumed in
1620, and after dragging on spasmodically were
finally given up in 1632. Now (August 1636),
hearing that the Dutch merchants had offered
a prize of 30,000 scudi to the inventor of a
sure method of taking longitudes at sea, Galileo
offered his plan to the States-General, his
friend Diodati of Paris being the go-between,
as he wished to keep the matter from the
knowledge of the Inquisition officials.
As far back as 1612, Galileo had drawn
up tables showing in advance the position of
the satellites for several months, and these had
been found to agree fairly well with subsequent
observations of their actual positions. Since
that time, amidst all his other employments,
1636-1641] LONGITUDE METHOD 373
he had for twenty-four years steadily continued
his observations, with the object of bringing
his tables to as high a state of accuracy as
possible. This was the point to which the
enquiries of the States, in accepting Galileo's
offer, were chiefly directed. On nth November
1636, the States appointed four Commissioners
to communicate with him, and to report upon
the various points on which they required in-
formation. They voted him a golden chain as
a mark of their respect, and assured him that
in case his plan proved successful he should have
no cause to complain of their generosity. A
long correspondence ensued, in the course of
which Galileo entered into minute details with
regard to the devices by which he proposed
to obviate the practical difficulties attending his
method.1
After much delay, caused partly by the secret
and roundabout way in which the corre-
spondence had to be carried on, and partly by
Galileo's gradual failure of sight, Hortensius, one
of the commission, was deputed to set out for
Italy, in July 1638, to confer with Galileo in
person ; but the journey was put off at the last
moment, as the following extract explains. We
quote from a letter of Galileo to Diodati, dated
1 4th August 1638 : —
"As ill-luck would have it, the Holy Office
came to know of my negotiations with the
States-General, which may do me great injury.
I am, therefore, obliged to you for having induced
1 See his letter to Lorenzo Realio, dated 6th June 1637.
374 GALILEO AT ARCETRI [1636-
Signor Hortensius to give up his intended
journey, and thereby averted some calamity to
me."
Soon after this, the brothers Ebers, Dutch
merchants trading in Florence, were com-
missioned to deliver the golden chain and a
letter from the States. On arriving at the
house in Via della Costa where Galileo was
staying (as will presently be explained), they
found the old man in bed, ailing, and totally
blind! He asked them to read the letter aloud,
and to give him the box containing the chain.
Taking it in his hands, he in a few measured
words expressed his thanks to them for their
courtesy, and to the States for the signal mark
of honour they had shown him. The box and
the letter he would keep, but the chain he
begged them to take back, as he did not think
it proper to retain it, seeing that, owing to his
blindness and increasing infirmities, the negotia-
tions must be postponed. Seeing, however, in
the action of the States- General a proof of
their desire to adopt his method, Galileo re-
solved to place all the papers containing his
observations and calculations in the hands of
Father Renieri, a former pupil and then professor
of mathematics at Pisa, who was to finish and
revise them, and then forward them to Holland.
Before this was done a new delay was occasioned
by the deaths in quick succession of every one
of the four commissioners, Hortensius, the last,
dying in April 1639. For two or three years
the negotiations were entirely interrupted, and
1641] MOON'S LIBRATIONS 375
were then renewed by Constantine Huygens,
but very ,soon after, Galileo himself died, and
again the business was interrupted. To complete
the singular series of misfortunes by which the
trial of this method was impeded, just as Renieri,
by order of the Grand Duke of Tuscany, was
about to publish the Ephemerides, he also was
attacked with a mortal malady, and after his
death the MSS. were nowhere to be found!
For two hundred years they were supposed to
be lost, but sixty years ago they were discovered
amongst the Galilean Papers by Alberi, and
may now be consulted in the fifth volume of
his edition of Galileo's Works.1
Just before his sight began to fail, Galileo
made his last astronomical discovery, which is
now known as the moon's libration. A remark-
able circumstance connected with the moon's
motion is that the same hemisphere is always
visible from the earth, showing that she turns
once on her axis in exactly the time of her
monthly revolution round the earth. Now,
Galileo who, if we may say so, was quite at
home in the moon, and was familiar with the
whole of her visible surface, observed that small
fringes of her other side come alternately into
view and again recede, according to her position
in the heavens.
This discovery was announced in a letter
1 Renieri died in November 1647, when the longitude papers are
supposed to have been stolen by one Giuseppe Agostini ; but see
Favard's doubts on this subject' in his "Documenti Inediti per la
Storia dei MSS. Galiletani," Rome, 1886, pp. 8-14.
376 GALILEO AT ARCETRI [1636-
of 7th November 1637, to Micanzio, Venice, as
follows : l —
"I see that you suppose I have not given up
speculating. It is true I do go on speculating, but
to the great prejudice of my health ; for thinking,
joined to various other molestations, destroys my
sleep and increases the melancholy of my nights ;
while the pleasure which I have taken hitherto in
making observations on new phenomena is almost
entirely gone.
" I have observed a most marvellous appearance
on the surface of the moon. Though she has been
looked at such millions of times by such millions
of men, I do not find that any have observed
the slightest alteration in her surface ; but that
exactly the same side has always been supposed
to be presented to our eyes. Now I find that
such is not the case, but that she changes her
aspect, as one who, having his full face turned
towards us, should move it sideways, first to the
right and then to the left ; or should raise or then
lower it ; or, lastly, should incline it first to the right
shoulder then to the left. All these changes I see in
the moon ; and the large anciently-known spots which
are seen on her face will help to make evident
the truth of what I say. Add to these a further
marvel, which is that these three mutations have
their several periods — the first daily, the second
monthly, the third yearly. Now what connection
does your Reverence think these three lunar periods
may have with the daily, monthly, and yearly move-
ments of the sea ? which by the common consent of
all philosophers are ruled over by the moon."2
Galileo was not long in detecting one of the
1 See also his letter to Alfonso Antonini with the significant
address "Dalla mio carcere di Arcetri, li 20 Febbraio 1637" (ab
incarnatione— 1638).
2 Compare pp. 171 and 259 on this subject of the tides.
i64i] MOON'S ITERATIONS 377
causes of this apparent libratory or rocking move-
ment. The diurnal or parallactic libration he saw
was occasioned by our distance as spectators from
the centre of the earth, which is also the centre
of the moon's revolution. In consequence of
this, as the moon rises we get an additional
view of the lower part and lose sight of the
extra portion of the upper part which was visible
while we were looking down upon her when
low in the horizon. The causes of the other
motions noticed by Galileo are not so easily ex-
plained without a reference to mathematics. Nor
is it certain that Galileo himself understood them ;
his conjecture of a connection with the tides is
certainly wide of the mark.
The moon in revolving round the earth spins
once on her axis in the time occupied by a revolu-
tion ; so turning, as is well known, the same side
always towards the earth's centre. But this familiar
truth is only approximate. The speed of rotation
is uniform ; but the speed of motion in the orbit is
not so, because that orbit is riot a circle but more
truly an ellipse, in which (as is always the case
with elliptic motion) the moving body travels faster
while near the centre of attraction than when farther
away. The result is that we see alternately a little
round the eastern edge, and a fortnight later a little
round the western. Combined with this libration in
longitude is a libration in latitude due to the fact
that the moon's axis of rotation is not exactly per-
pendicular to the plane of its orbital motion, leaning
a little towards us at one time, and a little away
from us at the end of a fortnight. This enables us
378 GALILEO AT ARCETRI [1636-
to see at times a few hundred miles beyond the
North Pole, and at other times a similar extent
beyond the South Pole.
These two librations, though (as explained) due
to independent causes, have approximately the same
period — about one month. Their effects, however,
vary according to the changing position of the earth
in its orbit; and any particular phase of the
libration is more nearly reproduced after twelve
months than after one. Galileo was, there-
fore, justified in suggesting an annual period,
although it is not customary at the present day
to associate the annual period with any very
distinct libration.
The complaint in his eyes, which began to be
troublesome towards the middle of 1636, steadily
grew worse for some months. By the end of June
1637, the sight of the right eye was gone, and that
of the other was dimmed by a constant discharge.
" I have been in bed for five weeks," he wrote to
Diodati on 4th July, "oppressed with weakness 'and
other infirmities from which my age (seventy-four
years) forbids me to hope for release. Added to this
(proh dolor ! ) the sight of my right eye — that eye
whose labours (I dare to say it) have had such
glorious results, is lost for ever. That of the left
'which was and is imperfect is rendered null by a coil-
tinual running." But in spite of this affliction and
his other sufferings (moral and physical) his interest
in all things scientific was still unflagging. We find
him carrying on an extensive correspondence with
learned men in Germany, France, and Italy; con-
tinuing the negotiations with the States-General
i64i] GALILEO TOTALLY BLIND 379
about his longitude method; and filling up his
leisure with astronomy and physics.
Early in December 1637 Galileo became totally
blind. "The noblest eye is darkened," wrote
Castelli, "which nature ever made — an eye so
privileged and so gifted with rare qualities that it
may with truth be said to have seen more than the
eyes of all who are gone, and to have opened the
eyes of all who are to come." His patience and
resignation under this terrible calamity are truly
wonderful ; and if occasionally a word of complaint
escapes him it is in the chastened tone of the
following words, written to Diodati on 2nd January
1638 :—
" Alas ! revered Sir, Galileo, your devoted friend
and servant, has been for a month totally and
incurably blind, so that this heaven, this earth, this
universe, which, by my remarkable observations and
clear demonstrations, I have, enlarged a hundred,
nay, a thousandfold bey'ond the limits universally
accepted by the learned men of all previous ages,
are now shrivelled up for me into that narrow
compass which is occupied by my own person. "
Hopes were entertained for a time that the
blindness was occasioned by cataracts, and that he
might hope for some relief from the operation of
couching; but it soon became manifest that the
disorder was not in the humours of the eye, but in a
cloudiness of the cornea, which all remedies failed to
alleviate.
Ever since his return to Arcetri from Siena,
Galileo's friends in Rome lost no opportunity of
interceding for him with the Pope, with a view to
380 GALILEO AT ARCETRI [1636-
his complete liberty from the galling restraints of
the Holy Office. Besides the ever faithful Castelli
and Niccolini, M, de Peiresc and Comte de Noailles,
as we have seen (p. 345), took up his case in the
warmest manner, and several times either them-
selves, or through the Pope's relatives, brought the
matter before his Holiness in an urgent way.
"They endeavoured/' wrote Galileo to Micanzio on
I2th July 1636, "to convince his Holiness that I
never had such an iniquitous thought as to make
game of him, as my wretched enemies had per-
suaded him, which was the prime motor of all my
troubles. At length, the Holy Father pronounced
my exculpation saying : c We believe it, we believe it
now/ but he added, all the same, that the reading of
my Dialogues was most pernicious to Christianity."
In these negotiations the Cardinals Antonio
and Francesco Barberini nobly seconded the efforts
of Galileo's other friends. Indeed, if the Pope had
meant more than fair speeches, there can be little
doubt that the whole Congregation of Cardinals
would have been ready to agree to Galileo's entire
liberation — another proof, if one be wanted, of the
vindictiveness of Urban personally,
At the end of September 1636, Galileo was
allowed to visit the Grand Duke at his Villa
Mezaomonte, outside Florence, going from Arcetri
in a closed carriage in the early morning and
returning late at night, so that he should not be
seen on the way. Again, on i6th October, in the
same year, he was allowed to go to Poggibonsi l to
1 Poggibonsi was the meeting-place of another famous Florentine
with another famous Frenchman. It was there, in June 1495,
i64i] HARSH TREATMENT 381
meet the Comte de Noailles on his way back to
France. This was the extent of the Papal
clemency for many months.
But now, on hearing of his blindness and many
infirmities, the Pope seemed to have relented a
little his savage treatment of the poor old man.
Father Castelli was given to understand that a
suitable petition would now be entertained, and
on Qth January 1638, he sent a draft one which
Galileo was to copy and return, with a medical
certificate, direct to the Assessor of the Holy Office
in Rome. This was done at once, but it was not
enough. The local Inquisitor in Florence was
instructed to see Galileo and make an exact report
as to his health, and as to the likelihood, if he
lived in Florence, of his promoting or encourag-
ing there the propagation of his errors. The
Inquisitor, Father Fanano, reported as follows,
on 1 3th February 1638, to Cardinal Francesco
Barberini : —
" In order the better to execute his Holiness's
commands I went myself, accompanied by a strange
physician, to see Galileo quite unexpectedly. My
idea was not so much to put myself in a position to
report on the nature of his ailments as to gain an
insight into the studies and occupations he is
carrying on, that I might be able to judge
whether he was in a condition, if he returned to
Florence, to propagate the condemned doctrine
of the double motion of the earth. I found him
entirely blind. He hopes for a cure, as the cataract
only formed six months ago ; but at his age, of over
Savonarola met King Charles VIII. of France on his skedaddle from
Naples, and by prophetic denunciations kept him from looting
Florence.
382 GALILEO AT ARCETRI [1636-
seventy [74] the physician considers it incurable.
He has besides a severe rupture, and suffers from
continual weariness of life and sleeplessness which,
as he asserts (and it is confirmed by the inmates of
his house), does not permit him one hour's sound
sleep in the twenty-four. He is besides so reduced
that he looks more like a corpse than a living man.
The villa is a long way from the city, and the
access is inconvenient, so that he can but seldom
and with much inconvenience and expense have
medical aid. His studies are interrupted by his
blindness, though he is read to sometimes ; and
intercourse with him is not much sought, as in his
poor state of health he can only complain of his
sufferings and talk of his ailments to occasional
visitors. I think, therefore, in consideration of
this, if his Holiness in his boundless mercy should
think him worthy and would allow him to live in
Florence, he would have no opportunity of holding
meetings, and if he had he is so prostrated that
I think it would suffice (in order to make quite sure)
to keep him in check by an-emphatic warning."
This report at last seems to have softened the
Papal heart, but only a little bit. A -partial relief
was decided on at a sitting of the Congregation on
26th February, under the presidency of the Pope,
a full release to this man "more like a corpse/'
appearing too dangerous to be ventured on ! On
9th March, Galileo was allowed to enter Florence
and occupy his son's little house, No. u Via
della Costa, near the gate San Giorgio. Here
the Inquisitor called and informed him, "for his
advantage/' of the orders of the Holy Office — not
to go out in the city, under pain of actual imprison-
ment for life and excommunication; not to speak
1641] MAKES HIS WILL 383
with any one whomsoever of the condemned
doctrines ; and not to receive any suspicious
visitors. It is characteristic of the ways of the
Inquisition that Fanano set Galileo's own son to
watch over his movements. The Inquisitor
enjoined upon Vincenzio to see that his orders
were obeyed, and, especially, to see that his
father's visitors did not stay too long. In his
report to Rome of loth March he remarks that
Vincenzio can be trusted, "for he is greatly
obliged for the favour granted to his father to be
medically treated in Florence, and fears that the
least offence might entail the loss of it. Besides,
it is very much to his own interest that his father
should behave properly, and keep up as long as
possible, for with his death a 1000 scudi will go,
which the Grand Duke allows him annually."
Galileo's confinement in Florence was so
rigorous that at Easter a special permission from
Rome was required to go to the little Church of
San Giorgio, one hundred yards down his street, to
perform his Easter devotions, and even this per-
mission only extended to Thursday, Good Friday,
Saturday, and Easter Sunday. On the other hand,
it would seem that he was allowed during June,
July, and August, to go to and fro between his
house in Via della Costa and his villa at Arcetri.
During the summer of 1638, Galileo gradually
sank so low that he and every one about him
thought that his last hour was approaching. In
this belief he dictated his will on 2ist August, and
directed that he should be buried in the family
vault of the Galilei in the Church of Santa Croce,
384 GALILEO AT ARCETRI [1636-
Florence. To his daughter -Sister Arcangela (who
survived him seventeen years) he left an annuity of
25 crowns; to his nephews Vincenzio, Alberto,
and Cosimo Galilei,1 he bequeathed 1000 crowns,
which, however, he revoked in a codicil added a
few months later (igth November). He willed
that any of his descendants who might enter a
religious Order were to be by such act deprived of
the enjoyment of any of his property that might
come to them. His son Vincenzio was to have the
rest, and, in the event of his death during the
minority of his three children, their mother Sestilia,
n£e Bocchineri, was to be guardian jointly with his
faithful disciple Mario Guiducci.
Early in September the Grand Duke paid his
sick Philosopher and Mathematician a visit of two
hours' duration, and helped to prepare his medicines.
These kindly visits were repeated more than once
either by the Sovereign himself, who used to say,
" I do so because I have only one Galileo/' or by
some member of the Medici family.2
1 At this time Alberto, "il Grazioso Albertino," as Maria Celeste
always called him, was staying with his uncle on a long visit Of
Michelangelo's large family but three sons now remained, Vincenzio,
who was teacher of music and singing to some Polish prince, Alberto,
lute and violin player in the service of the Duke of Bavaria, and a
younger boy, Cosimo, whom Alberto was maintaining. The wife,
a son, and three daughters, all are supposed to have perished in the
sack and burning of Munich a few years before (1634),
2 These visits are recorded on a white marble slab over the entrance
door as follows : —
Qui ove abito Galileo
Non sdegn6 Piegarsi alia Potenza del Genio
La Maesta di Ferdinando II.
Dei Medici
In the little garden at the back of the house is an old sundial, said to
be the work of Galileo.
1 ; GALILEO GALILEI
f * ' "
V,' / ,4, /„-,//, ,/C" // 7"/ '' ^"V" " • tfUtt
\\ .tfvwfyw M/f»/f> ,/ttm/f ilt . /, l( > '* >}t fa Mm ' fft </> • htwrt/. >b Jwwfr ,t't,t,'tt\ ,/'/i',f
' , *«v« v /y .a '*«*, ^ tf. «,- j s * * ' '-v* 'f~~i" ' '• /P '" ' "
Portrait of Galileo, aged about 75.
[TV face J, 384-
i64i] THOUGHT TO BE DYING 383
It had been for a long time Galileo's wish to
have with him in the evening of his life his
favourite disciple and lifelong friend Father
Castelli, and as it was now supposed that his
days were few, the Grand Duke sent the following
instructions to his Ambassador in Rome, in a
despatch from Cioli, on gth September 1638 : —
" Signor Galileo, from his great age and the
illnesses which afflict him, is in a condition soon
to go to the other world ; and although in this
the eternal memory of his fame is already
secured, yet his Highness is greatly desirous
that the world should sustain as little loss as
possible by his death, and that his labours may
not perish, but, for the public good, may be
brought to that perfection which he will not
now be able to give them. He has in his
thoughts many things worthy of him which he
cannot be prevailed on to communicate to any
but Father Benedetto Castelli in whom he has
entire confidence. His Highness wishes, there-
fore, that you should see Castelli, and induce
him to procure leave to come to Florence for
a few months for this purpose, which his
Highness has very much at heart And if he
obtains permission, as his Highness hopes, you
will furnish him with money and everything he
may require for his journey."
Niccolini replied that Castelli had been himself
to the Pope with this object ; that his Holiness,
suspecting his design was to see Galileo, taxed him
with it ; and upon Castelli stating that certainly he
could not go to Florence without attempting to see
him, he received permission to visit him, but only
in the company of an officer of the Inquisition.
2 B
386 GALILEO AT ARCETRI [1636-
Early in October Castelli reached Florence, and
was at once permitted to visit his old master,
but was expressly prohibited under pain of ex-
communication to converse with him on the
condemned doctrines. Finding, as he did very
soon, that the local officials of the Holy Office
were inclined to curtail his interviews with
Galileo, Castelli wrote repeatedly to Rome to
obtain greater liberty. He protests in these
letters that he would rather lose his life than
converse on subjects forbidden by the Church,
and gives as a reason for more frequent inter-
views that he had received from the Grand
Duke the twofold charge, to minister to Galileo
in spiritual matters, and to inform himself fully
about the Ephemerides of the Medicean Stars,
which Giovan. Carlo de Medici, Lord High
Admiral, wished to take with him to Spain.
Early in November, the necessary permission
arrived, "in consideration of these circumstances,
and under the known conditions/'
In January 1639 Galileo's general health was
said to have so far improved as to permit of
his returning to Arcetri, which he was never
to leave again till death. Was this move a
voluntary one? it may be doubted. In the first
place, it is difficult to reconcile a voluntary return
to his villa with his previous efforts to obtain
permission to live in Florence. Then, there
are many of his letters which bear the expressive
addresses "Rusculo meo" (i7th August 1634),
"Mio Carcere di Arcetri" (4th and i5th March
1635, 9th February 1636, 4th March 1637, and
1641] "MY PRISON AT ARCETRI" 387
20th February 1638), and " Dalla Villa Arcetri,
Mio continuato Carcerede Esilio" (2Oth January
1641). From such considerations it is allowable
to conclude that Galileo would have little pleasure
in going back to his "prison," and, therefore,
that his banishment from the city was not
voluntary, but the result of orders from
Rome.1
Some time after his return to Arcetri, Galileo
would appear to have solicited some favour
from Rome which was inexorably refused. After
this he came no more into direct contact with
the Roman authorities, as he now gave up all
hope of any amelioration of his lot from the
implacable Pope. "As it pleases God, so also it
should please us," was the refrain of many of his
letters. Father Castelli also had by this time
come to the conclusion that nothing more could
be done for his unfortunate master, for hence-
forth we find nothing in his letters but scientific
disquisitions and spiritual consolations.
The rest of Galileo's life was spent at
Arcetri, where indeed, even if granted full
liberty, his age and infirmities would probably
have detained him a prisoner. The rigid manner
in which the Holy Office had hitherto shadowed
1 The Pope was kept fully informed of Galileo's doings by the
local Inquisitor, and, doubtless, the publication of his Dialogues " in
a heretical country," his negotiations about the longitude, "with
heretical Hollanders," and the rumoured offer of a professorship
in the "heretical" Athenaeum in Amsterdam, were not pleasing
indications for his Holiness. The idea, at his advanced age and
with shattered health, of retiring to Holland shows how much
Galileo must have felt the restraints imposed upon him in his own
country.
388 GALILEO AT ARCETRI [1636-
him was now relaxed, and he was generally per-
mitted to see the friends who came to express
their respect and sympathy. The Grand Duke, as
we have seen, or some member of his family, visited
him frequently, and many distinguished strangers,
such as Gassendi and Diodati of Paris, came
into Italy solely for the purpose of testifying
their admiration of his genius. Amongst the
names of other Oltramontani is that of a young
Englishman, who was able to give him the
gratifying information that his Dialogues of
1632 were being eagerly read by the learned
men in England. This was John Milton, then in
his twenty-ninth year, and already known as a poet
of great promise. Milton left England for the
Continent some time in April 1638, and reached
Paris early in May ; thence travelling by way
of Nice, Genoa, Leghorn, and Pisa, he arrived
in Florence early in August Masson, in his
" Life of Milton," has collected what little we
know of this visit. The young poet was en-
thusiastically received by the members of the
Accademia della Crusca, and assisted at many
of their reunions. " In the private academies
of Italy," he says, "whither I was favoured to
resort, some trifles which I had in memory,
composed at under twenty or thereabouts, met
with acceptance above what was looked for; and
other things, which I had shifted, in scarcity of
books and conveniences, to patch up amongst
them, were received with written encomiums
which the Italian is not forward to bestow on
men of this side the Alps."
1641] MILTON AND GALILEO 389
The only specific reference by Milton to his
visits to Galileo occurs in the following passage
in the " Areopagitica," a discourse addressed to
the .Lords and Commons against the proposed
licensing of printed books : —
" I could recount what I have seen and
heard in other countries, where this kind of
Inquisition tyrannizes, when I have sat among
their learned men (for that honour I had) and
been counted happy to be born in such a place
of philosophic freedom, as they supposed England
was, while themselves did nothing but bemoan
the servile condition into which learning amongst
them was brought; that this was it which had
so dampt the glory of Italian wits, that nothing
had been written there now these many years
but flattery and fustian. There it was that I
found and visited the famous Galileo, grown old,
a prisoner to the Inquisition for thinking in
astronomy otherwise than the Franciscan and
Dominican licensers thought/'
Milton is said to have first met Galileo some
time in September 1638, in which case the meeting
probably took place in the little house in Via della
Costa. The poet left Florence, via Siena, early
in October, for Rome, where he spent the winter,
paying a short visit to Naples. Early in March
1639, he returned to Florence, where, according
to his own account, he was received with no less
eagerness than if the return had been to his native
country and friends at home. On this occasion he
stayed two months, and Masson believes that he
saw Galileo again and, probably, more than once.
390 GALILEO AT ARCETRI [1636-
These meetings would certainly have taken place
at the villa in Arcetri.
" There unseen
In manly beauty Milton stood before him
Gazing with reverent awe — Milton — his guest.
Just come forth, all life and enterprise ;
He in his old age and extremity,
Blind, at noonday exploring with his staff ;
His eyes upturned as to the golden sun,
His eyeballs idly rolling. Little then
Did Galileo think whom he received ;
That in his hand he held the hand of one
Who could requite him— who would spread his name
O'er lands and seas — great as himself, nay, greater ;
Milton as little that in him he saw,
As in a glass, what he himself should be,
Destined so soon to fall on evil days
And evil tongues — so soon — alas, to live
In darkness, and with dangers compassed round,
And solitude." l
Another great Englishman, Thomas Hobbes
of Malmsbury, during his travels abroad, 1634-37,
spent some time in Florence, circa 1635-6, and
often met his brother philosopher for whom he con-
ceived and ever retained the warmest admiration.2
The French philosopher Descartes was, prob-
ably, the only great man who, finding himself in
Florence, did not honour himself by calling on
Galileo. Arago tells us that during his wanderings
Descartes visited parts of Italy and returned to
France (1625), passing through the capital of
Tuscany. He adds — "One would be astonished
to learn that he had no wish to be presented to
1 Rogers' Italy (the Campagna of Florence). The meeting of
Milton and Galileo is the subject of a long poem by Giacomo Zanella.
"Versi," Florence, 1868.
2 See Galileo's letter to Micanzio, dated ist December 1635.
1641] LAST DISCIPLE OF GALILEO 391
Galileo, did we not know that by an inexplicable
aberration he was always indifferent to the works
and admirable discoveries of the Italian philo-
sopher." l In the same way, during his previous
peregrinations in Germany, as a soldier of fortune,
Descartes would not see Kepler, although he called
him his master in optics.
During the summer of 1639 Vincenzio Viviani,
then eighteen years old, came to live with Galileo and
remained with him to the end, glorying in the title
of " ultimo suo discepolo." Almost from the first day
a strong attachment sprang up between the two,
the old master conceiving a fatherly affection for
the talented youth, and the pupil, a love and venera-
tion for the master which he preserved through
life. In his old age when in his turn he had
acquired a claim to the reverence of another genera-
tion, our Royal Society, in electing him a member
(1696), appear to have felt that the complimentary
language in which they addressed him as the first
mathematician of the age would be incomplete
without an allusion to the friendship that gained
him the cherished title of "the last disciple of
Galileo."
Early in 1640, the peripatetic Professor in
Padua, Fortunio Liceti, published a book on the
phosphorescence of the Bologna Stone, so called
from its discovery in 1602 by Casiorolo, a shoe-
maker and alchemist of Bologna. In his fiftieth
chapter he treats of the faint light of that part of
1 He used to say that he saw nothing in the writings of Galileo to
make him envious, and hardly anything which he would care to call
his awn. See Martin's " GalUeV' pp, 290 and 311.
392 GALILEO AT ARCETRI [1636-
the new moon not directly illuminated by the sun,
holding that the moon was phosphorescent like the
Bologna Stone, and rejecting Galileo's explanation
that it arises from a reflection of the sun's rays
from our earth to the moon and their re-reflection
from the moon back to us. Galileo was undecided
whether it were not best to take no notice of
Liceti's objections, when a letter from Leopoldo
de Medici, brother of the reigning Grand Duke,
relieved him of his doubts. This prince, who some
years later gained a permanent place in the history
of science by founding the celebrated Accademia
del Cimento, solicited Galileo's views on Liceti's
arguments, This challenge sufficed to rouse all
his dialectic skill, and he dictated a reply (i3th
March 1640) in the form of a letter to Prince
Leopoldo, which in spirit and crushing argument,
is quite equal to the best controversial work of
his manhood. An extract will serve to show the
difficulties of this composition.
" I am obliged to have recourse to other hands
and other pens than mine since my sad loss of
sight. This of course occasions great loss of time,
particularly now that my memory is impaired by
advanced age, so that on placing my thoughts on
paper, many and many a time I must have the
foregoing sentences read to me before I can tell
what ought to follow; else I should repeat the
same thing over and over again. Your Highness
may take my word for it that between using one's
own eyes and hands and those of others there is
as great a difference as between playing chess with
one's eyes open and blindfolded."
This letter of fifty (printed) pages led to a
i64i] CORRESPONDENCE WITH LICETI 393
correspondence with Liceti, covering the period
from June 1640 to January 1641. The letters are
full of science and philosophy, and are pervaded by
a verve, an urbanity, and a piquant irony, which
make them refreshing reading even to-day. In
them he not only deals with the arguments and
pretensions of his adversary, but he delivers his
opinions very freely on the whole method of Aris-
totle and of the modern peripatetic school of his
debased followers. The correspondence ended in
Galileo sending a revised copy of his letter to
Prince Leopoldo to Liceti, which the latter printed
in 1642 together with his reply.
Ten months before his death, a last occasion of
discussing the Copernican theory was in a manner
forced upon Galileo. The mathematician Pieroni
having announced the discovery of a small annual
parallax for some of the fixed stars (which, if true,
would place the correctness of the Copernican
theory beyond all question), Francesco Rinuccini,
a former pupil, communicated this intelligence to
his old master on 23rd March 1641, and at the
same time begged his opinion on a recently
published argument against the revolution of the
earth, namely, since we see exactly one-half of
the firmament, it must follow that the earth is
in the centre of the starry sphere. This was the
impulse to Galileo's reply of six days later (2 9th
March), which, as Martin and Von Gebler say,
whether a jest or a mask, should never have been
written. He begins by saying that the falsity of
the Copernican doctrine can in no way be doubted,
especially by Catholics, since we have opposed to
394 GALILEO AT ARCETRI [1636-
it the irrefragable authority of Holy Scripture, as
interpreted by the greatest masters of theology,
whose unanimous declaration makes the stability of
the earth in the centre, and the mobility of the
sun around it, a certainty. This so resembles the
ironical style of his letter of 1618 to Prince
Leopold of Austria when forwarding his treatise
on the tides, the introduction to his Reply to
Ingoli in 1624, and his preface to the discreet
reader in his Dialogues of 1632, that it cannot be
taken as seriously meant He then goes on, as at
the end of the Dialogues just mentioned : —
"The grounds on which Copernicus and his
followers have maintained the contrary fall to
pieces before the fundamental argument of the
Divine Omnipotence. For, since this is able to
effect by many, aye, by endless means what, so far
as we can see, appears practicable in one way only,
we must not limit the power of God, and persist
obstinately in our mistaken notions. As I hold the
Copernican theory to be insufficient, so, that of
Ptolemy, Aristotle, and their followers, appears to
me far more delusive and mistaken, because its
falsity can be clearly proved without going beyond
the limits of human knowledge."
The Copernican theory being thus condemned,
and the alternatives, those of Ptolemy and Tycho
Brah6 being demonstrably untenable, it only remains,
he says, for philosophers to find some other system
of which both science and theology can approve.
Then coming to the new argument against the
mobility of the earth which so troubled his corre-
spondent, he shows that it is a mere petitio principii,
i64i] LAST WORDS ON COPERNICANISM 395
and has not the least foundation in astronomical
science ; and, finally, as to the reported discovery
of a stellar parallax, he says briefly that if Pieroni's
observation be correct, human reason would compel
us to conclude that the earth is not immobile
in the centre of the starry sphere. But, as if
repenting his audacity in saying this, he hastens
to add, "If Pieroni may be mistaken in supposing
that he had observed a parallax of a few seconds,
those others may be still more mistaken who assert
that the visible firmament never varies, not even
one or two seconds, for such an exact observation
is utterly impossible, partly from the insufficiency
of astronomical instruments, and partly from the
refraction of light/'
Cesare Cantu and some writers after him have
assumed from this letter that at the close of his
life Galileo had really renounced, and from pure
conviction, the astronomical doctrines for which he
had laboured and suffered for thirty years. But if
we bear in mind all the circumstances under which
the letter was written, we will see that this assump-
tion is quite untenable, and that we must conclude
with Martin and Von Gebler that the passages on
which Cantii and his followers rely were not meant
to be taken an pied de la lettre — that they were, as
Martin puts it, " la protestation habilement ironique
d'une pens^e contrainte £L se cacher." *
A few months before his mortal illness Galileo
once more gave evidence of his genius. It has
been remarked in the progress of science and
1 Martin's " Galilee," p. 235 ; Getter's " Galileo and the Roman
Curia," p. 305.
396 GALILEO AT ARCETRI [1636-1641
scientific invention that the steps, which on looking
back seem the easiest to make, are often those
which are the longest delayed. The application of
the pendulum to clocks is an instance of this. We
have seen that Galileo was early convinced of the
value of the pendulum as a measurer of time,
and that as far back as 1582 he used it in
the pulsilogia; yet fifty-five years later, although
constantly using it meanwhile, he had not de-
vised a more practicable application of it than
that described in his "Astronomical Operations/'
I637-8-
" I make use of a heavy and solid pendulum of
brass or copper, in the shape of a sector of twelve
or fifteen degrees, the radius of which may be two
or three palms (the greater it is the less trouble in
attending it). This sector I make thickest in the
middle radius, tapering gradually towards the edges,
where I terminate it in a tolerably sharp line, to
obviate as much as possible the resistance of the
air, which is the sole cause of its retardation. This
sector is pierced in the centre, through which is
passed an iron bar shaped like those on which
steelyards hang, terminated below in an angle, and
placed on two bronze supports. If the sector (when
accurately balanced) be removed several degrees
from the perpendicular, it will continue a to-and-fro
motion through a very great number of vibra-
tions before coming to rest ; and in order that
it may continue its oscillations as long as it is
wanted, the attendant must occasionally give it
a smart push so as to carry it back to large
oscillations.
" Now to save the fatigue of continually counting
the oscillations, this is a convenient contrivance — a
small delicate needle extends from the middle of the
GALILEO'S DESIGN OF A PENDULUM CLOCK (see next page).
From Favaro's " Galileo e Cristiano Huygens. Nuovi document!
sull' applicazione del pendolo all' orologio" (Nuovi studi
Galileiam] Venice, 1891).
398 GALILEO AT ARCETRI [1636-
sector which in passing strikes a rod hung at one
end. The lower end of this rod rests on the teeth
of a horizontal wheel as light as paper. The teeth
are cut like those of a saw. The rod striking
against the perpendicular side of a tooth moves it,
but when returning it slips over the oblique side of
the next tooth and falls at its foot, so that the
motion of the wheel will be in one direction only.
By counting the teeth you may see at will the
number passed, and, consequently, the number of
oscillations or periods of time which you wish to
measure. You may also fit to the axis of the wheel
a second, with a smaller number of teeth and in
gear with a third wheel having a greater number of
teeth, and so on. As the error of clocks consists
chiefly in the inability of mechanicians to adjust
what we call the balance of the clock so that
it may vibrate regularly, my very simple pendulum,
which is not liable to any alteration, affords a
means of maintaining the measures of time always
equal/'
It was chiefly because of the inadequacy of this
method that the negotiations with the States-
General were finally broken off. Now, in the
second half of 1641, it occurred to Galileo (as
stated by Viviani who was present) that the prob-
lem could be solved by adding the pendulum to
the ordinary clock as a regulator of its movements.
He explained his idea to his son, Vincenzio, who
made a drawing (of which we reproduce a facsimile)
from his father's dictation. Before the plan could be
tried Galileo fell ill, and this time did not recover.
The matter was laid aside, but seven years after his
father s death, Vincenzio resumed it, and was engaged
in constructing what would have been the first
1641] DESIGNS A PENDULUM CLOCK 399
pendulum clock, when he too fell ill and died, i6th
May I649.1
1 For more on this interesting subject, see Viviani's account which
he wrote expressly, 2Oth August 1659, for Prince Leopoldo de Medici
in Alberi's vol. 14. The application of the pendulum to clocks has
been claimed for the Swiss, Burgi, and for Richard Harris of London
in 1611 ; but Christian Huygens appears to have been the first to
actually construct a pendulum clock between 1654 and 1657.
CHAPTER XVII
DEATH OF GALILEO — CONCLUSION
1642
THE last few months of Galileo's life were soothed
by the devotion of his friends, and the homage
of all to whom his name was known. The Grand
Duke was most attentive in enquiries after his
health, and sent him supplies of his choicest
wines and other delicacies. Besides the creature
comforts thus supplied, Galileo had the pleasure of
once more meeting his old friend Castelli, and dis-
coursing with him on the things of that world to
which they both were tending. The good Father
arrived from Rome towards the end of September
1641, intending to stay to the end, but he had to
return to his duties early in November.
Towards the middle of October, Evangelista
Torricelli, then a rising philosopher of thirty-three,
came to stay at the villa, and did not leave it until he
followed the coffin of the great master. Torricelli first
studied under Castelli, and, later on, occasionally lec-
tured for him in Rome, in which manner he was em-
ployed when Galileo, who had seen his early treatises
on mechanics and on the motion of fluids, and had
augured the greatest success from such beginnings,
400
1642] LASTDAYS 401
invited him to Arcetri. He succeeded the master
in his appointment at the Court of Florence, but
survived him only a few years, dying in 1647, at the
early age of thirty-nine. The youthful Viviani, as
we know, was already in the villa, acting as a loving
son to an honoured father. He, Torricelli, and
Vincenzio Galilei shared between them the duties
of amanuensis and companion.
On the ist October, Bonaventura Cavalieri,
another of Castelli's distinguished pupils, whom
Galileo used to call " another Archimedes," wrote
from Bologna, expressing his grief at not being
able, on account of his infirmities, to join the dis-
tinguished company ; and another lifelong friend
and champion, Fra Fulgenzio Micanzio of Venice,
to whom Galileo had written in praise of his new
collaborateur., replied on 2nd November in similar
terms ; he envied, he said, the reunions of such an
illustrious triumvirate, Galileo, Castelli, and Torri-
celli.
On 5th November, Galileo was attacked by a
low fever with pains in the limbs, which confined
him to bed from which he never rose again. Yet
in spite of these sufferings, aggravated by insomnia,
and by frequent attacks of palpitations of the heart,
his mind was clear and busy to the last, and in
the intervals of pain he passed hours in scientific
discussions with Torricelli and Viviani who care-
fully noted his utterances. These related to the
Mechanical Problems of Aristotle, to his long
contemplated (since 1609) Treatise on the Move-
ments of Animals, to the properties of the cycloid,
but chiefly to the force of percussion. His notes
2 c
402 DEATH OF GALILEO [1642
on the first three subjects have not come down
to us, but those on percussion now form the
sixth Dialogue added to the later editions of the
u Dialogues on the Two New Sciences," as already
explained.
On the evening of 8th January 1642, the year
of Newton's birth, Galileo breathed his last, at the
age of nearly seventy-eight, fortified by the last rites
of the Church, and the benediction of Urban VIII.
His son Vincenzio and his wife, Torricelli and
Viviani, and the parish priest of Arcetri were
around his bed.
Not only was his power of making a will
disputed, but the propriety of laying his body in
consecrated ground was questioned by some
fanatics, who could only see in the life of this
great man the one fact, that he had died under
sentence of the Holy Office, " vehemently sus-
pected" of heresy. On a reference to the proper
authorities, his power of making a will was upheld,
and it was also ruled that his friends had full
right to place his remains in consecrated ground.
Accordingly, preparations were at once made
for a public funeral such as might best show the
sense of the Court and the city of the greatness
of their loss, and the sum of 3000 crowns was
quickly collected to cover the expense of a marble
monument in the Church of Santa Croce. These
and other particulars were reported to Rome,
whereupon the Pope sent for the Tuscan Ambas-
sador, Niccolini, and desired him to tell his
master that it would be a bad example for the
world if such honours were rendered to a man
1642] PERSECUTED BEYOND GRAVE 403
who had been arraigned before the Holy Office
for false and erroneous opinions ; who had com-
municated them to many others ; and, altogether,
had caused the greatest scandal to all Christendom.
Niccolini, reporting this interview on 25th January
1642, advised that the project of a funeral oration
and a monument be laid aside, at least for a time ;
since, as his Holiness claimed to be absolute
master of all churches and consecrated grounds,
it was likely that an insistence on these public
honours would draw on the Grand Duke himself
some such affront as was offered, not long before,
to the Duke of Mantua (by the removal of the
body of the Countess Matilda from Mantua to St
Peter's in Rome).1 So determined and threatening
was the Pope's attitude in this matter that the
weak Ferdinando II. was not able to resist
Proposals both for a public funeral and a
monument were laid aside, and the friends of the
great dead were constrained to hide away (there
was not even an epitaph) his beloved remains in
a little room or cell (9 feet by 6) to the right of
the altar in the Chapel of the Novices, situated at
the end of the corridor leading from the south
transept of Santa Croce to the great sacristy.2
It was not till nearly thirty-two years later
(September 1673) when Urban VIII. had long
1 At the same time the Inquisitor in Florence was instructed to
make similar representations to the Grand Duke ; and if without the
desired effect, he was to see that there was nothing in the epitaph
that could be construed as an insult to the Holy Office, and he was
to exercise the same care in the preparation of the funeral oration.
2 Here were also laid in 1703 the remains of Viviani who desired
to lie beside his master.
404 DEATH OF GALILEO [X642
been dead, that Father Gabriele Pierozzi of Santa
Croce ventured to honour the illustrious dead by
painting on the wall of the cell a somewhat
bombastic inscription, and placing on a plaster
bracket above it a small bust of Galileo in clay,
painted in imitation of marble. The bust was
removed in 1737, at the translation of Galileo's
remains (to be presently described), but the
inscription remains, partly obliterated, and in a fair
way of disappearing, by the scaling of the plaster.1
In 1693, Viviani ventured to erect the first
public monument to Galileo. On the front of his
house in Via dell' Amore (now Via San Antonino),
he placed a bronze bust of the philosopher, which
was cast from a mould of a terra-cotta bust made in
1610 by Giovanni Caccini, the sculptor, by desire of
Cosimo II. Over this and on both sides of the
entrance door, on large marble scrolls, are
engraved long eulogies of the master.2
But Viviani was not content with these pious
memorials. Dying in 1703, he left his property
to his nephew, the Abbe Jacopo Panzanini,
charged with the condition of erecting a suitable
monument in bronze and marble as soon as
permission to do so could be obtained. For over
thirty years no attempt was made to carry out his
wishes, and then the business was taken in hand,
1 Brewster ("Martyrs of Science ") gives a copy of this inscrip-
tion, but not quite accurately. See Albert's "Opere di Galileo,"
vol. xv. p. 405,
2 For these, see Alb&ri's vol. xv. pp. 373-80. Viviani had also
caused a medal to be struck in honour of Galileo ; and no less than
five other commemorative medals were issued during his residence
in Padua and Florence. All of these are reproduced in Nelli's and
Ventures works.
Galileo's Monument in Santa Croce, Florence.
[ To face /. 404,
i642] MONUMENT IN SANTA CROCK 405
not by Viviani's heir, but by the executor Gio.
Battista Nelli. In 1734, enquiries were made at
Rome as to whether there was any decree of the
Holy Office which would prevent the erection of
a monument. The reply, i6th June 1734, was
that there was nothing against such a proposal,
provided the intended inscription were submitted
for approval. The 'work was accordingly taken
in hand, but dragged on slowly for nearly three
years. Finally, on the night of i2th March 1737,
and in presence of the leading clergy, of all
the professors of the schools of Florence and Pisa,
and of learned, literary, and artistic men from all
parts of Italy, Galileo's remains were removed
with great pomp to the mausoleum in the north
aisle of Santa Croce — the Pantheon of the
Florentines — whither also were conveyed the
remains of Viviani, according to his last wishes.
The monument, which we reproduce from a
photograph, is the work of Gio. Battista Foggini,
assisted by his son, Vincenzio, and Girolamo
Ticciati, The bust of Galileo and the figure
representing astronomy are the work of Vincenzio
Foggini, while the figure of geometry is from the
chisel of Ticciati.
" In Santa Croce's holy precincts lie
Ashes which make it holier, . .
here repose
Angelo's, Alfieri's bones, and his
The starry Galileo, with his woes ;
Here Machiavelli's earth returned to whence it rose."
— BYRON, Childe Harold, Canto IV. 54.
Galileo's old resting-place was about two yards
406 DEATH OF GALILEO [1642
high, and consisted of rude masonry, built on the
floor and against the wall of the cell. Viviani's
was close beside it, of similar structure but smaller.
On breaking away the stonework of the latter,
which it was found convenient to remove first,
and on opening the coffin, a lead plate was found,
attached to the inside of the lid, on which was
inscribed —
" Vincenzio Viviani Morto il di xxii Settembre 1703."
The cover was then replaced, and the coffin was
transferred to its new resting-place.
Returning to the little chapel, the masonry of
Galileo's tomb was removed, and the coffin laid
open. Giovanni Targioni-Tozzetti, one of the pall-
bearers, tells us that the face was well preserved,
and like the bust by the sculptor Caccini, made in
1610, and also very like Sustermans' portrait,
circa 1635 (a copy of which forms the frontispiece
of the present work). A heavy iron girdle was
found in the coffin, so fashioned as to lead
Targioni-Tozzetti to suppose that the wearer must
have suffered from rupture on both sides. It was
also observed that the body was pierced, probably
to let escape an accumulation of water, and the
opening was filled with coarse wadding. This
seems to indicate dropsy, which must, therefore,
be added to the poor old man's other maladies.1
During the work of exhumation and identifica-
tion Canon Gio. Vin. Capponi, President of the
Sacra Accademia Fiorentina, took an opportunity
1 Targioni-Tozzetti: "Notizie degli Aggrandimenti delle Scienze
Fisiche in Toscana," Florence, 1780.
i642] TRANSLATION OF REMAINS 407
of removing with a knife the thumb and forefinger
of Galileo's right hand! because, as he said to
Targioni-Tozzetti, they held the pen with which
so many fine things were written ; but the latter
(who tells the story in the work just quoted) tapped
the skull, and said he would rather have some of the
brains which conceived the grand thoughts. These
relics were still preserved in the Capponi family
down to 1845, and are now apparently lost.
Soon after, Anton. Francesco Gori, Professor of
Ancient History in the University of Florence,
removed the index finger of the left hand, which,
at his death, passed to Canon Angelo Bandini.
At his death in 1803, it came into the custody of
the Laurenzian Library (of which Bandini had been
Keeper), and in 1841 it was transferred to its
present place in the Tribuna di Galileo in Florence.
It is enclosed in a crystal urn, and bears an inscrip-
tion from the pen of Tommaso Perelli, a celebrated
astronomer of Pisa, circa 1770 —
" Leipsana ne spernas digit! quo dextera coeli
Mensa vias nunquam visos mortalibus orbes
Monstravit, parvo fragilis molimine vitri
Ausa prior facinus cui non Titania quondam
Suffecit pubes congestis montibus altis
Nequidquam superas conata ascendere in arces."
At the same time, yet another idolater, Dr
Antonio Cocchi, Professor of Natural Philosophy
and Anatomy, took away the fifth lumbar vertebra,
which, after passing through many hands, came
into the possession of Dr Thiene, In 1823, he
presented it to the University of Padua, where it
is now preserved in the museum attached to the
physical science laboratory.
4o8 CONCLUSION [1642
From Viviani's biography of Galileo (1654) we
learn that he was of a cheerful and pleasant counte-
nance, especially in later life, square of frame, well-
proportioned, and rather above the middle height
His complexion was fair and sanguine, his eyes
sparkling, and his hair and beard, of which he had
an abundance, of a reddish hue. Up to the age
of thirty his constitution was sound, but after his
first serious illness in 1593 he was beset by various
complaints, which increased in gravity and frequency
as the years rolled on. Thus for nearly fifty years
he was subject to frequent attacks of fever,
hypochondria, and rheumatism, and, latterly, to
gout, rupture, and insomnia. Yet, with such a
multitude of complaints as would have made a
miserable valetudinarian of any other man, his
industry was extraordinary. It was said that no
one had ever seen him idle, and one of his favourite
sayings was that occupation is the best medicine for
both mind and body.
His temper was what we would call short ; he
was easily ruffled, but more easily pacified — a
condition which, if not produced, was certainly
aggravated by physical suffering, and the troubles
of all kinds, public and private, from which for sixty
years he was seldom free.
In his younger days he was fond of a country
residence. Besides believing that the city air
was prejudicial to his health, he was wont to say
that the city was in a manner a prison for the
speculative philosopher; that in the country alone
was the book of nature open to him whp cared to
read and learn from it ; that the characters in which
1642] TEMPERAMENT AND TASTES 409
that book was written were those of geometry ; and
that when once they were fully deciphered we might
hope to penetrate the deepest mysteries of nature.
Though he loved the quiet of a country life, he
was fond of the society of friends, to whom he
constantly dispensed a hospitality simple but
hearty. Gardening in all its forms was his
favourite and almost his only relaxation from the
severe studies which filled his days, and great part
of his nights. He was a connoisseur in wines, and
was diligent in tending his own vineyard. He used
to say that wine is a compound of humour and
light ; and Viviani has preserved one of his recipes
— for wine of the best quality, that juice only should
be taken which is pressed out by the mere weight
of the heaped grapes of the ripest kind.
All through life he was fond of wine, perhaps
sometimes too fond for his health and temper,1 and
even in old age the taste was apparently as keen as
ever, as the following curious letter will show. It
is headed " From my prison at Arcetri," and is
dated 4th March 1637 —
" I am forced to avail myself of your assistance,
agreeably to your obliging offers, in consequence
of the excessive chill both of weather and of old
age, and from having drained out my grand
stock of a hundred bottles which I laid in two
years ago — not to mention some minor par-
ticulars during the last two months which I
received from my serene master, from the
Cardinal de Medici, the princes, and the Duke
of Guise; besides clearing out two barrels of
the wine of this country. Now I beg that, with
1 See Favaro's "Galileo e Suor Maria Celeste," p. 141.
4io CONCLUSION [1642
all due diligence and industry and taking
counsel with the most refined palates, you will
provide me with two cases, ^.e. forty flasks of
different wines, the most exquisite that you can
find. Take no thought of expense, because I
stint myself so much in all other pleasures that
I can afford to lay out something at the shrine
of Bacchus, without giving offence to his two
companions Venus and Ceres. You must be
careful to leave out neither Scillo nor Carino (I
believe they should be called Scylla and
Charybdis), nor the country of my master
Archimedes of Syracuse, nor Greek wines, nor
clarets, etc. The expense I shall easily be able
to satisfy, but not the infinite obligation I shall
owe you."
In other expenditure Galileo observed a
just mean between avarice and prodigality. He
spared no cost necessary for the success of his
many and various experiments, and spent large
sums in charity, and in assisting those in whom
he discovered promise of any kind, many of whom
he entertained in his own house. Even in the
last year of his life, he had one such poor scholar
in the Villa, as may be seen from Cesare Monti's
letter of 3Oth May 1640, and Galileo's reply of
2nd November following.
He seldom conversed on mathematical or
philosophical topics, except with his intimate
friends ; and when such subjects were abruptly
brought before him by others, as was often
done by the numerous strangers who called upon
him, he showed great readiness in parrying
and turning the conversation into other channels,
in such manner, however, that he usually contrived
1642] TEMPERAMENT AND TASTES 411
to say something to satisfy the curiosity of the
enquirer. His demeanour, therefore, was modest
and unassuming. Of self-praise so much is re-
corded of him that, when his sight was decaying
beyond all hope of recovery, he used to comfort him-
self by saying that of all the sons of Adam none
had seen so much as he. He neither depreciated
nor envied the talents of other men, but gave to
each his due, according to his own lights. It
was the custom of many of his followers to
speak of Aristotle with contempt, not so the
master, he would only say that the methods of
reasoning of the great Stagirite philosopher
appeared to him unsatisfactory, or erroneous ;
and such of the works of Aristotle as he did
admire, he admired frankly, especially those on
Ethics and Rhetoric. He exalted Plato to the
skies, calling his eloquence golden. Pythagoras,
he thought, unequalled among philosophers ; but
Archimedes was the only one of the ancients
whom he called master. Much of Virgil, Ovid,
Horace, and Seneca, he knew by heart.
His memory was uncommonly tenacious, and
was stored with a variety of old songs and
stories which he would bring out on all suitable
occasions — The Sonnets of Petrarch, the Rime
of Berni, and the heroic stanzas of the "Orlando
Furioso" he could repeat in great part. As we
have already seen in our Chapter II, his excessive
admiration of Ariosto determined the side which
he took against Tasso in the virulent controversy
which had divided Italy so long on the merits
of these two poets. It should, however, be
4i2 CONCLUSION [1642
remembered that his matured taste receded from
the violence of his youthful prejudices, and,
towards the end of his life, he avoided as much
as possible making any comparisons, and, when
forced to give an opinion, he would say that
Tasso's appeared the finer poem, but that
Ariosto's gave him greater pleasure.1
Of his obiter dicta, not many have been
preserved. Besides those already noted, one or
two others may be quoted. The book of philo-
sophy, he used to say, is the book of nature
which lies always open before us, and is written
in characters of geometry. Not to know, then,
geometry, is to be ignorant of nature. Another
favourite axiom, conveying the same truth, was
Ignorato motu ignoratur natura. When the
understanding has experience to inform it, reason
is not indispensable, was another of his sayings.
He was wont to say that he had never met
with a man so ignorant that something might
not be learnt from him ; again, that ignorance in
others was his best teacher, for in learning how
to combat ignorance he taught himself. He used
to say that it was the privilege of the sad and
miserable not to be envied by the merry, and
of the wicked, not to be envied by the good.
As a teacher he was no less loved and
valued than as a friend. However clear a subject
might be to his own mind, he was not satisfied
till he made it as clear to the minds of his pupils.
"From Signor Galileo/' wrote Marsili (in 1637),
1 See his letters of 5th November 1639 and igth May 1640, to
Francesco Rinuccini.
1642] GREATNESS AS A TEACHER 413
" I learnt more in three months than I did in
as many years from other men." " I thank
God," said Paolo Aproino, "for having given
me for master the greatest man the world has
ever seen." "When/1 wrote Ciampoli, after
his retirement in disgrace to Montalto in 1633,
"When shall I embrace you as a father and
listen to you as an oracle ? " Viviani and Gherar-
dini are equally enthusiastic ; and even some of his
stoutest adversaries, as Lagalla and Grassi, readily
admitted his greatness in this respect.
Pages might be filled with expressions of
gratitude and devotion such as these culled
from the letters of Galileo's disciples. And truly
the master himself might adjudge them to be
of higher value, as a testimony to his greatness,
than the marble monument under which he now
reposes in the Church of Santa Croce,
On the occasion of the third congress of
scientific men in Italy, held in Florence in 1841,
the Tribuna di Galileo was opened by Leopoldo
II., the last Grand Duke of Tuscany. It is on
the first floor of the Museum of Physics and
Natural History, a building which the scientific
visitor to Florence should not fail to explore ;
for, besides the exquisite little temple of Galileo,
it contains a vast and splendid collection of scientific
apparatus of all kinds, for the most part the remains
of the once famous Accademia del Cimento.
An extract from the official Guide,1 will suffi-
ciently explain the design : —
1 " Guide de la Tribune de Galilee," Florence, 1843. It was
reprinted in 1861, and has long been out of print.
414 CONCLUSION [1642
" The temple being dedicated to the memory of
the great Galileo, the father of experimental philo-
sophy, and being destined to preserve the scientific
instruments, etc. — the products of his genius, and of
that of his school, it was desired that it should be, at
the same time, commemorative of the most famous
epochs of Tuscan philosophy, and of the men who
made them famous. And, in order to preserve the
distinctively national character of the work, it was
decided that only Tuscan artificers and Tuscan
materials should be employed in the building and
decorating. Thus the architect, Giuseppe Martelli,
was Tuscan, and the artificers, the painters, and the
sculptors were all Tuscan/'
The building, which is said to have cost ,£40,000,
consists of (i ) a vestibule which is lighted on the left
by a fine stained-glass window, and from which
opens, on the right, (2) a small rectangular hall,
which leads to (3) a semi-circular tribune. The
interiors are entirely lined with white marble, and
profusely decorated with frescoes, medallions, busts,
and drawings carved in low-relief and illustrative of
the discoveries and inventions of Galileo and his
immediate followers.
In the centre of the tribune stands the statue of
Galileo by Professor Costoli ; and in compartments
of the domed ceiling above the statue are three
frescoes, depicting three momentous periods of his
life— the rising, the zenith, and the setting of his
genius. In the first, we see the youthful Galileo
watching intently the swinging lamp in the Cathedral
of Pisa. In the second, he is presenting his telescope
to the Doge of Venice. In the third, old and blind,
he is seated at a table, with his left hand on a globe,
Tribuna di Galileo, Florence,
L To face p. 414.
1642] TRIBUNE OF GALILEO 415
and discoursing to Torricelli and Viviani ; the parish
priest of Arcetri, and Galileo's father confessor, are
seen listening at the open door.
In the (semi-circular) wall of the tribune are six
niches ; the first, second, fifth, and sixth, contain
busts of Castelli and Cavalieri, Torricelli and
Viviani, the two first and the two last disciples of
Galileo. In the third niche one sees, through a
glass frame, two of Galileo's later telescopes, and
the object-glass of the telescope with which he made
all his astronomical discoveries ; we have reproduced
a photograph of these precious relics to face p. 96.
In the fourth niche, also glass-covered, are seen (i)
a geometrical and military compass, (2) a loadstone
with Galileo's armature, and (3) the index finger of
his left hand.
In lunettes, above the walls of the vestibule and
rectangular hall, are four large frescoes. One,
which faces the visitor on entering the temple,
shows Leonardo da Vinci in presence of Ludovico
Sforza, Duke of Milan, to whom he is enumerat-
ing his numerous inventions. In the opposite
lunette Volta is seen explaining his electric pile
to the members of the French Institute, Napoleon
and Lagrange being prominent amongst the spec-
tators. The corresponding paintings in the hall
represent (i) Galileo in Pisa proving the law of
descent of falling bodies by experiments on an
inclined plane, and (2) Viviani, Borelli, and Redi
showing to the Grand Duke the apparent (but to
them real) reflection of cold by a parabolic mirror.
A thermometer is seen in the focus of the mirror,
and a block of ice is used as the source of cold.
416 CONCLUSION [1642
On the pilasters are fourteen white marble
medallions of members of the Accademia del
Cimento, and other distinguished Italian scientists.
And on pedestals in the vestibule are busts of the
Grand Duke, Ferdinando II. , the friend of Galileo,
and a patron of science ; of Prince Leopoldo, his
brother, also a great friend of Galileo, and founder
of the Accademia del Cimento ; of Grand Duke
Pietro Leopoldo I., founder of the Museum of
Physics and Natural History ; and of Grand Duke
Leopoldo II., under whose auspices the temple of
Galileo was erected. Scattered over the vaulted
roofs or ceilings are ten small paintings, emblematic
of nature, truth, perseverance, physics, philosophy,
astronomy, geometry, mathematics, hydraulics, and
mechanics.
On the floor of the hall, on stands, are four
instruments of great size: a brass astrolabe; an
odometer or distance-measurer ; a movable dial by
Rinaldini, mounted in walnut, with a Tychonic
scale in brass ; and the great crystal lens of Bregans
of Dresden, with which Averani and Targioni-
Tozzetti, and, many years later, our own Sir Hum-
phrey Davy made experiments on the combustion
of the diamond and other precious stones. Finally,
in large glass cases,, lining the walls of the hall and
vestibule, are preserved the most interesting speci-
mens of the instruments, etc., belonging to the
famous Accademia del Cimento, such as thermo-
meters, barometers, hygrometers, gravity-meters,
globes for experiments on the compressibility of
water, telescopes by Torricelli, Viviani, and other
early Italian makers; and collections of chemical
1642] TERCENTENARY OF GALILEO 417
(beautiful specimens of Florentine glass-work), astro-
nomical, nautical, and geodetic apparatus.1
In 1864, the tercentenary of Galileo's birth was
celebrated at Pisa, in a way which, if the news could
have reached him, would have gone far to make
amends for her ill-treatment in the flesh of her most
famous graduate and professor.2
On ;th December 1892, a far more imposing
ceremony took place in Padua, to commemorate the
three-hundredth anniversary of Galileo's first lecture
in that renowned seat of learning. We base the
following account of this historical function on an
article in " Nature/' 22nd December 1892.
" On 6th December, the rector, Professor C. F.
Ferraris, received in one of the courts of the old
University (adorned everywhere with portraits of
the most illustrious professors) delegates from the
universities, the polytechnic schools, and Italian
and foreign academies, amounting to nearly a
hundred, and among them many who shed most
lustre on contemporary science. The University
of Cambridge was represented by Professor George
Howard Darwin, F.R.S., who also represented the
Royal Society, as Mr Norman Lockyer, its
delegate, had been prevented from attending. The
University of Oxford by Professor E. J. Stone ;
1 At the foot of the stairs leading to the Tribune is a fine statue of
Torricelli in white marble, but it is practically hidden in a small
sombre recess. Surely the Museum authorities could find a more
suitable place.
z See " II terzo Centenario di Galileo," by Professor Benedetti, Pisa,
1864, or Giornale di Pisa, 2ist February 1864. On 2nd October 1839,
a fine marble statue of Galileo, by Emilio Demi, was unveiled in the
University. The figure, larger than life, is sitting, in professor's gown,
and holds a globe in the left hand- A partly unrolled scroll (showing
astronomical figures) rests on the knee, and the right hand is slightly
extended as if in the act of demonstrating.
2 D
4i8 CONCLUSION [1642
the Royal College of Physicians, London,^ by Sir
Joseph Fayrer, F.R.S. ; the Chemical Society and
British Association by Professor Ludwig Mond,
F.R.S. ; the Harvard University, Cambridge,
U.S.A., by Professor William James, and the
Princeton University by Professor Allan Marquand.
" The great academical celebration took place on
7th December in the large hall of the University,
in the presence of Signor Ferdinando Martini,
Minister of Public Instruction, who represented the
King of Italy. The ceremony was begun with a
discourse, prepared for the occasion, by the rector
magnifico, and devoted principally to a cordial
expression of thanks to the king and to the' minister
who represented him; to the foreign and Italian
delegates ; and to the ladies of Padua, who had
given the University a most beautiful banner, on
which were various emblems indicating the history
of the University, the genealogical tree of the
Galilei family, and the ancient inscription above
the door of the University — Gymnasium omnium
disciplinarum.
" Next came the commemoration of Galileo by
Professor Antonio Favaro, who has for nearly
fifteen [now twenty-five] years devoted himself,
almost exclusively, to the study of the life and
works of Galileo, and to whom was confided by
the government the care of the national edition of
the philosopher's works, under the auspices of the
King of Italy. The orator kept his discourse
within the limits marked out for him, speaking
chiefly of Galileo at Padua. Constrained to leave
the University of Pisa Galileo had been welcomed
in that of Padua, where he found the 'natural
home of his mind — a theatre worthy of his talents.'
The conditions at Padua at that time were eminently
favourable to Galileo's work, for the Venetian
senate granted the lecturers the utmost liberty, and
1642] TERCENTENARY OF GALILEO 419
experimental methods, which could not be learned
from books, had been practised at the University
for more than a century. Galileo had many
opportunities for the development of his genius,
both in the lecture-room and in the home, in the
preparation of scientific publications, and in the
workshops of scientific instrument-makers both in
Padua and Venice. To Venice he frequently went,
attracted by the means it afforded him for study ; by
that grand Arsenal, which had already been sung by
Dante, and which in his famous Dialogues is spoken
of by Galileo with admiration ; but, above all, by
the advantages he derived from scientific inter-
course with eminent men who resided in the lagoon
city. The culminating point of the discourse was
naturally reached when the orator had to deal with
the invention of the telescope, and with the
astronomical discoveries made by means of it, the
immediate result of which was the recall of Galileo
to Tuscany. This did not aid him in his glorious
career, or help to protect him from the attacks
which were for a long time made on him by
invidious adversaries. Even some of his own
friends changed at once to implacable and
dangerous enemies, and at last he was involved in
all the miseries which sprang from the memorable
trial before the Inquisition in Rome. This led the
orator to recall the fact that, when the clouds
assumed their most threatening aspect, the Venetian
republic, forgetting with real magnanimity what-
ever resentment it might have felt at Galileo's
abandonment of his chair at Padua, offered to
reappoint him, and to print at Venice the work
which had brought upon him so much trouble.
« After Professor Favaro's oration, discourses
were delivered by the foreign delegates, Holmgren,
Fayrer, Darwin, Tisserand, Lampe, Keller,
Foerster, Sohncke, Biasing, Lemcke, Farey,
420 CONCLUSION [l642
Lanczy, Schmourlo, and by Italian delegates,
Nardi-Dei, Mantovani-Orsetti, and Del Lungo.
Then followed the conferring of University
honours, of which seven had been set apart by
the council for seven men of science, one for each
nation, all distinguished for their devotion to the
studies in which Galileo excelled, viz., Schiaparelli,
Helmholtz, Thomson, Newcomb, Tisserand,
Bredichir, and Gylden. The degree of philo-
sophy and letters was given to the Minister
Martini ; of natural philosophy, and of philosophy
and letters, to the leading delegates. The ceremony
was closed by the inauguration of a commemorative
tablet in the large hall.
" Of the other festivities connected with the
celebration it would be out of place to speak
here, and it will be better to add a list of the
publications which were issued on the occasion.
The oration read in the great hall by Professor
Favaro has been published, with the addition of
twenty-five facsimiles of documents comprising
the various decrees of the senate concerning
Galileo ; several autographic records of Galileo,
chosen in order to give a more exact idea of
what are the most precious materials for his
biography; the frontispieces of the various
publications issued by Galileo, and relating to the
time of his sojourn in Padua ; the geometric and
military compass ; the writing presenting the tele-
scope to the Doge; and the first observations of
the satellites of Jupiter. A portrait of the great
philosopher, from a painting which represents him
at the age of forty, taken in 1604, is prefixed.
<l By favour of the University, there have also
been published two other works, one containing
all the notices of the studies at Padua in 1592,
the other proving which was the house inhabited
by Galileo and the place in which he made his
1642] TERCENTENARY OF GALILEO 421
astronomical observations. The ancient Academy
of Padua, among whose founders Galileo is
numbered, has issued a publication in which are
collected several works dedicated to his memory ;
and the students of the University have sought
to perpetuate the remembrance of this festival by
the publication of a 'unique number/ bringing
together all the documents relating to the sojourn
of Galileo in Padua. These publications will serve
as suitable memorials of a great and most interesting
celebration/'
BIBLIOGRAPHY
IN the last years of his life, Galileo was anxious to have
a complete edition of his works brought out in Latin, so
as to be accessible to students of all nations. As we
have already had occasion to show, this was impossible
in Italy, owing to the most stringent orders of the Pope
against the publication of any of his works, edita et edenda
— an order which was only partially relaxed many years
after his death. Thus, we have seen incidentally that in
February 1635, Fra Fulgenzio Micanzio was prohibited by
the local Inquisitor from bringing out in Venice a reprint
of the treatise " On Floating Bodies," which does not in
any way relate to the Copernican doctrine.
As, then, the presses of Italy were closed against him,
Galileo had to look abroad for a publisher. In this way
negotiations were opened, first about 1635, with Pierre
Carcavi, a distinguished mathematician and litterateur of
Paris, on the occasion of his visit to Florence ; and two
years later, with the Elzevirs of Leyden, through the
intermediary of Micanzio in Venice. But, after much
correspondence, and the translation into Latin of many
pieces, these attempts fell through, one after the other,
and for no reason that we can now know.
Von Gebler, who is usually very accurate, says (p. 281,
"Galileo and the Roman Curia") that before August 1636,
the Dialogues of 1632 had been translated into English, to
the great delight of their author. If by this he means
published, he must be mistaken, for the first English
translations of the famous Dialogues and a few other
pieces printed and published in England were those of
424 BIBLIOGRAPHY
Thomas Salusbury in 1661-65, as noted in the " List of
Works Consulted " which is appended to this bibliography.
Galileo does not appear to have had any regular corre-
spondents in England, for, amongst the thousands of
letters in his Carteggio^ there exists only one from George
Fortescue1; but Hobbes, Milton, and, probably, other
English travellers, were, of course, able to give him the
gratifying news that his works were largely read in
England ; as, indeed, we now know from other indications.
Thus, Tobie Matthew, writing to Bacon from Brussels,
2ist April 1616, refers to the polemical letter of 1613 to
Castelli; and in another letter, dated I4th April 1619, he
introduces a Mr Richard White as a gentleman lately
returned from Florence, where he had seen Galileo, and
had obtained copies of his works, "On the Tides,"
" Sidereus Nuncius," " On Sun-Spots," and " On Floating
Bodies" — all of which the writer was sending on to
Bacon.2
Amongst the British Museum MSS. there are early
English translations of two of Galileo's works as follows : —
Add. MSS. 23, 139. — "Of the profit which is drawen
from the Art Mechanique and its Instruments ; A Tract
of Sign Galileo Galilei, Florentine. Raptim ex Italico
in Anglicum sermonem transfusum. Novemb. H, 1636,
by Mr Robert Payen." This is evidently a translation of
the "Scienza Meccanica" of 1594.
Harl. MSS. 6320.—" The Dialogues of Galileus, etc.,
upon the two Greatest Systems of the World, etc., with a
dedicatory preface, and an explanatory introduction To
the Discreete Reder." This MS. bears no date, only the
initials W. N., which are supposed to be those not of the
translator but of a former owner.8
1 Dated London, i5th October 1629. Fortescue wrote, amongst
other things, the "Feriae Academicae" (London, 1630), a series of
essays in elegant Latin, in one of which, " Astrologorum Concessus,"
Galileo and his friends, Clavio and Griemberger, are the speakers.
3 Bacon must also have heard a great deal about Galileo from his
Venetian correspondents, Paolo Sarpi and Fulgenzio Micanzio.
3 Galileo may have heard of this performance through Thomas
Hobbes, who was travelling in Italy in 1635, and who then saw the
great Florentine. The latter probably alludes to Hobbes in his letter
BIBLIOGRAPHY 425
After Galileo's death, Viviani, then hardly twenty years
old, resolved to carry out what he knew to be the ardent
wish of his master, and at once set about collecting from
relatives, friends, and disciples of the great dead, books,
MSS., and documents, relating in any way to his subject.
His intention was to publish the works in two languages
in parallel columns, that is to say, to give a Latin version
of those pieces first printed in Italian, and an Italian
version of those which originally appeared in Latin. The
collection was to be preceded by a comprehensive Life,
of which he has left us the design — " Life of Galileo," in 3
books — I. "From Birth to Invention of the Telescope";
II. "From the Telescope to Death"; III. "Habitudes,
Maladies, Sayings and Pastimes, Doctrines and Unwritten
Opinions, Friends and Scholars, Letters of Distinguished
Men to Galileo, Illustrations from his Printed Works."
This was to be followed by the Works, in 4 volumes, 4to,
in Latin and Italian, in double columns — I, " Astronomical
Works"; II. "Mechanical, Physical, Mathematical Works" ;
III. "Suspected and Prohibited Works"; IV. "Posthumous
Works, Collectanea, and Letters." A frontispiece (copper-
plate) was to be prefixed to all the volumes ; and portraits
of Galileo, Salviati, and Sagredo, were to be given.1
Owing to ill-health and various obstacles, chief among
them being the ecclesiastical prohibition of 1633, and the
still active opposition of the Jesuits, Viviani was never
able to carry out his great design ; but through all his life
of ist December 1635 to Micanzio, in which he says : — " In the last
few days I have had many visitors from over the mountains, and
amongst them one of the principal men of England, who told me that
my unfortunate Dialogues had been translated into that language."
This would fix the date of the above MS. at some time prior to the
middle of 1634, the date of Hobbes' departure on his travels. It
would also go to show that the translator was known to Hobbes.
Who was he ? I suggest this as a problem for " Notes and
Queries."
1 A short and very inaccurate biography, intended, probably, as a
rough draft of the contemplated Life, was drawn up by Viviani in the
form of a letter to Prince Leopoldo (afterwards Cardinal) de Medici,
dated 29th April 1654. It was published for the first time in Salvini's
" Fasti Consolari dell' Accademia Fiorentina," Florence, 1717-
426 BIBLIOGRAPHY
he diligently added to his collection of the printed and
MS. remains of his revered master.
Meanwhile an edition of Galileo's works appeared in
Bologna, in 1655-56, in 2 volumes, ^.to.1 Although
Viviani supplied the editor with much interesting material
hitherto unpublished, this is little more than a reproduction
of pieces already printed separately, with two notable
exceptions, viz. the polemical letter of 1615 to the Grand
Duchess Cristina di Lorena, and the Dialogues of 1632.
At Viviani's death (22nd September 1703), his fine
library went by will to the Hospital of Santa Maria in
Campo, Florence, and his great collection of Galilean
remains, the result of sixty years' searching, passed into
the hands of his nephew and heir, the Abbe Jacopo
Panzanini. This man, ignorant or regardless of the value
of his inheritance, made no attempt to utilise it, or to add
to it, as he might easily have done in those days. He
appears to have stowed the books and MSS. away in
presses or cupboards, allowing, however, the use of them
to students, some of whom, it is sad to say, forgot to
return what they had borrowed. Thus, Tommaso Buona-
venturi and Benedetto Bresciani, the editors of the first
Florentine edition, were great sinners in this respect.2
Their sin would, perhaps, not be so great had they made
better use of the materials placed at their disposal. There
is no order or method in the arrangement, and their work
is in other respects imperfect ; not only are the Dialogues
of 1632 and other pieces banned by the Inquisition
omitted, but some of those which are included are not
published in their integrity.
A better edition was brought out in Padua in I/44.3
Here also many pieces, already published, are omitted,
but the Dialogues of 1632 are given "with ecclesiastical
permission/' The editor, however, appears to have been
1 " Opere di Galileo, etc. In questa nuova editione insieme
raccolte, e di varii trattati non pm stampati accresciute."
2 " Opere di Galileo, etc. Coll' Aggiunta di vari trattati non piu
dati alle stampe." 3 vols. 4to. Florence, 1718.
3 "Opere di Galileo, etc, Accresciute di Molte Cose Inedite."
4 vols. 4to. Padua, 1744.
BIBLIOGRAPHY 427
obliged to prefix some saving clauses. The sentence of
1633 and Galileo's abjuration are reprinted, and are
followed by a declaration that the theory of the double
motion of the earth can and must be regarded only as a
mathematical hypothesis to facilitate the explanation of
certain natural phenomena. Then follows, for greater
security I suppose, Father Calmet's essay,1 in which the
Scriptural passages relating to the order of the world
ought, presumably, to be interpreted in the orthodox
fashion. As a matter of fact, however, the learned Father's
line of argument differs little from that of Galileo. He
seeks to show that the Bible does not propound any
astronomical system whatever; that if it does, it is the
popular cosmography of the Hebrews, from which it often
borrows expressions or images, but without guaranteeing
their accuracy ; that this cosmography is scientifically
untenable, and, moreover, differs essentially from that of
Ptolemy and the Peripatetics, and, therefore, people have
no right to invoke the Scriptures in support of the latter.
In fact, in the first centuries of Christianity, the Ptolemaic
doctrine of a round earth was held by some fanatics as
heretical, being opposed to the Hebrew and Scriptural
presentment of the earth as a plain surface over which
the heavens are spread in tent fashion.
A few years after the appearance of the Paduan
edition an accident befell the Galilean papers, from which
they, or rather what remained of them, were saved by, so to
speak, a miracle. The story is told by Professor Giovanni
Targioni-Tozzetti in his "Notizie degli Aggrandimenti
delle Scienze Ffsiche in Toscana" (Florence, 1780), and
by Nelli in his " Vita e Commercio Letterario di Galileo
Galilei J> (Lausanne, 1793).
In the spring of 1750, the celebrated Dr Giovanni
Lami, Keeper of the Riccardian Library in Florence,
going one day, according to his wont, to lunch with some
friends in the suburbs (at the "Osteria del Ponte alle
Mosse "), and passing through the market-place, suggested
1 "Dissertation sur le Systeme du Monde des Anciens He'breux."
Paris, 1720.
428 BIBLIOGRAPHY
to Gio. Battista Nelli (his companion) to procure a Bologna
sausage from the shop of Cioci, a pork-butcher then noted
for his wares. Nelli did so, and brought away the purchase
wrapped in an old MS. paper. Arrived at the tavern, he
called for a plate, and, unrolling his sausage, remarked
that the wrapper was a letter in Galileo's handwriting!
Suppressing his surprise as well as he could, he cleaned
the paper and put it into his pocket, without saying a
word to Lami. After returning to the city, Nelli got rid
of his friend, and flew to the pork-seller's shop, where he
learnt that a servant, whom the proprietor did not know,
brought him from time to time similar writings which he
bought by weight as waste paper. Nelli purchased all
that he then had, and, after watching for several days the
return of the unknown domestic with another bundle, had
at last the good fortune to meet him, and to learn the
quarter whence the papers came. This was no other than
Viviani's house in Via delF Amore [now Via San Antonino]
then occupied by Carlo and Angelo Panzanini, nephews
and heirs of the Abbe, who died in 1733. After some
judicious enquiries Nelli found that it was the brothers
Panzanini themselves who were guilty of the atrocity of
selling from time to time bundles of these precious papers,
and with a little management he procured what remained
in their hands for the sum of eighty-eight scudi (about
£20). These comprised a great number of MSS. of
Galileo, Viviani, Torricelli, and Borelli, and a number of
mathematical instruments belonging to Viviani. At .the
same time he became the possessor of the emerald ring
which Prince Cesi gave to Galileo on his election as a
member of the Accademia dei Lincei in 1611, and a
collection of designs by the most celebrated architects
of Italy.
To this important acquisition so extraordinarily brought
about, Nelli added, in 1754, a number of portraits of
eminent mathematicians, forming part of the collection
made by Viviani, another part of which came, at about
the same time, into the hands of the astronomer, Perelli.
It would seem that the Panzaninis had sold these many
BIBLIOGRAPHY 429
years previously, besides a great number of Galileo's MSS.,
books full of marginal annotations in his autograph, and
letters from his correspondents. Most of these were
purchased, either directly from the Panzaninis, or from
third parties, by Felici, Cocchi, Capponi, Nelli (in 1754),
and more recently by Campori. Ultimately all these
collections were acquired by the Tuscan Government, and,
with the nucleus which already existed, gathered from
Florentine libraries and from other public and private
sources, now form the grand collection of Galilean books
and MSS. in the Biblioteca Nazionale in Florence. It is
comprised in some 303 large volumes, and arranged under
five heads or classes as follows : —
1. Before the time of Galileo 10 vols.
2. MSS. of Galileo . . 86 vols.
3. Contemporaries of Galileo 1 1 vols.
4. Disciples of Galileo . . 148 vols.
5. After the time of Galileo 48 vols.
Besides this collection, Professor Favaro, the learned
Director of the new edition of Galileo's Works now in
course of publication, has catalogued over 1200 MSS.
and documents relating to Galileo (many of which are
his autographs) dispersed in the public and private libraries
of Europe.1
Notwithstanding the zeal and industry of collectors,
many of Galileo's papers and letters are missing. Some
of these are mentioned in pp. 37, 120, 156, 194, ante,
to which we may now add the loss of his later notes on
(i) "The Mechanical Problems of Aristotle," and (2) "On
the Movements of Animals," on which he was engaged
only a short time before his fatal illness. No doubt many
valuable papers were lost through the sordid action of the
Panzaninis, and Viviani tells us that others were destroyed
by Galileo's grandson, Cosimo, who conceived that in so
1 " Material! per un Indice dei MSS. e Document! Galileiani non
posseduti dalla Biblioteca Nazionale di Firenze." Raccolti per cura
di Antonio Favaro, Venice, 1894.
43o BIBLIOGRAPHY
doing he was offering up a proper sacrifice before devoting
himself to the life of a missionary priest1
During the years 1808 to 1811 a new edition of
Galileo's Works appeared in Milan, in 13 volumes, 8vo, of
which it is only necessary to say that the first 12 volumes
are a simple reprint of the Paduan edition, whilst the
1 3th and last contains matter not found in that collection,
it is true, but yet nothing that had not been published
before. Another edition, and the worst of all, appeared
in Milan in 1832, and forms volumes xx. and xxi. of
Bettoni's " Biblioteca Enciclopedica Italiana."
The more recent editions of Alberi and Favaro are
noted in detail in the "List of Works Consulted"
subjoined to this notice.
A bibliography would not be complete without a
reference to the extraordinary collection of forged docu-
ments, with which the French Academy of Sciences was
convulsed in the years 1867-1869. They were acquired
by Michel Chasles, a member of the Academy, and by
him presented to that body in batches. They consisted
of letters and documents bearing the names of Galileo,
Viviani, Pascal, Newton, Milton, Huygens, Louis XIV.,
and other well-known persons of the period; and they
went to show, amongst other startling things, (i) that
Pascal borrowed from Galileo the idea of universal
gravitation, and that Newton in his turn borrowed from
both, without acknowledgments ; and (2) that Galileo's
blindness was feigned in order to induce the Inquisition
authorities to relax their surveillance ; and that he really
became blind only a short time before death.
The briefest rteumt of these papers will suffice here,
as the curious reader will find them, and the discussions
to which they gave rise, fully reported in the Comptes
1 Professor Favaro thinks there is little or no foundation for this
charge, and concludes, after reviewing the evidence, that if Cosimo
did burn any papers of his grandfather, they were such as were of no
importance, and of which Viviani already had copies, or, and this is
the more likely, they were his own youthful lucubrations of which his
later and ascetic temper could not approve.
BIBLIOGRAPHY 431
Rendus for the years mentioned, and the history of the
forgeries in Bordier and Mabille's " Une Fabrique de
Faux Autographes, ou R6cit de 1' Affaire Vrain Lucas,"1
It would appear from these documents that in the last
years of his life, Galileo discovered a satellite of Saturn
and made other astronomical observations, which, with
some found in Kepler's MSS. (which had come into
Galileo's hands), exceeded in extent and accuracy the
subsequent observations of Cassini, Bradley, and Pound,
and of which Newton availed himself in 1725, in the third
and perfected edition of his " Principia." Furthermore :
Galileo had deduced theoretically, from Kepler's Second
Law, that the reciprocal attraction of the heavenly bodies
ought to be in the inverse ratio of the squares of the
distances. He communicated this discovery, as also his
latest astronomical observations and those of Kepler, to
Pascal, and upon these materials the latter based his
Celestial Mechanics, including the calculation of the
planetary masses, and wrote a treatise on the subject, a
copy of which he sent to Galileo in 1641.
In 1652, Boyle put Pascal in communication with
Newton [then of the mature age of ten years !], and in
1654, Pascal communicated to Boyle and Newton the
aforesaid observations of Galileo and Kepler, together
with his own Celestial Mechanics, and calculations of the
planetary masses. In 1687, Newton published (in the
" Principia ") Pascal's work as his own, but spoilt it by
the employment of data less accurate than those of
Galileo and Kepler, of which, indeed, he made no use
until 1725 (as stated above), or seventy-one years after
receiving them ; and then, instead of mentioning Galileo
and Kepler, to whom he was really indebted, he quoted
the work of later astronomers who had arrived at similar
results. The communications made to Newton by Pascal,
and Newton's usurpation of them were facts known to
many scientific men in France and England ; but nothing
was said about them until Newton had committed a
1 Paris, 1870. On the forgeries of Vrain Lucas is founded
Alphonse Daudet's novel, " L'lmmortel,"
432 BIBLIOGRAPHY
further imprudence. In a letter to Huygens he appears
to have used some disdainful language abouf Pascal;
Huygens thereupon brought the whole matter before the
French Academy of Sciences, that jealous body com-
plained to Louis XIV., who in his turn complained to
James II. of England. The result was that Newton
withdrew his defamatory remarks, Louis XIV. expressed
his gratitude to Newton (to whom, strange to say, was
left all the glory which belonged to Pascal and Galileo),
and everybody was content! The affair was hushed up,
and soon entirely forgotten, until revived by the publication
of M. Chasles' wondrous " find." So much for the Galileo-
Pascal-Newton story.
As regards the fable of Galileo's blindness, it would
seem, from his letters and those of Viviani, Milton, and
others, that his sight became enfeebled only in 1637-38 ;
that up to September 1641 he was able to read and write,
and only complained of fatigue of the eyes ; and that he
became totally blind only towards the end of 1641, that is,
a few weeks before death. Galileo, who, probably, never
wrote a line in French, is made to say, in a letter of
28th November 1639, to Louis XIII. of France: —
"Du reste je veux bien assurer Vostre Majest6 que,
quoique ce soit pour moy une grande privation de ne
pouvoir continuer mes observations astronomiques, je
commence a my resigner, et je m'estime encore heureux
qu'a mon age, et apres tant de tribulations, je puisse encore
lire et escrire, ce qui est pour moy une grande satisfaction.
Quant a certains propos que des gens tiennent et font
circuler a cet egard, je ne cherche nullement a les
d6mentir, d'autant plus que c'est un moyen d'estre
moms obsed£ par mes ennemis, c'est & dire, par les
Inquisiteurs, qui ne cessoint de me faire surveiller. Nous
nous sommes mesme servi du pr^texte de c<£cit£ pour
qu'on me laisse plus en repos et & moy mesme."
As to this fable, there are two well-established facts,
which would seem to lend it some little support — (i) It
is certain that Galileo's blindness was due to glaucoma.
(2) In recent years a letter of Alberto Galilei (nephew) to
BIBLIOGRAPHY 433
Galileo, dated igth April 1640, has been brought to light,
from which it would appear that towards the end of
1639 Galileo had recovered somewhat the use of his eyes,
Professor Favaro, however, says (and there can be no better
judge) that, in all probability, the passage is either an
equivoque, or a question of being able to distinguish, more
or less, the day from the night.1
1 " Galileo e Suor Maria Celeste," p. 221.
LIST OF THE PRINCIPAL WORKS CONSULTED
IN PREPARING THE PRESENT VOLUME.
Le Opere di GALILEO GALILEI, prima edizione completa,1 con-
dotta sugli autentici manoscritti palatini, e dedicata a S, A. I. e R.
Leopoldo II granduca di Toscana, — Firenze, societa editrice fioren-
tina^ 1 842- 1856. Tomi XV e uno di supflemento.
Patrono dell' edizione : S. A. I. e R. il granduca LEOPOLDO II.
Direttore : EUGENIO ALBERT.
Coadiutore : CELESTINO BIANCHI, per i primi sette volumi.
Tomo primo (1842).
Lettera dedicatoria a S. A. I. e R. il granduca Leopoldo II,
patrono dell' edizione.
Prefazione generale.
Dialogo dei due massimi sistemi del mondo, tolemaico e
copernicano.
Tomo secondo (1843).
Prefazione con elenco ragionato degli oppositori al sistema
copernicano.
Lettera di GALILEO a lacopo Mazzoni, del 30 maggio 1597.
Lettera di GALILEO al p.e Benedetto Castelli del 21 dicembre
1613.
Lettera di GALILEO a monsignor Dini del 16 febbraio 1614
ab inc.
Lettera di GALILEO al medesimo del 23 marzo 1614 ab inc.
Lettera di GALILEO alia granduchessa Cristina di Lorena
del 1615.
Lettera di GALILEO a Francesco Ingoli, nella primavera
del 1624.
Esercitazioni filosofiche di ANTONIO Rocco intorno al dialogo
dei massimi sistemi.
1 This is by no means a complete, or even, so far as it goes, an accurate,
presentation of Galileo's works and writings. This can be seen by comparing
it with Favaro's national edition, now in course of publication, and of which
twelve out of twenty volumes have already appeared.
436 PRINCIPAL WORKS CONSULTED
Postille di GALILEO alle suddette esercitazioni.
Discorso di LODOVICO DELLE COLOMBE contro al moto della
Terra.
Postille di GALILEO al suddetto discorso.
Discorso sopra il flusso e reflusso del mare.
Tomo terzo (1843).
Trattato della sfera o cosmografia.
Sidereus Nuncius.
Lettere intorno alle apparenze della Luna.
De phaenomenis in orbe Lunae etc., auctore JULIO CESARE
LA GALLA.
Postille di GALILEO all' opera suddetta,
Lettere intorno alle macchie solari.
Tomo quarto (1844).
Ai lettori.
De tribus cometis anni 1618 disputatio astronomica, publice
habita in collegio romano societatis Jesu ab uno ex patribus
eiusdem societatis.
Discorso delle comete di MARIO GUIDUCCI.
Libra astronomica ac philosophica etc., auctore LOTHARIO
SARSIO sigensano [HORATIO GRASSIO salonensi],
Postille di GALILEO alia Libra astronomica.
II Saggiatore di GALILEO.
Ratio ponderum librae ac simbellae etc., auctore LOTHARIO
SARSIO.
Postille di GALILEO alia suddetta opera.
Tomo quinto (Parte prima, 1846).
Alcuni esemplari hanno la prima parte del tomo quinto, e la prima
sezione della seconda in lingua italiana, altri in latino.
Prefazione di EUGENIO ALBERI nella quale si dimostra che
tutti i lavori condotti da Galileo intorno i Satelliti di Giove, e
che da due secoli si reputavano perduti, esistono fra i manoscritti
galileiani della i. e r. biblioteca palatina de' Pitti.
Tavole dei moti medi de'Satelliti di Giove istituite da GA-
LILEO ecc.
Osservazioni originali e calcoli intorno i Satelliti di Giove.
PRINCIPAL WORKS CONSULTED 437
Giustificazioni delle lacune che si riscontrano tra le osserva-
zioni di GALILEO intorno i Satelliti di Giove.
Calcoli ed effemeridi.
Notae conclusione.
(Parte seconda, 1853).
Lavori del padre RENIERI intorno ai Satelliti di Giove.
Le operazioni astronomiche di GALILEO.
Frammenti di tre lezioni di GALILEO intorno la Stella nuova
del 1604.
Frammenti astronomici di GALILEO.
KEPLERI Dissertatio in Nuncium sidereum.
KEPLERI NTarratio de observatis a se Satellitibus Jovis.
KEPLERI Periochae ex introduction in Martem.
Lettera del p. FOSCARINI sul sistema copernicano.
CAMPANELLAE Apologia pro Galilaeo.
Dissertazione del p. CALMET intorno alia cosmogonia degli
antichi,
Lettera di MARIO GUIDUCCI al p. Galluzzi intorno le comete.
KEPLERI Spicilegium ex trutinatore Galilaei.
Appendix ad spicilegium.
KEPLERI Admonitio ad bibliopolas.
Discorso di A. DE FILIIS sulle Macchie solari di Galileo.
Tomo ststo a decimo (1847-1853).
Contengono un avvertimento e 1'epistolario, composto di 1376
lettere, dal 1588 al 1642, diviso in due parti. La prima di due
volumi (VI e VII, 1847-1848) comprende le lettere di GALILEO
che sono 296. L'altra in tre volumi (VIII, IX, e X, 1851-1853)
che coruprende le lettere a lui dirette^ in numero di 931, e fra
terzi a lui relative, che sono 149.
Tomo undecimo (1854),
Avvertimento all1 opera seguente.
Sermon es de motu gravium di GALILEO.
Delia scienza. meccanica di GALILEO.
NTote e proposizioni intorno le meccaniche di VINCENZO
VIVIANI*
Trattato di fortificazione di GALILEO con avvertimento.
438 PRINCIPAL WORKS CONSULTED
Le operazioni del compasso geometrico e militare di GALILEO
con avvertimento.
Usus et fabrica circini proportionis etc, opera et studio BAL-
THASARIS CAPRAE.
Difesa di GALILEO contro alle calunnie del Capra.
Tomo duodecimo (1854).
Avvertimento.
Discorso di GALILEO delle cose che stanno in su Pacqua o
che in quella si muovono.
Lettera di TOLOMEO NOZZOLINI a monsignor Marzimedici
nella quale si pronmovono alcune difficolta intorno al libro di
Galileo.
Lettera di GALILEO al Nozzolini in risoluzione delle accennate
difficolta.
Discorso apologetico di LODOVICO DELLE COLOMBE intorno al
suddetto discorso dei galleggianti di Galileo.
Considerazioni di VINCENZO DI GRAZIA intorno al medesimo
discorso.
Risposta di GALILEO, sotto nome del p. Castelli, alle oppo-
sizioni di Lodovico delle Colombe e di Vincenzo di Grazia.
Note al discorso dei galleggianti.
Esperimenti del cav. Gio. BATTA VENTURI intorno ai gal-
leggianti.
Tomo tredicesimo (1855).
Avvertimento.
Discorsi e dimostrazioni matematiche intorno a due nuove
scienze attinenti alia meccanica ed ai movimenti locali ; altri-
menti detti " Dialoghi delle nuove scienze."
Tomo quattordicesimo (1855).
Illustrazioni del VIVIANI e del GRANDI ai Dialoghi delle
nuove scienze.
Trattato delle resistenze principiato da VINCENZO VIVIANI
per illustrare le opere di Galileo, compiuto e riordinato dal p.
GXJIDO GRANDI.
Note del p. GRANDI al trattato del moto naturalmente
accelerato.
Scienza universale delle proporzioni, spiegata da GALILEO
nella quinta giornata, con nuovo ordine distesa dal VIVIANI.
PRINCIPAL WORKS CONSULTED 439
Componimenti minori e frammenti diversi in materie scien-
tifiche di GALILEO.
La bilancetta ecc. di GALILEO.
Note del MANTOVANI, del CASTELLI, e del VIVIANI alia
bilancetta.
Parere sopra una macchina per alzare acqua.
Lettere intorno alia stima di un cavallo.
Parere intorno all' angolo del contatto.
Considerazioni sopra il giuoco de3 dadi.
Risposta al problema : onde avvenga che V acqua a chl
v' entra appaia prima fredda e poi calda pih dell' aria temperata.
Parere su di una macchina da pestare.
Pensieri sulla confricazione.
Awertenza intorno al camminare del cavallo.
Theorica speculi concavi sphaerici.
Problemi vari.
Pensieri vari.
DelF oriuolo a pendolo, lettera di VINCENZO VIVIANI.
Tomo quindicesimo (1856).
Due lezioni di GALILEO intorno alia figura, sito, e grandezza
delP Inferno di Dante precedute da un avvertimento degli editori.
Postille e correzioni all' Orlando furioso precedute da un
avvertimento degli editori.
Considerazioni alia Gerusalemme liberata.
Due lettere a Francesco Rinuccini nelle quali si paragona il
Tasso con TAriosto,
Discorso di GIUSEPPE ISEO sopra il poema di M. Torquato
Tasso.
Capitol o in biasimo della toga.
Quattro sonetti.
Abbozzo di una commedia.
Racconto istorico della vita di Galileo scritto da VINCENZO
VIVIANI.
Bibliografia Galileiana.
Aggiunte e correzioni a diversi volumi della collezione.
Suppkmento (1856).
Avvertimento.
E. ALBERI. Esame della biografia di Galileo scritta da F.
ARAGO,
440 PRINCIPAL WORKS CONSULTED
Lettere (186) inedite dirette a Galileo dal 1592 al 1641, fra
le quali a pag. ir una di GALILEO all' abate Giugni da Venezia,
ii giugno 1605.
Appendice relativa al processo di Galileo.
E. ALBERI. DelForologio a pendolo di Galileo e di due
recenti divinazioni del meccanismo da lui immaginato.
Due lettere importantissime di GALILEO, una relativa alia sua
condanna, 1'altra ai tentativi da lui fatti per la misura della
cicloide.
Le Opere di Galileo Galilei. Edizione Nazionale sotto gli
auspicii di S. M. il Re d'ltalia. — Direttore, Antonio Favaro.
Coadiutore letterario, Isidoro del Lungo. Assistente per la cura
del testo, Umberto Marchesini. — Consultori, V. Cerruti, A.
Genocchi (>J<). G. Govi (>f<). G. V. Schiaparelli. — Firenze, tip.
G. Barbera, 1890-1902. . . .
Volume Primo (1890). — luvenilia. — Theoremata circa cen-
trum gravitatis solidorum. — La Bilancetta. — Tavola delle pro-
porzioni delle gravita in specie de i metalli e delle gioie pesate
in aria e in aqqua. — Postille ai libri de sphaera et cylindro di
Archimede. — De motu.
Volume Secondo (1891). — Breve instruzione air architettura
militare. — Trattato di fortificazione. — Le Mecaniche. — Lettera a
lacopo Mazzoni. — Trattato della Sfera owero Cosmografia. —
De motu accelerate. — Frammenti di lezioni e di studi sulla nuova
Stella dell' ottobre 1604. — Consideration astronomica circa la
Stella nova delP anno 1604 di Baldesar Capra, con postille di
Galileo. — Dialogo de Cecco di Ronchitti da Bruzene in per-
puosito de la Stella nuova. — Del compasso geometrico e militare :
saggio delle scritture antecedenti alia stampa.— Le operazioni
del compasso geometrico e militare. — Usus et fabrica circini
cuiusdam proportions, opera et studio Balthasaris Caprae; con
postille di Galileo. — Difesa contro alle calunnie et imposture di
Baldessar Capra. — Le matematiche nelP arte militare.
Volume Terzo. Parte prima (1892). — Sidereus Nuncius. —
loannis Kepleri Dissertatio cum Nuncio Sidereo. — Martini
Horky Brevissima peregrinatio contra Nuncium sidereum. —
Quatuor problematum contra Nuncium sidereum confutatio per
loannem Wodderbornium. — loannis Kepleri Narratio de obser-
vatis a se quatuor lovis satellitibus. — loannis Antonii Roffeni
Epistola apologetica contra peregrinationem Martini Horkii. —
PRINCIPAL WORKS CONSULTED 441
Dianoia astronomica, optica, physica, auctore Francisco Sitio;
con postille di Galileo. — Di Ludovico delle Colombe contro il
moto della terra; con postille di Galileo, — Nuntius Sidereus
Collegii romani. — De lunarium montium altitudine problema
mathematicum, — lulii Caesaris La Galla De phaenomenis in
orbe lunae novi telescopii usu nunc iterum suscitatis ; con postille
di Galileo.
Volume Quarto (1894). — Diversi fragmenti attenenti al trattato
delle cose che stanno su 1'acqua. — Discorso intorno alle cose
che stanno in su Tacqua o che in quella si muovono. — Considera-
zioni di Accademico Incognito; con postille e frammenti della
risposta di Galileo, — Operetta intorno al galleggiare dei corpi
solidi di Giorgio Coresio. — Errori di Giorgio Coresio nella sua
operetta del galleggiare della figura raccolti da d. Benedetto
Castelli. Con correzioni ed aggiunte di Galileo. — Lettera di
Tolomeo Nozzolini a monsignor Marzimedici arcivescovo di
Firenze. — Lettera a Tolomeo Nozzolini. — Discorso apologetico
di Lodovico delle Colombe. — Consider azioni di Vincenzio di
Grazia, — Frammenti attenenti alia scrittura in risposta a Lodovico
delle Colombe e Vincenzio di Grazia. — Risposta alle opposizioni
di Lodovico delle Colombe e di Vincenzio di Grazia contro al
trattato delle cose che stanno su Tacqua o che in quella si
muovono.
Volume Quinto (1895). — Apellis latentis post tabulam tres
epistolae de maculis solaribus. — Apellis latentis post tabulam de
maculis solaribus et stellis circa lovem errantibus accuratior
disquisitio; con postille di Galileo. — Istoria e dimostrazioni
intorno alle macchie solari e loro accidenti, comprese in tre
lettere scritte a Marco Velseri. — Frammenti attenenti alle lettere
sulle macchie solari. — Lettera a D. Benedetto Castelli. — Lettere
a mons. Piero DinL — Lettera a madama Cristina di Lorena
granduchessa di Toscana. — Considerazioni circa Topinione coper-
nicana. — Discorso del flusso e reflusso del mare. — Francisci
Ingoli De situ et quiete Terrae disputatio. — Proposte per la
determinazione della longitudine.
Volume Sesto (1896). — De tribus cometis anni MDCXVIII
disputatio astronomica publice habita in Collegio Romano
Societatis Jesu ab uno ex patribus eiusdem Societatis. — Discorso
delle co mete, con alcuni frammenti ad esso attenenti. — Lotharii
Sarsii Sigensani Libra astronomica ac philosophica ; con postille
di Galileo.— Lettera di Mario Guiducci al P. Tarquinio Galluzzi.
442 PRINCIPAL WORKS CONSULTED
— II Saggiatore.— Lotharii Sarsii Sigensani Ratio ponderum et
simbellae; con postille di Galileo. — Lettera a Francesco Ingoli
in risposta alia Disputatio de situ et quiete terrae. — Scritture
concernenti il quesito in proposito della stima d'un cavallo. —
Scritture attenenti all' idraulica.
Volume Settimo (1897). — I due massimi sistemi del mondo.
— Frammenti attenenti al dialogo sopra i due massimi sistemi
del mondo. — Dal libro di G. B. Morin "Famosi et Antiqui
Problematis de Telluris Motu vel Quiete," con le note di
Galileo. — Esercitazioni filosofiche di A. Rocco, con postille di
Galileo.
Volume Ottavo (1898). — Le nuove scienze. — Della forza della
percossa. — Sopra le difinizioni delle proporzioni d'Euclide. —
Frammenti attenenti ai discorsi e dimostrazioni matematiche
intorno a due nuove scienze. — Le operazioni astronomiche.—
Lettera al Principe Leopoldo di Toscana in proposito del cap.
L. del " Litheosphorus " di Fortunio LicetL — Frammenti attenenti
alia lettera al Principe Leopoldo di Toscana.
Scritture di data incerta.
A proposito di una macchina con gravissimo pendolo adattato
ad una leva. — A proposito di una macchina per pestare — Di
alcuni effetti del contatto e della confricazione. — Sopra le scoperte
de i dadi.— Intorno la cagione del rappresentarsi al senso fredda
o calda la medesima acqua a chi vi entra asciutto o bagnato. —
Problems — Nell' arte navigatoria. — Frammenti geometrici.
Volume Nono (1899). — La figura, sito, e grandezza del-
ITnferno di Dante. — Considerazioni al Tasso. — Postille air Ariosto.
— Argomento e traccia d'una commedia. — Poesie e Frammenti.
— Canzone di Andrea Salvador! per le Stelle Medicee, scritta e
corretta di propria mano da Galileo. — Saggio di alcune esercita-
zioni scolastiche di Galileo.
Volume Decimo (1900) — Carteggio, 1574-1610.
Volume Undecimo (1901). — Carteggio, 1611-1613.
Volume Duodecimo (1902). — Carteggio, 1614-1619.
In course of publication.
Volume Decimoterzo. — Carteggio, 1620-1628.
Volume Decimoquarto. — Carteggio, 1629-1632.
Volume Decimoquinto. — Carteggio, 1633.
Volume Decimosesto. — Carteggio, 1634*1636.
PRINCIPAL WORKS CONSULTED 443
Volume Decimosettimo. — Carteggio, 1637-1638.
Volume Decimottavo. — Carteggio, 163 9-1 642.*
Volume Decimonono. — Document!.
Volume Ventesimo. — Indici.
Besides editing this splendid collection, which alone is a
monumental work, Professor Favaro has written considerably
over one hundred papers, essays, and detailed studies, each
illustrative of some point in the life and writings of Galileo.
Some of these have been published in book form, but far the
greater part is scattered through the journals of learned societies
in Italy, dating back to 1878. Fortunately for the student, much
of the information they contain is reproduced in the numerous
(historical and critical) introductions and notes which enrich the
new national edition of Galileo's works and correspondence. In
the following list we give a few as of general interest, besides
which some other papers by the same author will be found
quoted in the body of our work.
FAVARO, PROF. ANTONIO. "Galileo e lo Studio di Padova,"
2 vols. Florence, 1883.
"Scampoli Galileiani." 12 Series (Atti e Memorie della
Accademia di Scienze^ Lettere\ ed Arti in Padova).
1886-1897.
" Document! Inediti per la Storia dei Manoscritti Galileiani
nella Biblioteca Nazionale di Firenze." Rome, 1886.
" Miscellanea Galileiana Inedita : Studi e Ricerche "
(Memorie del .R. Istituto Veneto di Scienze, Lettere, ed
Aril). 1887.
" Galileo Galilei e Suor Maria Celeste." Florence, 1891.
" Nuovi Studi Galileiani >; (Memorie del R. Istituto Veneto
di Sdenze^ Lettere^ ed Arti). 1891.
" Galileo ed il suo Terzo Centenario Cattedratico nelP
Universita di Padova" (Natura ed Arte). Milan, 1893.
The following items are arranged in chronological order,
VIVIANI, VINCENZIO. " Racconto Istorico della Vita di Galileo."
Florence, 1654 (printed in vol. xv. of Alb&ri's Edition,
quoted above).
1 The Carteggio contains considerably over 4000 letters from, to, and
concerning, Galileo, of which 420 are Galileo's.
444 PRINCIPAL WORKS CONSULTED
SALUSBURY, THOMAS. " Mathematical Collections and Transla-
tions," 2 vols. London, 1661 and 1665.
Contains following works of Galileo : —
(1) " On the System of the World."
(2) "Epistle to the Grand Duchess, Mother, Concerning the Authority
of Scripture in Philosophical Controversies."
(3) " Mathematical Discourses and Demonstrations touching Two
New Sciences, Pertaining to Mechanics and Local Motions."
(4) " On Mechanics, with some Additional Pieces."
(5) " Discourse on Natation."
Note.— Part II. of the Second Volume contains a "Life of Galileo," in five
books. Most of the copies of this part were destroyed in the Great
Fire of London, and very few perfect copies now exist ; that in the
British Museum is imperfect.
WESTON, THOMAS. " Mathematical Discourses Concerning Two
New Sciences relating to Mechanics and Local Motion,
in Four Dialogues, by Galileo Galilei, Chief Philosopher
and Mathematician to the Grand Duke of Tuscany.
With an Appendix Concerning the Centre of Gravity of
Solid Bodies." Done into English from the Italian.
London, 1730.
NELLI, Gio. BATISTA CLEMENTE. "Vita e Commercio
Letterario di Galileo Galilei," 2 vols. Lausanne, 1793.
MONTUCLA, J. F. "Histoire des Mathematiques depuis leur
Origine jusqu'a Nos Jours," 3 vols. Paris, 1802.
NEUMAYR, ANTONIO. "Illustrazione del Prato della Valle, ossia
della Piazza delle Statue di Padova," 2 parts. Padua,
1807.
VENTURI, GIAMBATISTA. "Memorie e Lettere Inedite Finora
o Disperse di Galileo Galilei," 2 parts. Modena, 1818-
1821.
MOLL, Dr G. " On the first Invention of Telescopes, collected
from the Notes and Papers of the late Prof. Van Swinden "
(Journal of the Royal Institution), London, 1831,
DRINKWATER-BETHUNE, J. E. " Life of Galileo. With Illustra-
tions of the Advancement of Experimental Philosophy."
(Library of Useful Knowledge). London, 1833.
POWELL, BADEN. " Historical View of the Physical and Mathe-
matical Sciences from the Earliest Ages to the Present
Times' (Lardner's Cabinet Cyclopaedia). London, 1834.
WHEWELL, WILLIAM. "History of the Inductive Sciences," 3
vols. London, 1837 ; or later editions.
PRINCIPAL WORKS CONSULTED 445
BREWSTER, SIR DAVID. "Martyrs of Science, or Lives of
Galileo, Tycho Brah£, and Kepler." London, 1841.
The Biography of Galileo first appeared in Lardner's Cabinet
Cyclopaedia— "Eminent Literary and Scientific Men of Italy,
Spain, and Portugal," 2 vols. London, 1835.
LIBRI, GUILLAUME. " Histoire des Sciences Math^matiques en
Italie depuis la Renaissance des Lettres jusqu'a la fin du
17 Si£cle," 4 vols. Paris, 1841.
" Essai sur la Vie et les Travaux de Galilee." Paris, 1841.
(Reprint from the Revue des Deux Mondes of isth
July 1841).
ROSINI, GIOVANNI. " Descrizione della Tribuna di Galileo in
Firenze." Florence, 1841.
ANTINORI, VINCENZO. "Notices sur La Tribune de Galilee."
Florence, 1843. (Reprinted 1861).
GRANT, ROBERT. " History of Physical Astronomy." London,
1852.
ARAGO, FRANCOIS. " Oeuvres Completes, de," edited by J. A.
Barral, 3 vols. Paris, 1855.
CHASLES, PHILAR&TE. " Galileo Galilei : Sa Vie, Son Proces, et
Ses Contemporains." Paris, 1862,
VARIOUS AUTHORS. " Nel Trecentesimo Natalizio di Galileo in
Pisa, 18 Febbraio 1864." Pisa, 1864.
PARCHAPPE, MAX. " Galilee, Sa Vie, Ses D&ouvertes, et Ses
Travaux." Paris, 1866.
PONSARD, FRANCOIS. " Galilee : Drame en Trois Actes en Vers."
Paris, 1867.
MARTIN, TH. HENfei. " Galilee : Les Droits de la Science, et la
Mdthode des Sciences Physiques." Paris, 1868.
FIGUIER, Louis. " Vies des Savants Illustres depuis 1'Antiquite
jusq'au 19 Si&cle," 4 vols. Paris, 1869,
ANONYMOUS (MRS OLNEY). " Private Life of Galileo. Compiled
Principally from his Correspondence and that of his
Eldest Daughter, Sister Maria Celeste, Nun in the Fran-
ciscan Convent of St Mathew in Arcetri." London, 1870.
NEWCOMB, SIMON. "Popular Astronomy. London, 1878."
CLERKE, A. M. "Biography of Galileo," in Ency. Brit Ninth
Edition. Edinburgh, 1879.
GEBLER, KARL VON. "Galileo Galilei and the Roman Curia."
(Mrs Sturge's Translation). London, 1879.
BALL, SIR R. S. " Story of the Heavens." London, 1885 ; or
later editions.
446 PRINCIPAL WORKS CONSULTED
WEGG-PROSSER, F. R. "Galileo and his Judges," London,
1889.
Govi, GILBERTO. "The Compound Microscope invented by
Galileo." (Journal of the Royal Microscopical Society}.
London, 1889.
BERRY, ARTHUR. "Short History of Astronomy." London,
1898.
GORI, PIETRO- "Le Preziosissime Reliquie di Galileo Galilei."
Florence, 1900.
NEWCOMB, SIMON. " The Stars." London, 1901.
INDEX
ABJURATION, GALILEO'S, 319
Accademia dei Lincei, 128, 132, 155,
428
del Cimento, 363, 392
della Crusca, 18, 29, 388
Acoustics, Galileo's experiments in,
363
Air, specific gravity of, 350
Apology, Galileo's, 157
Aproino, Paolo, advice re Dialogue
of 1632, 264; tribute to Galileo,
413
Arcetri, Galileo's villa at, 235 ;
memories of Galileo, 237 ; called
by Galileo " my prison," 386 ;
visited by Milton, 390
Archimedes and Hiero's crown, 14
Ariosto, 29, 286, 411
Aristotle, doctrines of, 8, 22-6, 56,
100, no, 123, 130, 137, 147, 150,
248 et s&q.> 350 et seq.t 370, 394,
411
Arrighetti, Andrea, 327, 333
Astrology, 54, 64
Aula Magna, Padua University, 57
BACON, FRANCIS, 53, 65, 424
Balance, Hydrostatic, 14
Barberini, Cardinal Antonio, 264,
292* 307, 333, 336, 380
Cardinal Francesco, 263, 270,
273, 278-80, 285, 300, 321-2, 380-1
Cardinal Maffeo. See Urban
VIII.
Beams, strength of, 360
Bellarmine, Cardinal, 51, 127, 155,
163, 166-9, 196, 275, 294, 314,
316
Bellosguardo, Galileo's villa at, 192
Bentivoglio, Cardinal, 287-8, 290,
321-2
Bibliography, Galilean, 423-33
Bologna-stone, phosphorescent, 391
Borgia, Cardinal, 321-2
Boscaglia, Professor, 149
Brane", Tycho, 36, 50, 55, 65, 394
Bridge with cycloidal arches, 22
Bruno, Giordano, burnt, 325
Burgi and pendulum-clock, 399
CACCINI, FATHER, denounces Gali-
leo, 152, 155; begs pardon, 159
the sculptor, 404, 406
Calculus, indivisible or fluxional, 120,
360
Calmet, Father, cosmography of the
Bible, 319, 427
Campanella, Tommaso, 226, 271
Canalisation schemes, 242
Capra, claims to be true inventor of
the geo. and mil. compass, 44-6
Cardan, the algebraist, and astrology,
65
Castelli, Benedetto, forbidden to teach
Coperhicanism, 9, 147 ; on the air
thermometer, 51 ; on Galileo's load-
stone, 6 1 ; on Saturn's ring, 113;
defends Galileo's treatise on Float-
ing Bodies, 144 ; Galileo's letter to,
149, 202, 215, 219, 226, 328, 379*
385> 400
Catenary curve, 359
Cavalieri, Bonaventura, 120, 401
Cesalpino, Andrea, 8
Cesi, Prince, 112, 128, 156, 200, 240
Chiaramonti, Scipione, 256, 343
Christmann, 103
Church of Santa Croce, 2 ; Galileo's
grave and monument in, 402-6 ;
sentence of Inquisition publicly read
in, 327
Santa Maria Novella, Galileo
denounced from pulpit of, 152
Ciampoli, Giovanni, 156, 272, 328,413
Cigoli, the painter, 7, 134
Clavio, Cristoforo, 19, 101, 127
Clock, pendulum, 396
Cohesion, molecular, 349, 360, 370
Comets of 1618, 181
Compass, geometrical andj military,
42,93, 119
Concords, musical, 363
447
448
INDEX
Constellations, the, 89
Conti, Cardinal, the Bible and science,
150
Copernicus, book suspended, 164
Coresio, Giorgio, 144
Cosimo II., Grand Duke, 44, 57, 62,
64,85,96, 117, 121, 123, 126, 128,
137, 158, 170, i77> 215, 404
Costoli, his statue of Galileo, 414
Cremonino, Cesare, 101
Cristina, Grand Duchess, 64, 149 ;
Galileo's letter to, 157, 204
Cycloid, the, 22, 401
DANTE'S " Inferno," 18
Da Vinci, Leonardo, 23, 88
De Dominis, Marc' Antonio, 325
D'Elci, Arturo, 144
Delle Colornbe, Lodovico, 144
Del Monte, Cardinal, 21, 127-8, 155,
170
Guidobaldo, 18, 20, 22, 28, 34
De Medici, Giovanni, his dredger,
26
De Medici, Leopoldo, 53, 96, 239,
392, 399, 4i6, 425
Marie, and the telescope, 99
Demi, Emilio, bust and statue of
Galileo, 193, 417
" De Motu Gravium," 24
De Noailles, Comte, 345, 347, 380
De Peiresc, Niccol6, 209, 345, 380
Descartes, 371, 390
Dialogue on the Two Systems of the
World, 214, 226; plan of, 243;
contents of, 248 ; value of, 261 ;
publication of and consequences,
263; sale of interdicted, 271 ; and
numerous references in subsequent
pages
Dialogues on the two new Sciences,
333, 344; publication of, 346;
contents of, 349 ; value of, 366
Digges, father and son, 62
Di Grazia, Vincenzio, 145
Diodati, EHa, 239, 339, 366, 372,
378, 388
Di Zuniga, Diego, book suspended,
164
Drebbel, Cornelius, 53, 209
' ' EPPUR si MUOVE," 324
FABRICIXJS, JOHANN, 132
Faculae (sun-spots), 131
Falling bodies, laws of, 25, 350
Favaro, Professor, 8, 13, 21, 28, 30,
41, 49, 109, 112, 168, 175, I93>
196, 288, 322, 418, 429, 430, 433,
Ferdinando I., Grand Duke, 13, 1 8,
20, 6 1, 64
Ferdinando II., 53, 206, 215, 225,
239, 242-3, 271,283, 309, 333, 375,
380, 3^4-5, 400, 403, 4i6
Firenzuola, Father, 294, 299, 300,
306
Floating bodies, discourse on, 136
Fogginis, the, sculptors, 405
Foscarini, his book prohibited, 164
Foscolo, Ugo, 192
GALILEI, family of the, i
Livia (Galileo's daughter), 73,
191. 195, 384
Livia (Galileo's sister), 33, 66,
68
Michelangelo, 33, 67, 99> 216,
384
Vincenzio (Galileo's father), 2,
I3> 33
Vincenzio (Galileo's son), 30, 73,
190, 197, 202, 215, 223, 231, 305,
340, 38?, 398
Virginia (Galileo's sister), 32, 66
Virginia (Suor Maria Celeste),
73, 190-336 passim; death, 338
Galileo, birth and early youth, 4 ;
youthful abilities, 6; enters on
medical studies at Pisa, 8 ; observa-
tions on the pendulum, 9; con-
structs the pulsilogia, 10 ; takes up
mathematics, 12 ; leaves Pisa for
Florence, 14; constructs hydro-
static balance, 14 j studies centre of
gravity in solids, 17, 22 ; lectures
on Dante's ''Inferno," 18; first
visit to Rome, 19 ; seeks a professor-
ship, 18-20 ; appointed professor in
Pisa, 21 ; discovers the cycloid, 22 ;
attitude towards Aristotle, 22 ;
writes "De Motu Gravium," 24;
experiments on falling bodies, 24 ;
resigns professorship, 26; literary
works, 28-32 ; sister's wedding
present, 32 j appointed professor in
Padua, 34 j early writings in Padua,
37; declares for Copernicanism, 319 ;
serious illness, 40 ; invents machine
for raising water, 42 ; constructs
geometrical and military compass,
42 ; appointment as professor re-
newed, 46 ; reputation spreads, 47 ;
at home, 47 ; friends, 49; constructs
air-thermometer, 51 j lectures on
new stars, 53; appointment as
professor renewed, 56 ; experiments
on loadstones, 59 ; on the sympa-
thetic needle telegraph, 63 ; rela-
tions with the Medici family, 64;
INDEX
449
Galileo [continued] —
dabbles in astrology, 64 ; family
affairs, 66 et seq.; constructs the
telescope, 74; appointed professor
for life, 78 ; first telescopic observa-
tions, 85 et seq.\ distributes his
telescopes, 98 ; reception of his
telescopic discoveries, 100; Horky's
attack, 106; observations on Saturn,
1 08; quits Padua for Florence, 1 16;
contemplated writings, 118; ap-
pointment at Court of Tuscany,
121 ; observes phases of Venus,
I23 t goes to Rome, 126 ; observa-
tions on Sun-spots, 128 ; on lunar
mountains, 133 ; the moon not
habitable, 134; discourse on float-
ing bodies, 136 ; gathering storms,
146 ; polemical letter to Castelli,
149 ; denounced to the Inquisition,
1 52 ; polemical letter to Grand
Duchess Cristina, 157 ; goes to
Rome, 158 ; admonished by
Cardinal Bellarmine, 163 j recalled
to Florence, 170 ; treatise on the
tides, 171 ; proposes his method for
rinding longitudes, 172 ; ironical
letter to Archduke Leopold, 179;
observations on comets, 181 ; writes
" II Saggiatore," 183; metaphysics,
1 88; his children, 190; moves to
Bellosguardo, 192 ; his eldest
daughter, 193 ; goes to Rome,
200, 204 ; Papal pension, 206 ;
explains and constructs the micro-
scope, 207 ; reply to Ingoli, 211 ;
begins his Dialogue on the two
systems of the world, 214 ; family
worries, 215 ; threatened loss of
salaried leisure, 225 ; goes to
Rome with the Dialogue, 229 ;
moves to Arcetri, 235 ; difficulty
as regards Imprimatur^ 239; plan
and contents of Dialogue, 243 ;
Dialogue denounced, 265 ; before
the Inquisition, 270 et seq. ; sentence
and abjuration, 312 et seq.; exiled
to Siena, 331 ; retirement to
Arcetri, 338; depression, 340;
behind the scenes, 342 ; publishes
Dialogues on the New Sciences, 346;
contents of Dialogues, 349 ; value
of, 366; resumes longitude pro-
posals, 372; moon's librations, 375;
blindness, 378 ; sad condition, 381 ;
moves into Florence, 382 ; makes
his will, 383 ; returns to his
"prison," 386; visited. by Milton,
388 ; Viviani joins him, 391 ; con-
troversy with Liceti, 391 ; last
words on Copernicanism, 393 ;
designs pendulum -clock, 396 ; last
days and death, 400 ; burial, 402 ;
monument, 404 ; translation of
remains, 406 ; relics, 407 ; tempera-
ment and tastes, 408 ; obiter dicta^
412; greatness as a teacher, 413;
tribune of Galileo, 413 ; tercen-
tenary of birth at Pisa, 417 ; ter-
centenary of professorship in Padua,
417; bibliography, 423
Gilbert, William, 59 ; the earth a
magnet, 62 ; hazy notion of gravi-
tation, 62 ; Galileo's appreciation
of, 258
Grant, Robert, on value of Galileo's
work in mechanics, 370
Grassi, Orazio, attacks on Galileo,
182, 213 ; concedes Galileo's great-
ness as teacher, 413
Gravitation, Gilbert's idea of, 62 ;
Galileo's idea of, 250
Gravity, centre of, in solids, 17, 22
of air, 350
Gregory, James, designs reflecting
telescope, 95
Griemberger, 127, 132; admits Jesuiti-
cal origin of Galileo's persecution,
342
Guicciardini has Galileo recalled from
Rome, 170
Guiducci, Mario, discourse on comets,
181, 327, 384
HABITATION of moon and planets,
134
Hariot, Thomas, Sun-spots, 132
Harris, Richard, pendulum-clock,
399
Harrison, John, his chronometer, 173
Harvey, William, student in Padua,
47
Henri Quatre, 99, 108
Hiero, story of his crown, 14
Hobbes, Thomas, and Galileo, 390,
424
Horky, Martin, attack on Galileo,
105
Huygens, Christian, on the telescope,
80 ; on planets' satellites, 105 ; dis-
covers Saturn's ring, 115 ,* con-
structs pendulum-clock, 399
Hydrostatics, 136 et seq.
" IL SAGGIATORE," 183, 186 et seq.
Inchofer, Melchior, 270, 297, 343
Ingoli, Francesco, 211
Inquisition, 153-171, 270-326; also
frequent references in subsequent
pages
450
INDEX
Inquisition, extra judicial pressure,
300, 306
proceedings not ratified by
Pope, 273, 322
unjust and illegal, 276, 323
sentence, were Judges unani-
mous ? 321
Irradiation, effects of, 88, 133
JACK, PROFESSOR, 37, 360, 371
Jansen, Zacharias, invents microscope
and telescope, 76, 209
Jesuits, the, 121, 129, 186, 265, 284,
342, 345, 425
Jupiter, 89-92
KEPLER, 39, 55, 65, 94, 104, 122,
212, 259, 363
Kuffler and the microscope, 209
LAGALLA, 135, 413
Lagrange, 136,^348,370
Lamp, Possenti's, in Pisa, 9
Landucci, Benedetto, 32, 66, 218
Lecture-desk, Galileo's, in Padua, 57
Libri, Julius, 101
Liceti, Fortunio, 327, 391
Light, velocity of, 362
Line of quickest descent, 356
Lipperhey, Hans, invents telescope,
74
Loadstone, 61
Longitude, proposals for finding, 172
et seq.y 372 et seq.
Lorini, Father, denounces Galileo,
153 ; contemptible excuse, 1 60
MACHINE, dredging, de Medici's, 26
for raising water, Galileo's, 42
Maestlin, 39, 54, 88, 105
Magalotti, Conte Filippo, 263, 265,
267, 273
Magini, Giovanni Antonio, 18, 35,
106
Magnetic needle, 59 ; magnetic needle
telegraph, 63
Magnetism, 59 et seq. , 258
Malatesti, the poet, 30
Mars, 125
Marsili, Cesare, 263, 331, 413
Mathematics, low estimate of, 10, 13,
34
Mayer, Simon, 46, 107, 132
Mazzoni, Jacopp, 26, 40
Mechanics, Galileo's work in, 37, 348,
370
Medals, commemorative, 62, 96, 404
Mellini, Cardinal, 153-154, 163
Mercury, 126
Metius, James, and the telescope, 75
Micanzio, Fulgenzio, 50, 270, 344,
346, 376; 423
Michelangelo, 4, 13
the younger, 126, 279
Microscope, 207 et seq.
Milton, John, 5, 30
and Galileo, 125, 388
Montucla, J. F., 343, 371
Moon, Galileo's observations on, 86,
133
Hbrations of, 375
not habitable, 134
Moons of Jupiter, 89, 119
Morosini, Francesco, 283
! Motion, accelerated, 355
laws of, 367
parabolic, 359
projectile, 356
uniform, 354
MSS., Galilean, collected by Viviani,
425 ; sold as waste paper, 427 ;
subsequent recovery of, 428 ;
recent extraordinary forgery of,
43°
Vatican, 168, 308, 321
NEEDLE, magnetic, 59
telegraph (by sympathy), 63
Newton, 6, 9, 61, 95, 182, 360, 367,
37*, 43i
NelH erects monument to Galileo,
405; recovers many Galilean
MSS., 4^7
Niccolini and his despatches, 271
et seq*
OPTICS, 88, 133, 362. Aha under
Telescope
Orsini, Cardinal, 171, 179
PARALLAX, stellar, 253, 393
Pascal, 214, 35°, 43*
Paul V., i2i, 127, 170
Pendulum, vibrations of, 9, 26, 363
applied to clocks, 396
Pension, Papal, to Galileo, 206,
219
Percussion, force of, 37, 366, 401
Perelli, Tommaso, 407, 428
Piccolomini, Ascanio, 331
Pieroni, Giovanni, 347, 393
Pierozzi, Father, epitaph over Galileo's
grave, 404
Pinelli, Gianvincenzio, 34, 36, 49
Plague in Florence, 231, 240, 263,
285
Plane, inclined, 25, 356, 369
Planets, new, predicted, 255
question of their habitability,
134
INDEX
Playfair, Professor, appreciation of the
Dialogue of 1632, 261
Poggibonsi, famous meeting- place,
380
Ponsard, his drama " Galilee," 102
Portraits of Galileo, 239
Possenti, his lamp in Pisa, 9
Problems, mathematical, 19, 214,
366, 401
Pulsilogia, 10
QUERENGO, ANTONIO, 161
RENIERI, FATHER, and the longitude
papers, 374
Riccardi, Niceolo, 183, 205, 226, 230,
240, 272, 328
Ricci, Ostilio, 12, 14
Rimiccini, Francesco, 30, 393
Tommaso, 200
Roemer, on velocity of light, 363
Roiti, Professor, measurements of
Galileo's object-glass, 97
Ruskin, John, 2
Ruzzante (Angelo Beolco), 244
SAGREDO, GIAN. FRANCESCO, 50, 53,
122, 178, 245
Salviati, Filippo, 131, 192, 245
Santorio, 10, 53
Sarpi, Paolo, 44, 49. 122, 148, 155
Satellites of the planets, 105, 115
Saturn's ring, 108-115
Scaglia, Cardinal, 286, 288, 290, 322
Schemer, Father, 105, 129, 265, 347
Seggett, Thomas, 51, 104
Serristori, Mgr., 264, 286
" Sidereus Nuncius," 85-92
Simplicio = the Simpleton, 268-9, 273,
393> 322> 38°
Sirturo, Girolamo, and his first tele-
scope, loo
Sizzi, Francesco, 103, 106
Sphere, Galileo's treatise on the, 39
Stars, fixed, 88, 251-6
Stars, rrew, 45, 53
Sun-spots, 128-132
Suor Maria Celeste. See Galilei,
Virginia (Galileo's daughter)
Sustermans, the painter, 238
TARDE, GIOVANNI, 207
Targioni-Tozzetti, 416; on Galileo's
MSS., 427 ; on translation of
Galileo's remains, 406
Tasso, 29, 411
Telegraph, sympathetic needle, 63
Telescope, 74-97, 109
binocular, 75, 175
Thermometer, 51-53
Tides, the, 62, 171, 179, 213, 259,
376
Torre del Gallo, 237
Torricelli, 22, 92, 94, 400, 417
Torture, was it applied ? 3 10, 323
stages of, 323
Tower, leaning, Pisa, 24
URBAN VIII., 127, 137, 148, 156,
184, 200, 205, 213, 227, 229, 268,
and after, passim
VACUUM, nature's horror of, 349
Vallombrosa, 4
Vatican MSS., 168, 308
history of, 321
Venus, phases of, 123
Verses of Galileo quoted, 31
Virtual Velocities, principle of, 37,
136, 371
Viviani, Vincenzio, 8, 40, 208, 356,
366, 391, 398, 404. See also Bib-
liography
WEDDERBURN, JOHN, 51, 106, 207
Welser, Mark, 101, 129
Willoughby, Richard, 50
ZACCHIA, CARDINAL, 321-2
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