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ever, he saw reason to abandon this last opinion. He
found, that the spots must be in contact with the sur-
face of the sun ; that their figures were irregular ; that
they had different degrees of darkness; that one spot
would often divide itself into three or four; that three
or four spots would often unite themselves into one ;
and that ah 1 the spots revolved regularly with the sun,
which appeared to complete its revolution in about
twenty-eight days.

Previous to the invention of the telescope, spots had
been more than once seen on the sun's disc with the
unassisted eye. But even if these were of the same
character as those which Galileo and others observed,
we cannot consider them as anticipations of their dis-
covery by the telescope. As the telescope was now in
the possession of several astronomers, Galileo began to
have many rivals in discovery ; and it is now placed
beyond the reach of doubt, that he was not the first dis-
coverer of the solar spots. From the communication
which I received from the late Dr. Robertson, of


Oxford*, it appears that Thomas Harriot had disco-
vered the solar spots on or before the 8th of December,
l6'10. His manuscripts, in lord Egremont's possession,
incontestably prove that his regular observations on the
spots commenced on the 8th of December, l6lO, at
least three months before Galileo discovered them ; and
that they were continued till the 18th of January, 1613.
The observations which he has recorded are 199 in
number ; and tbe accounts of them are accompanied
with rough drawings representing the number, position,
and magnitude of the spots. t

Another candidate for the honour of discovering the
spots of the sun, was John Fabricius, who undoubtedly
saw them previous to June, l6ll. The dedication of
the w r ork in which he has recorded his observation,
bears the date of the loth of June, 1611 ; and it is
obvious, from the work itself, that he had seen the spots
during the year l6lO : but as there is no proof that he
saw them before the 8th of December, 16' 10, and as it
is probable that Harriot had seen them before that date,
we are compelled to assign the priority of the discovery
to our distinguished countryman.

The claim of Scheiner, professor of mathematics at
Ingolstadt, is more intimately connected with the history
of Galileo. This learned astronomer having, early in
l6ll, turned his telescope to the sun, necessarily dis-
covered the spots which at that time covered his disc.
Light flying clouds happened, at the time, to weaken
the intensity of his light, so that he was able to show
the spots to his pupils. These observations were not
published till January, 1612 ; and they appeared in the
form of three letters, addressed to Mark Velser, one of the
magistrates of Augsburg, under the signature of Apelles
post Tabulam. Scheiner, who, many years afterwards,
published an elaborate w r ork on the subject, adopted the
same idea which had at first occurred to Galileo, that

* See page 22.

t Edin. PhiL Journ. 1822, vol. vi. p. 317.

j Job. Fabricii Phrysii de Maculis in Sole observatis, et apparente ea-
rum cum Sole conversione, Narratio. Witte.nb. 1611.


the spots were the dark sides of planets revolving round
and near the sun.*

On the publication of Scheiner's letters Velser trans-
mitted a copy of them to his friend Galileo, with the ,
request that he would favour him with his opinion of
the new phenomena. After some delay, Galileo ad-
dressed three letters to Velser, in which he combated
the opinions of Scheiner on the cause of the spots.
These letters were dated the 4th of May, 1 6l 2 ; but though
the controversy was carried on in the language of mu-
tual respect and esteem, it put an end to the friendship
which had existed between the two astronomers. In
these letters, Galileo showed that the spots often dis-
persed like vapours or clouds; that they sometimes had
a duration of only one or two days, and at other times
of thirty or forty days ; that they contracted in their
breadth when they approached the sun's limb, without
any diminution of their length ; that they describe cir-
cles parallel to each other ; that the monthly rotation of
the sun again brings the same spots into view; and that
they are seldom seen at a greater distance than 30
from the sun's equator. Galileo, Likewise, discovered on
the sun's disc faculcs, or luculi, as they were called,
which differ in no respect from the common ones but in
their being brighter than the rest of the sun's surface. t

* It does not appear from the history of solar observations, at what time,
and by whom, coloured glasses were first introduced for permitting the eye
to look at the sun with impunity. Fabricius was obviously quite ignorant
of the use of coloured glasses. He observed the sun when he was in the
horizon, and when his brilliancy was impaired by the interposition of thin
clouds and floating vapours ; and he advises those who may repeat his ob-
servations, to admit at first to the eye a small portion of the sun's light, till
it is gradually accustomed to its full splendour. When the sun's altitude
became considerable, Fabricius gave up his observations ; which he often
continued so long, that he was scarcely able, for two days together, to see
objects with their usual distinctness.

Scheiner, in his " Apelles post Tabulam," describes four different waysof
viewing the spots: one of which is by the interposition of blue or green glasses.
His first method was to observe the sun near the horizon ; the second was to
view him through a transparent cloud ; the third was to look at him through
his telescope with a blue or a green glass of a proper thickness, and plane
on both sides, or to use a thin blue glass when, the sun was covered with a
thin vapour or cloud ; and the fourth method was to begin and observe the
sun at his margin, till the eye gradually reached the middle of his disc.

f See Istoria e Demostrazioni, intorna alle macchie solari. Roma, 1613.
See Opere di Galileo, vol. v. p. 131293.


In the last of the letters which our author addressed
to Velser, and which was written in December, 1612,
he recurs to his former discovery of the elongated shape,
or rather the triple structure, of Saturn. The singular
figure which he had observed in this planet had en-
tirely disappeared ; and he evidently announces the fact
to Velser, lest it should be used by his enemies to dis-
credit the accuracy of his observations. " Looking on
Saturn/' says he, " within these few days, I found it
solitary, without the assistance of its accustomed stars,
and, in short, perfectly round and defined like Jupiter;
and such it still remains. Now, \vhat can be said of
so strange a metamorphosis? Are the two smaller
stars consumed like the 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 a
time mocked me, and so many others who have often
observed with me ? Now, perhaps, the time is come
to revive the withering hopes of those who, guided by
more profound contemplations, have followed all the
fallacies of the new observations, and recognised their
impossibilities. I cannot resolve what to say in a chance
so strange, so new, and so unexpected ; the shortness of
the time, the unexampled occurrence, the weakness of
my intellect, and the terror of being mistaken, have
greatly confounded me." Although Galileo struggled
to obtain a solution of this mystery, yet he had not the
good fortune of succeeding. He imagined that the two
smaller stars would reappear, in consequence of the
supposed revolution of the planet round its axis ; but
the discovery of the ring of Saturn, and of the obliquity
of its plane to the ecliptic, was necessary to explain the
phenomena which were so perplexing to our author.

The ill health to which Galileo was occasionally subject,
and the belief that the air of Florence was prejudicial
to his complaints, induced him to spend much of his
time at Selve, the villa of his friend Salviati. This
eminent individual had ever been the warmest friend of


Galileo, and seems to have delighted in drawing round
him the scientific genius of the age. He was a member
of the celebrated Lyncaean Society, founded by Prince
Frederigo Cesi ; and though he is not known as the author
of any important discovery, yet he lias earned, by his
liberality to science, a glorious name, which will be in-
dissolubly united with the immortal destiny of Galileo.
The subject of floating bridges having been discussed
at one of the scientific parties which had assembled at
the house of Salviati, a difference of opinion arose re-
specting the influence of the shape of bodies on their
disposition to float or to sink in a fluid. Contrary to
the general opinion, Galileo undertook to prove that it
depended on other causes ; and he was thus led to com-
pose his discourse on floating bodies*, which was pub-
lished in 1612, and dedicated to Cosmo de' Medici.
This work contains many ingenious experiments, and
much acute reasoning in support of the true principles
of hydrostatics ; and it is now chiefly remarkable as a
specimen of the sagacity and intellectual power of its
author. Like all his other works, it encountered the
most violent opposition; and Galileo was more than once
summoned into the field to repel the aggressions of his
ignorant and presumptuous opponents. The first attack
upon it was made by Ptolemy Nozzolini, in a letter to
Marzemedici, archbishop of Florence t ; and to this
Galileo replied in a letter addressed to his antagonist. ^
A more elaborate examination of it was published by
Lodovico delle Colombe, and another hy M. Vincenzo
di Grazia. To these attacks, a minute and overwhelm-
ing answer was printed in the name of Ben^'letti Castelli,
the friend and pupil of Galileo ; but it was discovered,
some years after Galileo's death, that he was himself the
author of this work.

* Discorso intorno alle cose che stanno in sa 1'acqua, o che in quella si
rauovono. Opere di Galileo, vol. ii. pp.. 163 311.

f Opere di Galileo, vol. ii. pp. 355367.

t Ibid. 367390.

$ These three treatises occupy the whole of the third volume of the
Opere di Galileo.


The current of Galileo's life had hitherto flowed in
a smooth and unobstructed channel. He had now at-
tained the highest objects of earthly ambition. His
discoveries had placed him at the head of the great
men of his age ; he possessed a professional income far
beyond his wants., and even beyond his anticipations ;
and, what is still dearer to a philosopher, he enjoyed the
most perfect leisure for carrying on and completing his
discoveries. The opposition which these discoveries
encountered, was to him more a subject for triumph than
for sorrow. Prejudice and ignorance were his only
enemies j and if they succeeded for a while in harassing
his march, it was only to give him occasion for fresh
achievements. He who contends for truths which he
has himself been permitted to discover, may well sus-
tain the conflict in which presumption and error are
destined to fall. The public tribunal may neither be
sufficiently pure nor enlightened to decide upon the
issue ; but he can appeal to posterity, and reckon with
confidence on " its sure decree."

The ardour of Galileo's mind, the keenness of his
temper, his clear perception of truth, and his inextin-
guishable love of it, combined to exasperate and prolong
the hostility of his enemies. When argument failed
to enlighten their judgment, and reason to remove their
prejudices, he wielded against them his powerful weapons
of ridicule and sarcasm ; and in this unrelenting warfare,
he seems to have forgotten that Providence had withheld
from his enemies those very gifts w r hich he had so liber -
ally received. He who is allowed to take the start of
his species, and to penetrate the veil which conceals
from common minds the mysteries of nature, must
not expect that the world will be patiently dragged at
the chariot wheels of his philosophy. Mind has its
inertia, as well as matter; and its progress to truth can
only be insured by the gradual and patient removal of
the obstructions which surround it.

The boldness may we not say the recklessness ?
with which Galileo insisted upon making proselytes of


his enemies, produced the very opposite effect. Errors
thus assailed, entrenched themselves in general feelings,
and were embalmed in the virulence of the passions.
The various classes of his opponents marshalled them-
selves for their mutual defence. The Aristotelian pro-
fessors,, the temporising Jesuits, the political church-
men, and that timid but respectable body who at all
times dread innovation, whether it be in religion or in
science, entered into an alliance against the philoso-
phical tyrant who threatened them with the penalties of

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 supported his views. His pupils had been ap-
pointed to several of the principal professorships in
Italy. The enemies of religion w r ere on this occasion
united with the Christian philosopher ; and there were,
even in these days, many princes and nobles who had felt
the inconvenience of ecclesiastical jurisdiction, and w r ho
secretly abetted Galileo in his crusade against established

Although these two parties had been long dreading
each other's power, and reconnoitring each other's posi-
tion, yet we cannot exactly determine w T hich of them
hoisted the first signal for war. The church party, par-
ticularly its high dignitaries, were certainly disposed to
rest on the defensive. Flanked on one side by the logic
of the schools, and on the other by the popular inter-
pretation of Scripture, and backed by the strong arm of
the civil power, they were not disposed to interfere with
the prosecution of science, however much they may have
dreaded its influence. The philosophers, on the con-
trary, united the zeal of innovators with the firmness
of purpose which truth alone can inspire. Victorious in
every contest, they w r ere flushed with success, and they
panted for a struggle in which they knew they must

In this state of warlike preparation Galileo addressed


a letter,, in 1613,, to his friend and pupil, the abbe Cas-
telli, the object of which was to prove that the Scriptures
were not intended to teach us science and philosophy.
Hence he inferred, that the language employed in the
sacred volume in reference to such subjects should be
interpreted only in its common acceptation ; and that it
was in reality as difficult to reconcile the Ptolemaic as
the Copernican system to the expressions which occur
in the Bible.

A demonstration was about this time made by the
opposite party, in the person of Caccini, a Dominican
friar, who made a personal attack upon Galileo from the
pulpit. This violent ecclesiastic ridiculed the astro-
nomer and his followers, by addressing them in the
sacred language of Scripture ; " Ye men of Galilee,
why stand ye here looking up into heaven ? " But
this species of warfare was disapproved of even by
the church ; and Luigi Maraffi, the general of the
Dominicans, not only apologised to Galileo, who had
transmitted to him a formal complaint against Caccini,
but expressed the acuteness of his own feelings on being
implicated in the " brutal conduct of thirty or forty
thousand monks."

From, the character of Caccini, and the part which he
afterwards played in the persecution of Galileo, we can
scarcely avoid the opinion that his attack from the pulpit
was intended as a snare for the unwary philosopher.
It roused Galileo from his wonted caution ; and stimu-
lated, no doubt, by the nature of the answer which he
received from Maraffi, he published a longer letter of
seventy pages, defending and illustrating his former
views respecting the influence of scriptural language on
the two contending systems. As if to give the impress
of royal authority to this new appeal, he addressed it to
Christian, grand- duchess of Tuscany, the mother of
Cosmo ; and in this form it seems to have excited a new
interest, as if it had expressed the opinion of the grand-
ducal family. These external circumstances gave ad-


ditional weight to the powerful and unanswerable reason-
ing which this letter contains ; and it was scarcely
possible that any man, possessed of a sound mind, and
willing to learn the truth, should refuse his assent to
the judicious views of our author. He expresses his
belief that the Scriptures were given to instruct mankind
respecting their salvation,, and that the faculties of our
minds were given us for the purpose of investigating the
phenomena of nature. He considers Scripture and
nature as proceeding from the same divine author, and,
therefore, incapable of speaking a different language ;
and he points out the absurdity of supposing that pro-
fessors of astronomy will shut their eyes to the phe-
nomena which they discover in the heavens, or will refuse
to believe those deductions of reason which appeal to
their judgment with all the power of demonstration.
He supports these views by quotations from the ancient
fathers ; and he refers to the dedication of Copernicus's
own work to the Roman pontiff, Paul HI., as a proof
that the pope himself did not regard the new system of
the world as hostile to the sacred writings. Copernicus,
on the contrary, tells his holiness, that the reason of in-
scribing to him his new system was, that the authority
of the pontiff might put to silence the calumnies of some
individuals, who attacked it by arguments drawn from
passages of Scripture twisted for their own purpose.

It was in vain to meet such arguments by any other
weapons than those of the civil power. His enemies
saw that they must either crush the dangerous innova-
tion, or allow it the fullest scope ; and they determined
upon an appeal to the inquisition. Lorini, a monk of
the Dominican order, had already denounced to this
body Galileo's letter to Castelli ; and CaccinL bribed by
the mastership of the convent of St. Mary of Minerva,
was invited to settle at Rome for the purpose of em-
bodying the evidence against Galileo.

Though these plans had been carried on in secret,
yet Galileo's suspicions were excited ; and he obtained
leave from Cosmo to go to Rome about the end of


l6l 5.* Here he was lodged in the palace of the grand
duke's ambassador, and kept up a constant correspond-
ence with the family of his patron at Florence ; but, in
the midst of this external splendour, he was summoned
before the inquisition to answer for the heretical doc-
trines which he had published. He was charged with
maintaining the motion of the earth, and the stability of
the sun, with teaching this doctrine to his pupils, with
corresponding on the subject with several German
mathematicians, and with having published it, and
attempted to reconcile it to Scripture, in his letters to
Mark Velser in l6l2. The inquisition assembled to
consider these charges on the 25th of February, 16'15 ;
and it was decreed that Galileo should be enjoined by
cardinal Bellarmine to renounce the obnoxious doctrines,
and to pledge himself that he would neither teach, de-
fend, nor publish them in future. In the event of his
refusing to acquiesce in this sentence, it was decreed that
he should be thrown into prison. Galileo did not he-
sitate to yield to this injunction. On the day following,
the 26th of February, he appeared before cardinal
Bellarmine, to renounce his heretical opinions ; and,
having declared that he abandoned the doctrine of the
earth's motion, and would neither defend nor teach it, in
his conversation or in his writings, he was dismissed
the court.

Having thus disposed of Galileo, the inquisition con-
ceived the design of condemning the whole system of
Copernicus as heretical. Galileo, with more hardihood
than prudence, remained at Rome for the purpose of
giving his assistance in frustrating this plan ; but there
is reason to think that he injured by his presence the
very cause which he meant to support. The inquisition
had determined to put down the new opinions ; and they
now inserted among the prohibited books Galileo's letters
to Castelli and the grand duchess, Kepler's epitome of

* It is said that Galileo was cited to appear at Rome on this occasion j
and the opinion is not without foundation.



the Copernican theory, and Copernicus's own work on
the revolutions of the heavenly bodies.

Notwithstanding these proceedings, Galileo had an
audience of the pope, Paul V., in March, l6'l6. He was
received very graciously, and spent nearly an hour with
his holiness. When they were about to part, the pope
assured Galileo, that the congregation were not disposed
to receive upon light grounds any calumnies which
might be propagated by his enemies, and that, as long as
he occupied the papal chair, he might consider himself
as safe.

These assurances were no doubt founded on the be-
lief that Galileo would adhere to his pledges; but so bold
and inconsiderate was he in the expression of his opi-
nions, that even in Rome he was continually engaged in
controversial discussions. The following very interest-
ing account of these disputes is given by Querenghi, in
a letter to the cardinal D'Este :

" Your eminence 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 ah 1 of them to
scorn, and even if the novelty of his opinions pre-
vents entire persuasion, at least he convicts of emptiness
most of the arguments with which his adversaries en-
deavour to overwhelm him. He was particularly ad-
mirable on Monday last in the house of signer Freclerieo
Ghisilieri ; and what especially pleased me was, that
before replying to the contrary arguments, he amplified
and enforced them with new grounds of great plausi-
bility, so as to leave his adversaries in a more ridiculous
plight, when he afterwards overturned them all."

The discovery of Jupiter's satellites suggested to
Galileo a new method of finding the longitude at sea.
Philip III. had encouraged astronomers to direct their
attention to this problem, by offering a reward for its
solution j and in those days, when new discoveries in
science were sometimes rejected as injurious to man-


kind, it was no common event to see a powerful sove-
reign courting the assistance of astronomers in promoting
the commercial interests of his empire. Galileo seems
to have regarded the solution of this problem as an
object worthy of his ambition ; and he no doubt antici-
pated the triumph which he would obtain over his
enemies, if the Medicean stars, which they had treated
with such contempt, could be made subservient to
the great interests of mankind. During his residence
at Rome in 1615 and l6l6, Galileo had communicated
his views on this subject to the comte di Lemos, the
viceroy of Naples, who had presided over the council of
the Spanish Indies. This nobleman advised him to
apply to the Spanish minister, the duke of Lerma ; and,
through the influence of the grand duke Cosmo, his
ambassador at the court of Madrid was engaged to
manage the affair. The anxiety of Galileo on this
subject was singularly great. He assured the Tuscan
ambassador that, in order to accomplish this object, "he
was ready to leave all his comforts, his country, his
friends, and his family, to cross over into Spain, and to
stay as long as he might be wanted at Seville or at
Lisbon, or wherever it might be convenient to com-
municate a knowledge of his method." The enthusiasm
of Galileo seems to have increased the lethargy of the
Spanish court ; and though the negotiations were oc-
casionally revived for ten or twelve years, yet no steps
were taken to bring them to a close. This strange pro-
crastination has been generally ascribed to jealousy or in-
difference on the part of Spain ; but Nelli, one of
Galileo's biographers, declares, on the authority of Flo-
rentine records, that Cosmo had privately requested
from the government the privilege of sending annually

Online LibraryDionysius LardnerEminent literary and scientific men of Italy, Spain, and Portugal .. (Volume 2) → online text (page 3 of 34)