506 
NATURE 
(Marcu 31, 1904 
only be divided into two equal parts; a circle had not 
an infinite number of radii, for from the centre only 
six lines could be drawn; a line could not always 
be bisected, for it might contain an odd number of 
atoms, and geometrical bisection was at best an approx- 
imation. 
In his views on the value of riches, on progress, 
peace, happiness and such matters there is little to 
which objection could be raised nowadays. He 
appears to have believed in the transmigration of souls. 
In other matters of religion he arrived at views not dif- 
fering much from those of a thinking man of the pre- 
sent age. He approved of religious worship as 
appealing to a class of intellect to which a purely 
philosophical religion would be incomprehensible. 
Against the philosophers who, in the words cf 
Socrates, ‘‘ think they are wise when they are not,” 
Bruno casts many a dash of sarcasm. ‘‘ Many of the 
Peripatetics,’’ he says in the Cena, ‘‘ grow angry and 
flush and quarrel about Aristotle, yet do not understand 
even the titles of his books ’’ (see p. 122). Does not this 
represent the position of the average present-day 
politician in regard to the Fiscal Question ? 
Bruno’s philosophy was so far in advance of the 
narrow views of his time that he could not fail to make 
enemies. His endeavour to influence men for the better 
brought on him a fate which others had shared before 
him, and his name was quickly forgotten, not to be 
restored until nearly two centuries later. 
The discoveries of Galileo have been brought more 
conspicuously before the world than the philosophy of 
Bruno, and their study presents little difficulty to the 
least advanced student of physics; nevertheless, there 
is much for everyone to learn from a perusal of this 
excellent biography. His discovery of the pendulum, 
whether from observations of the famous ‘‘ Lampa di 
Galileo ’’ at Pisa or otherwise, his restatement of the 
principle of Archimedes, his claims to be regarded as 
the inventor of the telescope, his discoveries of Jupiter’s 
satellites, and of the appendages of Saturn, recognised 
as a ring forty-six years later by Huyghens, his observ- 
ations of the crescent form of Venus, of the mountains 
of the moon, and of sun-spots, his attempts to solve 
the problem of longitude at sea by means of Jupiter’s 
satellites, his investigations on floating bodies, and on 
uniformly accelerated motion, his discovery of the 
librations of the moon, his geometrical and military 
compass, all these and many other results of his genius 
are well and faithfully described. 
In regard to the telescope we infer that, although the 
inverting telescope had been previously arrived at by 
accident by Dutch opticians, Galileo’s erecting tele- 
scope with concave eyepiece embodied a different 
principle, but the biographer might have made this 
point clearer. 
Of the difficulties against which Galileo had to 
contend much is said. His futile early attempts to 
obtain a chair of mathematics met at last with success 
at Pisa when he was only twenty-five, but his salary 
there was but 13/. per annum. Moreover, his refusal 
to adopt blindly the doctrines of Aristotle brought him 
NO. 1796, VOL. 69] 
into conflict with the University authorities, who 
showed their animosity against him by fining him for 
loss of lectures and by the countless little persecutions 
which the dons of unenlightened universities have from 
the earliest times brought to bear against men of inde- 
pendent reasoning power. The same hostility against 
Galileo was maintained by Pisa up to the end. 
His happiest years were spent as professor at Padua, 
where students from all parts of the world flocked to 
hear his lectures and to receive private tuition frony 
him. His classes overflowed the great hall of the uni- 
versity, and he even had to lecture in the open air. His 
discoveries attracted the admiration and esteem of the 
great potentates of the age, and his telescopes were 
eagerly sought for. His very success was indirectly 
the cause of his later troubles. That there is no rest 
but the grave for the pilgrim of science is well illus- 
trated by his experience. For though his public duties 
only occupied him for sixty half-hours in the year (p. 
118) his time was so taken up with private pupils that 
he gladly accepted an offer from his friend and old 
pupil, Cosimo II., Grand Duke of Tuscany, of a per- 
manent endowment for research under the title of First 
Mathematician and Philosopher. 
So long as he was under the Venetian Republic 
Galileo breathed in a free atmosphere. A comparison 
with Bruno’s unfortunate experience in no way con- 
tradicts this view. Galileo was only appointed at 
Padua in September, 1592, about two months after the 
Venetian tribunal had concluded its sittings on Bruno, 
and it further appears that the State offered consider- 
able resistance to Bruno’s extradition, and only yielded 
to Papal pressure after it had been pointed out 
that Bruno was not a Venetian subject, and further 
that he was the subject of charges instituted previously 
in Naples and Rome. It was not till eighteen years 
later that Galileo left Padua for Florence, where his 
real troubles began. The discoveries of his telescope 
excited the hostility of the Aristotelian faction, and 
they supported the Copernican doctrine to such an ex- 
tent as to bring him under the ban of the Romish 
Church. He was denounced to the Inquisition in 1612, 
but it was not until 1633 that proceedings were taken 
which resulted in the philosopher of seventy years being 
bound by oath to abjure the Copernican doctrine and 
being treated as a prisoner for the last nine years of 
his life. During that time, in his exile at Siena and 
Arcetri, his interest in science never waned, despite his 
infirmities, and he devoted his attention to dynamical 
problems on which he was still at liberty to express 
opinions. That Galileo discovered the principle of 
virtual velocities is a fact that may come as news to 
some of us. 
In all the proceedings against Galileo his old Alma 
mater and enemy, Pisa, figures prominently. Of the 
obstinate spirit of the Aristotelians we have instances 
in Galileo’s early experiments in dropping falling 
bodies from the Leaning Tower. 
‘“ With the sound of the simultaneously fallen weights 
ringing in their ears they still persisted that the rolb. 
weight would reach the ground in 445 of the time taken 
