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The progress of cosmical knowledge was purchased by all

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298 EPOCHS IN THE HISTOBT OF THE CONTEMPIATION OF

the violence and all the horrors whieh conquerors^ the so-
called extenders of civilisation^ spread over the earth. Yet
it would be an indiscreet and rash boldness which, in the
interrupted history of the development of humanity, should
venture to decide dogmatically on the balance of good or
ilL It is not for men to pronounce judgment on events
which, slowly prepared in the womb of time, belong but
partially to the age in which we place them.

The first discovery of the middle and southern parts of
the United States of America by the Scandinavians ahnost
coincides in point of time with the appearance and myste-
rious arrival of Manco Ca])ac in the highlands of Peru ; it
preceded by almost 200 years the arrival of the Aztecs in
the valley of Mexico. The foundation of the principal city,
Tenochtitlan, dates folly 825 years later. If these coloniza-
tions by Northmen had been more permanent in their
results, — ^if they had been fostered and protected by a power-
fill and politically united mother country, — ^the advancing
Germanic race would have still found many wandering
tribes of hunters, (*^) where the Spanish conquerors found
settled agriculturists.

The period of the conquists;, the end of the 15th and
beginning of the 16th centuries, is marked by a wonderful
coincidence of great events in the political and moral life of ,

the nations of Europe. In the same month in which
Heman Cortes, after the battle of Otumba, advanced to be-
siege Mexico, Martin Luther burnt the papal bull at Wit-
tenberg, and laid the foundation of the Eeformation, which
promised to the mind of man freedom and progress in almost
untried paths. (*5^) Somewhat earlier, those long buned
glorious monuments of ancient Grecian art, the Laocoon, ]

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THE UNIVEKSE.— OCJBANIC DISCOVBEIBS. 299

the Torso, the Belvedere Apollo, and the Medicean Venus
had been disclosed. Michael Angelo, Leonardo da Vinci,
Titian, and Eaphael flourished in Italy, and Holbem and
Albert Durer in our German country. In the year in which
Columbus died, fourteen years after the discovery of the
new continent, the order of the universe was discovered,
though not pubUcly announced, by Copernicus.

The consideration of the importanpe of the discovery of
America, and of the first European settlements therein,
touches on other fields of thought besides those to which these
pages are especially devoted ; it would include all those intel-
lectual and'moral infiuences, which the sudden enlargement
of the entire mass of ideas exercised on the improvement of
the social state. We recal only by a passing allusion, how,
since that great era, a new activity of thought and feeling,
courageous wishes, and hopes hard to relinquish, have gra-
dually pervaded all classes of civil society; — ^how the scanti-
ness of the population of one hemisphere of the globe,
especially on the coasts opposite to Europe, favoured the
settlement of colonies, which by their extent and position have
been transformed into independent states, unrestricted in
the choice of free forms of government, — and how, lastly, the
religious Reformation, the precursor of great poHtical revo-
lutions, passed through the different phases . of its develop-
ment in a region which became the refuge of all religious
opinions, and of the most different views in Divine things.
The boldness of the Genoese navigator is the first linTc in
tlie immeasurable chain of these fate-fraught events; and it
was accident, and not fraud or strife, (*^7) which deprived
the continent of America of his name. The new world,
roL. II. ' X

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800 mSTOBT 07 THE CONTEMPLATION 07 THE 17NIVEBSE.

brought dming the last half centuiy continiially neaarer to
Europe by commercial interconrsey and bj the improvement
g[ navigation^ has exercised an important influence on the
political institutions^ (^^) and on the ideas and tendendes
of those nations who dwell on the eastern shore of the con-
stantly narrowing valley of the Atlantic Ocean.



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SPOCflS DT THE HISTOBT OP THE CONTEMPLATIOK OF THB
ONIVESSE. — ^DISCOVEBIES IN THE CELESTIAL SPACES.

vn.

Great Discoveries in Space by the application of the Telescope.—
The great Epoch of Astronomy and Mathematics from Galileo
and Kepler to Newton and Leibnitz. — ^Laws of the Planetary
Motions, and general Theory of Gravitation.

In attempting to recount the most distinctly marked pe-
riods and gradations of the development of cosmical con-
templation, we have in the last section endeavoured to
depict the epoch, in which one hemisphere of the globe first
became known to the cultivated nations inhabiting the
other. The epoch of the most extensive discoveries upon
the surface of our planet was immediately succeeded by
man's first taking possession of a considerable part of the
celestial spaces by the telescope. The application of a
newly formed organ, of an instrument of space-penetrating
power, called forth a new world of ideas. Now began a
brilliant age of astronomy and mathematics; and in the
latter the long series of profound investigators, leading to
the '^all-transforming^' Leonard Euler, the year of whose
birth (1707) is so near the year of Jacob Bemouilli's death.
A few names may suffice to recal the giant strides with
which the human mind advanced in the 17 th century, less
from any outward incitements than from its own indepen-
dent energies^ and especially in the development of matho-

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302 EPOCHS IN THE HISTOBt OP THE CONTEMPLATION Of

matical thought. The laws that regulate the fall of bodies^
and the planetary motions, were recognised ; the pressure of
the atmosphere, the propagation of light, and its refraction and
polarisation, were investigated. Mathematico-physical science
was created, and established on firm foundations. Tlie in-
vention of the infinitesimal calculus marks the close of the
century ; and, reinforced by its aid, the human intellect has
been enabled, in the succeeding hundred and fifty years, to
attempt successfully the solution of problems presented by
the perturbations of the heavenly bodies, by the polarisation
and interference of the waves of light, by radiant heat, by
the electro-magnetic re-entering currents, by vibrating chords
and surfaces, by the capillary attraction of tubes of small
diameter, and by so many other natural phsenomena.

In this world of thought the work proceeds uninter-
ruptedly, and its different portions lend to each other mu-
tual support. No earlier fruitful germ is stifled. We see
increase, simultaneously, the abundance of materials, the
strict accuracy of methods, and the perfection of instruments.
r propose to limit myself principally to the consideration of
the 17th century, the age of Kepler, Galileo, and Bacon, of
Tycho Brahe, Descartes, and Huygens, of Eermat, Newton,
and Leibnitz. What they have done is so generally known,
that shght indications will suffice to point out through what
part of their achievements they have more especially contri-
buted to the enlargement of cosmical views.

We have already shewn {*^^) how, by the discovery of
telescopic vision, there was lent to the eye, — ^the organ of
the sensuous contemplation of the visible universe, — a power
of which we are yet far from having reached the limit, but
n{ which the first feeble commencement (magnifying hardly

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THE TTNIVEBSB. — DISCOVERIES IN THE CELESTIAL SPACES. 303

as much as 32 times in linear dimension), (*^) sufficed to
penetrate into cosmical depths before unknown. The exact
knowledge of many heavenly bodies belonging to our solar
system, the unchanging laws according to which they re-
volve in their orbits, and the perfected insight into the true
structure of the universe, are the characteristics of the
epoch which we here attempt to describe. The results
which this age produced have defined the leading outlines of
the picture of nature or sketch of the Cosmos, and have added
an intelligent, recognition of the contents of the celestial
spaces, — at least in the well-understood arrangement of one
planetary group, — to the earlier explored contents of terres-
trial space. Seeking to fix attention on general views, I
here name only the most important objects of the astrono-
mical labours of the 1 7th century ; and would point to their
influence in inciting at once to great and unexpected mathe-
matical discoveries, and to a more comprehensive and
grander contemplation of the materia^ universe.

I have already remarked, that the age of Columbus, (Jama/
and Magellan, the age of nautical discoveries, coincided with
other great and deeply influential events, with the awaken-
ing of religious liberty of thought, with the development of
art, and with the promulgation of the Copemican system of
the universe. Nicholas Copernicus (in two still existing
letters he calls himself Kopemik) had already attained his
21st year, and had observed with the astronomer Albert
Brudzewski, at Cracow, when Columbus discovered America.
Hardly a year after the death of the great discoverer, Coper-
nicus having returned to Cracow from a six years' residence
at Padua, Bologna, and Eome, we find him occupied with an
entire revolution in the astronomical view of the universe.

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804 EPOCHS IN THE HISTOBY OP THE CONTEMPLATION OF

Bj the favour of his uncle, Lucas Waissetode von Allen, (*^*)
Sishop of Ermland, he was named, in 1510, Canon at
Frauenburg, where he was engaged for thirty-three years in
the completion of his work '^De Revolutionibus Orbium
Ccelestium/^ The first printed copy was brought to him
when in immediate preparation for death, and when his
strength of body and mind were failing: he saw it and
touched it; but temporal things were no farther heeded,
and he died, not, as Glassendi says, a few hours, {*^^) but
some days afterwards, on the 24th of May, 1543. Tvro
years previously, an important part of his doctrine had been
made known in print, by a letter from one of his most
zealous pupils and adherents, Joachim Ehseticus, to Johann
Schoner, Professor at Nuremberg. Tet it was not the pro-
mulgation of the Oopernican theory, the renewed doctrine
of the solar orb forming the centre of our system, which
led, somewhat more than half a century after its first ap-
pearance, to the brilliant discoveries in space which mark
ttie beginning of the 17th century : — 'these discoveries were
the result of an invention accidentally made, — ^that of the
Telescope. Through them the doctrine of Copernicus was
perfected and enlarged. His fundamental views, confirmed
and extended by the results of physical astronomy (by the
newly discovered system of the satellites of Jupiter, and
by the phases of Venus), — ^pointed out to theoretical
astronomy the paths which must conduct to the sure at-
tainment of her aims, and incited to the solution of pro*
blems which required that the analytical calculus should be
carried to still higher degrees of perfection. As George
Peuerbach and Eegiomontanus (Johann Mtlller, of Konigs-
berg, in Franconia), exerted a beneficial influence on Coper-

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^:he univebse."— disooyebibs in the celestial spaces* 805

niciis and his scholars^ Eliseticiis^ Bemhold^ aad Mostlin, so
also did these (though divided from them by a longer inter-
val of time) exert a rimilar influence on the labours of
Kepler, Galileo, and Newton. This is the connecting link
which, in the enchainment of ideas, unites the 16th and
17th centuries, and requires that, in describing the en-
larged astronomical views of the later of these two periods,
we should allude to the incitements which descended to it
from the former.

An erroneous, and unhappily still recently prevailing
opinion, (*^) regards Copernicus as having, through
timidity and fear of priestly persecution, represented the
earth's planetary movement, and the sun's position in the
centre of the whole planetary system, as a mere ''hypo-
thesis,'' which fulfilled the astronomical object of subjecting
the orbits of the heavenly bodies to convenient calculation,
''but which need not be regarded as true, or even as
probable.^' These singular words (*^) are indeed found
in the anonymous preface placed at the commencement
of Copemicus's work, and entitled '^De Hypothesibus
hujus operis/' but ihey do not belong to Copernicus,
end are in direct contradiction to his dedication to the
Pope, Paul m. The author of this preliminary notice
was, as Oassendi says most distinctly in his life of Copemi-
CQB, a mathematician named Andreas Osiandar, then living
rt Nuremberg, who, conjointly with Schoner, superintended
the printing of the book ''De Eevolutionibus,'' and who,
although he does not make express mention of any religious
scruples, would appear to have thought it advisable to term
the new views an hypothesis, and not, like Copernicus, a
demonstrated truth. The founder of our present system of

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806 EPOCHS IN THE HISTORY OF THE CONTEMPLATION 01

the universe (the most important parts of that system, the
grandest traits in the picture of the universe, unquestionably
belong to him) was no less distinguished by the courage
and confidence with which he propounded it, than by his
knowledge. He was in a high degree deserving of the fine
eulogium of Kepler, who, speaking of him in the introduc-
tion to the Eudolphine Tables, says, '^vir fuit maximo in-
genio, et quod in hoc exercitio (in combating prejudices)
magni momenti est, animo liber" Copernicus, in his de-
dication to the Pope, does not hesitate to term the generally
received opinion of the immobility and central position of
the earth an " absurd acroama,^' and to expose the stupidity
of those who adhere to so erroneous a belief. ''If,'' said
he, " any empty babbler (/laraioXoyoi), ignorant of mathe-
matical knowledge, should yet rashly pronounce sentence
upon his work, by wresting for that purpose some passage
from Holy Scripture (propter aliquem locum scripturse male
a^ suum propositum detortum), he should despise so pre-
sumptuous an assault. It was, indeed, generally known
that the celebrated Lact^mtius (who could not, it is true, be
reckoned among mathematicians), had spoken very child-
ishly (pueriliter) of the form of the earth, deriding those
who hold it to be. spherical. On mathematical subjects one
must write for mathematicians only. In order to shewthat,-
deeply penetrated with the truth of his results, he had na
cause to fear any condemnation, he addressed himself, from
a remote comer of the world, to the supreme visible head of
the Church, that he might protect him fr-om the tooth of
slander; adding, that the Churdi would, moreover, be
advantaged by his investigations on the length of the year
and the movements of the moon/' In regard to this last

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THE TJmVERSE. — ^DISCOVERIES IN THE CELESTIAL SPACES 307

remark it may be noticed, that astrology, and amendments
in the Calendar, were long chiefly efficacious in obtaining for
astronomy the protection of secular or ecclesiastical power;
as chemistry and botany were long regarded solely as sulv
servient to medicinal knowledge.

The free and powerful language employed by Copernicus,
the evident outpouring of deep internal conviction, suffi-
ciently refutes the assertion, that the system which bears his
immortal name was proposed as an hypothesis convenient
to calculating astronomers, but which might very well be
without foundation. '' By no other arrangement,'' he ex-
claims, with inspured enthusiasm, " have I been able to dis-
cover so admirable a symmetry of the universe^ so harmo-
nious a combination of orbits, than by placing the light of
the world (luceniam mundi), the sun, as on a kingly throne,
in the midst of the beautiful temple of nature, guiding
from thence the entire family of circum-revolving planets
(drcumagentem gubemans astrorum familiam) /' (^^^) Even
the idea of universal gravitation or attraction (appetentia
queedam naturalis partibus indita) towards the centre of the
world (centrum mundi), the sun, inferred from the force of
gravity in spherical bodies, appears to have floated before
the mind of this great man, as is shewn by a remarkable
passage {^^^) in the 9th chapter of the 1st book of the
'' Eevolutions/'

In passing in review the different stages of the develop-
ment of cosmical contemplations, we discover from the
earliest times more or less obscure anticipations of the
attraction of masses, and of centrifugal forces. Jacobi, in Im.
investigations on the mathematical knowledge of the Greeks,
(which are unfortunately still in manuscript), dweUs with

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808 EPOCHS IN THE HISTORY OP THE CONTEMPLATION Of

justice on ''the deep consideration of Nature by Anaxagoras,
from whom we hear> not without astonishment, that the
moon (*^7) if its force of rotation ceased would fall to the earth
ss a stone discharged from a sling/^ I have already, in my fir^
volume, when treating of the fall of aerolites, {^^) noticed
similar expressions of the Qazomenian, and of Diogenes of
Apollonia, respecting the " cessation or interruption of the
force of rotation/' Of the attracting force which the centre
of the earth exerts on all heavy masses removed from it^
Plato had a clearer idea than Aristotle ; who was, indeed,
like Hipparchus, acquainted with the • acceleration of bodies
in falling, but who did not correctly apprehend its cause.
In Plato, and according to "Democritus, attraction is
limited to bodies which have afiSnity with each other; or in
other words, to the tending together of homogeneous ele-
mentary substances. (*^9) But at a later period, probably in
the 6th century, the Alexandrian John Philoponus, a pupil of
Ammonius Hermese, ascribes the movements of cosmical bo-
dies to a primitive impulse, and combines with this idea that
of the fall of bodies, or the tendency of aU substances, heavy
or light, to come to the ground. (*7o) But the idea which
Copernicus divined, and which Kepler enunciated more
dearly in his fine work " de Stella Maitis,'' even applying
it (*^^) to tlie ebb and flood of the Ocean, we find invested
with new life, and rendered more fruitful (1666 and 1674)
by the sagacity of the ingenious Eobert Hooke. The
Newtonian theory of gravitation came next, and presented
ihe grand means of transforming the whole of physical
astronomy into a system of celestial mechanics, (^y^)

Copernicus, as we perceive not only from his dedication
^ the Pope, but also from several passages in the book

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l-HB TJNIVBESB. — DISCOVERIES IN THE CELESTIAL SPACES. 809

itself, was tolCTably well accquainted with the representations

which the ancients formed to themselves of the structure of

the Universe. In the period before Hipparchus, he however

only names Hicetas of Syracuse, (whom he always calls

Nicetas), Philolaus the Pythagorean, the Timseus of Plato,

• Ecphantus, Heraclides of Pontus, and the great geometer

ApoUonius of Perga. Of the two mathematicians who

oame nearest to his system, Aristarchus of Samos, and

Sdeucus the Babylonian, (*73) he only names the first .

without farther notice, and does not mention the second at

all. It has often been said that Copernicus was not

accquainted with the opinion of Aristarchus of Samos,

relative to the central position of the Sun and the planetary

character of the Earth, because the '^ Arenarius," and all

ihe works of Archimedes, were only published a year affcer

his death, a full century after the invention of the art of

printing; but in saying this, it is forgotten that, in the

dedication to Pope Paul III., Copernicus quotes a long

passage on Philolaus, Ecphantus, and Heraclides of Pontus,

from Plutarch's work "on the opinions of Philosophers'*

(iii. 13), and that he might have read in the same work

(ii. 24), that Aristarchus of Samos regarded the Sun as one

of the fixed stars. Among aU the opinions of the Ancients,

the greatest influence on the direction and gradual develop-

.iftcnt of the views of Copenaicus, would appear, irom (Jas-

sendi's statements, to have been exercised by a passage in the

enqrclopsedic work of Martianus Mineus Ca^tella of Madaura,

written in a semi-barbarous language, and by the System of

the World of ApoUonius of Perga. According to the system

described by Martianus Mineus, which has been confidently

ascribed (^^4^ sometimes to the Egyptians, and sometimes.

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810 EPOCHS TN THE HISTORY OF THE CONTEMPLATION OP

to the Chaldeans, the Earth rests immoveably in the centre,
and the Sun revolves round it as a planet, while Mercury
and Venus accompany, and revolve round the Sun as his
sateUites. Such a view of the structure of the Universe
might tend to prepare the way for that of the Sun's central
force. There is nothing either in the Ahnagest, or in the
writings of the Ancients generally, or in the work of
Copernicus " de Revolutionibus,'' to justify Gassendi's
decided assertion as to the perfect similarity of the System
of Tycho Brahe with that of ApoUonius of Perga. Aftet
Booth's complete investigation, nothing more need be said
respecting the confusion of the System of Copernicus with
that of the Pythagorean Philolaus, in which the non-rotating
Earth (the Antichton or opposite earth is not itself a planet,
but only the opposite hemisphere of our planet,) moves, as
well as the sun, round the " hearth of the world,'' the central
foe or flame of life of the entire planetary system.

The scientific revolution commenced by Copernicus had
the rare good fortune (setting aside a brief retrograde
movement in Tycho Brahe's hypothesis), of proceeding
uninterruptedly forward to its object, — the disicovery of
the true structure of the universe. The rich supply of
exact observations which were famished by Tycho Brahe
himseK, the zealous opponent of Copernicus, laid the
foundation of the discovery of those unchanging laws of
the planetary movements, which prepared for Kepler im-
perishable fame, and which, when interpreted by Newton,
and shewn by him to be theoretically necessary, were
transferred to the bright domain of thought, and became
the " intelligent recognition of nature." It has been
' -'eniously said, (*76) though perhaps with too feeble an

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THE ITNIVERSB. — ^DISCOVEBIES IN THE CELESTIAL SPACES. 311

appreciation of the free, great, and independent spirit
which conceived the theory of gravitation, " Kepler wrote a
book of laws, Newton the spirit of the laws/'

The figurative poetic myths of the Pythagorean and
Platonic pictures of the universe, {*76) variable as the
imagination from which they had their birth, still found
a partial reflex in Kepler; they warmed and cheered his
often saddened spirits, but they did not divert him from
the earnest path which he steadfastly pursued, and of which
he reached the goal, (*77) 12 years^ before his death, on the
memorable night of the 15th of May, 1618. Copernicus
had afforded a sufficient explanation of the apparent
revolution of the heaven of the fixed stars, by the diurnal
rotation of the Earth around her axis; and by the annual
movement round the sun, had given an equally perfect
solution of the most striking movements of the planets
(their retrogressions and stationary appearances), — and had
thus found the true cause of what is called the "second
inequality of the planets.^' The first inequality, the non-
uniform movement of the planets in their orbits, he left
unexplained. True to the ancient Pythagorean principle, of
the inherent perfection of circular movements, Copernicus, in
his structure of the universe, needed to add to the " excen •
trie" circles having unoccupied centres, some of the epicv les
of ApoUonius of Perga. Bold as was the path struck out,
men could not free themselves at once from all earlier view?.

The equal distance at which the fixed stars continue from
each other, whilst the whole heavenly vault moves from East
to West, had led to the representation of a firmament,-^
a solid crystal sphere, — ^in which Anaximenes, (who was
perhaps not much later than Pj^hagoras), imagined the stars

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812 EPOCHS IN THE HISTOBY OP THE CONTEMPLATION OP

to be fastened as if nailed. (*78) Geminus the Ehodian, a
cotemporary of Cicero^s, doubted the constellations being
all in the same plane ; some, he thought, were higher and



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