F. (François) Arago.

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known to all engineers ; it guides them in practice, and
secures them from the gross faults committed by their



To give an idea of its importance to the generality of
tlae world, I should be inclined to say, notwithstanding
the fantastic appearance of the comparison, that Carnot
has extended to the material world a proverb whose
truth was only established, before his time, in the moral
world ; that " much noise * and little work " is a saying
henceforth quite as applicable to the effective labours of
machines, as to the enterprises of certain individuals
whose petulance gives rise to the hope of wonders des-
tined not to be realized. In addressing men of learning,
I would beg them to distinguish carefully between the
invention of the material organs by whose aid forces
transmit their action from one point to another, and the
discovery of those primordial truths which are applicable
indistinctively to all imaginable systems ; I will endeav-
our to show that in this first respect the ancients wei-e
perhaps not inferior to us. The screw of Archimedes,
the series of toothed wheels of Ctesibius, the hydrostatic
fountains of Heron of Alexandria, the steam rotating
machine of the same engineer, a great number of war-
like machines, and amongst them the balista, might all be
brought forward to strengthen my view. In the field of
theoretical truths, on the contrary, the preponderance of
the moderns would show itself incontestable. f There
we should see successively, in all their brilliancy, in Hol-

* The proverb does not fit at all neatly, unless "noise " be taken
to mean " iiTegnlarity ; " some good machines are very noisy. —

t The question is rather unfairly stated ngainst the ancients; for
Arago speaks as if Archimedes, &c., had only made their machines,
and not been masters of the principles, which involved as much pri-
mordial truth as any other discoveries. A fairer distinction seems to
be, that the moderns launched out into realms where theory alone
couhl point out the wny ; the ancients were led on by experiment and
observation. — Translator.


land, Stevin and Huyghens ; in Italy, Galileo and Tor-
ricelli ; in England, Newton and Maclaurin ; in Swit-
zerland, Bernouilli and Euler ; in France, Pascal, Va-
rignon, D'Alembert, Lagrange, and Laplace.

Well, Gentlemen, those are the illustrious personages
amongst whom Carnot made a place for himself by his
beautiful theorem.

Perhaps, indeed, I ought to be afraid that, by insisting
any longer on the inconvenience of abrupt changes, I
may inspire my audience with the desire that I should,
notwithstanding every inconvenience, pass "abruptly" to
another subject ; nevertheless, I will hazard a few more

We have just been talking frequently of lost force ; the
expression is correct when we compare the actual effect
of a machine with that which it might have produced if,
all other circumstances remaining the same, the construc-
tor had carefully avoided sudden changes of speed ; but
it must not be imagined that any force, or fraction of a
force, can be ever annihilated, in the grammatical accep-
tation of the word ; all that which is not found in the
useful effect produced by the motive power, nor in the
amount of foi'ce which it retains after having acted, must
have gone towards the shaking and destroying of the

This last remark was necessary for the appreciation of
the eminent and incontestable services which Carnot's
theorem has already rendered and will render more and
more to art and industry. If I were not afraid of the
incredulity which would, at first sight, attach itself to my
words, I would add that this same theorem of analysis and
mechanics has also played a great part in the numerous
events of our Revolution, whose character Carnot's deter-


minations were able to change. However, I have said
too much not to complete the idea.

In my youth, encouraged by the good-will and friend-
ship with which Carnot was kind enough to honour me,
I sometimes took the liberty of calling his recollection to
those great epochs of our revolutionary annals, when
parties, in their frenzied convulsions, were destroyed,
conquered, or merely appeased, by abrupt and violent
measures, by real coups d'etat. Then I would ask our
colleague how he, alone amongst all the others, had con-
stantly hoped to arrive at the goal without shocks, and
without infringement of the laws ; his answer, always
the same, had become deeply graven on my memory ;
but what was my surprise when, emerging one day from
the round of studies which a young astronomer should
always impose on himself, I found, word for word, this
constant answer which we have just been discussing in
the enunciation of a theorem of mechanics ; when I saw
that our colleague had always discoursed with me on the
political organization of society precisely in the same
manner as he speaks in his work of a machine, in which
abrupt changes necessarily involve great losses of force,
and sooner or later bring about the comj^lete dislocation
of the system ! *

Can it then be true, Gentlemen, that in the weakness
of the human race, the loftiest spirits have been so little
convinced of the goodness and truth of the determinations
which their hearts inspire them with, that they have
found it necessary to confirm and corroboi'ate them with
more or less forced assimilations ?

* This pai-allel cannot be deemed exact: in the Revolution they
wanted to destroy one machine altogether, and supply quite another;
so the rules applicable to steady machinery, or government, do not
apply. — Translalor.


This doubt will not astonish you if I add that one of
the learned men whose works have conferred the great-
est distinction on this Academy, conducted himself on all
difficult occasions (so we are to believe) according to the
following assuredly very convenient maxim : " Water
takes exactly the form of the vase which contains it ; a
wise mind should as faithfully model itself on the circum-
stances of the moment."

I might quote also another of our colleagues, equally
celebrated, of whom a certain personage asked one day
in my presence, by what secret he had passed through
the terrible periods of our civil discords without mishap :
" Every country in a state of revolution," answered he,
"is a carriage of which the horses have taken the bit
between their teeth ; to wish to stop the horses is to rush
on a catastrophe from gayety of heart ; he who leaps from
the carriage exposes himself to being crushed under the
wheels ; the best plan is to abandon one's self to the
movement, and shut one's eyes ; so did I ! "*

In the work whose analysis has carried me farther
than I expected, Carnot has devoted some lines to the
question of perpetual motion ! He shows not only that
every machine, of whatever form, abandoned to itself will
stop, but he moreover assigns the moment at which that
must happen.

The arguments of our colleague are excellent ; no
geometer will dispute their exactness ; may we yet hope
that they will nip in the bud the numerous projects which
every year, or rather "every spring," sees burst into
flower ?

This is what we cannot hope for. The contrivers of

* If the horses could not be stopped, surely an attempt should be
made to guide them. — Translator.


perpetual movements would no more comprehend the
work of Carnot, than the discoverers of the quadrature
of the circle or the trisection of the angle understand the
geometry of Euclid.* Science is not needed by them ;
they owe their discovery to a sudden supernatural inspi-
ration. Moreover, nothing discourages them, nothing un-
deceives them ; take, for example, that artist, otherwise
highly estimable, who, without perceiving any thing inno-
cently burlesque in the terms of his request, begged me
to go and see ^^wliy all his perpetual movements had


Carnot was one of the first officers of the French army
that loyally and enthusiastically embraced the regenera-
tive views of the National Assembly. Nevertheless, the
annals of the Revolution only commence making mention
of him in 1791.

Certain writers wrongly take the spirit of proselytism
as the just measure of the sincerity of political convic-
tions ; they do not understand how a retired and studious
life may ally itself to a profound desire for social reforms ;
Carnot's two years of inaction seem to them quite a phe-
nomenon. Now, guess how they deemed it advisable to
explain it. They place our member amongst the emigres
of Coblentz ; thus his republican tendencies would only
date from the period at which he furtively reentered
France. I will not oflfend you. Gentlemen, by refuting
such a ridiculous supposition.

In 1791 Carnot was in garrison at Saint-Omer, and

* Not quite a just comparison. There is no reason why these geo-
metric feats must be impossible, as is the case with perpetual motion.
— Translator.


there married Mademoiselle Dupont, daughter of a mili-
tary administrator born in that country. His political
principles, the moderation of his conduct, and his varied
knowledge, shortly procured him the honour of represent-
ing the department of the Pas-de-Calais in the Legisla-
tive Assembly. From this period Carnot gave himself
up entirely to the imperious duties which were imposed
on him, either by the choice of his fellow-citizens, or the
voice of his colleagues. The public character almost
entirely absorbed that of the geometer : this last only
showed itself henceforth at long intervals.

Here, Gentlemen, two roads present themselves to me ;
one is smooth and open, the other bordered by precipices.
If I listened to some persons whose good will towards me
has rendered them timid, I should not hesitate to choose
the first. To take the other would be to incur, I am
well aware, the reproach of imprudence and blindness.
Heaven keep me from supposing that I am strong enough
to struggle against such clear and decided opinions ; but
wretched considerations of self-love will always vanish
from my sight before the sentiment of duty. Now, I ask,
should I not deeply wound the public conscience if, in this
area consecrated to the arts, letters, and sciences, I con-
fined myself to speaking of Carnot as an academician ?
Without doubt one might, whilst developing before you
the long series of discoveries of this or that illustrious
savant, endowed during his life with the title of senator,
legitimately — very legitimately — cry out that posterity
would not preserve any recollection of functions without
effect, and which, moreover, descending from one degra-
dation to another, had ended by reducing themselves to a
monthly communication with the treasury ; but it would
be an antinational and ungrateful act to apply such words


to the great shade of Carnot. I am desired, wished, and
almost ordered to do this. Well ! I consent, I will not
speak of the drama whose "denouement" was the tragic
death of the successor of a hundred kings, and the over-
throw of the monarchy ; nevertheless I, a decided parti-
san of the abohtion of the punishment of death, do not
perceive the supposed difficulties of position which should
have hindered me from abandoning myself here publicly
to the inspirations of my conscience ; nor do I see any-
better, why I should have abstained from rendering this
assembly aware of the deep aversion which I profess for
every political decree issued by a political body. Must I
say it, in a word ? — a fraternal solicitude for the memory
of Carnot did not appear to me to require the sacriSce
which is imposed upon me. Is it forgotten how contem-
poraneous history would have furnished me with accusing
documents against the thousand courtiers whose inter-
ested, hypocritical, and antinational manoeuvres cast the
monarch into a labyrinth without exit, caused him to be
unanimously declared culpable by the national represen-
tatives, and were much more instrumental than the ardent
deraocratical ideas of the Convention in rendering the
catastrophe of the 21st of January inevitable ? If from
these high moral considerations I had descended to a
minute appreciation and technical discussion of facts,
such as one has to submit to a court of appeal or of re-
peal, I should, in company with all upright minds — with
our Daunou, for example, — have found the illegality of
the celebrated trial, less in the nature of the sentence,
less in the severity of the punishment inflicted, than in
the very composition of the tribunal, or in the usurpation
of power which had given birth to it. Now, Gentlemen,
— and this is a point I should not have failed to remark



on, — when the Convention was investing itself with the
riglit of pronouncing on the fate of Louis XVI. ; wlien
after this stroke it was regulating its jurisprudence ; when
it was simultaneously attributing to itself the functions of
accuser and judge, Carnot was absent from Paris ; he
was fulfilling with the armies one of those important
missions, the difficulties of which his ardent pati'iotisni
always found the secret of surmounting.



The concession which was required of me, if I con
formed exactly to it, nevertheless authorizes me to show
myself less docile on the subject of another period of
Carnot's life, which is still more stormy and difficult.
Let us avoid — I wiUingly consent to it — carrying our at-
tention back to certain irritating phases of our civil dis-
cords ; for my own part, I will only put one condition on
it ; that is, that the memory of none of our members
shall suffisr by it. Well, Gentlemen, suppose for a mo-
ment that I be now silent concerning the " Member of
the Committee of Public Safety ; " would it not be con-
cluded from my silence — nay more, would it not be right
to conclude from thence — that I have recognized the
impossibility of repelling the violent, numerous, and
trenchant attacks of which he was the object ? These
attacks Carnot, whilst living, was able to disdain ; in me,
on the contrary, it was incumbent to seek for their origin,
and conscientiously weigh their value. I say it with-
out exaggeration, no human power should have decided
me to cause the name of Carnot to reecho here, unless
I had discovered the honourable and patriotic causes of
certain acts which the most atrocious of calumnies, politi-



ciil calumny, had soiled with its infected slaver. My
work, furthermore, was not without some difficulties.
Perhaps no one henceforth will have the opportunity
to reunite its elements. In a few years, indeed, the
colleagues and fellow labourers of Carnot, from whom
I have been able to gather some lights and evidences,
will have paid the debt of nature.

In 1793 the convention was the only organized power
in the State, capable of opposing an effective dyke
against the overflow of enemies, who came from all
parts of Europe to cast themselves on France, and
menace her nationality. The nationality of a people is
like honour : the slightest wound to it becomes mortal.
Such were, Gentlemen, the sentiments of very many
members of the Convention, whose memory France re-
veres ; such were the ties which attached them to the
perilous post whither election had called them.

In creating the " Committee of Public Safety," (6th
April 1793,) the Convention had reserved to itself the
choice of its members. Up to the famous 31st of May,
it counted only neutral members, or at any rate such as
were strangers to the factions of the Assembly who were
combating each other to the death. After several partial
renewals it was composed, on the 11th September 1793,
of Robespierre, Saint-Just, Couthon, Collot d'Herbois,
Billaud-Varennes, Prieur (of the Marne), Prieur (of the
Cote-d'Or), Carnot, Jean-bon Saint- Andre, Barere, He-
rault de S(;chelles, and Robert Lindet.

The Convention, when vt delegated such great powers
to the Committee of Public Safety, desired that every
affair should be a subject of profound discussion and de-
liberation in that committee ; that the majority of voices
should decide. The decisions, to acquire the force of


law, under p.ain of being null, must be furnished with a
certain number of signatures. These prescriptions had
the greatest of all faults, that of being completely im-
practicable. Man has discovered in our days the secret
of going ten times as flist when he travels, of using less
force when he acts, and of casting his searching gaze
into the regions of infinity ; but he has not yet discovered
the means of reading a page of manuscript in less time
than it formerly occupied. We must allow that in that
respect, the most humble merchant's clerk would advance
equally with Caesar or Cicero, Descrates or Bossuet. The
innumerable dispatches which the Committee of Public
Safety received daily, from all points of the frontiers
menaced or invaded, from all the towns and villages of
the interior where the promoters of a new political or-
ganization were in violent conflict with the prejudices
and interests of the privileged classes, could not be ma-
turely examined. Zeal, activity, and devotion were not
sufficient to expedite so many weighty affairs ; a reform '
was indispensable ; it concerned the safety of France.
Two different ways presented themselves : they could
demand the reorganization of the Committee, or divide
the work amongst its various membei-s. The reor-
ganization of the Committee, in presence of a powerful
enemy, and in the midst of unheard-of difficulties (such
as no period of the history of nations had given an ex-
ample of), would have excited in the Convention new
ferments of disorder, enervated its magic power, and
compromised the defence of the territory. The division
of labour should prevail, and it did prevail. Carnot
was charged with the organization of the armies and
with their operations ; Prieur (of the Cote-d'Or) with
arming them ; Robert Lindet with provisioning them ;


Robespierre, Saint-Just, Couthon, Billaud-Varennes, and
Collot d'Herbois, reserved to themselves politics, general
police, and measures of security. In each species of
subject one signature alone was important, and .carried
responsibility ; the others, though requii^ed by law, were
to be regarded as the accomplishment of a simple for-
mality : it was evident, indeed, that they would have to
be given without discussion and even without examina-

Such were. Gentlemen, the bases of the agreement
which Robert Lindet, for his personal security, caused
to be put down in a written declaration, and by the aid
of which the members of the Committee of Public Safety
expected to be able, without passing beyond the terms of
their mandate, to exorcise the storms which were menac-
ing the country from all sides. This confiding arrange-
ment will doubtless be blamed : some will cry out at its
illegality, others at its imprudence. I will remind the
first, that the members of the Committee, entangled in a
faulty organization, were every day at issue with an im-
possibility, and that the w^ord impossible is French, what-
ever national amour propre may have said of it at a
period when the admirable triumphs of our armies seemed
to warrant all hyperbolic speeches. The reproach of im-
prudence I admit without reserve. I add that, on the
part of Carnot, this imprudence was voluntary ; that in
resigning himself to signing, without examination, the
decisions of all his colleagues, he wittingly made the
greatest of all sacrifices to France ; that he placed his
honour in the hands of several of his declared enemies ;
that, counting eventually on the tardy justice of posterity,
he hoisted that almost superhuman motto of one of the
most powerful organizations which the Revolution brought


to land from tlie waves of the people, — that motto which
moreover every sincere patriot endowed with any warmth
of soul might avow : Perish my reputation sooner than
my country.

You will have already understood, Gentlemen, that my
design is to divide into two distinct categories the mem-
bers of the Committee of Public Safety, and the long
series of its acts.

The terrible Committee contributed powerfully to the
defence of the territory : thanks to the Committee !
There was no other way of resisting the thousand pas-
sions let loose, than by vigour of determination ; by
energy of will ; by seizing everywhere with a grasp of
iron the barbarians who, auxiharies of i\\Q foreigner,
would have torn out the entrails of their country ; the
Committee showed itself energetic and vigorous ; it
often showed the grasp of iron : all praise to the Com-
mittee !

But, Gentlemen, firmness soon degenerates into frenzy ;
soon they immolate the rich for the sole reason that they
are rich ; soon terror reigns through France from one
end to the other ; terror carries mourning and despair
without distinction, as well into the family of the com-
mon soldier as into that of the general ; she seizes her
victims equally in the humble dwelling of the artisan, as
in the gilded palace of the former duke and peer : she
spares neither age nor sex ; she strikes blindly all shades
of opinion ; finally, adding dissimulation to cruelty, she
parodies the forms of justice ! Ah ! Gentlemen, at this
spectacle the heart grows faint, and hope withers ; tlie
liveliest and most ardent sympathies gives jilace to pro-
found grief.

I am aware that attempts have been made to explain.


even to excuse, those bloody saturnalia, by referring them
to the will of the people. But if I judge of the people
of 1793, whom I have not known, by that which I saw
in action in 1830, the explanation is false. I do not
hesitate to say so. The people in a moment of efifer-
vescence and blindness, sometimes fall into culpable
actions, but it has never associated itself with daily
barbarities. It is degrading the people to say, that fear
only could drive it to meet inimical hordes : nor are its
sentiments better known, when it is insinuated that it
wished for the death of one of the members of this
Academy who honoured France by his genius ; and the
death of another of our co-academicians, who did honour
to human nature by his vh-tue^ No, Gentlemen ; no !
in the noble country of France, the death of Lavoisier,
the death of Malesherbes, could not be ordered by con-
siderations for the public good. No excuses for such
crimes ; they must be branded to-day, they must be
branded to-morrow ; they must be branded for ever.
Devoted by sentiment, by conviction, by the irresistible
power of logic to the worship of liberty, let us repel far
from us the execrable thought, that the scaflfold is the
inevitable auxihary of democracy.

The crimes that I have been openly denouncing have
been in some measure personified by France, by Europe,
by the whole world : these crimes are Robespierre !
Some young, some estimable writers, who are now de-
spoiling our revolutionary annals with the indefatigable
patience of the Benedictines of former ages, think they
have discovered that public opinion is quite wrong.
According to them, llobespierre and his partisans have
much less contributed to the sanguinary acts of terror,
than the Billaud-Vai'cnnes, the Collot d'Herbois, or the


Heberts. There is courage, Gentlemen, in coming for-
ward as the defenders of a man, who for nearly half a
century has been regarded as the symbol, the type, of
political cruelty. On this claim alone the new historians
hope to be listened to without prejudice : an honourable
character, joined to incontestable talent, gives them no
less a right to the serious attention of the public. For
my part, I have no business here to try to pierce those
thick clouds ; my subject does not require it ; I will ab-
solve Carnot from all participation in great crimes,
without examining whether they should be imputed to
Collot d'Herbois, or to Billaud-Varennes, rather than to
Robespierre, Saint-Just, and Couthon.

In no instance of his long political career, was Carnot
a party-man. Never was he found to try to bring for-
ward his opinions, his systems, his principles, by tortuous
ways that honour, that justice, that probity, could not
have acknowledged.

In reporting on the 9th of June 1792, on the commis-

Online LibraryF. (François) AragoBiographies of distinguished scientific men (Volume 2) → online text (page 3 of 38)