Biographies of Distinguished Scientific Men Part 8

INTRODUCTION.

Gentlemen,--The learned man, ill.u.s.trious in so many ways, whose life I am going to relate, was taken from France half a century ago. I hasten to make this remark, so as thoroughly to show that I have selected this subject without being deterred by complaints which I look upon as unjust and inapplicable. The glory of the members of the early Academy of Sciences is an inheritance for the present Academy. We must cherish it as we would the glory of later days; we must hallow it with the same respect, we must devote to it the same worship: the word _prescription_ would here be synonymous with ingrat.i.tude.

If it had happened, Gentlemen, that amongst the academicians who preceded us, a man, already ill.u.s.trious by his labours, and, without personal ambition, yet thrown, despite himself, into the midst of a terrible revolution, exposed to a thousand unrestrained pa.s.sions, had cruelly disappeared in the political effervescence--oh! then, any negligence, any delay in studying the facts would be inexcusable; the honourable contemporaries of the victim would soon be no longer there to shed the light of their honest and impartial memory on obscure events; an existence devoted to the cultivation of reason and of truth would come to be appreciated only from doc.u.ments, on which, for my part, I would not blindly draw, until it shall be proved that, in revolutionary times, we can trust to the uprightness of parties.

I felt in duty bound, Gentlemen, to give you a sketch of the ideas that have led me to present to you a detailed account of the life and labours of a member of the early Academy of Sciences. The biographies which will soon follow this, will show that the studies I have undertaken respecting Carnot, Condorcet, and Bailly, have not prevented me from attending seriously to our ill.u.s.trious contemporaries.

To render them a loyal and truthful homage, is the first duty of the secretaries of the Academy, and I will religiously fulfil it; without binding myself, however, to observe a strict chronological order, or to follow the civil registers step by step.

Eulogies, said an ancient authority, should be deferred until we have lost the true measure of the dead. Then we could make giants of them without any one opposing us. On the contrary, I am of opinion that biographers, especially those of academicians, ought to make all possible haste, so that every one may be represented according to his true measure, and that well-informed people may have the opportunity of rectifying the mistakes which, notwithstanding every care, almost inevitably slip into this sort of composition. I regret that our former secretaries did not adopt this rule. By deferring from year to year to a.n.a.lyze the scientific and political life of Bailly with their scruples, and with their usual talents, they allowed time for inconsiderateness, prejudice, and pa.s.sions of every kind, to impregnate our minds with a mult.i.tude of serious errors, which have added considerably to the difficulty of my task. When I was led to form very different opinions from those that are found spread through some of the most celebrated works, on the events of the great revolution of 1789, in which our fellow-academician took an active part, I could not be so conceited as to expect to be believed on my own word. To propound my opinions then was insufficient; I had also to combat those of the historians with whom I differed. This necessity has given to the biography that I am going to read an unusual length. I solicit the kind sympathy of the a.s.sembly on this point. I hope to obtain it, I acknowledge, when I consider that my task is to a.n.a.lyze before you the scientific and literary claims of an ill.u.s.trious colleague, to depict the uniformly n.o.ble and patriotic conduct of the first President of the National a.s.sembly; to follow the first Mayor of Paris in all the acts of an administration, the difficulties of which appeared to be above human strength; to accompany the virtuous magistrate to the very scaffold, to unroll the mournful phases of the cruel martyrdom that he was made to undergo; to retrace, in a word, some of the greatest, some of the most terrible events of the French Revolution.

INFANCY OF BAILLY.--HIS YOUTH.--HIS LITERARY ESSAYS.--HIS MATHEMATICAL STUDIES.

John Sylvain Bailly was born at Paris in 1736. His parents were James Bailly and Cecilia Guichon.

The father of the future astronomer had charge of the king's pictures.

This post had continued in the obscure but honest family of Bailly for upwards of a century.

Sylvain, while young, never quitted his paternal home. His mother would not be separated from him; it was not that she could give him the instruction required from masters in childhood, but a tenderness, allowed to run to the utmost extreme, entirely blinded her. Bailly then formed his own mind, under the eye of his parents. Nothing could be better, it seemed, than the boyhood of our brother academician, to verify the oft-repeated theory, touching the influence of imitation on the development of our faculties. Here, the result, attentively examined, would not by a great deal agree with the old hypothesis. I know not but, every thing considered, whether it would rather furnish powerful weapons to whoever would wish to maintain that, in its early habits, childhood rather seeks for contrasts.

James Bailly had an idle and light character; whilst young Sylvain from the beginning showed strong reasoning powers, and a pa.s.sion for study.

The grown man felt in his own element while in noisy gayety.

But the boy loved retirement.

To the father, solitude would have been fatal; for to him life consisted in motion, sallies, witty conversations, free and easy parties, the little gay suppers of those days.

The son, on the contrary, would remain alone and quite silent for whole days. His mind sufficed to itself; he never sought the fellowship of companions of his own age. Extreme steadiness was at once his habit and his taste.

The warder of the king's pictures drew remarkably well, but did not appear to have troubled himself much with the principles of art.

His son Sylvain studied those principles deeply, and to some purpose; he became a theoretic artist of the first cla.s.s, but he never could either draw or paint even moderately well.

There are few young people who would not, at some time or other, have wished to escape from the scrutinizing eyes of their parents. The contrary was the case in Bailly's family, for James used sometimes to say to his friends or to his servants, "Do not mention this peccadillo to my son. Sylvain is worth more than I am; his morals are very strict.

Under the most respectful exterior, I should perceive in his manner a censure which would grieve me. I wish to avoid his tacit reproaches, even when he does not say a word."

The two characters resembled each other only in one point--in their taste for poetry, or perhaps we ought to say versification, but even here we shall perceive differences.

The father composed songs, little interludes, and farces that were acted at the _Italian Comedy_; but the son commenced at the age of sixteen by a serious work of time,--a tragedy.

This tragedy was ent.i.tled _Clothaire_. The subject, drawn from the early centuries of the French History, had led Bailly by a curious and touching coincidence to relate the tortures inflicted on a Mayor of Paris by a deluded and barbarous mult.i.tude. The work was modestly submitted to the actor Lanoue, who, although he bestowed flattering encouragement on Bailly, dissuaded him frankly from exposing _Clothaire_ to the risk of a public representation. On the advice of the comedian-author, the young poet took _Iphygenia in Tauris_ for the subject of his second composition. Such was his ardour, that by the end of three months, he had already written the last line of the fifth act of his new tragedy, and hastened to Pa.s.sy, to solicit the opinion of the author of _Mahomet II_. This time Lanoue thought he perceived that his confiding young friend was not intended by nature for the drama, and he declared it to him without disguise. Bailly heard the fatal sentence with more resignation than could have been expected from a youth whose budding self-esteem received so violent a shock. He even threw his two tragedies immediately into the fire. Under similar circ.u.mstances, Fontenelle showed less docility in his youth. If the tragedy of _Aspar_ also disappeared in the flames, it was not only in consequence of the criticism of a friend; for the author went so far as to call forth the noisy judgment of the pit.

Certainly no astronomer will regret that any opinions either off-hand or well digested, on the first literary productions of Bailly, contributed to throw him into the pursuit of science. Still, for the sake of principle, it seems just to protest against the praises given to the foresight of Lanoue, to the sureness of his judgment, to the excellence of his advice. What was it in fact? A lad of sixteen or seventeen years of age, composes two tolerable tragedies, and these essays are made irrevocably to decide on his future fate. We have then forgotten that Racine had already reached the age of twenty-two, when he first appeared, producing _Theagenes and Charicles_, and the _Inimical Brothers_; that Crebillon was nearly forty years of age when he composed a tragedy on _The Death of the Sons of Brutus_, of which not a single verse has been preserved; finally, that the two first comedies of Moliere, _The three rival Doctors_ and _The Schoolmaster_, are no longer known but by their t.i.tles. Let us recall to mind that reflection of Voltaire's: "It is very difficult to succeed before the age of thirty in a branch of literature that requires a knowledge of the world and of the human heart."

A happy chance showed that the sciences might open an honourable and glorious path to the discouraged poet. M. de Moncaville offered to teach him mathematics, in exchange for drawing-lessons that his son received from the warder of the king's pictures. The proposal being accepted, the progress of Sylvain Bailly in these studies was rapid and brilliant.

BAILLY BECOMES THE PUPIL OF LACAILLE.--HE IS a.s.sOCIATED WITH HIM IN HIS ASTRONOMICAL LABOURS.

The mathematical student soon after had one of those providential meetings which decide a young man's future fate. Mademoiselle Lejeuneux cultivated painting. It was at the house of this female artist, known afterwards as Madame La Chenaye, that Lacaille saw Bailly. The attentive, serious, and modest demeanour of the student charmed the great astronomer. He showed it in a most unequivocal manner, by offering, though so avaricious of his time, to become the guide of the future observer, and also to put him in communication with Clairaut.

It is said that from his first intercourse with Lacaille, Bailly showed a decided vocation for astronomy. This fact appears to me incontestable.

At his first appearance in this line, I find him a.s.sociated in the most laborious, difficult, and tiresome investigations of that great observer.

These epithets may perhaps appear extraordinary; but they will be so only to those who have learnt the science of the stars in ancient poems, either in verse or in prose.

The Chaldaeans, luxuriously reclining on the perfumed terraced roofs of their houses in Babylon, under a constantly azure sky, followed with their eyes the general and majestic movements of the starry sphere; they ascertained the respective displacements of the planets, the moon, the sun; they noted the date and hour of eclipses; they sought out whether simple periods would not enable them to foretell these magnificent phenomena a long time beforehand. Thus the Chaldaeans created, if I may be allowed the expression, _Contemplative Astronomy_. Their observations were neither numerous nor exact; they both made and discussed them without labour and without trouble.

Such is not, by a great deal, the position of modern astronomers.

Science has felt the necessity of the celestial motions being studied in their minutest details. Theories must explain these details; it is their touchstone; it is by details that theories become confirmed or fall to the ground. Besides, in Astronomy, the most important truths, the most astonishing results, are based on the measurement of quant.i.ties of extreme minuteness. Such measures, the present bases of the science, require very fatiguing attention, infinite care, to which no learned man would bind himself, were he not sustained, and encouraged by the hope of attaining some capital determination, through an ardent and decided devotion to the subject.

The modern astronomer, really worthy of the name, must renounce the distractions of society, and even the refreshment of uninterrupted sleep. In our climates during the inclement season, the sky is almost constantly overspread by a thick curtain of clouds. Under pain of postponing by some centuries the verification of this or that theoretic point, we must watch the least clearing off, and avail ourselves of it without delay.

A favourable wind arises and dissipates the vapours in the very direction where some important phenomenon will manifest itself, and is to last only a few seconds. The astronomer, exposed to all the transitions of weather, (it is one of the conditions of accuracy,) the body painfully bent, directs the telescope of a great graduated circle in haste upon the star that he impatiently awaits. His lines for measuring are a spider's threads. If in looking he makes a mistake of half the thickness of one of these threads, the observation is good for nothing; judge what his uneasiness must be; at the critical moment, a puff of wind occasioning a vibration in the artificial light adapted to his telescope, the threads become almost invisible; the star itself, whose rays reach the eye through atmospheric strata of various density, temperature, and refrangibility, will appear to oscillate so much as to render the true position of it almost una.s.signable; at the very moment when extremely good definition of the object becomes indispensable to insure correctness of measures, all becomes confused, either because the eye-piece gets steamed with vapour, or that the vicinity of the very cold metal occasions an abundant secretion of tears in the eye applied to the telescope; the poor observer is then exposed to the alternative of abandoning to some other more fortunate person than himself, the ascertaining a phenomenon that will not recur during his lifetime, or introducing into the science results of problematical correctness.

Finally, to complete the observation, he must read off the microscopical divisions of the graduated circle, and for what opticians call _indolent vision_ (the only sort that the ancients ever required) must subst.i.tute _strained vision_, which in a few years brings on blindness.[6]

When he has scarcely escaped from this physical and moral torture, and the astronomer wishes to know what degree of utility is deducible from his labours, he is obliged to plunge into numerical calculations of repelling length and intricacy. Some observations that have been made in less than a minute, require a whole day's work in order to be compared with the tables.

Such was the view that Lacaille, without any softening, exhibited to his young friend; such was the profession into which the adolescent poet plunged with great ardour, and without having been at all prepared for the transition.

A useful calculation const.i.tuted the first claim of our tyro to the attention of the learned world.

The year 1759 had been marked by one of those great events, the memory of which is religiously preserved in scientific history. A comet, that of 1682, had returned at the epoch foretold by Clairaut, and very nearly in the region that mathematical a.n.a.lysis had indicated to him. This reappearance raised comets out of the category of sublunary meteors; it gave them definitely closed curves as...o...b..ts, instead of parabolas, or even mere straight lines; attraction confined them within its immense domain; in short, these bodies ceased for ever to be liable to superst.i.tion regarding them as prognostics.

The stringency, the importance of these results, would naturally increase in proportion as the resemblance between the announced orbit and the real orbit became more evident.

This was the motive that determined so many astronomers to calculate the orbit of the comet minutely, from the observations made in 1759, throughout Europe. Bailly was one of those zealous calculators. In the present day, such a labour would scarcely deserve special mention; but we must remark that the methods at the close of the eighteenth century were far from being so perfect as those that are now in use, and that they greatly depended on the personal ability of the individual who undertook them.

Bailly resided in the Louvre. Being determined to make the theory and practice of astronomy advance together, he had an observatory established from the year 1760, at one of the windows in the upper story of the south gallery. Perhaps I may occasion surprise by giving the pompous name of _Observatory_ to the s.p.a.ce occupied by a window, and the small number of instruments that it could contain. I admit this feeling, provided it be extended to the Royal Observatory of the epoch, to the old imposing and severe ma.s.s of stone that attracts the attention of the promenaders in the great walk of the Luxembourg. There also, the astronomers were obliged to stand in the hollow of the windows; there also they said, like Bailly: I cannot verify my quadrants either by the horizon or by the zenith, for I can neither see the horizon nor the zenith. This ought to be known, even if it should disturb the wild reveries of two or three writers, who have no scientific authority: France did not possess an observatory worthy of her, nor worthy of the science, and capable of rivalling the other observatories of Europe, until within these ten or twelve years.

The earliest observations made by Bailly, from one of the windows in the upper story of the Louvre gallery that looks out on the Pont des Arts, are dated in the beginning of 1760. The pupil of Lacaille was not yet twenty-four years old. Those observations relate to an opposition of the planet Mars. In the same year he determined the oppositions of Jupiter and of Saturn, and compared the results of his own determinations with the tables.

The subsequent year I see him a.s.sociated with Lacaille in observing the transit of Venus over the sun's disk. It was an extraordinary piece of good fortune, Gentlemen, at the very commencement of his scientific life, to witness in succession two of the most interesting astronomical events: the first predicted and well established return of a comet; and one of those partial eclipses of the sun by Venus, that do not recur till after the lapse of a hundred and ten years, and from which science has deduced the indirect but exact method, without which we should still be ignorant of the fact that the sun's mean distance from our earth is thirty-eight millions of leagues.

I shall have completed the enumeration of Bailly's astronomical labours performed before he became an academician, when I have added, from observations of the comet of 1762, the calculation of its parabolic orbit; the discussion of forty-two observations of the moon by La Hire, a detailed labour destined to serve as a starting point for any person occupying himself with the lunar theory; finally, also the reduction of 515 zodiacal stars, observed by Lacaille in 1760 and 1761.

FOOTNOTE:

[6] This long list of supposed difficulties in making an exact observation is hardly worthy of a zealous astronomer. Our author shows no enthusiasm for his subject here, and ends by ascribing the whole jeremiad to Lacaille, a man of very great practical perseverance. It is to be regretted that Arago never refers to observations of his own, but constantly quotes from others, nor does he always select the best.