MacTutor
JEAN FRANÇOIS ARAGO was born on the 26th of February, 1786, at Estagel, near Perpignan, a town in the south of France. His father, who inherited a small patrimony, was Treasurer to the Mint at Perpignan. François was the eldest of a family of five children, consisting of three sons and two daughters. In early life he contracted a strong predilection for a military life, an avowal of which on one occasion had the effect of determining his future career as a philosopher. Happening to meet an officer of Engineers on the ramparts of Perpignan, he inquired of him by what means he might become qualified to wear a similar uniform. The officer told him that he would require to study the military art at the Polytechnic School. Accordingly, soon afterwards, when he was still very young, he repaired to Paris, and entered the Polytechnic School, where he soon distinguished himself by his extraordinary vivacity and intelligence. At this time the French Revolution had occurred, and a new system of education was generally introduced throughout France, from which the study of classical literature was almost wholly excluded. It happened, in consequence, that Arago did not enjoy the advantages of a good classical education, a circumstance which he regretted very much during the subsequent period of his life.
In 1803, he entered the University of Toulouse, where he made such rapid progress in the study of mathematics and physical science, that, at the close of a year, he was induced, at the suggestion of the elder Monge, to attach himself to the Observatory of Paris, which was then directed by Bouvard.
In 1804, being the year of his entrance into the Observatory, Arago was appointed by Laplace to co-operate with Biot in a series of experimental researches for determining the refractive powers of different gases. Biot was also at this time an assistant at the Observatory, but he was older than Arago by twelve years. The results of their joint labours were embodied in a paper which was communicated in both their names to the Institute of France, and which was published in the Memoirs of that body for the year 1806. The paper was entirely drawn up by Biot, to whom these experimental researches must be considered as mainly due. Arago, however, by his activity and intelligence, made such a favourable impression upon his elder colleague, that he was received by him into his house and treated as a member of his family.
In 1806, MM. Biot and Arago were appointed by the French Government to execute the geodetical operations required for prolonging the French Arc of the Meridian from Barcelona, in Spain, to Formentera, one of the Balearic Isles. During the latter period of that year and the beginning of the following year, they succeeded in connecting the kingdom of Valentia with the Island of Yviça, by means of an immense triangle, the spherical excess of which amounted to 39". This had hitherto been regarded as a hazardous operation, of the success of which Méchain had altogether despaired.
The triangulation was now rapidly continued on to Formentera, the southern extremity of the Arc. Upon their arrival here, however, they found themselves unable to determine the latitude, in consequence of the repeating circle having been accidentally broken in the course of their expeditionary journeys. Biot was induced, in consequence, to return to France for the purpose of obtaining another instrument, leaving Arago and the Spanish Commissioners, Rodriquez and Chaix, to execute the triangulation of Valentia. During the summer of 1807, Arago was employed in this operation, in the execution of which, says M. Biot, he displayed uncommon ability as an observer and great powers of endurance, having been exposed to devouring heats, the effects of which his southern origin alone enabled him to withstand.
In the autumn of 1807, M. Biot returned to Spain, and in concert with Arago determined the latitude of Formentera. The facility of connecting their operations with a small arc of parallel having been recognised, they resolved to measure the latter, but for this object two observers were no longer necessary. Biot accordingly proposed to Arago either to return to France, or to remain in Spain and complete the additional operations which they had decided upon executing. Arago chose the latter alternative, and Biot returned to France.
While Arago was engaged in the operations connected with the determination of the arc of parallel, the war between France and Spain broke out, and he became henceforth exposed to great danger. Rumours were spread abroad that the fires which blazed at the signal stations on Mount Galatzo were telegraphic messages to the invading army, and it was even alleged that the astronomical instruments were pregnant with danger to the country. Arago was accordingly denounced as a spy, and he was saved from the fury of the multitude only by the authorities imprisoning him. On the 2d of June, 1808, he escaped to Algiers, where he remained ten days, and then embarked for France in an Algerine frigate. The vessel had reached the Gulf of Lyons, and was already within sight of the coast of Provence, when it was captured by a Spanish privateer and conducted to Rosas. Arago, dreading that he might be recognised by persons who had formerly seen him in Spain, was induced to assume the character of a pedlar. He was first confined in a windmill, but he was subsequently imprisoned along with the crew of the Algerine vessel in the Fort of Trinity, from which, after a short confinement, he was transferred to the hulks of Palamos, where he was subjected to much cruel treatment, having almost perished for want of food.
The Dey of Algiers, upon becoming acquainted with the capture of one of his vessels by a privateer of Spain, demanded satisfaction of the Spanish Government, insisting at the same time upon the immediate liberation of the crew of the vessel, including Arago. It has been said that he was prompted to this spirited act more especially by the circumstance that there had been two lions on board the vessel which were intended as a present to Napoleon, and one of which had been killed by the Spanish sailors.
Arago, having been thus liberated by the intercession of the Dey, again embarked for Marseilles on the 28th of November, 1808. Once more, however, his hopes of returning to his native country were frustrated. Just as the ship was about to enter the harbour of Marseilles, a sudden storm drove it out to sea and carried it to the coast of Sardinia, which was then at war with Algiers. The vessel, although much shattered, dared not make for the land, but directed its course towards the coast of Africa, which it reached on the 5th of December, entering a place called Bougia, about three days' journey from Algiers. Arago arrived at Algiers on the 25th of December. The Dey, who had rescued him from the hulks of Palamos, had been beheaded in his absence. The new Dey opposed his departure, believing him to possess great wealth; and he was saved from a cruel death only by the interference of the Danish Consul. Fortunately the Dey was soon afterwards executed, and Arago, after a residence of six months, quitted Algiers on the 21st of June, 1809. On the 1st of July, when the vessel was within sight of Marseilles, it was chased by an English cruiser, but fortunately it escaped, and Arago safely arrived in his native country, bringing with him all his instruments, manuscripts, and plans.
The friends of Arago, who had received no intelligence respecting him since the return of Biot, believed him to be dead. His mother, during his absence, had succeeded in obtaining possession of the watch which he had been obliged to sell at Rosas; but she had despaired of ever more seeing her beloved son. The first letter which Arago received, while he was yet in the Lazaretto of Marseilles, was one from the illustrious Humboldt. Then commenced a close friendship between these two distinguished men, which continued without interruption till death put an end to it.
Upon the arrival of Arago in Paris, he was received with great attention by Laplace, Monge, and many of the other savans who then adorned the metropolis of France. In 1809, when he was only twenty-three years of age, he was elected a Member of the Institute of France in the room of Lalande, whose death had occasioned a vacant place in the section of astronomy. Soon afterwards he was appointed one of the Professors of the Polytechnic School, and also one of the astronomers attached to the Imperial Observatory.
The discovery of the polarisation of light by Malus, in the year 1811, had the effect of directing the attention of Arago to that interesting branch of optical science. His brilliant labours on this subject, and his subsequent researches on magnetism, will always secure for him a high place among the successful cultivators of experimental physics. It would be unsuitable, however, to give any detailed account of them on the present occasion.
In 1816, Arago, in conjunction with Gay-Lussac, established the Annales de Chimie et de Physique. In the same year he visited England, when he became personally acquainted with Dr. Young, and several other distinguished philosophers of this country. In 1818 he was appointed along with Biot to execute the geodetic operations required for connecting the French Arc of the Meridian with the English Arc. In 1821, the results of their joint labours in Spain, and on the present occasion, including Biot's pendulum experiments in Scotland, were published in a work entitled, "Recueil d'Observations Géodésiques, Astronomiques et Physiques, exécutées par ordre du Bureau des Longitudes." It is right to mention that the text and the calculations of this work are exclusively due to Biot. It may be stated, also, that the work does not contain any account of Arago's operations relative to the measurement of the arc of parallel in Spain, to which allusion has been made in a former part of this notice.
In 1822 Arago was appointed a Member of the Bureau des Longitudes. Henceforward he continued to publish in the Annuaire of that body a series of scientific notices relative to different subjects, which, besides being remarkable for the lucid and charming style in which they are expressed, are highly valuable on account of the light which they throw upon many interesting points of physics.
In 1830, when the revolution of July broke out, M. Arago, who had always been an ardent friend of liberty, gave his cordial adhesion to the movement party. He was consequently elected member of the Chamber of Deputies for the Lower Seine, and thus became involved in the strife of political warfare. In the same year he was appointed Director of the Observatory of Paris, and also Perpetual Secretary of the Institute for the Mathematical and Physical Sciences in the room of M. Fourier.
Although gifted with great powers of eloquence, M. Arago seldom spoke in the Chamber of Deputies except when advocating some question relating to the interests of science. On every such occasion his opinion was listened to with profound deference, and was generally effectual in persuading the Chamber to sanction the project recommended by him. It was mainly by his influence that the Observatory of Paris was repaired and furnished with new instruments, and thus placed in a condition of rivalling the other great Observatories of Europe. He was also instrumental in procuring the publication of new editions of the works of Laplace and Fermat at the expense of the country. In short, every project of a scientific nature -- whether relating to engineering, surveying, telegraphs, or any similar object, which recommended itself for adoption on the ground of its practical utility, found in M. Arago an indefatigable and eloquent advocate.
As Perpetual Secretary of the Academy it became the duty of M. Arago to write the éloges of eminent deceased Members and Associates of that body. His compositions of this nature are all remarkable for the chaste and eloquent language in which they are clothed.
In 1834 M. Arago visited England a second time, and attended the meeting of the British Association for the Advancement of Science, which was held that year in Edinburgh. In 1840 he was elected Member of the Council General of the Seine.
In 1848, when the revolution of February broke out, M. Arago was appointed a Member of the Provisional Government, having been nominated to the vacant offices of Minister of War and of Marine. During the insurrection of the working classes, which occurred in the month of June 1849, he displayed great personal courage in endeavouring to appease the angry multitude, but although formerly the object of their reverence, he was no longer able to exercise any influence over them. The hopes which he had long entertained of the establishment of a Republic in France were thus completely frustrated by the folly of the people. Henceforward he ceased to occupy his attention with politics. Unfortunately about this time his health became impaired and his sight began to fail. Warned by these symptoms, he now resolved to prepare for publication the great mass of scientific writings which he allowed to accumulate during his active career.
The coup d'état of the 2nd of December, 1852, formed the death-blow to the illusion which he had so long cherished relative to the establishment of a Republic in France. When summoned to take the oath of allegiance to the new Government, he refused to do so. On that occasion he addressed a memorable letter to the Government justifying his conduct, and setting forth his claims to the favourable consideration of his countrymen. Notwithstanding his refusal to comply with the demands of the Government, he was allowed to retain his appointment as Director of the Observatory.
In the summer of 1853 the health of M. Arago having become very feeble, he proceeded to the Eastern Pyrenees, under the care of his niece, Madame Laugier, his friends having advised him to try the effect of his native air upon his constitution. He soon afterwards, however, returned to Paris, without any hope of recovery. He died on the 2nd of October, 1853, in the sixty-seventh year of his age. His remains were interred in the cemetery of Père La Chaise. A funeral oration was pronounced over his grave by M. Flourens, the Perpetual Secretary of the Academy.
M. Arago in early life married a lady of the south of France, who has been dead many years. He had two sons by her, both of whom have survived their parents.
In his family relations he seems to have enjoyed a source of great happiness. "This man," says M. Flourens, "in whom were united so many excellencies, devoted a portion of his life to the cultivation of domestic affections. He had experienced all the sweets of filial piety; the cord of his affections extended itself without being weakened; his brothers, his sisters, were always with him, under the paternal roof; his own children and theirs were equal objects of his regard thus he found a daughter whose pious and touching cares ought to receive this day the grateful acknowledgment of the Academy."
Researches on subjects which have no immediate connexion with astronomy form the principal claims of this distinguished man to the remembrance of posterity; but his acute and brilliant intellect, combined with his extraordinary energy and his enthusiasm in the cause of science, exercised a powerful influence upon the cultivation of almost every branch of physical inquiry, more especially among his own countrymen. He possessed a remarkable aptitude for expounding the principles of science, and rendering them intelligible to the uninitiated classes of the community. His eloquent lectures on astronomy delivered at the Royal Observatory of Paris were always listened to with attention by a crowded audience.
M. Arago was endowed with an ardent temperament, which occasionally had the effect of involving him in controversies tending to detract from the influence so justly due to his high intellectual qualities. These, however, are faults which are more or less inseparable from human nature in its present existence. Assuredly when they have been long forgotten the name of François Arago will still continue to occupy a distinguished place in the annals of science.
It has been announced since the death of M. Arago that his writings are about to be published in twelve volumes octavo, under the superintendence of M. Barral, an intimate friend of the deceased.
In 1803, he entered the University of Toulouse, where he made such rapid progress in the study of mathematics and physical science, that, at the close of a year, he was induced, at the suggestion of the elder Monge, to attach himself to the Observatory of Paris, which was then directed by Bouvard.
In 1804, being the year of his entrance into the Observatory, Arago was appointed by Laplace to co-operate with Biot in a series of experimental researches for determining the refractive powers of different gases. Biot was also at this time an assistant at the Observatory, but he was older than Arago by twelve years. The results of their joint labours were embodied in a paper which was communicated in both their names to the Institute of France, and which was published in the Memoirs of that body for the year 1806. The paper was entirely drawn up by Biot, to whom these experimental researches must be considered as mainly due. Arago, however, by his activity and intelligence, made such a favourable impression upon his elder colleague, that he was received by him into his house and treated as a member of his family.
In 1806, MM. Biot and Arago were appointed by the French Government to execute the geodetical operations required for prolonging the French Arc of the Meridian from Barcelona, in Spain, to Formentera, one of the Balearic Isles. During the latter period of that year and the beginning of the following year, they succeeded in connecting the kingdom of Valentia with the Island of Yviça, by means of an immense triangle, the spherical excess of which amounted to 39". This had hitherto been regarded as a hazardous operation, of the success of which Méchain had altogether despaired.
The triangulation was now rapidly continued on to Formentera, the southern extremity of the Arc. Upon their arrival here, however, they found themselves unable to determine the latitude, in consequence of the repeating circle having been accidentally broken in the course of their expeditionary journeys. Biot was induced, in consequence, to return to France for the purpose of obtaining another instrument, leaving Arago and the Spanish Commissioners, Rodriquez and Chaix, to execute the triangulation of Valentia. During the summer of 1807, Arago was employed in this operation, in the execution of which, says M. Biot, he displayed uncommon ability as an observer and great powers of endurance, having been exposed to devouring heats, the effects of which his southern origin alone enabled him to withstand.
In the autumn of 1807, M. Biot returned to Spain, and in concert with Arago determined the latitude of Formentera. The facility of connecting their operations with a small arc of parallel having been recognised, they resolved to measure the latter, but for this object two observers were no longer necessary. Biot accordingly proposed to Arago either to return to France, or to remain in Spain and complete the additional operations which they had decided upon executing. Arago chose the latter alternative, and Biot returned to France.
While Arago was engaged in the operations connected with the determination of the arc of parallel, the war between France and Spain broke out, and he became henceforth exposed to great danger. Rumours were spread abroad that the fires which blazed at the signal stations on Mount Galatzo were telegraphic messages to the invading army, and it was even alleged that the astronomical instruments were pregnant with danger to the country. Arago was accordingly denounced as a spy, and he was saved from the fury of the multitude only by the authorities imprisoning him. On the 2d of June, 1808, he escaped to Algiers, where he remained ten days, and then embarked for France in an Algerine frigate. The vessel had reached the Gulf of Lyons, and was already within sight of the coast of Provence, when it was captured by a Spanish privateer and conducted to Rosas. Arago, dreading that he might be recognised by persons who had formerly seen him in Spain, was induced to assume the character of a pedlar. He was first confined in a windmill, but he was subsequently imprisoned along with the crew of the Algerine vessel in the Fort of Trinity, from which, after a short confinement, he was transferred to the hulks of Palamos, where he was subjected to much cruel treatment, having almost perished for want of food.
The Dey of Algiers, upon becoming acquainted with the capture of one of his vessels by a privateer of Spain, demanded satisfaction of the Spanish Government, insisting at the same time upon the immediate liberation of the crew of the vessel, including Arago. It has been said that he was prompted to this spirited act more especially by the circumstance that there had been two lions on board the vessel which were intended as a present to Napoleon, and one of which had been killed by the Spanish sailors.
Arago, having been thus liberated by the intercession of the Dey, again embarked for Marseilles on the 28th of November, 1808. Once more, however, his hopes of returning to his native country were frustrated. Just as the ship was about to enter the harbour of Marseilles, a sudden storm drove it out to sea and carried it to the coast of Sardinia, which was then at war with Algiers. The vessel, although much shattered, dared not make for the land, but directed its course towards the coast of Africa, which it reached on the 5th of December, entering a place called Bougia, about three days' journey from Algiers. Arago arrived at Algiers on the 25th of December. The Dey, who had rescued him from the hulks of Palamos, had been beheaded in his absence. The new Dey opposed his departure, believing him to possess great wealth; and he was saved from a cruel death only by the interference of the Danish Consul. Fortunately the Dey was soon afterwards executed, and Arago, after a residence of six months, quitted Algiers on the 21st of June, 1809. On the 1st of July, when the vessel was within sight of Marseilles, it was chased by an English cruiser, but fortunately it escaped, and Arago safely arrived in his native country, bringing with him all his instruments, manuscripts, and plans.
The friends of Arago, who had received no intelligence respecting him since the return of Biot, believed him to be dead. His mother, during his absence, had succeeded in obtaining possession of the watch which he had been obliged to sell at Rosas; but she had despaired of ever more seeing her beloved son. The first letter which Arago received, while he was yet in the Lazaretto of Marseilles, was one from the illustrious Humboldt. Then commenced a close friendship between these two distinguished men, which continued without interruption till death put an end to it.
Upon the arrival of Arago in Paris, he was received with great attention by Laplace, Monge, and many of the other savans who then adorned the metropolis of France. In 1809, when he was only twenty-three years of age, he was elected a Member of the Institute of France in the room of Lalande, whose death had occasioned a vacant place in the section of astronomy. Soon afterwards he was appointed one of the Professors of the Polytechnic School, and also one of the astronomers attached to the Imperial Observatory.
The discovery of the polarisation of light by Malus, in the year 1811, had the effect of directing the attention of Arago to that interesting branch of optical science. His brilliant labours on this subject, and his subsequent researches on magnetism, will always secure for him a high place among the successful cultivators of experimental physics. It would be unsuitable, however, to give any detailed account of them on the present occasion.
In 1816, Arago, in conjunction with Gay-Lussac, established the Annales de Chimie et de Physique. In the same year he visited England, when he became personally acquainted with Dr. Young, and several other distinguished philosophers of this country. In 1818 he was appointed along with Biot to execute the geodetic operations required for connecting the French Arc of the Meridian with the English Arc. In 1821, the results of their joint labours in Spain, and on the present occasion, including Biot's pendulum experiments in Scotland, were published in a work entitled, "Recueil d'Observations Géodésiques, Astronomiques et Physiques, exécutées par ordre du Bureau des Longitudes." It is right to mention that the text and the calculations of this work are exclusively due to Biot. It may be stated, also, that the work does not contain any account of Arago's operations relative to the measurement of the arc of parallel in Spain, to which allusion has been made in a former part of this notice.
In 1822 Arago was appointed a Member of the Bureau des Longitudes. Henceforward he continued to publish in the Annuaire of that body a series of scientific notices relative to different subjects, which, besides being remarkable for the lucid and charming style in which they are expressed, are highly valuable on account of the light which they throw upon many interesting points of physics.
In 1830, when the revolution of July broke out, M. Arago, who had always been an ardent friend of liberty, gave his cordial adhesion to the movement party. He was consequently elected member of the Chamber of Deputies for the Lower Seine, and thus became involved in the strife of political warfare. In the same year he was appointed Director of the Observatory of Paris, and also Perpetual Secretary of the Institute for the Mathematical and Physical Sciences in the room of M. Fourier.
Although gifted with great powers of eloquence, M. Arago seldom spoke in the Chamber of Deputies except when advocating some question relating to the interests of science. On every such occasion his opinion was listened to with profound deference, and was generally effectual in persuading the Chamber to sanction the project recommended by him. It was mainly by his influence that the Observatory of Paris was repaired and furnished with new instruments, and thus placed in a condition of rivalling the other great Observatories of Europe. He was also instrumental in procuring the publication of new editions of the works of Laplace and Fermat at the expense of the country. In short, every project of a scientific nature -- whether relating to engineering, surveying, telegraphs, or any similar object, which recommended itself for adoption on the ground of its practical utility, found in M. Arago an indefatigable and eloquent advocate.
As Perpetual Secretary of the Academy it became the duty of M. Arago to write the éloges of eminent deceased Members and Associates of that body. His compositions of this nature are all remarkable for the chaste and eloquent language in which they are clothed.
In 1834 M. Arago visited England a second time, and attended the meeting of the British Association for the Advancement of Science, which was held that year in Edinburgh. In 1840 he was elected Member of the Council General of the Seine.
In 1848, when the revolution of February broke out, M. Arago was appointed a Member of the Provisional Government, having been nominated to the vacant offices of Minister of War and of Marine. During the insurrection of the working classes, which occurred in the month of June 1849, he displayed great personal courage in endeavouring to appease the angry multitude, but although formerly the object of their reverence, he was no longer able to exercise any influence over them. The hopes which he had long entertained of the establishment of a Republic in France were thus completely frustrated by the folly of the people. Henceforward he ceased to occupy his attention with politics. Unfortunately about this time his health became impaired and his sight began to fail. Warned by these symptoms, he now resolved to prepare for publication the great mass of scientific writings which he allowed to accumulate during his active career.
The coup d'état of the 2nd of December, 1852, formed the death-blow to the illusion which he had so long cherished relative to the establishment of a Republic in France. When summoned to take the oath of allegiance to the new Government, he refused to do so. On that occasion he addressed a memorable letter to the Government justifying his conduct, and setting forth his claims to the favourable consideration of his countrymen. Notwithstanding his refusal to comply with the demands of the Government, he was allowed to retain his appointment as Director of the Observatory.
In the summer of 1853 the health of M. Arago having become very feeble, he proceeded to the Eastern Pyrenees, under the care of his niece, Madame Laugier, his friends having advised him to try the effect of his native air upon his constitution. He soon afterwards, however, returned to Paris, without any hope of recovery. He died on the 2nd of October, 1853, in the sixty-seventh year of his age. His remains were interred in the cemetery of Père La Chaise. A funeral oration was pronounced over his grave by M. Flourens, the Perpetual Secretary of the Academy.
M. Arago in early life married a lady of the south of France, who has been dead many years. He had two sons by her, both of whom have survived their parents.
In his family relations he seems to have enjoyed a source of great happiness. "This man," says M. Flourens, "in whom were united so many excellencies, devoted a portion of his life to the cultivation of domestic affections. He had experienced all the sweets of filial piety; the cord of his affections extended itself without being weakened; his brothers, his sisters, were always with him, under the paternal roof; his own children and theirs were equal objects of his regard thus he found a daughter whose pious and touching cares ought to receive this day the grateful acknowledgment of the Academy."
Researches on subjects which have no immediate connexion with astronomy form the principal claims of this distinguished man to the remembrance of posterity; but his acute and brilliant intellect, combined with his extraordinary energy and his enthusiasm in the cause of science, exercised a powerful influence upon the cultivation of almost every branch of physical inquiry, more especially among his own countrymen. He possessed a remarkable aptitude for expounding the principles of science, and rendering them intelligible to the uninitiated classes of the community. His eloquent lectures on astronomy delivered at the Royal Observatory of Paris were always listened to with attention by a crowded audience.
M. Arago was endowed with an ardent temperament, which occasionally had the effect of involving him in controversies tending to detract from the influence so justly due to his high intellectual qualities. These, however, are faults which are more or less inseparable from human nature in its present existence. Assuredly when they have been long forgotten the name of François Arago will still continue to occupy a distinguished place in the annals of science.
It has been announced since the death of M. Arago that his writings are about to be published in twelve volumes octavo, under the superintendence of M. Barral, an intimate friend of the deceased.
Jean François Arago's obituary appeared in Monthly Notices of the Royal Astronomical Society 14:4 (1854), 102-107.