Chapter XXXVI: Conclusion: Of the CIVIL War (22)

Rumford, on his return to Munich, was occupied in very important affairs. The advance of the French republican army under Moreau obliged the elector to quit the capital, leaving a council of regency, with Rumford at its head. Rumford succeeded in the arduous task of freeing Bavaria from invasion, and his conduct on this occasion increased his reputation with the elector and with the people. Among other tokens of the elector’s gratitude for his services, he was permitted to settle one-half of the pension which he enjoyed on his daughter, to be paid during her lifetime. In 1798 the elector, partly with a view to gratify him with an honor which he knew he desired, and partly to afford him another opportunity of relaxation for the improvement of his health, appointed him ambassador at the court of Great Britain. On arriving in London, however, Rumford found, that in consequence of the English legal fiction, by which a born subject of the country is declared incapable of ever alienating his allegiance, he could not be received as the Bavarian ambassador. Mortified as he must have been by this circumstance, and still more deeply grieved by the loss of his friend and patron, the Elector Charles Theodore, who died in 1799, Rumford contemplated returning to spend the remainder of his life in the land of his birth. In compliance with a formal invitation which he received from the United States government, he was making preparations for his return, and had written to a friend to secure a cottage in the vicinity of Boston, as a ‘quiet little retreat,’ when he was led to change his design, and remain in London, in the society of which he occupied a conspicuous place. During several years, a great part of the Count Rumford’s time was devoted to the interests of the Royal Institution, of which he may be considered the founder. The objects of this institution, now one of the recognized scientific establishments of the world, and one which can boast of having given employment to such men as Young, Davy, Brande, and Faraday, were ‘to diffuse the knowledge and facilitate the general introduction of useful mechanical inventions and improvements, and to teach, by courses of philosophical lectures and experiments, the application of science to the useful purposes of life.’ Such an institution was precisely the one which Rumford was qualified to superintend; and in its early history, the influence of his peculiar habits of thought is discernable in the choice of subjects for investigation by the members. Subsequently, the institution assumed the high scientific character which it yet holds.

In 1802, Count Rumford left England, and spent some time in travel. Revisiting Munich, he found the workhouse which he had planned, and which had been instrumental in producing so much good, abolished, and the new elector, Maximilian, friendly indeed but indisposed to follow the footsteps of his predecessor. Accordingly, after assisting in modeling a Bavarian academy of sciences, he took farewell of his adopted country, and went to reside in Paris, retaining an income of about £1200 from the Bavarian court. At the same time his daughter returned to America, her father having abandoned his intention of returning along with her. In Paris, Count Rumford appears at first to have gained the good-will and esteem which had attended him so remarkably during his previous life; and not long after he began his residence there, he contracted a second marriage with the widow of the celebrated Lavoisier, put to death during the French Revolution. From 1804 to 1814 he resided with his wife at Auteuil, a villa at a short distance from Paris, the property of Madame Lavoisier, and the scene of many of her former husband’s discoveries. Here Rumford employed himself in scientific pursuits of a miscellaneous nature. The union of the American-born citizen of the world with the widow of the illustrious Frenchman does not appear to have been a happy one; and there is evidence that, towards the end of his life, Rumford had become unpopular in Parisian society. Cuvier attributes this to a certain coarseness and want of urbanity of manner; possibly, however, the fault was less in the person criticised than in the Parisian standard of criticism, for the charge seems inconsistent with the tenor of Rumford’s life.

Rumford’s death took place at Auteuil on the 21st of August 1814, in the sixty-second year of his age. He left some bequests for the promotion of science in America; the rest of his property, which does not appear to have been great, he left to his relatives. His only daughter inherited the title of Countess of Rumford, with the continuation of her father’s Bavarian pension. She is, we believe, still alive, and has long resided in Paris.

Rumford, whose memoirs we have now detailed, was not a faultless character, or a person in every respect exemplary; but making due allowances for circumstances in which he was at the outset unfortunately placed, and keeping in mind that every man is less or more the creature of the age in which he lives, we arrive at the conclusion, that few individuals occupying a public position have been so thoroughly deserving of esteem. The practical, calm, and comprehensive nature of his mind, his resolute and methodical habits, the benevolence and usefulness of his projects, all excite our admiration. Cuvier speaks of Rumford as ‘having been the benefactor of his species without loving or esteeming them, as well as of holding the opinion that the mass of mankind ought to be treated as mere machines.’ A remark this which is applicable to not a few men who have been eminent for labors of a humane description, and which naturally gives rise to this other remark――that a good intellectual method, directed to practical ends, is often of more value to mankind than what is called a good heart.

NICOLAS COPERNICUS.

In the whole range of human science, no subject is calculated to excite such sublime ideas as astronomy; and to its study, therefore, the greatest minds have been directed both in ancient and modern times. Ancient, however, as are the investigations into the relations of the heavenly bodies, a correct idea of the planetary system was scarcely known before the sixteenth century of the Christian era. The theory generally received on that subject by the Chaldeans, Egyptians, Greeks, and other ancient nations, and which continued predominant till a comparatively recent period, described the earth as the center of all bodies occupying space, while the Moon, Venus, Mercury, the Sun, the planets, and the stars, revolved around it on a succession of solid spheres, at different distances, and at different rates of speed, so as to produce the appearances which are daily and nightly presented to our eyes in the heavens. Six centuries before the commencement of our era, Anaximander, Pythagoras, and other Grecian philosophers, had conceived some faint notion of a more correct system; but when they ventured to suggest that the sun was a fixed body, and that the earth was only one of a set of planets moving round it, they experienced so much persecution on account of the inconsistency of their doctrines with the religious ideas of the people, that they failed to establish their theory on a permanent basis. When learning and the arts revived in Italy in the fourteenth and fifteenth centuries, some attention was paid in the universities to astronomy; but the system taught was no better than that which Aristotle, Ptolemy, and other ancient astronomers had sanctioned, and which represented the sun and planets as moving round the earth. The time at length arrived for the revival of the correct notions entertained by Anaximander and Pythagoras.

Nicolas Copernicus, the modern to whom the honor of reviving that doctrine is due, was born, February 19, 1473, at Thorn, on the Vistula――a place now included in the dominions of the king of Prussia. The father of Copernicus was a native of Westphalia, a part of Germany: he had chanced to settle at Thorn, as a surgeon, about ten years before the birth of his son. Young Copernicus was educated for the profession of medicine at the university of Cracow; but his favorite studies were mathematics, perspective, astronomy, and painting. At an early age, inspired by an eager wish to distinguish himself in astronomy, he proceeded to Italy, and studied that science at the university of Bologna. It is supposed that a discovery of his teacher Dominic Maria, respecting the changes of the axis of the earth, was what first awakened his mind to the errors of the planetary system then taught. From Bologna he proceeded to Rome, where for some time he taught mathematics with great success――pursuing all the while, as far as circumstances would permit, his astronomical observations.

When he afterwards returned to his native country, his maternal uncle, the bishop of Ermeland, appointed him a canon in the cathedral of Frauenburg and at the same time he was nominated by the inhabitants of his native town to be archdeacon in one of their churches. He then resolved to devote his life to three objects――the performance of his clerical duties, gratuitous medical attendance on the poor, and the pursuit of his favorite studies. His residence was established in one of the houses belonging to the canons of Frauenburg, on the brow of a height near the cathedral, where astronomical observations could be conducted under very favorable circumstances; and in its walls are still to be seen the openings which he made, in order to observe the passage of stars across the meridian. It is supposed to have been about the year 1507 that he first became convinced of the superiority of the planetary theory of Pythagoras. He determined, however, to be very cautious in adopting, and still more cautious in announcing, an opinion so much at variance with the ordinary ideas of mankind. Mathematical instruments were in that age very rude, and the telescope had not been invented. The only implements which Copernicus had for making observations were two, coarsely framed of firwood, with measures marked by lines of ink. Thus provided, he devoted himself for several years to the inquiries necessary for proving his theory; and at length, about the year 1530, he had completed a work, in which the whole system was expounded――namely, the immobility of the sun in the centre of the planetary system; while its apparent motion, and the alternations of day and night, were to be attributed to the annual and diurnal movements of the earth. The real distances of the planets, and the declination of the pole of the earth, were also explained.

The doctrines of Copernicus were already known to a considerable number of learned and comparatively enlightened persons, who received them with due respect; and it is creditable to the Romish church that several of its dignitaries were among the number. But the bulk of mankind, including their religious teachers, were then comparatively ignorant, and accordingly prejudiced; and however firm the conviction of the astronomer as to the truth of his theory, he yet hesitated to make it public, dreading the opposition it would have to encounter――seeing that it opposed the inveterate prejudices of the learned, and the illusory testimony of the senses. In reasoning, they acted under the guidance of rules which made it scarcely possible for them to ascertain truth, or to acknowledge it when it was presented to them in the clearest light. If anything had been said in former times by a person whose memory they respected, they would not willingly listen to anything which contradicted, or seemed to contradict it. They walked, in short, by authority, and not by the dictates of reflection; and the consequence was, that every new truth which experience or the inquiries of the best minds brought forth, had to contend with the less worthy notions which had come down from earlier and darker ages. Amongst the opinions received by them, was that which represented the earth as the immovable centre of the universe. It was sanctioned by the greatest men of ancient times; it had long been taught; it was conformable to the common appearances of things; and various passages in the Scriptures were believed to assert it, though in reality those passages only do not contradict (and this probably for wise purposes) the ordinary ideas of mankind respecting the stability of the earth. Copernicus only acted, therefore, with necessary caution, when he hesitated to publish the work which had cost him the labor of so many years.

Rheticus, one of the friends to whom he had communicated his theory, at length, in 1540, ventured to give an outline of it to the world in a small pamphlet, which he published without his name. As this excited no disapprobation, the same person reprinted it next year with his name. In both publications the doctrines were ascribed openly to Nicolas Copernicus. About the same time, a learned man, Erasmus Reinhold, in a work which he published, spoke of the new doctrines with the greatest respect, and styled their author a second Ptolemy; for it often happens that the greatest compliment that can be paid to the discoverer of truth, is to mention him in the same breath with some founder of error. Copernicus now allowed himself to be pursuaded by his friends to publish his work; and it was accordingly put to press at Nuremburg, under the care of some learned persons of that city. But he was now an old man, and it was not his lot to live to see the book published. As soon as it was printed, a copy of it was sent to him by his friend Rheticus, but it only reached him, May 23, 1543, a few hours before he expired. He appeared to be scarcely conscious of the object to which so many years of his life had been devoted. But his mission was accomplished. Committed to the perpetuating operations of the infant printing-press, all danger was over of losing the germ of those great and fertile truths which in our days render astronomy the most perfect of sciences.

The theory of Copernicus was thus brought before the world; but, whether from the death of the philosopher, or because little disturbance of popular notions was anticipated from so learned a work, or from whatever other circumstances, it was visited with no marks of reprobation from any quarter at the time. In proportion, however, as it became known, so did its opponents increase. Those were the days when the fagot and stake made short work with those who presumed to strike out a course of thinking for themselves; and though the author of the system and its immediate adopters passed unmolested, yet during the century which ensued were its followers and supporters persecuted with all the zeal and cruelty that bigotry and ignorant prejudice could devise. Truth, however, is imperishable; and, though repressed and retarded for a season, is ever sure to take its right place among the established beliefs of mankind. And thus it has been with the Copernican theory, whose importance to the progress of accurate science we cannot in reality over-estimate. To form anything like an adequate idea of the value of its author’s services to the cause of science, we must place ourselves back in the time and circumstances which saw their birth. Then, it must be remembered, the want of telescopes rendered all appearances in the sky much more difficult of explanation than they would have been a century later. The accumulated errors and superstitions of fourteen centuries were not to be easily shaken and removed; neither were the prejudices and dogmas of the learned to be disturbed with impunity. What might have been astronomical science, was, even in the writings of the fathers, little better than a mass of absurd and subtle disquisitions on the substance of the heavens and the heavenly bodies. All these Copernicus had to surmount; and the elaboration of his theory presents an ever-memorable example of the power of patient and earnest thought in the investigation of a complicated subject, and acuteness of discrimination between the true and the fallacious.

TYCHO BRAHE.

Of eminent astronomers, the next in point of time was Tycho Brahè, who, though adopting the Ptolemaic notion of the earth being the fixed and immovable centre of the universe, yet did good service to the progress of the science by his numerous observations and discoveries. Descended of an ancient and noble family, originally of Sweden, but settled in Denmark, Tycho was born December 14, 1546, at Knub Strup, in the bailiwick of Schönen, the jurisdiction of which was then held by his father. When seven years old, he commenced the study of the classics, his education, as well as that of his brothers, being intrusted to private tutors. His father dying, his uncle sent him, in 1559, to study philosophy and rhetoric at Copenhagen, where it was intended to train him for some civil employment. The great eclipse of the sun on the 21st August 1560, happening at the precise time the astronomers foretold, he began to look upon astronomy as something divine; and purchasing the tables of Stadius, gained some notion of the theory of the planets. His thoughts were now wholly engrossed with astronomy; and though sent by his uncle, in 1562, to study jurisprudence at Leipsic, mathematics, and not law, were the subject of his private labors. It is told of him, that, having procured a small celestial globe, he was wont to wait till his tutor had gone to bed, in order to examine the constellations and learn their names; and that, when the sky was clear, he used to spend whole nights in viewing the stars. He abandoned the amusements and pleasures fitting for his age, and devoted his pocket-money to the purchase of mathematical and astronomical books, the perusal of which he persisted in, in spite of the remonstrances and rebukes of his preceptor. About this time he also began to apply himself to chemistry, less perhaps for the cause of the science, than with a view to discover the Philosopher’s Stone and the grand Elixir of Life――a digression from his astronomical career, prompted no doubt by the natural supersition and enthusiasm of his constitution.

In 1571 he returned to Denmark; and was favored by his mother’s brother, Steno Belle, a lover of learning, with a convenient place at the castle of Herritzvad, near Knub Strup, for conducting his observations and building a laboratory: but marrying a peasant girl beneath his rank, such a violent quarrel ensued between him and his relations, that Frederick II, king of Denmark, was obliged to interpose to reconcile them. In 1575, he began his travels through Germany, and proceeded as far as Venice, meeting with the kindliest attention from various philosophers and crowned heads. This attention, conjoined with certain offers made him by the Landgrave of Hesse, and the greater facility of procuring better apparatus, induced him to think of removing his family to Basil; but Frederick of Denmark, being informed of his design, and unwilling to lose such an ornament to his country, promised (to enable him to pursue his studies) to bestow upon him for life the island of Hveen in the Sound, to erect an observatory and laboratory there, and to defray all the expenses necessary for carrying on his designs. Tycho Brahè readily embraced this proposal; and, accordingly, the first stone of the observatory was laid in August 1576. The king also bestowed on him a pension of two thousand crowns, a fee in Norway, and a canonry, which brought him one thousand more. In this retreat he was visited by various princes; among others, by James VI of Scotland, when proceeding to Denmark to marry the princess Anne. This monarch, of literary memory, made the astronomer several presents, and with his own hand wrote some verses in his praise. In Uranienborg, for such he had styled his new erection, he framed that system of the universe which is yet known by his name; namely, that the earth remains fixed and immovable as the grand centre, and that the sun and all the heavenly bodies revolve around it――a doctrine the reverse of that of Copernicus, which all succeeding astronomers have adopted. But though mistaken in this conception, we are indebted to him for a more correct catalogue of the fixed stars; for several important discoveries respecting the motions of the moon and comets, and the refraction of the rays of light; and for valuable improvements in astronomical instruments. Tycho was likewise a skillful chemist, and found in poetry his recreation from severer studies. His Latin poems are said to exhibit considerable merit; but his chemical manipulations partook too much of the alchemy of his day to be of use to future inquirers.

Happy might our philosopher have been in the castle of Uranienborg, had not his impetuous character, and his fondness for satire, made him many enemies, who prejudiced Christian IV, the successor of Frederick II, against him. On the death of his patron, he was deprived of his pension, fee, and canonry; and finding himself incapable of bearing the expenses of his observatory, he went to Copenhagen, whither he brought some of his instruments, and continued his observations in the city, till Valkendorf, chamberlain to Christian, commanded him, by the king’s orders, to discontinue them. He then removed his family to Rostock, and afterwards to Holstein, to solicit Henry Ranzon to introduce him to the Emperor Rodolphus, who was a great friend to astronomy and astrology. Succeeding in his wishes, he was received by the emperor with the greatest civility and respect; provided with a magnificent house, till he could procure one more fit for astronomical observations; allotted a pension of three hundred crowns; and promised, upon the first opportunity, a fee for himself and his descendants. Unluckily he did not long enjoy this happy situation; for, being suddenly taken ill with a fatal disease, he was cut off on the 24th of October 1601, in the fifty-fifth year of his age. He was interred with great pomp and ceremony in the principal church of Prague, where a noble monument was erected to his memory; thus like many other men of eminence, receiving in a strange land the honors that had been denied him in his own.

Tycho was, notwithstanding his faults and weaknesses, a remarkable man for the age in which he lived; his errors and misjudgments being to a great extent those of his era. His skill in astronomy is universally admitted; and though failing to establish his system over that of Copernicus, yet no one can deny him the merit of advancing by his labors the progress of the science. That he was addicted to astrology, presages, and the occult sciences, is true; but these were features of the age more than of individuals: that he was impetuous, sarcastic, and unamiable, is to be regretted; but it must also be admitted that the grossest injustice was done him and the cause of science by the successor of his patron. Most of his works, which were numerous, and written in Latin, are still extant. The Emperor Rodolphus purchased his expensive astronomical and other instruments; but they were mostly destroyed after the battle of the Weisseberg, near Prague, in 1620. A large sextant alone remains in Prague. The famous brass celestial globe, which was six feet in diameter, and cost about a thousand pounds, returned to Copenhagen after various adventures, but perished in the great fire of 1728. The castle of Uranienborg, where he nightly watched and pondered, has long been in ruins, leaving scarcely a trace of its structure and character. All, however, has not perished, nor been fruitless. ‘It was the friendship of Tycho,’ says an eminent authority, ‘which formed Kepler, and directed him in the career of astronomy. Without this friendship, and without the numerous observations of Tycho, of which Kepler found himself the depositary after the death of his master, he would never have been able to discover those great laws of the system of the world which have been called ‘Kepler’s Laws,’ and which, combined with the theory of central forces, discovered by Hüygens, conducted Newton to the grandest discovery which has ever been made in the sciences――that of universal gravitation.’

GALILEO.

The Copernican theory, which Tycho had labored in vain to supersede, was next received and supported by an Italian philosopher, whose name and history are inseparably interwoven with the progress of astronomy. That illustrious individual, Galileo Galilei, usually known by his Christian name, was born at Pisa in 1564. His father, a Tuscan nobleman of small fortune, caused him to be educated for the profession of medicine at the university of his native city. While studying there, he became deeply sensible of the absurdities of the philosophy of Aristotle, as it had then come to be taught, and he became its declared enemy. That spirit of observation for which he was so distinguished was early developed. When only nineteen years old, the swinging of a lamp suspended from the ceiling of the cathedral in Pisa, led him to investigate the laws of the oscillation of the pendulum, which he was the first to employ as a measure of time. He left it incomplete, however, and it was brought to perfection by his son, Vincenzo, and particularly by Hüygens, the latter of whom must be regarded as the true inventor of the pendulum. About this period Galileo devoted himself exclusively to mathematics and natural science, and in 1586 was led to the invention of the hydrostatic balance. In 1589, his distinction in the exact sciences gained for him the chair of mathematics in his native university, where, immediately on his installation, he began to assert the laws of nature against a perverted philosophy. In the presence of numerous spectators, he performed a series of experiments in the tower of the cathedral, to show that weight has no influence on the velocity of falling bodies. By this means he excited the opposition of the adherents of Aristotle to such a degree, that, after two years, he was forced to resign his professorship. Driven from Pisa, he retired into private life; but his genius being appreciated in another part of Italy, he was, in 1592, appointed professor of mathematics in Pudua. He lectured here with unparalleled success. Scholars from the most distant regions of Europe crowded round him. He delivered his lectures in the Italian language instead of Latin, which was considered a daring innovation.

During eighteen years which he spent at Padua, he made many discoveries in natural philosophy, which he introduced into his lectures, without regard to their inconsistency with the doctrines previously taught. Among these may be mentioned his discovery of the rate of descent in falling bodies; certain improvements on the thermometer; some interesting observations on the magnet; and a number of experiments relative to the floating and sinking of solid bodies in water. In 1609, hearing that one Jansen, a Dutchman, had made an instrument by which distant objects were made to appear near, Galileo, whose mind was prepared for the discovery, instantly conceived on what principle it was constructed, and, without losing a day, he fashioned a similar instrument with many improvments: such was the origin of the telescope, the most interesting of all instruments connected with science.

Turning his optical tube towards the heavens, Galileo perceived the moon to be a body of uneven surface, the elevations of which he computed by their shadows; and the sun to be occasionally spotted; and from the regular advance from east to west of these spots, he inferred the rotation of the sun, and the inclination of its axis to the plane of the ecliptic. From a particular nebula, which his rude instrument enabled him to resolve into individual stars, he even conjectured, what Lord Rosse has but recently proved, that the whole Milky Way was but a vast assemblage of stars and systems. He discovered that the planet Venus waxed and waned like the moon, that Saturn had something like wings by its sides (afterwards found to be a ring), and that Jupiter was surrounded by four satellites. It is now altogether impossible to imagine the wonder and delight with which these discoveries must have filled the mind of a philosopher like Galileo, who had perhaps long surmised that all was not as it seemed in the heavens, but despaired of ever being able to penetrate the mystery. In the year 1611, while entering upon his investigations, he was induced, by the invitation of his prince, the Grand Duke of Tuscany, to return to Pisa, and resume the chair of mathematics there, with a large salary. It was consequently at that city that he first gave his discoveries to the world. That persecution which had only been suspended by accident in the case of Copernicus, now fell with full weight on the head of the Italian philosopher. Having openly declared, in a work which he published, that his discoveries proved the truth of the Copernican theory, he was denounced by the clergy as a heretic, and obliged, in 1615, to proceed to Rome, and appear before the court of Inquisition, who obliged him to promise that he would never more broach such dangerous doctrines. It has been stated, but is not quite certain, that he was on this occasion imprisoned by the Inquisition for five months, and that he would have suffered still more severely if the Grand Duke had not interceded for him.

For several years he observed the silence enjoined upon him, but continued to pursue the study of the true theory of the heavens. Panting to make known to the world a complete account of the system of Copernicus, yet dreading the prejudices of his enemies, he fell upon the expedient of writing a work, in which, without giving his own opinion, he introduces three persons in a dialogue, of whom the first defends the Copernican system, the second the Ptolemæan (or that of Aristotle), and the third weighs the reasons of both in such a way, that the subject seems problematical, though it is impossible to mistake the preponderance of arguments in favor of Copernicus. With this great work, which is still held in reverence, Galileo went to Rome in 1630, in the sixty-sixth year of his age, and, by an extraordinary stretch of favor, received permission to print it. Scarcely had it appeared at Rome and Florence, when it was attacked by the disciples of Aristotle, and most violently of all by the teacher of philosophy at Pisa. A congregation of cardinals, monks, and mathematicians, was appointed to examine his work, which they unhesitatingly condemned as highly dangerous, and summoned him before the tribunal of the Inquisition. This blow fell heavily on the head of Galileo, now an old man, and left defenseless by the death of his friend and patron, Cosmo II. He was compelled to go to Rome in the winter of 1633, and was immediately immured in a cell in one of the prisons of the Inquisition. There he remained for several months, when, being brought before an assembly of his judges, he was condemned to renounce, kneeling before them, with his hand upon the gospels, what were called the ‘sinful and detestable errors and heresies’ which he had maintained. The firmness of Galileo gave way at this critical moment of his life: he pronounced the recantation. But at the moment he rose, indignant at having sworn in violation of his conviction, he exclaimed, stamping his foot, ‘_E pur si muove!_’――(‘It still moves!’) Upon this dreadful relapse into heresy, he was sentenced to imprisonment in the Inquisition for life, and every week for three years was to repeat the seven penitential psalms; his ‘Dialogues’ were also prohibited, and his system utterly condemned. Although Galileo was in this manner sentenced to confinement, it appeared to those who judged him that he would not be able, from his age, to endure such a severe punishment, and they mercifully banished him to a particular spot near Florence.

Here Galileo lived for several years, employing his time in the study of mechanics and other branches of natural philosophy. The results are found in two important works on the laws of motion, the foundation of the present system of physics and astronomy. At the same time he tried to make use of Jupiter’s satellites for the calculation of longitudes; and though he brought nothing to perfection in this branch, he was the first who reflected systematically on such a method of fixing geographical longitudes. He was at this time afflicted with a disease in his eyes, one of which was wholly blind, and the other almost useless, when, in 1637, he discovered the libration of the moon. Blindness, deafness, want of sleep, and pain in his limbs, united to embitter his declining years; still his mind was active. ‘In my darkness,’ he writes in the year 1638, ‘I muse now upon this object of nature, and now upon that, and find it impossible to soothe my restless head, however much I wish it. This perpetual action of mind deprives me almost wholly of sleep.’ In this condition, and affected by a slowly-consuming fever, he expired in January, 1642, in the seventy-eighth year of his age. His relics were deposited in the church of Santa Croce, at Florence, where posterity did justice to his memory by erecting a splendid monument in 1737.

Galileo is represented by his biographers as of diminutive stature, but strong and healthy, of agreeable countenance, and lively conversation and manner. He preferred living in the country, where his relaxations consisted in the cultivation of his garden, and in the company and conversation of his friends. He loved music, drawing, and poetry; and is said to have been so fond of Ariosto, that he knew the whole of the ‘Orlando’ by heart. He had few books; ‘the best book,’ he said, ‘is nature.’ A complete edition of his works, in thirteen volumes, appeared at Milan in 1803, the style of which is natural and fluent, so elegant and pure, that it has been held up by competent judges as a model of classical Italian. ‘Altogether,’ says Professor Playfair, ‘Galileo is one of those to whom human knowledge is under the greatest obligation. His discoveries in the theory of motion, in the laws of the descent of heavy bodies, and in the motion of projectiles, laid the foundation of all the great improvements which have since been made by the application of mathematics to natural philosophy. If to these we add the invention of the telescope, the discoveries made by that instrument, the confirmation of the Copernican system which these discoveries afforded, and lastly, the wit and argument with which he combated and exposed the prejudice and presumption of the schools, we must admit that the history of human knowledge contains few greater names than that of Galileo.’

KEPLER.

Cotemporary with Tycho Brahé and Galileo, and to some extent the associate and successor of the former, was John Kepler, one of the most eminent astronomers who have appeared in any age, and to whom the science is indebted for much of its present perfection. He was born December 27, 1571, at Wiel in Wurtemberg, and was descended of a noble but reduced family. His father, originally an officer of distinction in the army of Wurtemberg, was, at the time of young Kepler’s birth, in the humble capacity of a small inn-keeper; and thus, as is too often the case with genius, our philosopher had to struggle into fame through poverty and the vicissitudes of his father’s fortune. Poor, unbefriended, of a weakly constitution, and one of the most diminutive of children, Kepler received the rudiments of knowledge at the Monastic school of Maulbrunn, where he gave early indications of talent, and of that irrepressible spirit which, amid the severest obstructions, was never diverted from the main object of its pursuit. After his father’s death, which took place in his eighteenth year, he left Maulbrunn, and succeeded in entering the college of Tubingen. Here he completed the course of study then prescribed――first philosophy and mathematics, and then theology; taking the degree of Bachelor in the year 1588, and that of Master of Philosophy in the year 1591. Of apt inquiring powers as a divine, and of more than average eloquence as a preacher, Kepler could now have readily succeeded in the church; but mathematics and the exact sciences were his favorite themes; and it may be fairly questioned if ever he turned a single thought to the clerical profession, beyond what the curriculum of the university compelled. In 1593-4, his reputation as a geometrician had so increased, that he was invited to fill the mathematical chair in the university of Gratz, in Styria. Here he pursued his astronomical studies with the most commendable zeal, devoting himself especially to the investigation of the physical causes of the motion of the celestial bodies.

Shortly after his installment, he married a lady descended from a noble family, and was beginning to enjoy that domestic happiness and studious quiet so congenial to his wishes, when persecution on account of his religion compelled him to leave Gratz, to which, however, he was afterwards recalled by the states of Styria. Meanwhile Tycho Brahé, who had come to Germany, and was comfortably settled under the munificent patronage of Rodolphus, fixed upon Kepler as a suitable assistant, and soon induced him, by urgent letters and flattering promises, to accept of the situation. Compelled in a great measure by the unsettled state of affairs in Austria, Kepler speedily repaired to Prague, and applied himself, in conjunction with Tycho, to the completion of the Rodolphine Tables, which were first published at Ulm in 1626. At Tycho’s recommendation, he was established at that place; but as his office and science did not afford him a subsistence, he studied medicine, in order to gain a livelihood by its practice. The emperor had assigned him a salary, but in the period of trouble which preceded the Thirty Years’ War, it was not paid. Even when he was appointed imperial mathematician by Matthias, Rodolphus’ successor, his hopes of recovering his arrears were disappointed. Fresh controversies with the clergy, and the disturbed state of the country, made his situation very uncomfortable: he therefore left Lintz, repaired to Ratisbon, declined an invitation to England, was confirmed by the succeeding emperor, Ferdinand, in the office of imperial methematician, and afterwards went to Ulm to superintend the printing of the Rodolphine Tables. In 1627 he returned to Prague, and received from the emperor six thousand guilders. He finally became a professor at Rostock, on the recommendation of Albert, duke of Wallenstein, but did not receive the promised compensation. In 1630 he went, by permission of the emperor, to Ratisbon, to claim payment of the arrears of his pension; but he was there seized with a violent fever, supposed to have been brought upon him by too hard riding; and to this he fell a victim in the month of November, in the fifty-ninth year of his age. In 1808, a monument, consisting of a Doric temple enshrining his bust, was erected to his memory in Ratisbon by Charles Theodore Von Dalberg.

Kepler is represented by his biographers as a man of small stature, thin, of a weak constitution, and defective sight; but of somewhat gay and sportive manners. He was attached to his science with the most fervent enthusiasm; he sought after truth with eagerness, but forgot, in the search, the maxims of worldly prudence. To him were allotted but a scanty share of what are commonly esteemed the pleasures of life; but he endured all calamities with firmness, being consoled by the higher enjoyments which science never fails to impart to her true and cordial votaries. ‘As an astronomer,’ says Lalande, ‘he is as famous in astronomy for the sagacious application which he made of Tycho’s numerous observations (for he was not himself an observer), as the Danish philosopher for the collection of such vast materials.’ To him, says another authority, the world is indebted for the discovery of the true figure of the planetary orbits, and the proportions of the motions of the solar system. Like the disciples of Pythagoras and Plato, Kepler was seized with a peculiar passion for finding analogies and harmonies in nature; and though this led him to the adoption of strange and ridiculous conceits, we shall readily be disposed to overlook these, when we reflect they were the means of leading him to the most important discoveries. He was the first who discovered that astronomers had been mistaken in ascribing circular orbits and uniform motions to the planets, since each of them moves in an ellipse, having one of its foci in the sun; and after a variety of fruitless efforts, he, on the 15th of May 1618, made his splendid discovery, that the squares of the periodic times of the planets are always in the same portion as the cubes of their mean distances from the sun. The sagacity of this wonderful man, and his incessant application to the study of the planetary motions, pointed out to him some of the genuine principles from which these motions originate. He considered gravity as a power that is mutual between bodies; that the earth and moon tend toward each other, and would meet in a point so many times nearer to the earth than to the moon as the earth is greater than the moon, if their motions did not prevent it. His opinion of the tides was, that they arise from the gravitation of the waters towards the moon; but his notions of the laws of motion not being accurate, he could not turn his conceptions to the best advantage. The prediction he uttered at the end of his epitome of astronomy, has been long since verified by the discoveries of Sir Isaac Newton; namely, that the determination of the true laws of gravity was reserved for the succeeding age, when the Author of Nature would be pleased to reveal these mysteries.

NEWTON.

The year in which Galileo died, was that in which Isaac Newton was born. This eminent individual, who was destined to establish the truth of the discoveries of his illustrious predecessors, Copernicus and Galileo, was born on the 25th of December 1642, at Coltersworth, in Lincolnshire, where his father cultivated his own moderate paternal property. After receiving the rudiments of education, under the superintendence of his mother, he was sent, at the age of twelve, to the grammar school at Grantham, where the bias of his early genius was shown by a skill in mechanical contrivances, which excited no small admiration. Whilst other boys were at play, his leisure hours were employed in forming working models of mills and machinery; he constructed a water-clock from an old box, which had an index moved by a piece of wood sinking as the drops fell from the bottom, and a regular dial-plate to indicate the hours.

On his removal from school, it was intended that he should follow the profession of a farmer, but his utter unfitness for the laborious toils of such a life was soon manifested. He was frequently found reading under a tree when he should have been inspecting cattle, or superintending laborers; and when he was sent to dispose of farming produce at Grantham market he was occupied in solving mathematical problems in a garret or hay-loft, whilst the business was transacted by an old servant who had accompanied him to town. These strong indications of the bias of his disposition were not neglected by his anxious mother; she sent him again for a few months to school, and on the 5th of June 1660, he was admitted a student of Trinity College, Cambridge.

The combination of industry and talents, with an amiable disposition and unassuming manners, naturally attracted the notice of his tutors, and the friendship of his admiring companions; amongst these was Isaac Barrow, afterwards justly celebrated as a preacher and a mathematician. Saunderson’s Logic, Kepler’s Optics, and the Arithmetic of Infinites by Wallis, were the books first studied by Newton at Cambridge. He read the geometry of Descartes diligently, and looked into the subject of judicial astrology, which then engaged some attention. He read little of Euclid, and is said to have regretted, in a subsequent part of his life, that he had not studied the old mathematician more deeply.

The attention of Newton, while he was pursuing his studies at Cambridge, was attracted to a branch of natural philosophy hitherto little understood――namely, light. It was the opinion of the celebrated philosopher Descartes that light is caused by a certain motion or undulation of a very thin elastic medium, which he supposed pervaded space. Newton overturned this theory. Taking a piece of glass with angular sides, called a prism, he caused the sun to shine upon it through a small hole in the shutter of a darkened apartment. By this experiment he found that the light, in passing through the glass, was so refracted or broken, as to exhibit on the wall an image of seven different tints or colors; and after varying his experiments in a most ingenious way, he established the very interesting facts, that light is composed of rays resoluble into particles, that every ray of white light consists of three primary and differently colored rays (red, yellow, and blue), each of which three is more or less refrangible than the other. This remarkable discovery laid the foundation of the science of optics.

In 1665, the students of the university of Cambridge were suddenly dispersed by the breaking out of a pestilential disorder in the place. Newton retired for safety to his paternal estate: and though he lost for a time the advantages of public libraries and literary conversation, he rendered the years of his retreat a memorable era in his own existence, and in the history of science, by another of his great discoveries――that of the theory of gravitation, or the tendency of bodies towards the center of our globe. One day, while sitting in his garden, he happened to see an apple fall from a tree, and immediately began to consider the general laws which must regulate all falling bodies. Resuming the subject afterwards, he found that the same cause which made the apple fall to the ground, retained the moon and planets in their orbits, and regulated, with a simplicity and power truly wonderful, the motions of all the heavenly bodies. In this manner was discovered the principle of gravitation, by a knowledge of which the science of astronomy is rendered comparatively perfect.

On his return to Cambridge in 1667, he was elected Fellow of Trinity College; and two years afterwards, he was appointed professor of mathematics in the place of his friend Dr. Barrow, who resigned. His great discoveries in the science of optics formed for some time the principal subject of his lectures, and his new theory of light and colors was explained, with a clearness arising from perfect knowledge, to the satisfaction of a crowded and admiring audience. He was elected a Fellow of the Royal Society in 1671, and is reputed to have been compelled to apply for a dispensation from the usual payment of one shilling weekly, which is contributed by each member towards the expenses. He had at this period of life no income except what he derived from his college and professorship, the produce of his estate being absorbed in supporting his mother and her family. His personal wishes were so moderate, that he never could regret the want of money, except as much as it limited his purchases of books and scientific instruments, and restricted his power of relieving the distresses of others. About the year 1683, he composed his great work, _The Principia_, or _Mathematical Principles of Natural Philosophy_. In 1688, the memorable year of the Revolution, he was chosen to represent the university in parliament, and the honor thus conferred on him was repeated in 1701. His great merit at last attracted the notice of those who had it in their power to bestow substantial rewards, and he was appointed warden of the Mint, an office for which his patient and accurate investigations singularly fitted him, and which he held with general approbation till his death. Honors and emoluments at last flowed upon him. Leibnitz, having felt envious of the discoveries of Newton, tried to revenge himself by transmitting a problem, which he thought would show his superiority, by baffling the skill of the English mathematician. It was received by Newton in the evening, after his usual day’s labor at the Mint, and he solved it before he retired to rest. After this there was no further attempt made to traduce his fame. In 1705 he received the honor of knighthood from Queen Anne.

Newton’s benevolence of disposition led him to perform all the minor duties of social life with great exactness; he paid and received frequent visits; he assumed no superiority in his conversation; he was candid, cheerful, and affable: his society was therefore much sought, and he submitted to intrusions on his valuable time without a murmur; but by early rising, and by a methodical distribution of his hours he found leisure to study and compose, and every moment which he could command, he passed with a pen in his hand and a book before him. He was generous and charitable――one of his maxims being, _that those who gave nothing before death, never, in fact, gave at all_. His wonderful faculties were very little impaired, even in extreme old age; and his cheerful disposition, combined with temperance and a constitution naturally sound, preserved him from the usual infirmities of life. He was of middle size, with a figure inclining to plumpness; his eyes were animated, piercing, and intelligent; the general expression of his countenance was full of life and kindness; his sight was preserved to the last; and his hair in the decline of his days was white as snow. The severe trial of bodily suffering was reserved for the last stage of his existence, and he supported it with characteristic resignation. On the 20th of March 1727, he expired at the advanced age of eighty-four years.

The character of Newton cannot be delineated and discussed like that of ordinary men; it is so beautiful, that the biographer dwells upon it with delight, and the inquiry, by what means he attained an undisputed superiority over his fellow-creatures, must be both interesting and useful. Newton was endowed with talents of the highest order; but those who are less eminently gifted, may study his life with advantage, and derive instruction from every part of his career. With a power of intellect almost divine, he demonstrated the motions of the planets, the orbits of the comets, and the cause of the tides of the ocean; he investigated with complete success, the properties of light and colors, which no man before had even suspected; he was the diligent, sagacious, and faithful interpreter of nature, while his researches all tended to illustrate the power, wisdom, and goodness of the Creator. Notwithstanding, also, his reach of understanding and knowledge, his modesty was such, that he thought nothing of his own acquirements; and he left behind him the celebrated saying, ‘that he appeared to himself as only a child picking up pebbles from the shore, while the great ocean of truth lay unexplored before him.’

HUYGENS.

While Newton, in England, was thus enlarging the boundaries of astronomy, and conferring upon it a degree of accuracy and system hitherto unknown, a number of continental philosophers were contributing materials, which, though of an humble character, were not the less necessary to the future progress of the science. First among these was Christian Hüygens, Lord of Zeelhem, born at the Hague on the 14th of April 1629, and descended of a rich and respected family. His father, secretary and counselor to the Princess of Orange, and distinguished as a scholar and poet, was not slow in observing the genius of his son, and, full of paternal solicitude for his improvement, became his first instructor. He early taught him music, arithmetic, and geography――says a writer in the Encyclopædia, from which we select the materials of this notice――and initiated him, when about thirteen, in the knowledge of mechanics, for which the boy had evinced a surprising aptitude. At fifteen, he received the assistance of a master in mathematics, under whose tuition he made great progress; and at sixteen, was sent to Leyden, to study law under the eminent jurisconsult Vinnius. He did not, however, permit jurisprudence to divert him from his mathematical studies, which he now prosecuted with success as well as afterwards at Breda, at the university of which he resided from 1646 to 1648. In these two cities he had respectively as masters two very able geometers, Francis Schooten and John Pell; and his first essays were so successful, that they attracted the notice of Descartes, to whom the author, in his admiration of that great philosopher, had communicated them. Descartes predicted his future greatness, but did not live to appreciate his discoveries.