NATHANIEL BOWDITCH.

THE subject of this sketch was the son of a cooper, and was born at Salem, Massachusetts, March 26th, 1773. At an early age he had the misfortune to lose his mother, to whom, like most men of eminence, he owed much that was good and beautiful in his nature. He was only ten years of age when this happened, and previous to it had attended school for a short time. It is related that, even at this early day, he displayed a remarkable aptitude for figures, and intuitively performed arithmetical feats far in advance of his studies.

When little more than ten years of age he was bound apprentice to Messrs. Ropes & Hodges, who were ship-chandlers, and while in their service always kept a slate and pencil by his side, so that, when not engaged in serving customers, he could pursue his favorite study. Every moment that he could call his own was devoted to the same object. He rose early, and went to bed late, so that, by thus economizing his time, he was able to make considerable progress in the mathematics. The labor which he cheerfully undertook to make himself master of the subject was

prodigious. Most of his books he borrowed from the Salem Athenæum, and, in spite of dryness, copied them. The fruits of his diligence still exist in more than twenty folio and quarto volumes. He did not allow any thing to impede his progress. That he might read Newton's "Principia," he learned Latin, the tongue in which it is written, and so with the French language. With these two powerful auxiliaries, he translated the former elaborate work, and the extensive one of La Place.

In a few years Mr. Bowditch became known as an extremely accomplished man of science, and was employed with another gentleman to make a thorough survey of the town of Salem. After this (1795) he was induced to undertake a voyage to the East Indies, under Captain Prince. The vessel returned after a year's absence, and Bowditch was so satisfied with the voyage that he made a second, third, and fourth with the same captain. The leisure which this occupation afforded him was doubtless one of its charms, for he was able not only to prosecute his mathematical studies, but to perfect himself in several languages, the French especially, and Italian, Spanish, and Portuguese to a great extent. His method of learning a language was peculiar. He obtained a New Testament in the desired language, and, with the aid of a Dictionary, worked through it. At the time of his death he possessed New Testaments in no fewer than twenty-five languages, and Dictionaries of a still larger number. He was by no means stingy of his knowledge, but, knowing its advantage, tried to diffuse it. Among the sailors he was eminently popular, and made the ship a perfect school of learning. Slates and pencils were in great demand, and conversations like the following are recorded: "Well, Jack, what have you got?" "I've got the sine.” "That ain't right; I say it's the cosine." According to Captain Prince, there were twelve men on board capable of working lunar observations for all practical purposes. Bowditch's habits at this time have been described very accurately by a companion. "His practice was to rise at a very early hour in the morning, and pursue his studies till breakfast; immediately after which he walked rapidly for about half an hour, and then went below to his studies till half past eleven o'clock, when he returned, and walked till the hour at which he commenced his meridian observations. Then came dinner, after which he was engaged in his studies till five o'clock; then he walked till tea-time, and after tea was at his Р

studies till nine o'clock in the evening. From this hour till half past ten o'clock he appeared to have banished all thoughts of study, and while walking he would converse in the most lively manner, giving us useful information, intermixed with amusing anecdotes and hearty laughs, making the time delightful to the officers who walked with him, and who had to quicken their pace to accompany him. Whenever the heavenly bodies were in proper distance to get the longitude, night or day, he was sure to make his observations once, and frequently twice in every twenty-four hours, always preferring to make them by the moon and stars, on account of his eyes. He was often seen on deck at other times walking rapidly, and apparently in deep thought; and it was well understood by all on board that he was not to be disturbed, as we supposed he was solving some difficult problem; and when he darted below, the conclusion was that he had got the idea. If he were in the fore part of the ship when the idea came to him, he would actually run to the cabin, and his countenance would give the expression that he had found a prize.”

The nicety of Bowditch's observations enabled him to detect many errors in the existing books on navigation, and especially one in which the year 1800 was set down as a leap-year. The immediate effect of this error, producing a difference of twentythree miles in the reckoning, was to cause the loss of many vessels. The publisher of the work, hearing of Mr. Bowditch's corrections, applied to the young navigator for assistance, and at his suggestion the latter undertook the laborious task of revising all the tables. In this operation he discovered no fewer than ten thousand errors. Concerning some of these, Mr. Bowditch remarks that, although they would not seriously affect the result of any nautical calculation, yet, since most of the tables were useful on other occasions where great accuracy was needed, it was not useless to have them corrected. Such a fabulous number of blunders have not been common since Bowditch's day.

In 1802 Mr. Bowditch published his first edition of the "Practical Navigator," a work of inestimable value to the maritime world, and which is still used to a great extent in the French and English navies. It gave the author a wide-spread reputation, and was no doubt instrumental in directing his attention to the publication of other scientific works. In part payment for his "Navigator," Bowditch received a copy of La Place's splendid

Mécanique Céleste, a work with which our author's name became closely associated. About this time he abandoned the sea as a profession. He had a reputation to rest on, and had been honored by several learned societies. He was a member of the American Academy of Arts and Sciences, and just before his last voyage Harvard University conferred upon him the honorary degree of Master of Arts (1802).

Soon after the close of his seafaring life, Mr. Bowditch was chosen president of the Essex Fire and Marine Insurance Company, in which office he remained nearly twenty years. Mainly owing to his good and practical management, the shareholders were able to secure large dividends on their investments. "For this situation," says one of his biographers, "his affability, regular habits, sagacity, and strict integrity, no less than his great scientific attainments, remarkably fitted him. The duties he had to discharge were severe, and occupied most of his time, but his favorite studies were never neglected. He never went down to the office without a volume of mathematics in his pocket, and every moment that he was not engaged in business he pored over its contents. During his residence at Salem he contributed twenty-three papers to the several volumes of the Transactions of the American Academy of Arts and Sciences. Some of these were on mathematical subjects, but the majority were astronomical. On the preparation of these he expended an amount of labor which even an enthusiast may contemplate with wonder. On the subject of the orbit of the comet of 1811, the manuscript volume containing his calculations (still in existence) was filled with one hundred and forty-four pages of closely-written figures, probably exceeding a million in number. The article itself was but twelve pages in length. Mr. Bowditch was a contributor to the Monthly Anthology, the North American Review, Silliman's Journal, the Analyst and Mathematical Diary. He also wrote several articles for the American edition of Rees' Cyclopedia.

We have already referred to La Place's great work, Mécanique Céleste. Bowditch's admiration for this masterly production— describing the entire mechanism of the heavens on mathematical principles—was so complete that he determined on translating it, and accompanying it with a copious commentary. The varied accomplishments required for the latter task can only be understood by taking a comprehensive glance at the subjects treated

by La Place. Some of them are as follows: The laws of equilibrium and motion; the law of universal gravitation, and the motions of the centres of gravity of the heavenly bodies; the figures of the heavenly bodies deduced theoretically, and then compared with the actual observations made of the figures of the earth and the planet Jupiter; the oscillations of the sea and the atmosphere; the motions of the heavenly bodies about their own centres of gravity; the theory of the planetary motions, and their inequalities and perturbations; the theory of comets; light, and the theory of astronomical refractions, etc., etc. The work was

declared by Professor Playfair to be an example "solitary in the history of human knowledge, of a theory entirely complete; one that has not only accounted for all the phenomena that were known, but that has discovered many before unknown, which observation has since recognized. To translate a work of this kind, and to write a commentary on it, was a task of prodigious labor, and required powers and attainments of the highest order." Dr. Bowditch used to say, "Whenever I meet in La Place with the words Thus it plainly appears,' I am sure that hours, and perhaps days of hard study, will alone enable me to discover how it plainly appears."

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It was the object of the translator to elucidate the difficult demonstrations by supplying the deficient steps, and carrying the processes still farther, if necessary; and to continue the work to the present time, so as to put the reader in full possession of all the recent "improvements and discoveries in mathematical science." He accomplished this truly Herculean task, and placed the great work before the public in a luminous and perfectly intelligible shape. On almost every page the notes exceeded the text; indeed, these have in themselves a value almost equal to the original matter. They are thoroughly critical, and examine the truth without any blind adherence to La Place's version of it. Some idea of the pains bestowed on the work may be formed from the fact that it was not published until twelve years after the translation was completed. It appeared at last-four quarto volumes of a thousand pages each; the fifth volume of the original work was never translated.

In 1823 Dr. Bowditch (he was made a doctor by Harvard University in 1816) accepted an engagement in Boston as actuary to the Massachusetts Hospital Life Insurance Company. On his