# Popular Science Monthly/Volume 42/January 1893/Sketch of Lewis Morris Rutherfurd

Layout 4
LEWIS MORRIS RUTHERFURD.
* SKETCH OF LEWIS MORRIS RUTHERFURD.
AN article by M. L. Niesten, published in the thirty-ninth volume of the Monthly, showed how greatly science is indebted to amateur astronomers; that about half of the living astronomers whose work had gained a footing in science were amateurs; that many of the most important discoveries in the heavens had been made by them; and further, that "other laborers than astronomers have assisted in the advance of the science by furnishing amateurs easier means of examining the sky and bringing the greatest exactness into their observations." An eminent demonstration of the truth of M. Niesten's remark, and of the value of the assistance which an amateur has been able to render astronomy in both sides of the work as described by him, is afforded by the subject of this sketch. Educated for the legal profession, and having begun his career in it, he gave it up for the more favored pursuit of astronomical observation; perfected instruments; and performed the most essential part in introducing and establishing the photographic method under which the most rapid advances in the science are now made.
Lewis Morris Rutherfurd was born at Morrisania, N. Y., November 25, 1816, and died at his country home, Tranquillity, N. J., May 30, 1892. He could trace a Scottish ancestry on his father's side through seven hundred years. His grandfather, John Rutherfurd, was a nephew of our Revolutionary major-general William Alexander, or Lord Stirling, and was United States Senator from New Jersey from 1791 to 1798. His mother was a direct descendant of Lewis Morris, one of the signers of the Declaration of Independence. He entered the sophomore class of Williams ​College when fifteen years old, and was graduated from that institution in 1834. Having studied law with William H. Seward in Auburn, he was admitted to the bar in 1837, and practiced with John Jay, and after his death with Hamilton Fish. His tastes, however, drew him toward the physical sciences. While in college, he had yielded to them, and became assistant to the Professors of Chemistry and Metaphysics in preparing their class lectures, and had made pieces of apparatus with his own hands for them; and having found the scattered parts of an old telescope in the lumber-room of the college laboratory, he had reconstructed the missing pieces and put the whole in order. His own means, to which was afterward added the fortune brought by his wife, made the transition from a life of professional work to one of travel and study and amateur experiment an easy one. During a residence of several years in Europe, he studied optics under Prof. Amici, a famous adept in that science, and acquired knowledge which he was destined to put to most fruitful use in after-years.
After his return home he built upon the lawn of his home at Eleventh Street and Second Avenue, New York, an observatory which has been called the finest and best-equipped private astronomical observatory in the country. It had a transit instrument, and a refracting telescope with an object-glass eleven and a half inches in diameter, made by Fitz, with a second glass for photographing, corrected by his own new methods and finished by himself; the seeing lens, when photographs were to be taken, being unscrewed from the tube and the photographing lens being put in its place. A similar instrument was constructed under his direction for Dr. Gould and taken by him to the Argentine Republic, where it is still in use, a portion that was broken during the voyage having been replaced under Mr. Rutherfurd's directions.
For use in his own observatory, in place of this instrument, Mr. Rutherfurd made with his own hands an equatorial telescope having an object-glass of thirteen inches aperture. In order to employ it for photography without being compelled to take out the seeing object-glass, he constructed a third lens, which, being placed outside of the ordinary object-glass, converted the telescope into a photographing instrument. The visual focus of this telescope was of fifteen feet two inches distance, and its photographic focus of thirteen feet. In this construction he took account of the effect of temperature on the length of the galvanized iron tube. He devised and constructed a measuring machine for measuring the star-plates, arranged to determine the position-angle and distance of every star on a plate from a central star; and with this had measures made on many of the star-plates, among them the ​Pleiades and Praesepe clusters. The measuring machine was improved in 1868 by using a glass scale, one division of which was equal to ten revolutions of the micrometer screw. Mr. Rutherfurd continued his photographic work for twenty years, or till 1877, after which year no photographs were taken by him. "Mr. Rutherfurd," says Prof. Gould, "was the originator and the introducer of the photographic method of observation. To him is due the first idea and employment of an object-glass constructed for employing the chemical rays rather than the visual ones; as also, later, that of the 'photographic corrector' for adapting an ordinary object-glass to its best use in securing sharp definition of the stars upon the sensitive plate. He personally planned the construction of the first instruments of these classes, prescribed the curves for the several surfaces of the lenses, and superintended the preparation of the object-glasses, which were made, with the assistance of Mr. Zitz's son, in his own house, by methods devised and made practical by himself alone. So, too, was it he who introduced the precautions by which the sensitive film was guarded against distortion; it was he who first devised and constructed micrometric apparatus for measuring the impressions upon the plates; and he who first put this apparatus into practical use in executing his measurements. The large and delicate micrometer screws were made by him or under his constant supervision, at his dwelling-house in this city [New York], and the measurements were effected in his study." It is related by a writer in Nature, in illustration of the pains he took to secure the utmost perfection in the cutting of the threads of his micrometer screw, that he took three years to make a single screw. "In order to test the quality of his work, it struck him that it would be a happy thought to see if it would enable him to rule a grating. He accordingly set the apparatus up in his workroom, and by means of an automatic arrangement kept it going all night, as at that time the local vibrations were fewest. The result was that he was able to make the most perfect gratings [then] known."
For many years Prof. Gould says Mr. Rutherfurd labored at the photographic method of observation without the sympathy or encouraging faith of astronomers generally; "and in 1865 he did me the honor of placing in my hands a large number of measurements, and giving me permission to study and compute them. They had been made in his house, with apparatus designed and in great degree constructed by himself, from photographs which he had personally taken by aid of the telescope which he had himself devised and which was also in his house." At the session of the National Academy of Sciences, held in Northampton, Mass., in August, 1866, Prof. Gould presented a memoir containing the results of computations, made from these data, for ​determining the relative positions of thirty-one stars in the Pleiades. On the same day Mr. Rutherfurd communicated orally to the Academy a detailed account of his experiments, difficulties, and successes, and of the methods which he had finally adopted. His photographs of the moon are remarkable for the fineness of their details.
In 1863 Mr. Rutherfurd published in the American Journal of Science a paper dealing with the spectra of the stars, the moon, and the planets, the first published work of the kind after that of Bunsen and Kirchhoff, and the first attempt at classifying the stars according to their spectra. In this paper he said: "The star spectra present such varieties that it is difficult to point out any mode of classification. For the present, I divide them into three groups: first, those having many lines and bands, and mostly resembling the sun, viz.—Capella, β Geminorum, α Orionis, etc. These are all reddish or golden stars. The second group, of which Sirius is the type, present spectra wholly unlike that of the sun, and are white stars. The third group, comprising α Virginis, Rigel, etc., are also white stars, but show no lines; perhaps they contain no mineral substance, or are incandescent without flame." In 1864 he presented to the National Academy of Sciences a photograph of the solar spectrum obtained by means of bisulphide-of-carbon prisms, containing more than three times the number of lines that had been laid down within similar limits on the chart by Bunsen and Kirchhoff. In the course of his spectrum work, to which he now gave increasing attention, he found, as he had done in photographing, that the apparatus in use was insufficient for his purposes. He noticed that diffraction gratings of finely ruled lines upon glass and metal were preferable to series of prisms for the decomposition of light in spectral study. The best gratings in existence—still imperfect—were those of Nobert, who kept his process a secret. Mr. Rutherfurd—as usual helping himself in invention—devised a ruling engine capable of turning out much finer gratings than those of Nobert, some of which had about seventeen thousand lines to the square inch, and which have been surpassed only by those since made by Prof. Rowland. With these gratings his great photographs of the solar spectrum—more than eleven feet long—were made.
After he ceased to take an active part in astronomical work, Mr. Rutherfurd gave his instruments and photographs to Columbia College: the telescope in December, 1883—and it is now mounted in the observatory one hundred and ten feet above the ground; the machine for making measures in the same year; and his best negatives in November, 1890. This valuable collection of photographs of the sun, the moon, and the star clusters has been placed in a fire-proof vault. It contains, according to a list ​published in the annals of the New York Academy of Sciences, one hundred and seventy-five plates of the sun, one hundred and seventy-four of the solar spectrum, four hundred and thirty-five of the moon, and six hundred and sixty-four of star clusters. The reduction of the measures of the Pleiades plates, taken with the thirteen-inch instrument and measured with the improved machine, undertaken according to the understanding between Mr. Rutherfurd and the college authorities by Prof. Rees and Mr. Harold Jacoby of the observatory, and completed and published only a few days before Mr. Rutherfurd's death, but too late to be examined by him, seem, says Prof. Rees, to indicate an accuracy of measures comparable with the best recent heliometer work. Yet they were all taken between 1865 and 1874. It is intended to continue the reductions till all the measures made with the improved machine—filling some twenty folio volumes of about two hundred pages each—are finished; then to measure the negatives that remain unmeasured, and proceed to their reduction.
Prof. Gould emphasizes the fact that all these plates were made some years before the discovery of the dry-plate process, by the aid of which celestial photography has made such wonderful progress in recent years; and "we owe to him not merely the first permanent records of the relative positions, at a given moment, of all the celestial objects impressed upon the sensitive plates, but the means and the accomplishment of the actual conversion of these records into actual numerical data."
Mr. Rutherfurd demonstrated, contrary to the prevailing opinion, that the albuminated collodion film could be made stable on glass under all conditions of atmospheric change.
Mr. Rutherfurd was a member of the International Meridian Conference that met in Washington in October, 1885, and took a prominent part in its work, framing and presenting the resolution that embodied the conclusions of the conference. He was invited by the French Academy of Sciences in 1887 to become a member of the International Conference on Astronomical Photography held in Paris in that year, and was given by the President of our National Academy of Sciences the appointment as its representative, but the condition of his health forbade his serving. He was an Associate of the Royal Astronomical Society. He was an original member of the National Academy of Sciences, which was incorporated by act of Congress in 1863. In 1867 he was elected President of the American Photographical Society, in the official board of which he had served for many years as first vice-president. During his administration the society became the Photographical Section of the American Institute. For many years he was not only a trustee of Columbia College, but one of the most active and hard-working members of that body. Mr. ​Rutherfurd's physical condition was delicate during the later years of his life, and not suitable for sedentary occupation, or that which exposed him to sudden changes of weather; but he continued his astronomical work as long as prudence permitted it, then retired wholly from it. His death was brought on by a cold, contracted while traveling to his winter residence in Florida, to which was added the shock caused by the sudden death of his daughter.
Of his personality, Mr. O. G. Mason says, in the Photographic Times: "No one could be long in his presence without feeling that he was a man of rare ability. His tall, erect figure and scholarly face made him conspicuous wherever he went. His dignified, courtly bearing and genial nature made earnest friends of all his acquaintances. His dislike of ostentation and show was a conspicuous trait of his character. He was never known to wear any one of the many decorations, emblems of rank, or acquirements which had been conferred upon him." His signature was his plain name, without the addition of any of the literary and scientific honors and titles he had a right to use. "His liberality in the diffusion of the knowledge which he had gained was known and appreciated by hundreds who sought his advice"; and "his wise counsel was sought and recognized as being of the highest value."