Popular Science Monthly/Volume 49/May 1896/Sketch of Henry Augustus Rowland
HENRY AUGUSTUS ROWLAND.
|SKETCH OF HENRY AUGUSTUS ROWLAND.|
By CHARLES EDWARD LLOYD.
AMONG the distinguished physicists America has produced Prof. Henry Augustus Rowland, of Johns Hopkins University is unanimously accorded a leading place. He was born at Honesdale, Pa., November 27, 1848. His forefathers were among the earliest settlers of Fairfield, Conn. Three generations of clergymen of well-known prominence in the Congregationalist Church of Windsor, Conn., are his immediate paternal ancestors. His father, the Rev. Henry Augustus Rowland, had a great love for all scientific pursuits, and only gave them up for what he considered a higher calling. Prof. Rowland's mother is descended from representatives of several Knickerbocker families of Manhattan Island. She was Harriette Heyer, the daughter of a wealthy merchant of New York. Her mother was Miss Suydam.
In 1855 Prof. Rowland's father removed to Newark, N. J. He died there in 1859. Prior to his death, however, he had discovered the scientific bent of his young son, and heartily sympathized with and encouraged it. During the residence of his family in Newark the boy spent most of his time making chemical experiments. He used a book on chemistry belonging to an older sister, and worked in a crude laboratory he made for himself in the cellar of his father's house. Between the ages of eleven and fifteen he also commenced experiments in electricity and magnetism, making many small electric motors, electric machines, and repeating all the experiments he could find mentioned in the few scientific books to which he had access.
When he was about sixteen years old his mother sent him to Andover, Mass., to prepare for college. While here he was so engrossed in his electrical and magnetic experiments that his Greek and Latin studies were neglected. He was severely reprimanded by Mr. Taylor, the head of the school. This lecture, delivered to him in an arbitrary manner, without any inquiry as to the cause and with no word of kindness or sympathy, made a profound impression on the boy and increased, if possible, his dislike for the stones of the Latin and Greek languages which were forced upon him when he was starving for the bread of scientific knowledge. On returning home from Andover he expressed his dislike for this course of study so strongly to his mother that she determined to send him to the Rensselaer Polytechnic Institute at Troy, N. Y., at that time the leading engineering school in the country. Here the young man maintained a good position in his classes, although much of his time was spent in his own experiments and studies, The subjects taught, however, were so congenial to him that one reading of the lessons assigned him was sufficient to insure a creditable recitation.
Owing to an injury to his knee during a snowball fight, he gave up his classes in Troy and studied chemistry for half a year at the Sheffield Scientific School. Here he invented and made the first continuous current dynamo ever constructed, which has since been exhibited at the World's Fair at Chicago. Young as he was, he was busily engaged in researches and experiments on magnetism. He was an earnest student of Faraday's Researches, Tyndall's Heat, Youmans's Conservation of Energy, and books of similar nature, although he had never studied the subject of physics under a competent teacher.
He returned to Troy and was graduated in 1870 with the degree of C. E. On his return home he continued to work on his favorite subjects of electricity and magnetism. About this time he published his first paper, a letter to the Scientific American describing a visit to an inventor, who professed to obtain great power from a single cell of a battery. Mr. Rowland, being familiar with the laws of the conservation of energy, knew there must be some swindling device somewhere, and finally exposed it, although a number of capitalists had already been defrauded of large sums of money by this man's claims. For part of a year Mr. Rowland was connected with a railroad in western New York as civil engineer, but routine work of this nature was so distasteful to him that he accepted the place of Instructor in Natural Science in Wooster University in Ohio. After a few months' experience here, he went to Troy, N. Y., to teach physics. During this period he had been engaged in researches on magnetic distribution, and what is now called magnetic permeability, using a system of absolute magnetic units of his own invention and calculating many cases of magnetic distribution by the method of the magnetic circuit, now always used for the calculation of dynamos and motors, and often ascribed to Hopkinson, but really due to Rowland. These researches he rewrote three separate times, and sent for three consecutive years to the leading scientific journal of America. Each time the editor, who was not a physicist, said that he had consulted the most eminent physicists of the country, and their advice to Mr. Rowland was that he had better study the subject before attempting to write any more papers. This criticism naturally discouraged and depressed the ambitious and studious' man. Since his earliest youth he had studied electricity and magnetism in spite of all opposition, traveling from place to place with his trunks full of galvanic batteries and electrical material, never receiving one word of encouragement, but always looked at askance as one no better than he ought to be, or reprimanded by ignorant pedagogues for not studying languages, dead in every sense to one who could judge of the relative value of things. This repeated rejection of his manuscript by the leading American journal was the most depressing factor in his life.
About this time. Maxwell's great work on Electricity and Magnetism appeared, and Mr. Rowland recognized there the system of units which he had himself invented, as well as many other of his ideas. He also recognized in the author a master mind of the very highest order. He compared this work with his rejected manuscript and said to himself: "This is the judge I want; I am either a fool, suitable for an asylum only, or my work is good. I shall send my papers to this great man and find out." The paper went, and the kindest of letters from the great Maxwell came back, saying that the paper was of the highest value, and had been sent to the Philosophical Magazine of London! This verdict naturally eliminated the "depressing factor" above referred to.
This "paper" appeared promptly and established Mr. Rowland's reputation. It is considered to-day the beginning of the modern exact study of magnetism. It was, perhaps, the main cause of his selection for the chair of Physics in the Johns Hopkins University.
While teaching at Troy, he visited his uncle, who was chaplain at West Point. Here he first met Prof. Gilman, who had just been elected President of the projected Johns Hopkins University. Prof. Rowland had been cordially introduced to Prof. Gilman by Prof. Michie. President Gilman was anxious to secure the best man in both hemispheres for the chair of Physics in the new university, over which he was to preside, and at his suggestion the Board of Trustees of Johns Hopkins University wrote to Clerk Maxwell, Lord Rayleigh, Lord Kelvin (then Sir William Thompson), Baron von Helmholtz, and other European scientists for the name of the ablest physicist known to them. With singular unanimity these foreign specialists replied that the most original thinker in the domain of physics was, in their opinion, an American named Rowland, of the Rensselaer Polytechnic Institute, of Troy,N. Y.! Thus indorsed by Europe and America, the position was offered to Prof. Rowland and accepted. He still holds it.
When this flattering offer was accepted, Johns Hopkins University was not prepared to open its doors to students, and President Gilman suggested that Prof. Rowland should take a year's leave of absence. This suggestion coincided perfectly with Prof. Rowland's plans. He went abroad, and was for a while the guest of the great Maxwell. Now, for the first time, he was able to converse with one who knew more about his favorite subjects than he did. The wonderful and profound knowledge of Clerk Maxwell, combined with a childish simplicity and the kindliest of natures, made a great impression on Prof. Rowland. He looks back to this visit as one of the most notable events of his life. From England he went to France, thence to Germany, where he entered the laboratory of Baron von Helmholtz. It was here he carried out his research on the magnetic action of electric convection—an idea he had conceived in 1868 while reading Faraday's Researches. He returned to America in 1876, and assumed his duties as Professor of Physics in the Johns Hopkins University.
Prof. Rowland was at this time only twenty-seven years of age, a period at which many of his graduate students now begin the study of physics under his able tutelage. His students are sincerely
First Continuous-Current Armature made by Prof. Rowland in 1869.
attached to him, and have so profound a respect for his knowledge and ability that many of them emulate his example and gladly spend hours of extra time in testing interesting experiments suggested by his lectures.
During the early years of Prof. Rowland's life in Baltimore he made a new determination of the mechanical equivalent of heat, in which he introduced exact thermometry for the first time. He made a considerable correction in Joule's value. He also discovered that water had a minimum value of its specific heat, a fact unnoticed before. Soon after he made a determination of the unit of electrical resistance, the ohm, which demonstrated the error of the British Association Committee. This experiment he repeated with a Government appropriation as a member of the International Congress for fixing this standard. When this congress met at Paris, in 1884, Prof. Rowland protested against the value there adopted, as it did not agree with his experiment. At the Congress of Electricians, held at the Centennial Exposition at Chicago, in 1893, the International Chamber of Delegates, of which Prof. Rowland was president, decided unanimously to adopt the value advocated in 1884, and this is now the standard of the civilized world, a triumph of which Prof, Rowland is very proud.
Prof. Rowland's work in physics not only includes that published under his own name, but his influence is felt in the theses of his students who aspire to the degree of Doctor of Philosophy. One of the most notable of these was written by S. H. Hall, and describes a new phenomenon now known as the "Hall effect." The experiment leading to this discovery was described by Prof. Rowland in his lectures, and Mr. Hall was encouraged by his teacher to carry it out to a successful termination. The influence of Prof. Rowland's students in the recent revival of interest in physics, including electricity and magnetism, has been considerable, and the highest position in practical electricity available to an American is held by Dr. Louis Duncan, President of the Society of Electrical Engineers, who is associated with Prof. Rowland and is one of his students.
Prof. Rowland has, with rare exceptions, devoted his time to pure research, and has never endeavored to accumulate a fortune. If he had patented his dynamo, which was finished ten years before Edison applied for a patent, his bank account would be large enough to enable him to perfect any idea he might conceive. Of late years Prof, Rowland has devoted himself principally to the improvement of the apparatus for use in spectrum analysis. He has made three dividing engines for ruling the gratings used, each better than the one before it, and each producing gratings better than those of Mr. Rutherford, hitherto admitted to have been the best. At the present time, all the work of the world in spectroscopy requiring high dispersion is made with "Rowland's gratings."
Prof. Rowland has also invented the concave grating which can be used without lenses, and with which photographic work is best done. These results have been achieved principally by Prof. Rowland's skill as a mechanical designer, and his dividing engines have been constructed not only after his own design, but by processes invented by him and carried out under his own eye. So far nobody has been able even to copy the machines, although the processes have been freely described in his article Screw in the Encyclopædia Britannica."Rowland's grating" is made by ruling parallel lines on a concave plate of what is known as speculum metal. This metal is an alloy of two parts copper and one part tin. The parallel grooves are made with a delicately adjusted diamond point. The machine on which the grating was made was manufactured after eighteen months' hard work by Theodore C. Schneider, the machinist at the university (a pupil of George M. Phelps, of Brooklyn), from the
Dividing Engine for Ruling Gratings (The Second Constructed). The legs are slender and put in loosely in order to prevent the tremors of the earth reaching the working parts.
designs of and by processes invented by Prof, Rowland, who was constantly at hand to direct every movement. This machine is in a dark vault under the laboratory. When a "grating" is being made, it runs night and day. The vault is locked, and no one is allowed to enter it, for the machine is so sensitive that the temperature of a human body would disarrange it. When a new diamond point is being tested, as is now the case. Prof. Rowland will permit a few people to visit it. Sir William Thomson, the Earl of Rosse, Lord Rayleigh, Prof. Ball, Astronomer Royal of Ireland, the late Prof. Helmholtz, of Berlin, Prof. Mascart, of Paris, and Prof. Lemström, of Sweden, are among those to whom this courtesy has been extended. The motive power of the machine is a hydraulic engine. The water is kept at a constant height in a tank near the roof, to insure unvarying speed. It is driven by a belt attached to a solid brass driving wheel on the machine. A crank is turned by the same on the other end of the shaft. This crank moves the carriage that conveys the diamond point back and forth over the surface of the "grating" or plate. This carriage rests on two steel ways, which are flat on top and slanting slightly outward, so that there are three points on one way or rail on which the carriage rests. These "ways" are ground so as to make them as nearly accurate as possible. But they can not be made perfect, for Mr. Rowland tested them with a microscope and found that they were "out"—that is, not exactly perfect—by one fifty-thousandth of an inch. He did not attempt to improve them.
One of the most difficult problems that Prof. Rowland and Mr. Schneider have to solve is to find a diamond point that is exactly right. Some are too blunt, some have one defect, some another, and it generally takes from two to eight months to find an available diamond.
As the diamond carriage moves exactly in the same line backward and forward every time, the metal plate or grating beneath must move slightly when the diamond makes a stroke. These tiny grooves must be exactly the same distance apart, and as there must be from ten thousand to forty-eight thousand parallel grooves or lines made within the space of one inch, it is readily seen that the lateral movement of the metal plate is very small. At every stroke of the diamond, the carriage carrying the plate is moved by means of a steel screw. It is the only absolutely exact screw ever made. The "ways" mentioned above, when tested by the microscope, are one fifty thousandth part of an inch "out" of the exact, but the strongest microscope can find no flaw in the exactness of the screw. In order to manufacture this screw, it was necessary to make it under water, which was kept at a certain temperature. If it had been made in the air, or the temperature of the water changed, the slight expansion caused by the friction would have made the threads vary slightly. This would have caused the carriage that runs on it to vary slightly, and consequently the spaces between the grooves on the "grating" would vary, and render it useless for scientific purposes. The screw is turned by a solid steel wheel with seven hundred and fifty teeth on the ring, which is moved the space of one tooth at a time by an ingenious contrivance attached to the driving shaft. The screw having twenty threads, the carriage is moved one fifteen-thousandth part of an inch each time, thus making that many grooves to the inch on the metal "grating." The number of grooves may be regulated. "Gratings" have been made with forty-eight thousand grooves to the inch. By the strongest microscope made, the human eye could not see the lines if there were more than a hundred and twenty-five thousand to the inch. Prof. Rowland says he gets the best results from "gratings" with fifteen thousand grooves to the inch. The machine now in use at Johns Hopkins University is the third of the kind made. The first was completed years ago, and is still in use in the vault. The European, and especially the German universities, have tried repeatedly to make a machine of the kind, but have never succeeded. Hence all their best universities get the "gratings" for their spectroscopes from the machine at the Hopkins.
When a "grating" is completed, it is taken out, tested, packed in a handsome hardwood case, and sent to Mr. Brashear in Allegheny, Pa. This gentleman attends to the sale of the valuable "gratings," which cost from twenty to three hundred dollars. The proceeds are divided between Mr. Brashear and the university.
When these tiny grooves, cut with a diamond point on the polished metal plate, are completed and are perfect, the grating breaks up a ray of light into its various colors as a prism does. Some of the gratings produce "ghosts," and are then considered imperfect. Prof. Rowland deals with these "ghosts" of the spectrum in a recent article in the Astro-Physical Journal, of Chicago. He says: "A periodic displacement of one millionth of an inch in a grating will produce visible ghosts which are seen in the secondand are troublesome in the third. With very bright spectra these might even be seen in the first spectrum. An over-exposed photographic plate would readily bring them out."
With the concave grating Prof. Rowland has made an immense photographic map of the solar spectrum, and has determined a system of standard wave lengths which is now universally adopted. He is now having measured the wave length of every line of the solar spectrum and is determining the elements to which they all belong. This is a work of years, as is also the measurement of the wave lengths of the spectrum lines of all the elements.
These measurements are carried on mostly by assistants, and are paid for by appropriations made from the Rumford fund, the Bruce fund, or the Bache fund. But, at times, money for this work is very scarce. Nothing can come from Johns Hopkins University, as it has lost so much of its endowment that its work is greatly hampered. Thus, Prof. Rowland, in the prime of his life, and at the age of greatest mental activity, finds himself compelled to relinquish carrying out many of his best ideas. He has determined, if possible, to remedy the defect himself. Whether he will be able to do so remains to be seen, but he has never failed to accomplish his purposes, and those who know him best have found that discouragements only spur him to greater effort.
In this connection, however, he remembers one of the most disagreeable incidents of his life. Recently he worked six months for the Cataract Construction Company, of New York, in developing the plans for the transmission of the power of Niagara, in which he overthrew the plans of their engineers and substituted rational ones. He consulted two friends as to the bill he should render for his services. He accepted their advice, as they were admitted to be the most competent judges in such matters. The company sent him a check for one third of the amount, accompanied by an insulting letter! Although abhorring petty disputes about money, his sense of justice was so shocked at this treatment that he immediately brought suit against them, rejecting all offers of compromise. In spite of the fact that the company was backed by half the money power of New York and its best lawyer, a jury of twelve intelligent and impartial gentlemen unanimously pronounced his bill correct and just.
During the course of Prof. Rowland's life he has received many honors, mostly from abroad, where he is probably best known and most thoroughly appreciated. In 1881 he became a chevalier of the Legion of Honor of Paris, and in 1896, at the centennial of the Institute of France, of which he is a corresponding member, he was nominated officer of the Legion of Honor. At the exposition at Paris, in 1890, his gratings and map of the spectrum received a grand prize and gold medal. About 1881 he received the grand prize of the Venice Academy of Sciences for an essay on the Mechanical Equivalent of Heat. In 1884 Prof. Rowland received the Rumford medal from the American Academy of Sciences in Boston for his researches in light and heat. In 1890 the Draper medal was awarded him for his researches in spectroscopy.
He is an associate fellow of the American Academy of Sciences of Boston, and member of the National Academy of Sciences, Washington; honorary member of the Royal Society, of London; one of the twelve honorary members of the London Physical Society; one of the ten honorary members of the Paris Physical Society; honorary member of the Royal Society of Göttingen; of the Accademia dei Lincei, Rome; Academy of Sciences, Catania, Sicily; of the Manchester Literary and Scientific Society; of the Cambridge (England) Philosophical Society; of the Swedish Academy of Sciences, Stockholm, of the Italian Society of Spectroscopists, etc. He is corresponding member of the British Association, of the Institute of France, etc.
In 1883 he presided over the Section of Physics of the American Association for the Advancement of Science at Minneapolis, before which body he delivered an address, A Plea for Pure Science, which was published and read with great interest throughout the world.
He was foremost among the members of the Electrical Congress at Chicago, and was President of the International Chamber of Delegates for the establishment of electrical units. The students of the University of Chicago, who occupied front seats in the Academy of Fine Arts when this body of learned men was called to order, regarded Henry Augustus Rowland as second only to his great teacher, the late Baron von Helmholtz. It is possible that those who were privileged to be present on that occasion will never again see, on a single platform, so many men of international reputations.
In 1880 the Johns Hopkins University conferred on him the degree of Doctor of Philosophy. In 1895 Yale University conferred on him the degree of LL. D.
In 1890 Prof. Rowland was married to Miss Henrietta Harrison, of Baltimore, who is thoroughly interested in his work, and is in perfect sympathy with him. They have two bright and interesting children. His oldest, a little daughter, Harriette, named for his mother, is four years old. His son, Henry Augustus Rowland, though only three years of age, already bids fair to follow in the footsteps of his distinguished father. The lad is very fond of visiting the physical laboratory, and will for a long time watch with silent and absorbed interest the movements of the intricate machinery, which is kept constantly going under the supervision of Mr. Schneider.
Prof. Rowland is a tall, strongly built man, and can frequently be seen at one of the windows in the basement of the physical laboratory of Johns Hopkins University industriously working and deeply absorbed in making investigations and experiments which the vast majority of his fellow-citizens would not comprehend. Every one who approaches him is at once impressed by his genuineness. His favorite exercise is horseback riding. During the winter he rides every day many miles in the country around Baltimore, and sits his horse like a Centaur. He especially enjoys a fox-hunt of the old-fashioned sort, for which Maryland has been famous for a century, the first requisite of which is such perfect horsemanship that seven-rail fences and deep ditches are not considered obstacles to the chase. A "paper chase" he would probably regard with as much contempt as he does the pamphlets in his "crank library," a collection of so-called scientific papers written by people who know nothing of science. He intends to deliver a lecture soon on the contents of this "crank library."
His vacation is usually spent in his native New England. He cruises along the coast in a small yacht of his own design, in whose seagoing capacity he has great confidence. It is said by some of his students, who assume to know more of nautical science than of physics, that this yacht does not "ride the waves" properly, and that some day they expect to hear that their teacher has been drowned in a rough sea off the Atlantic coast. These critics are not aware of the fact that during his boyhood a part of Prof. Rowland's vacations were spent in New York city, and that his favorite pastime was rowing or sailing his own boat in New York harbor. A glance at the shipping in that port, with steamships and sailing vessels coming from and going to all parts of the world, with ferryboats constantly passing from pier to pier, and the shrill whistle of the omnipresent tugboat constantly rising above the roar of commerce, ought to convince the most skeptical that even as a boy he was a seaman who knew his business.
This sketch of Prof. Rowland's life should be read with pride and interest by every one of his fellow-citizens. It should encourage every ambitious and gifted American youth to persevere in an effort to overcome obstacles which prejudice and ignorance often interpose to obstruct the career of those who are born with mental powers too great to be trammeled by ancient traditions or to be made pliant to an uncongenial routine.