Popular Science Monthly/Volume 26/February 1885/Sketch of Sir David Brewster
THE contributions of Sir David Brewster to the progress of science were principally connected with his researches in optical properties and phenomena; and many of his discoveries in this line were almost immediately turned to practical use. He also did a wholesome work in diffusing knowledge and awakening interest in scientific subjects by the publication of his popular and readable but accurate and carefully prepared books.
Sir David Brewster was born at Jedburgh, Scotland, December 11, 1781. His father was rector of the grammar-school, and a teacher of considerable reputation, whom neighborhood fame characterized as "the best Latin scholar and the quickest temper in Scotland"; but he was kindly withal. It was intended that David should become a minister, and he was sent to the University of Edinburgh, to be educated with a view to that profession, when only twelve years old. His tastes had, however, even before this time, turned into another direction. It is recorded of his earlier school-days that, though he was never seen to pore over his books like the other boys, he always had his lessons, kept a prominent place in his classes, and was frequently applied to by his fellow-pupils for assistance. And it was in the days of his childhood "that a dilapidated pane of glass in an upper window of his father's house produced the inquiring thoughts which led him afterward to search into the mysteries of refracted light."
He had become acquainted with James Veitch, of Inchbonny, half a mile from Jedburgh, whom Sir Walter Scott has mentioned as a "self-taught philosopher, astronomer, and mathematician." Veitch was a plow-maker by trade, but was well versed in astronomical calculations and observations, having been the first discoverer of the great comet of 1811, and was in his most congenial pursuit when he was making telescopes, a work to which he brought much mechanical skill and scientific accuracy. His "scientific workshop," on the Jedburgh turnpike, "became a gathering-place for all the young men of intelligence in the neighborhood, most of them being in training for the ministry, for medicine, and other liberal pursuits. They had lessons in mathematics and mechanics, but especially in the favorite science of astronomy. The telescopes were tested in the day-time by the eyes of the birds perching on the topmost branches of the 'King of the Wood,' a noble relic of the past forest days, about half a mile from Inchbonny. When the bright sparkle of the bird's eye was distinctly visible by day, James Veitch's specula and lenses were considered fit to show the glories of the sky by night." David "was the very youngest," says his daughter, Mrs. Gordon, from whose book we borrow our anecdotes, "of the quaint and varied group. When he began his visits I do not know, but we find that at the age of ten he finished the construction of a telescope at Inchbonny, which had engaged his attention at a very early period, and at which he worked indefatigably, visiting the workshop daily, and often remaining till the dark hours of midnight to see the starry wonders and test the powers of the telescopes they had been making."
Brewster gave faithful attention at the university to the studies which were assigned to him, having no intention as yet, nor for a considerable time afterward, to allow them to be superseded by any other. Yet all the time we find scientific questions prominent in his thoughts, and growing in interest to him. At every holiday he would make the journey to his home, a distance of forty-five miles, on foot, and then, before the day had ended, of another half mile to Inchbonny, to have a scientific chat with his friend Veitch. His letters to Veitch during this period are frequent, and full of references to scientific questions and scientific men. He is making an electrical machine, and tells of all his experiments and difficulties; he has made a map of the stars near our planet, and offers suggestions about grinding speculums; he is greatly satisfied with his telescope, to which, or any of Veitch's instruments, the great Newtonian reflector at the observatory can no more be compared than "a dirty common refractor with a fine achromatic telescope"; and he describes how a galvanic column may be made by combining copper or silver coins and pieces of tin or zinc with disks of card or leather soaked in water. These things were much more novel in those days than they are now. "He had," says his daughter, "a sincere attachment to the principles and constitution of the Established Church of Scotland, and a thorough acceptance of her doctrinal standards," and was duly licensed to preach. His first sermon was preached in the West Kirk of Edinburgh, one of the largest churches in Scotland, before an unusually crowded congregation; and he preached frequently for some time afterward. His ministrations "seem always to have been most acceptable from the beauty and earnestness of his style, and his well-known gift of creating interest out of the driest subjects." But he was excessively nervous, and his efforts were attended with intense suffering, in the shape of a nervous faintness, which only occurred when he was making a public appearance. For this reason he finally desisted from preaching.
His regular philosophical studies began in 1799, when, at the suggestion of his friend Brougham, he repeated Newton's experiments in the inflection of light, and in connection with them made his first discovery. His after-life was one of almost uninterrupted research. His investigations were to a large extent parallel with those which Malus and Fresnei and others were carrying on during the same period in France, and in some cases room was left for question as to priority of discovery. But in no case is Brewster's claim to independence in research and originality impaired. Professor Forbes has summarized the most important subjects of Brewster's inquiries at this time, as the laws of polarization by reflection and refraction, and other quantitative laws of phenomena; the discovery of the polarizing structure induced by heat and pressure; the discovery of crystals with two axes of double refraction, and many of the laws of their phenomena, including the connection of optical structure and crystalline forms; the laws of metallic refraction, and experiments on the absorption of light. Of his discoveries, primary importance belongs to those of the connection between the refractive index and the polarizing angle, of biaxial crystals, and of the production of double refraction by irregular heating.
In 1816 he devised the kaleidoscope, which became at once very popular, and spread his name widely among all classes of people. The patent which he took out for it was of little value to him, for the authorized manufacturers seem to have wholly failed to supply the demand for the instruments, and the device was speedily patented by enterprising adventurers who made their fortunes out of it. He afterward made earnest and long-continued efforts to promote reforms in the patent laws that should make them more just to inventors.
Several years later, in 1849-'50, he perfected the stereoscope, the principle of which had been discovered and applied by Wheatstone in 1838. Wheatstone employed mirrors to effect the merging of the binocular pictures into one; Brewster substituted lenses for the mirrors, and gave us the instrument substantially as it is.
For the improvements that were made in lighthouses during the second decade of this century, the credit must be divided between Brewster and the Frenchman Fresnei. Both worked independently, and arrived in some cases at nearly identical results. Sometimes Brewster, sometimes the Frenchman, was ahead on a particular point. Their works have outlived them, and commercial men and sailors have reason every day to bless the memory of both; and of the Englishman, his successor as Principal of the University of Edinburgh has said with truth, "Every lighthouse that burns round the shores of the British Empire is a shining witness to the usefulness of Brewster's life."
Hardly less important in forwarding the progress of science than his direct labors, was the part which Brewster took in the formation of the British Association for the Advancement of Science. "The decline of science" had been much talked of among scientific men for several years, and much thought had been given to the consideration of means of reviving scientific interest, when Brewster, reviewing in the "Quarterly Review" a work on the subject by Babbage, proposed "an association of our nobility, clergy, gentry, and philosophers," as that which "can alone draw the attention of the sovereign and the nation to this blot upon its fame." In the course of a few succeeding months, the plan of the British Association met with general acceptance, and was soon thoroughly matured; and the first meeting, held at York, in September, 1831, at which three hundred and twenty-five members enrolled their names, and a zeal for science was excited "which will not soon subside," was attended with a success that "infinitely surpassed all our most sanguine expectations." At the twentieth meeting of the Association, held in Edinburgh in 1850, Brewster was the president.
Brewster's literary activity kept pace with his scientific work. It was begun at the same time, in 1799, when he became a regular contributor to the "Edinburgh Magazine," and was continued in various shapes as he had new investigations of his own to describe, the work of others or any marked progress in science to review, or views of his own to publish on the topics which from time to time became prominent in the various regions of thought. In 1807, acting upon a casual hint given him by the Rev. Mr. Ramsay, of Tranent, of how much a good and thorough encyclopædia was needed, he began the "Edinburgh Encyclopædia," which was not completed till 1830. In connection with this work we find him, just after the first two numbers had been published, writing to his friend Veitch for a drawing and description of his new plow, to be inserted in the article "Agriculture," and mentioning an intention also "to publish in the same article a curious paper by Mr. Jefferson, President of the United States, on a plow-ear which offers the least possible resistance." This work was strongest in the scientific department, to which the editor contributed many of the most valuable articles. Like all such works requiring a combination of many minds, it was difficult to manage, and cost Brewster much labor, vexation, and anxiety. He was afterward a contributor to the "Encyclopædia Britannica," to the seventh and eighth editions of which he furnished articles on hydrodynamics, magnetism, microscope, optics, stereoscope, voltaic electricity, etc. In 1819 he assisted in establishing the "Edinburgh Philosophical Journal," afterward the "Edinburgh Journal of Science," which took the place of the "Edinburgh Magazine," and subsequently became its sole editor. He also had a part in founding the "North British Review," and was a regular contributor to it, having been the author of seventy-five articles that appeared in it. In 1838 he was appointed Principal of the United Colleges of St. Salvator and St. Leonard, St. Andrews, and in 1859 became Principal of the University of Edinburgh. His life at St. Andrews was checkered by transient difficulties that grew out of his excessively nervous temperament. At Edinburgh, a minute recorded by the University Court after his death described him as "one whose warm interest in the university never abated to the last, and who, on the many occasions on which he presided over their deliberations, or was associated with them in business, evinced the sagacity of a clear and disciplined intellect and the courtesy of a kind and Christian gentleman, while each member of it feels that by his death he has lost a valued and respected friend."
In 1825 Brewster was made a corresponding member of the French Institute. From this time, says Mrs, Gordon, "honors crowded in so rapidly upon him that, except any of special interest, it would be tedious to enumerate them in their order and succession. Suffice it to say that the large book in which the letters, diplomas, burgess-tickets, announcements of medals, etc., are collected is a remarkable one for size and value. The large towns of Switzerland, France, Germany, Holland, Italy, Russia, Belgium, Portugal, Austria, Sweden and Norway, South Africa, Antigua, the various States of America, besides the towns and universities of England, Scotland, and Ireland, all contributed their quota of honors to this man of research and industry. A cape received his name in the Arctic regions, a river in the Antarctic, and a new plant discovered by Dr. Muellin in Australia was named Cassia Brewsteri. He received, besides the Copley, Rumford, and Royal medals, two Keith medals from the Royal Society of Edinburgh, two from the French Institute, one from Denmark, one from the Société Française de Photographic, and various others; of some of the most valuable of these, duplicates were sent to him, one of gold, which he turned into plate, and a fac-simile of frosted silver—all being preserved as heirlooms. He was knighted in 1831, the year of the first meeting of the British Association, and also received the Hanoverian Order of the Guelph."
In examining Mrs. Gordon's most interesting work we have been struck with the variety of subjects in which Sir David Brewster was interested, and of the discussions in which he took part. We can only mention some of them, as we find them laid down in the table of contents. Connected with his researches on light were all matters relating to photography and color-blindness, which was strikingly exemplified in his friend Dalton, and on which he wrote an article for the "North British Review." In church matters, he made one of the first suggestions that led to the formation of the Evangelical Alliance; he took a prominent part in the disruption of the Church of Scotland, and was one of the founders of the Free Church—at the cost of much tribulation and an unsuccessful suit to eject him from his chair as Principal of St. Andrews; and throughout his life he stoutly upheld the harmony between the results of scientific investigation and his orthodox religious faith. Then we find him a warm believer in the authenticity of Mr. Macpherson's "Poems of Ossian"; an interested spectator of the beginnings of the electric telegraph; putting aside his dislike to prominent positions to act as President of the Peace Congress in 1851; discussing the doctrine of the plurality of worlds; investigating the spirit-rappings; and finally inquiring into every new phenomenon, and busying himself with everything that could contribute to the advancement of knowledge or the benefit of mankind.
The reform of abuses was one of the passions of his life. For three years he lived at Belleville, on the estate of his wife's sister, and had a full field for gratifying it on a property which had been for many years "too indulgently superintended." He "awakened a warm and abiding attachment among the majority of the Highland tenantry, who anticipated with delight the time, which never came, when he might be their landlord in very deed. They were proud of his scientific fame, which indeed spread far and near. I remember four working-men coming a considerable distance from Strathspey, with the petition that they might see the stars through his telescope; while on another occasion a poor man brought his cow a weary long journey over the hills, that the great optician might examine her eyes, and prescribe for her deficiencies of sight; and all, as was ever his wont, were received courteously, and had their questions not only answered, but answered so clearly and patiently that the subjects were made perfectly intelligible and interesting."
"All who knew him," says Miss Forbes, afterward the wife of the Rev. Canon Harford Battersby, "will, I am sure, unite in testifying to his readiness to explain, it might be, the simplest principles of a science to some insignificant person, and the wonderful enjoyment he seemed to find in so doing—quite as much, indeed, as in talking of some of his latest discoveries to the most learned—if only his listener were thoroughly interested and anxious to learn." One person, "himself the possessor of genial gifts and genius," is quoted as having remarked, "When I have been with other great men, I go away saying, 'What clever fellows they are!' but when I am with Sir David Brewster, I say, 'What a clever fellow I am!' "Miss Horsbrugh, whose tutor he was from 1799 to 1804, gives a pleasant picture of him as a great favorite with the children, especially with those who could enter into his own pursuits, and fond of experimenting before them, particularly with his electrical machine. She remembers the starts and shocks she received, and also being occasionally left alone in the dark, when Mr. Brewster would appear among them with his outstretched hand and fingers all in an apparent blaze from phosphorus. Some of his scientific practices greatly incensed Mrs. Dickson, the housekeeper, who declared that he would never rest till he had set the house on fire.
His principal literary works, many of which have obtained a wide popular circulation, are his "Life of Sir Isaac Newton," published in Murray's "Family Library," and the larger memoirs embodying the fruits of twenty years of investigation, published in 1855; his notes and introduction to Legendre's "Geometry" (1824); his "Treatise on Optics" (1831); "Letters on Natural Magic" (1831); "The Martyrs of Science" (1841); and "More Worlds than One" (1854). The list of his briefer scientific papers and miscellaneous writings includes, besides the seventy-five articles contributed to the "North British Review," three hundred and fifteen titles.
A monition of the waning of his vital powers came to Sir David in the spring of 1867, when he lost consciousness in a fainting-fit in his class-room at the university. He attended the British Association at Dundee, in September of the same year, and had another fainting-fit, after enduring the crowd and heat of the public assembly. He returned to his home, never to leave it again, but had to occupy himself with the papers of the forged Pascal-Newton correspondence, and to ward off from Newton's memory the blot which it was attempted to put upon it. This was the last act of his scientific and literary career. "He went straight from this controversy into the gathering silences," and died, at Allerly, Melrose, February 10, 1868.