Note:The date of death given in the Encyclopędia Britannica Eleventh Edition was December 19, 1887 while the official Obituary in the Royal Society referenced December 18, 1887. In crosschecking the facts with The Times from December 1887, Monday December 19, 1887 was in fact the date on which Balfour Stewart died. His place of death was his estate at Ballymagarvey, Balrath, County Meath which is near Drogheda, County Louth, Ireland.
Dr. Balfour Stewart was born in Edinburgh on November 1, 1828, and died in Ireland on
December 18, 1887, having just entered his sixtieth year. He was educated for a mercantile profession, and in fact spent some time in Leith, and afterwards in Australia, as a man of business. But the bent of his mind towards physical science was so strong that he resumed his studies in Edinburgh University, and soon became assistant to Professor J. D. Forbes, of whose class he had been a distinguished member. This association with one of the ablest experimenters of the day seems to have had much influence on his career; for Forbes's researches (other than his Glacier work) were mainly in the department of Heat, Meteorology, and Terrestrial Magnetism, and it was to these subjects that Stewart devoted the greater part of his life. In the classes of Professor Kelland, Stewart had a brilliant career; and gave evidence that he might have become a mathematician, had he not confined himself almost exclusively to experimental science.
In 1858, while he was still with Forbes, Stewart completed the first set of his investigations on Radiant Heat, and arrived at a remarkable extension of Prevost's “Law of Exchanges." His paper (which was published in the 'Transactions of the Royal Society of Edinburgh') contained the greatest step which had been taken in the subject since the early days of Melloni and Forbes. The fact that radiation is not a mere surface phenomenon, but takes place like absorption throughout the interior of bodies, was seen to be an immediate consequence of the new mode in which Stewart viewed the subject. Stewart's reasoning is, throughout, of an extremely simple character, and is based entirely upon the assumption (taken as an experimentally ascertained fact) that in an enclosure, impervious to heat and containing no source of heat, not only will the contents acquire the same temperature, but the radiation at all points and in all directions will ultimately become the same, in character and in intensity alike. It follows that the radiation is, throughout, that of a black body at the temperature of the enclosure. From this, by the simplest reasoning, it follows that the radiating and absorbing powers of any substance must be exactly proportional to one another (equal, in fact, if measured in proper units), not merely for the radiation as a whole, but for every definitely specified constituent of it. In Stewart's paper (as in those of the majority of young authors) there was a great deal of redundant matter, intended to show that his new views were compatible with all that had been previously known, and in consequence his work has been somewhat lightly spoken of, even by some competent judges. These allow that he succeeded in showing that equality of radiation and absorption is consistent with all that was known; but they refuse to acknowledge that he had proved it to be necessarily true. To such we would recommend a perusal of Stewart's article in the 'Philosophical Magazine' (vol. 25, 1863, p. 354), where they will find his own views about the meaning of his own paper. The only well-founded objection which has been raised to Stewart's proof applies equally to all proofs which have since been given, viz., in none of them is provision made for the peculiar phenomena of fluorescence and phosphorescence.
The subject of radiation, and connected properties of the lumini-ferous medium, occupied Stewart's mind at intervals to the very end of his life, and led to a number of observations and experiments, most of which have been laid before the Royal Society. Such are the “Observations with a Rigid Spectroscope," and those on the "Heating of a Disk by rapid Rotation in vacuo" in which the present writer took part. Other allied speculations are on the connexion between “Solar Spots and Planetary Configurations," and on “Thermal Equilibrium in an Enclosure containing Matter in Visible Motion."
From 1859 to 1870 Stewart occupied, with distinguished success, the post of Director of the Kew Observatory. Thence he was transferred to Manchester as Professor of Physics in the Owens College, in which capacity he remained till his death. His main subject for many years was Terrestrial Magnetism; and on it he wrote an excellent article for the recent edition of the 'Encyclopędia Britannica.' A very complete summary of his work on this subject has been given by Schuster in the 'Manchester Memoirs' (4th series, vol. 1, 1888). In the same article will be found a complete list of Stewart's papers.
Among the separate works published by Stewart, his 'Treatise on Heat,' which has already reached its fifth edition, must be specially mentioned. It is an excellent introduction to the subject, though written much more from the experimental than from the theoretical point of view. In the discussion of radiation, however, which is given considerable length, a great deal of theoretical matter of a highly original character is introduced.
On another work, in which Stewart took a great part, 'The Unseen Universe,' the writer cannot speak at length. It has passed through many editions, and has experienced every variety of reception ... from hearty welcome and approval in some quarters to the extremes of fierce denunciation, or of lofty scorn, in others. Whatever its merits or demerits it has undoubtedly been successful in one of its main objects, viz., in showing how baseless is the common statement that “Science is incompatible with Religion." It calls attention to the simple fact, ignored by too many professed instructors of the public, that human science has its limits; and that there are realities with which it is altogether incompetent to deal.
Personally, Stewart was one of the most loveable of men, modest and unassuming, but full of the most weird and grotesque ideas. His conversation could not fail to set one a-thinking, and in that respect he was singularly like Clerk-Maxwell. In 1870 he met with a frightful railway accident, from the effects of which he never fully recovered. He passed in a few months from the vigorous activity of the prime of life to grey-headed old age. But his characteristic patience was unruffled and his intellect unimpaired.
He became a Fellow of the Royal Society in 1862, and in 1868 he received the Rumford Medal.
His life was an active and highly useful one; and his work, whether it took the form of original investigation, of accurate and laborious observation, or of practical teaching, was always heartily and conscientiously carried out. When a statement such as this can be truthfully made, it needs no amplification.P.G.T.
The Times, December 21, 1887, Page 1On the 19th Dec., at Ballymagarvey, Balrath, county Meath, Ireland, BALFOUR STEWART M.A, LL.D., F.R.S., Professor of Natural Philosophy. Owens College, Manchester, age 59.
The Times, December 21, 1887, Page 5We regret to announce the death of Professor Balfour Stewart, M.A., LL.D., F.R.S. Mr. Balfour Stewart, who had only just completed his 59th year, was educated at the Universities of St. Andrews and Edinburgh. In 1859 he was appointed to the directorship of the Kew Observatory, and in 1867 to the secretaryship of the Meteorological Committee, which last appointment he resigned on his promotion to the Professor's chair of Natural Philosophy in Owens College, Manchester, in the year 1870, a post which he held until his death. Two years before this distinction as conferred upon him he had been awarded the Rumford medal by the Royal Society for his discovery of the law of equality between the absorptive and radiative powers of bodies. Together with Messrs. De la Rue and Loewy he wrote "Researches on Solar Physics," and he and Professor Tait published their researches on "Heating produced by Rotation in Vacuo." Besides these he wrote a number of treatises especially on the subjects of meteorology and magnetism. The article in the "Encyclopędia Britannica" on "Terrestrial Magnetism” is from Professor Balfour Stewart's pen. Among the many works of which he was sole or joint author may be mentioned the “Elementary Treatise on Heat," “Lessons in Elementary Physics” (1871); “Physics” (1872), “The Conservation of Energy” (1874), and "Practical Physics” (1885). Most of these are text-books on the subjects of which they treat. He and Professor Tait also produced the “Unseen Universe," a work of which 12 editions have been Published. At the time of his death he was President of the Physical Society of London, and was a member of the committee appointed to advise the Government on solar physics. Professor Balfour Stewart died on Monday last at Ballymagarvey, Balrath, in the county of Meath.
The Times, December 24, 1887, Page 6Dublin, Dec. 23.
Much regret is expressed in scientific and literary circles at the death of Professor Balfour Stewart, LL.D., whose interment took place to-day in the family burial-ground at Ballymagarvey, his Irish residence, near Drogheda. This property was left to him a year or two ago by his uncle. The family had just welcomed his return from Manchester for the Christmas holidays, apparently in good health and excellent spirits, when he was seized with an effusion of blood on the brain which rendered him unconscious and in a few hours proved fatal. He was Professor of Natural Philosophy at Owens College, Manchester, president of the Physical Society of Great Britain, president of the Literary and Philosophical Society of Manchester, and a Fellow of the Royal Society and of many other learned societies. In 1868 the Royal Society conferred upon him the Rumford medal in recognition of his eminent services in scientific discovery, and he was a member of the council of that society for several years. The University of Edinburgh conferred upon him the honorary degree of LL.D. on the occasion when Carlyle delivered his rectorial address. The loss to science by the death of Professor Balfour Stewart will be much felt. He had won a distinguished reputation by his discoveries and writings in physics and meteorology and honours from widely distant places were conferred upon him. His industry was indefatigable. The textbooks on physics and practical physics which he has written are well known to every student of science.