Dr. James Prescott Joule (1818-1889)
DR. JAMES PRESCOTT JOULE.
Manchester is preparing to do honour to one of its most worthy sons. When a great man falls, or finishes his life-work with distinction, his admirers, as they begin to realize his merit by a calm contemplation of his labours and achievements, are worthily desirous to perpetuate his memory and to mark his fame. In the case of Dr. Joule (whose death we recorded in our first number) posthumous fame is assured, as the universal testimony of the greatest scientific men of the. day, and the movements on foot to raise both an international and a local memorial, eloquently attest. The circular issued by the Royal Society with reference to the international memorial strikes the following keynote of his great scientific attainments: "To the scientific and industrial value of Dr. Joule's work it is needless to refer further than to point to his recognition as the discoverer of the universal law of the conservation of energy, a law the importance of which can only be compared with that of the laws of gravitation and of chemical combination; and to indicate the material benefits that have already flowed from his discoveries, which, whilst increasing production, have promoted economy in all the principal industries of mankind, and thus widely extended the beneficent influence of science throughout the world. We feel confident that not only will men of science gladly contribute towards a fund to do honour to Joule's memory, and to assist others to follow in his footsteps, but that those also who devote themselves to the practical application of scientific principles will be anxious to aid in the promotion of a fitting memorial of one whose work has exerted so great an influence on industries"
Professor Dewar, F.R.S., who recently brought" The Scientific Work of Joule" before the members of the Royal Institution, gave probably as interesting and as concise a history of the scientific discoveries of Joule as has yet appeared, although his biographers have been numerous, and the transactions of many learned Societies are enriched with records of his work. Mr. J. T. Bottomley, in a valuable paper which he contributed to Nature in 1882, also gave a comprehensive sketch of his discoveries, and though probably many of Dr. Joule's neighbours in and around Manchester were unacquainted up to the time of his death with the extent of his research or the reality of his discoveries, these had been long patent to the most eminent of our scientific men, and his achievements in the inexhaustible field over which his mind ranged had, though somewhat tardily recognised at first, been fully acknowledged for years past. This is testified by the fact that in 1852 Mr. Joule received the Gold Medal of the Royal Society, the Copley Gold Medal of the Royal Society in 1870, and the Albert Medal of the Society of Arts from the hands of the Prince of Wales in 1~80. In June, 1878, he received a recognition of his labours by his country which was a source of much gratification to him-a letter from the Earl of Beaconsfield, announcing to him that Her Majesty the Queen had been pleased to grant him a pension of £200 per annum. Though his claim to distinction is worldwide, Mr. Joule was essentially one of the Manchester "Faces"; and the excellent portrait which by the aid of the photographic art of Messrs. Brothers, of St. Ann's Square, Manchester, we are enabled to give in this number, will he greeted as a faithful likeness by the residents in Manchester and Salford, amongst whom he was brought up and spent such a large portion of his studious and useful life.
James Prescott Joule was born at Salford on Christmas Eve of the year 1818. His father and his grandfather before him were brewers, and the business in due course descended to Mr. Joule and his elder brother and by them was carried on with success, till it was sold in 1854. Mr. Joule's grandfather came from Elton in Derbyshire. His father, one of a numerous family, married a daughter of John Prescott, of Wigan. They had five children, one of whom, James Prescott Joule, was the second, and of whom three were sons - Benjamin, the eldest, James, and John-and two daughters-Alice and Mary. Mr. Joule's
mother died in 1836, at the age of forty-eight, and his father, who was an invalid for many years before his death, died at the age of 74 in the year 1858. Young Joule was a delicate child and was not sent to school. His early education was commenced by his mother's half-sister and was carried on at his father's house, Broomhill, Pendlebury, by tutors, till he was about fifteen years of age. At fifteen he commenced working in the brewery, which, as his father's help declined, fell entirely into the hands of his brother Benjamin and himself. Interesting accounts have appeared of the plodding but persistent steps by which Mr. Joule mounted the ladder of splendid scientific attainment We must content ourselves with noting that he obtained his first instruction in physical science from the celebrated Dalton, to whom his father sent the two brothers to learn chemistry. Dalton-a Manchester man-one of the most distinguished chemists of any age or country, was then president of the Manchester Literary and Philosophical Society, and lived and received pupils in the rooms of the Society's house. Before his death (says Professor Dewar) Joule had a record of nearly 40 years of constant scientific research. His work was represented by I 15 papers dealing with various and complex subjects. The period between 1838 and 1843 was that within which Joule educated himself in experimental methods, and at this time he was principally engaged in the study of electricity and electro-magnetic engines. His researches led, in 1840, to the discovery of the true law representing the relation between electric energy and thermal evolution. His great success was achieved by an elaborate examination into the relations of supply of electricity and its distribution, not only in the conductors exterior to it. but also in the battery cell itself. This law, which seemed so simple, was of the greatest importance,
It was that the amount of heat produced by a given amount of electric current varied as the square of the intensity of the current and directly as the resistance, always provided that a given unit of time were used. Joule saw that this was easily proved in a relative degree, but to account for the whole of the distribution of the current was more difficult. This led him to the study of electrolysis; and it was marvellous that. with the great difficulties which the method presented, he was able to discover all the impediments to an electric current, and to prove conclusively that the whole distribution of energy could be accounted for. In 1841 he had practically completely analyzed the distribution of energy in the electric circuit; and he had discovered the law regulating the distribution of heat in all parts of it. In 1842 he had really his great discovery in hand, as was shown by a foot-note to a paper written on the 25th of January, 1842. It seemed extraordinary that always the most difficult and complex methods of dealing with a subject were at first taken; and to anyone who read Joule's paper on the determination of the mechanical value of heat by means of an electric current it seemed astounding that he should ever have overcome his difficulties. To produce a thermal effect was easy enough; but the difficulty was to prove the permanent and persistent relation between the energy expended and the heat produced through the electric current. There were the fluctuations of the current, the effects of radiation, the movements of the air, and other circumstances to be allowed for; and Joule had to depend on very small variations of temperature, using, therefore, very delicate thermometers. By the end of July, 1843, Joule was able to state the quantity of heat capable of increasing the temperature of a pound of water by one degree Fahrenheit-and that was equal to, and might be converted into, a mechanical force, capable of raising 770 lb. to the perpendicular height of one foot. After his first determination of the mechanical equivalent of heat, he stated that he had arrived at a nearly similar determination by a more direct method-namely, by the friction of water passing through small tubes.
In all great scientific discoveries it is difficult to distribute merit exactly. There are those who, while admiring the broad and rapid generalizer, cannot understand the patient and plodding experimentalist. Joule never pretended to be anything else but an experimentalist. He would go step by step through intricate masses of work and research and never generalize until he was perfectly sure. It is difficult to know how it was that Joule's great discovery had not been anticipated. Rumford, who first clearly defined the relation between the constant production of heat and the loss of motion from friction, went near to doing so. Humphrey Davey continued Rumford's experiments in a different manner, and entirely dissipated the idea of the separate existence of caloric ; and Young did much in analyzing the position. After 1843 Joule several times, up to a late date, made fresh determinations of the mechanical value of heat, on each occasion varying his methods and ever reaching nearer to exactness. Thus in 1878 he stated that he found that 1 lb. of water would be raised in temperature 1 deg. Fahrenheit by 772.55 foot pounds of work. Besides the work on his mechanical equivalent, Joule was conducting in the forties elaborate investigations on the maximum density of water, specific gravity, and atomic volume.
Joule's last research was long and laborious, extending over a period of nearly ten years, and was conducted with Sir William Thomson. The one subject of their research was the study of gases passing through narrow apertures, and the other the study of the velocity of bodies through air, and the temperature the bodies would ultimately attain by moving through air. They found, in the former subject, that instead of the Product of the pressure and volume of gases being proportional to the absolute temperature, a new term was needed-a constant, multiplied by the temperature and divided into the volume. Thus they were able to enunciate what must be called the true gaseous law.
Sir William Thomson has been referred to. Writing to the author of the notice in Nature, already referred to, he gives the following interesting reminiscence as to his meeting with Joule and making his acquaintance for the first time at the British Association Meeting at Oxford in 1847, at which Joule read a fresh paper" On the Mechanical Equivalent of Heat." It was in this year (IS47) that Mr. Joule was married to Amelia, daughter of Mr. John Grimes, Comptroller of Customs, Liverpool. Sir William Thomson writes :-" I heard his paper read in the section, and felt strongly impelled at first to rise and say that it must be wrong, because the true mechanical value of heat given, suppose in warm water, must, for small differences of temperature, be proportional to the square of its quantity. I knew from Carnot that this must be true (and it is true; only now I call it 'motivity,' to avoid clashing with Joule's mechanical value ').But as I listened on and on, I saw that (though Carnot had vitally important truth, not to be abandoned) Joule had certainly a great truth and a great discovery, and a most important measurement to bring forward. So instead of rising with my objection to the meeting I waited till it was over, and said my say to Joule himself, at the end of the meeting. This made my first introduction to him. After that I had a long talk over the whole matter at one of the conversaziones of the Association, and we became fast friends from thenceforward. However, he did not tell me he was to be married in a week or so; but about a fortnight later I was walking down from Chamounix to commence the tour of Mont Blanc, and whom should I meet walking up but Joule, with a long thermometer in his hand and a carriage with a lady in it not far off. He told me he had been married since we had parted at Oxford; and he was going to try for elevation of temperature in waterfalls. We trysted to meet a few days later at Martigny, and look at the Cascade de Sallanches, to see if it might answer. We found it too much broken into spray. His young wife, as long as she lived, took complete interest in his scientific work, and both she and he showed me the greatest kindness during my visits to them in Manchester, for our experiments on the thermal effects of fluid in motion, which we commenced a few years later. Joule's paper at the Oxford meeting made a great sensation. Faraday was there and was much struck with it, but did not enter fully into the new views. It was many years after that before any of the scientific chiefs began to give their adhesion. It was not long after, when Stokes told me he was inclined to be a Joulite."
Sir Lyon Playfair, who was one of Joule's fellow-workers, has also given some highly interesting reminiscences of his acquaintance with the Manchester philosopher :-He writes to Professor Dewar: "You ask for some of my memories of Joule from 1842 to 1845, when I was Professor of Chemistry at the Royal Institution in Manchester. The great Dalton died in the autumn of 1044, and had long been president of the Manchester Philosophical Society. He naturally gave impulse to the study of science in the town, where there was an active band of young workers in research. Joule was even then foremost among these, and the names of Binney, Williamson, Schunck, Angus Smith, Young, and others show that the spirit of scientific inquiry was active. We were also stimulated by the fact that Baron Liebig and Bunsen came to pay me visits during that time. They were men to excite research. Joule was a man of singular simplicity and earnestness. We used to meet at each other's houses at supper to help the progress of our work by discussion. Joule was an earnest worker, and was then engaged on his experiments on the mechanical equivalent of heat. He took me to his small laboratory to show me his experiments, and I, of course, quickly recognised that my young friend the brewer was a great philosopher. We jointly worked upon questions of far less importance than his great central discovery, but he was equally interested. I was very anxious that he should devote his life to science, and persuaded him to become a candidate for the Professorship of Natural Philosophy at St. Andrews. He was on the point of securing this, but his personal slight deformity was an objection in the eyes of one of the electors, and St. Andrews lost the glory of having one of the greatest discoverers of our age. When Joule first sent an account of his experiments to the Royal Society, the paper was referred among others to Sir Charles Wheatstone, who was my intimate personal friend. Wheatstone was an eminently fair man and a good judge. but the discovery did not then commend itself to his mind. For a whole Sunday afternoon we walked on Barnes Common, discussing the experiments and their consequences, if true, to science. But all my arguments were insufficient to convince my friend, and I fear that then the Royal Society did not appreciate and publish the researches. I write from memory only, for I know that later no society or institution honoured Joule more than the Royal Society and its members. Not for one moment, however, did Joule hesitate in the accuracy of his experiments or his conclusions. He once suggested to me that we might take a trip together to the Falls of Niagara, not to look at its beauties, but to ascertain the difference of temperature of the water at the top and bottom of the fall. Of course the change of motion Into heat was a necessary consequence of his views. No more pleasant memory of my life remains than the fact that side by side at my lectures in the Royal Institution used to sit the illustrious Dalton, with his beautiful face, so like that of Newton, and the keenly intelligent Joule. I can give no other explanation than the fact of organic chemistry being then a new science that two philosophers of such eminence should come to the lecture of a mere tyro in science. I used to look upon them as two types of the highest progress in science. Newton had introduced law of order and number into the movements of masses of matter in the universe. Dalton introduced the same into the minute masses which we call atoms, and Joule. with a keen insight into the operations and correlation of forces, connected them together and showed their mutual equivalence."
The" illustration of character" mentioned above has elicited from Mr. B. A. Joule, deceased's son, the following note :-" Among some reminiscences of my father given by Sir 1.yon Playfair there is one from which an erroneous deduction might be made. It is as follows: 'As an illustration of his character, Sir Lyon Playfair stated that Joule once proposed a journey with him to Niagara, not to see its beauties, but in order to take the difference of the temperature of the water at the bottom and at the top of the Falls.' From this it would appear that he was either insensible or indifferent to the beauties of Nature, whereas the exact contrary was the reality, since he always possessed a deep love and appreciation for them. He was also a skilful limner, taking great pleasure in sketching any interesting scene. In fact, had he devoted himself to art as he did to science, nothing short of success would have been his. It will also interest some to know that he was an enthusiastic photographer, enriching the art science, as it has been termed by several important inventions."
What form the proposed memorials of the late Dr. Joule will assume has not yet been decided upon; it is to be hoped. however, that they will be worthy the distinguished subject.
|Reprinted from Manchester Faces & Places Vol. 1 No. 6 10 March 1890|