Popular Science Monthly/Volume 32/February 1888/Sketch of Sir Joseph Whitworth
|SKETCH OF SIR JOSEPH WHITWORTH.|
THE value of Sir Joseph Whitworth's work, and the extent to which it has entered into common life, are exemplified whenever a screw-tap is fitted to a bolt. A biographical sketch of him, published on the occasion of his death, designated his name as the greatest of our time in mechanical engineering, and characterized him as a person of remarkable individuality and one whose efforts have left a permanent impress upon the workshops of the whole civilized world.
Joseph Whitworth was born at Stockport, England, on the 21st of December, 1803, and died at Monte Carlo, January 22, 1887. He was taught by his father, who was a schoolmaster, and at a school at Idle, near Leeds, till he was fourteen years old, when he was placed with his uncle, a cotton-spinner in Derbyshire. The operations of manufacturing were not to his taste, but he soon made himself at home with the machinery of the establishment, and in time became its practical managing engineer. After six years of this work he desired to find a wider field for the development of his mechanical abilities, and, although the value of his services was appreciated by his uncle, he ran away to Manchester, where he spent four years in acquiring a practical knowledge of the manufacture of cotton-machinery. Applications of steam-power were still new and crude, and tools adapted to use in connection with the new force were imperfect or wanting. In order to qualify himself to supply the need thus indicated, he went to London and sought employment in the best shops—Maudsley's, Holtzapfel's, and Clement's. Maudsley, recognizing his skill, took him into his own private room, and placed him next to his best workman. He worked in off-hours at his own devices, and in this way completed the true plane, an instrument which conferred the power of making surfaces for all kinds of sliding tools, by which the resistance arising from friction was reduced to its smallest figure, and of which he published a description in 1840. He showed his device and its operation to his fellow-workman, Hampson, who had been accustomed to ridicule his experiments, but now testified his appreciation of the work by saying, "You've done it." At Clement's he worked upon Babbage's calculating machine, which he always maintained would have operated perfectly if it had been gone on with; and here also he learned to make a true screw.
In 1833 Mr. Whitworth engaged in manufacturing on his own account at Manchester, establishing himself in one room and putting out the sign, "Joseph Whitworth, tool-maker." It was in the infancy of extensive manufacturing, and there were no fixed standards of adjustment, no guarantees for accuracy of work, or attempt at symmetry or uniformity in any respect, but each maker was a rule to himself. Whitworth foresaw that if industrial enterprise would prosper it must be systematized, and workmen must install harmony in their designs, and must aim at minute exactness in their forms and measurements. His attention was particularly directed to the inconveniences which were produced by the variations in the pitch and thread of the screws used in the construction of machinery—variations so considerable, if we may quote the words of an English sketch of his work, "that every maker had screws of his own special sizes, and that the failure of a single one might cripple a machine in a distant country until the original maker could be communicated with and could send out another of the same proportions. Mr. Whitworth not only saw the immense advantages which would arise from rendering the pitch and thread of screws uniform, but also the difficulty which might be experienced in inducing any maker to adopt the proportions used by any other. With rare sagacity, he obtained specimens of all the screws used by leading manufacturers, and then designed one which was the average of them all, and a copy of none. By this expedient he evaded opposition, and worked a revolution in the construction of machinery. The new screw was universally adopted; and, in the present day, every screw of the same diameter has a thread of the same pitch and of the same number of turns to the inch, and all screws of the same size, from whatever maker obtained, are interchangeable."
Mr. Whitworth next took up appliances for accurate measurements, and constructed an instrument capable of measuring the millionth part of an inch, and which, worked by touch, "was so delicate as instantly to communicate the expansion of a steel bar three feet in length when this was warmed by momentary contact with a finger-nail." With these and his other inventions, "Whitworth's standard gauges, his taps and dies, his uniform system of screw-threads, his great refinements in the manufacture of lathes, planing-machines, drills, etc., all became available at the moment when they had become indispensable,... if the imperative demands for mechanical appliances in every direction were to be worthily met."
In 1853 Mr. Whitworth was appointed a commissioner to the great exhibition in New York, and in that capacity wrote a report on American manufacturing industries which attracted much attention at the time, and still has interest. In the next year he was requested by the British Government to design and produce machinery for the manufacture of rifles for the army. He found it with the rifles as it was with nearly all mechanical appliances before he touched them to improve them—no two of them were alike. He imposed as a condition of his accepting the commission that he should be permitted to determine what form and dimensions of guns and bullets would produce the best results. Besides consenting to this condition, the Government erected a shooting-gallery five hundred yards long on Mr. Whitworth's grounds at Rusholme, where he was able to devote himself to most careful and thorough experiments. Here he determined the effects of every pitch and kind of rifling, and of every length of projectile, from the sphere to a missile having a length of twenty times its diameter; and the principles which he determined upon, of a projectile elongated to from three to five times its diameter, with a rapid rotation and a quick uniform rifling pitch of polygonal form, have been extensively adopted.
The same principles were found to be equally applicable to large guns, and the continued labors of the discoverer of them resulted in the production of the Whitworth cannon, which are declared to be the best the world has yet witnessed, "the most enduring, the most accurate, the most powerful in penetration, and the longest in range." But with all these advantages "the principles established by Whitworth were not adopted into the service, for reasons which it would probably be more curious than edifying to investigate."
Mr. Whitworth was embarrassed in the prosecution of his experiments by the difficulty of getting metal of the right kind. Mild steel, which gave the nearest approach to the desired qualities, was not wholly satisfactory, because the same properties which gave it toughness and ductility, gave also a tendency in the course of cooling, to imprison the escaping gases and cause unsoundness. To obviate this defect he applied the process of compression with hydraulic power, whereby the particles of the fluid metal were driven into closer contact and the gases were squeezed out. This process, by which the greatest strength was combined with the least weight and bulk, proved to be generally applicable, and is now largely employed for those structures in which it is desired that those qualities shall dwell together.
Early in 1869 Mr, Whitworth founded the Whitworth scholarships, assigning for the purpose £3,000 a year in perpetuity, or the interest on a capital sum of £100,000. The fund was vested in the President of the Privy Council, or other minister of public instruction for the time being, and was intended, as its institutor explained in a letter to Mr. Disraeli, to promote the engineering and mechanical industry of the country by a system of scholarship prizes to be made accessible on fairly equal terms of competition to students combining some practice with their theory, and to intelligent artisans uniting some theoretical knowledge with perfection of workmanship. The scholarships were valued at £100 a year, and were tenable for three years, to be obtained on competitions which were open to all Her Majesty's subjects at home, in India, and in the colonies, who had not completed their twenty-sixth (afterward changed to twenty-third) year. By regulations afterward prescribed to insure the holders of the scholarships devoting themselves to the studies and practice necessary for mechanical engineering during the tenure of the scholarships, it was required that every candidate should produce a certificate that he had worked in a mechanical engineer's shop or in the drawing-office of a mechanical engineer's shop, for two years consecutively; that he should be examined in the appointed sciences; in smith's work, turning, filing, and fitting, pattern-making, and molding, "as already established"; and that after 1875 each holder of a scholarship should be required to produce satisfactory evidence, by examination, at the termination of every year, that he had made proper advances in the sciences and practice of mechanical engineering. Additional prizes were offered for the best evidences of scholarship) at the annual and final examination, so that it became possible for the best of the scholars at the end of his tenure of the scholarship to have obtained £800, and the others in proportion. The benefaction was added to, in 1875, by the foundation of a number of "Whitworth exhibitions."
Mr. Whitworth was made a Fellow of the Royal Society in 1857; he received degrees from Trinity College, Dublin, and the University of Oxford; obtained, in 1867, for his collection of engineer's tools and rifled ordnance and projectiles, at the Paris Exhibition, one of the five "Grando Prix "allotted to England; had conferred upon him by Napoleon III, in 1868, the decoration of the Legion of Honor; was awarded the Albert Gold Medal of the Society of Arts" for the invention and manufacture of instruments of measurement and uniform standards, by which the production of machinery has been brought to a degree of perfection hitherto unapproached"; and, in 1860, he was created a baronet, and became Sir Joseph Whitworth. He suffered for several years from the severities of the English winter, and went every year to the Riviera. Two years before his death he had built a winter-garden at Stanley Dale, to which he was confined for several months; but on the approach of cold weather in the fall of 1886, be determined, although he was so weak that his friends saw him depart with much misgiving, to try the Mediterranean coast again." He leaves behind him," says the "London Times," "a reputation unapproached in his department, and he was scarcely less remarkable for the sagacity which he brought to bear upon great public questions, than for the severity with which he saw his conclusions put aside by men in official positions, whose minds were not mechanical, and toward whom his feelings scarcely rose to the level of contempt. The characteristics of his intellect were peculiar in that he was distinctly an experimentalist as opposed to a reasoner. When a problem in mechanics was presented to him, it was his habit to say, 'Let us try,' and he possessed the rare gift of being able to devise conclusive experiments." His principal published book was a collection of "Essays on Mechanical Subjects," including true planes, screw-threads, and standard measures, which was published in 1882. He left a large part of his estate to be applied to purposes of instruction in mechanical engineering.