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Page:Popular Science Monthly Volume 32.djvu/570

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THE POPULAR SCIENCE MONTHLY.

periments. 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 engi-