When Whitworth determined to make a better set of planes than any in use at the Maudslay shop, we are told that he was laughed at by Hampson and his other fellow workmen for undertaking an impossible job. He not only succeeded, but the truth of the planes he produced aroused the admiration and wonder of all who saw them. Nasmyth distinctly mentions scraping, but it should be remembered that he worked at Maudslay’s four or five years after Whitworth went there, and scraping may have been introduced into their older methods of making triple surface-plates by Whitworth, and have accounted for the wonderful accuracy of which Nasmyth speaks. Having realized what he considered the first element in good workmanship, Whitworth began on the second,--improved methods in measurement. He introduced the system of “end measurements,” relying ordinarily on the sense of touch rather than eyesight; and, for extreme accuracy, on the falling of a tumbler held by friction between two parallel planes. At the presentation of the address before the Institution of Mechanical Engineers, in 1856, he exhibited a measuring machine built on this principle which detected differences of length as small as one-millionth of an inch. The address was largely devoted to the advantages of end measurement. Referring to the machine before him, he said: “We have in this mode of measurement all the accuracy we can desire; and we find in practice in the workshop that it is easier to work to the ten-thousandth of an inch from standards of end measurements, than to one-hundredth of an inch from lines on a two-foot rule. In all cases of fitting, end measure of length should be used, instead of lines.” This principle has become almost universal for commercial work, although for extremely accurate work upon final standards line measurements, aided by the microscope, are used. It was Whitworth who brought about the standardization of screw thread practice in England. He had come into contact with the best thread practice at Maudslay’s and at Clement’s, but in the other shops throughout the country there was chaos, so far as any recognized standard was concerned. Using their work as a basis, and collecting and comparing all the screws obtainable, Whitworth arrived at a pitch for all sizes and a thread contour, which he proposed in a paper before the Institution of Civil Engineers in 1841.[105] It was received with favor, and by 1860 the “Whitworth thread” had been generally adopted throughout the country. [105] The Minutes of the Institution, Vol. I, give only an abstract of this paper. A recent writer, however, in the _American Machinist_, Vol. XLIII, p. 1178, quotes Whitworth as follows: