To the end of his life he retained his personal dexterity at both the anvil and the bench. One of his greatest delights was to go into the shop and “have a go” at a piece of work which his workmen found impossible to do. One of his old workmen, years afterward, speaking in kindling pride of him, said: “It was a pleasure to see him handle a tool of any kind, but he was quite splendid with an 18-inch file.” Nasmyth confirms this, saying: “To be permitted to stand by and observe the systematic way in which Mr. Maudslay would first mark or line out his work, and the masterly manner in which he would deal with his materials, and cause them to assume the desired forms, was a treat beyond all expression. Every stroke of the hammer, chisel, or file, told as an effective step towards the intended result. It was a never-to-be-forgotten lesson in workmanship, in the most exalted sense of the term.... No one that I ever met with could go beyond Henry Maudslay himself in his dexterous use of the file. By a few masterly strokes he could plane surfaces so true that when their accuracy was tested by a standard plane surface of absolute truth they were never found defective; neither convex nor concave nor ‘cross-winding,’--that is, twisted.”[43] [43] “Autobiography of James Nasmyth,” pp. 147-148. London, 1883. Whitworth is usually credited with having been the originator of the method of making plane surfaces three at a time, using them to correct each other. Nasmyth, however, says that Maudslay used this method and that surface plates so made were in daily use in his shop. His testimony is so clear that it is given in full: “The importance of having Standard Planes caused him [i.e., Maudslay] to have many of them placed on the benches beside his workmen, by means of which they might at once conveniently test their work. Three of each were made at a time so that by the mutual rubbing of each on each the projecting surfaces were effaced. When the surfaces approached very near to the true plane, the still projecting minute points were carefully reduced by hard steel scrapers, until at last the standard plane surface was secured. When placed over each other they would float upon the thin stratum of air between them until dislodged by time and pressure. When they adhered closely to each other, they could only be separated by sliding each off each. This art of producing absolutely plane surfaces is, I believe, a very old mechanical ‘dodge.’ But, as employed by Maudslay’s men, it greatly contributed to the improvement of the work turned out. It was used for the surfaces of slide valves, or wherever absolute true plane surfaces were essential to the attainment of the best results, not only in the machinery turned out, but in educating the taste of his men towards first-class workmanship.”[44] Whitworth’s later success with the generation of plane surfaces seems clearly to be a refinement and outgrowth of Maudslay’s work. [44] _Ibid._, pp. 148-149.