appears to have immediately grasped the importance of the invention, and the information which he and his manager obtained was sufficient to enable them to construct a steam-hammer, which was set to work about 1841. Nasmyth first became aware of this in April 1842, when he saw his own hammer at work on the occasion of a chance visit to Creuzot. Upon his return to England he lost no time in securing his invention by taking out a patent (No. 9382, 9 June 1842), but Schneider had anticipated him in France by patenting the hammer in his own name on 19 April.
The first steam-hammer set up in this country was erected at Patricroft in the early part of 1843, and, after working for some time, it was sold to Muspratt & Sons of Newton-le-Willows for breaking stones (cf. Rowlandson, History of the Steam Hammer, Manchester, 1875, p. 9). The valves of the early hammers were worked by hand, and much time was spent in making the machine self-acting, so that immediately upon the delivery of the blow steam should be admitted below the piston to raise the hammer up again. This self-acting gear was patented by Nasmyth in 1843 (No. 9850), but the invention is claimed for Robert Wilson, one of the managers at Patricroft (op. cit. p. 6). Self-acting gear is now generally discarded, except in small hammers, where straightforward work is executed. Large hammers are now universally worked by hand, according to Nasmyth's original plan, the introduction of balanced valves giving the hammer-man perfect control, even over the most ponderous machines (Pract. Mech. Journ. July 1848 p. 77, November 1855 p. 174). The patent of 1843 contained a claim for the application of the invention as a pile-driver, and the first steam pile-driver was used in the Hamoaze in July 1845. In that year Nasmyth took out a further patent for a special form of steam-hammer for working and dressing stone. So much was the machine in his mind that he designed a steam-engine in which the parts were arranged as in a steam-hammer, the cylinder being inverted. For this engine he received a prize medal at the exhibition of 1851, and the design has since been largely adopted for marine engines (cf. Engineer, 3 May 1867, p. 392).
Attempts have been made to deprive Nasmyth of the credit of the invention of the steam-hammer, and it has been pointed out that James Watt in his patent of 1784 (No. 1432), and William Deverell in 1806 (No. 2939), had both suggested a direct-acting steam-hammer. In 1871 Schneider gave evidence before a select committee of the House of Commons, in the course of which he stated that the first idea of a steam-hammer was due to his chief manager. Thereupon Nasmyth obtained leave to be heard by the committee for the purpose of placing his version of the matter before them. The question of priority is fully discussed in the ‘Engineer,’ 16 May 1890 p. 407. A working model of the hammer, with the self-acting gear, made at Patricroft, may be seen at South Kensington, together with an oil-painting by Nasmyth himself, representing the forging of a large shaft.
The fame of Nasmyth's great invention has tended to obscure his merits as a contriver of machine-tools. Though he was not the discoverer of what is known as the self-acting principle, in which the tool is held by an iron hand or vice while it is constrained to move in a definite direction by means of a slide, he saw very early in his career the importance of this principle. While in the employment of Maudslay he invented the nut-shaping machine, and in later years the Bridgewater foundry became famous for machine-tools of all kinds, of excellent workmanship and elegant design. He used to say that the artistic perception which he inherited from his father was of singular service to him. Many of these are figured and described in George Rennie's edition of Buchanan's ‘Essays on Millwork’ (1841), to which Nasmyth contributed a section on the introduction of the slide principle in tools and machines. Most of his workshop contrivances are included in the appendix to his ‘Autobiography.’ As far back as 1829 he invented a flexible shaft, consisting of a close-coiled spiral wire, for driving small drills. This has been re-invented several times since, and is now in general use by dentists as a supposed American contrivance. He seems also to have been the first to suggest the use of a submerged chain for towing boats on rivers and canals. He proposed the use of chilled cast-iron shot at a meeting of the British Association at Cambridge in 1862, some months before Palliser took out his patent in May 1863. Having been requested by Faraday to furnish some striking example of the power of machinery in overcoming resistance to penetration, he contrived a rough hydraulic punching-machine, by which he was enabled to punch a hole through a block of iron five inches thick. This was exhibited by Faraday at one of his lectures at the Royal Institution. Subsequently Nasmyth communicated his ideas to Sir Charles Fox, of Fox, Henderson, & Co., and a machine was constructed for punching by
