STEAM-HAMMER, THE, has doubtlessly contributed more than any other mechanical invention of modern times in developing the wonderful resources of the iron trade, and is still looked upon as a marvel of engineering skill and ability. The first idea of a steam-hammer appears to belong to James Watt, the great father of engineers, and was patented by him in 1784. In 1806, a William Deverell, described as "an engineer of Surry," also took out a patent for a steam-hammer; but in neither case does it appear that steam-hammers were actually constructed. From this time till 1837, the idea seems to have been entirely lost sight of, when it was again taken up by Mr, James Nasmyth, of the Bridgewater foundry, Patricroft, near Manchester, as the result of an application made to hiM by Mr. Francis Humphreys, engineer to the Great Western Steamship company, who had been unable to induce any forge-master to undertake the forgings required for the paddle-shafts of the Great Britain steamship, then in course of construction. ?17. Nasmyth sent a sketch of his hammer plan to Mr. Humphreys, who, along with Mr. Brunel and others, heartily approved of the scheme, but in consequence of an alteration being made itt the propelling arrangement of the great ship, the paddle-shaft was not required, and the hammer was not then constructed. The scheme was offered to many of the large forge-masters and engineers; but while all seemed to admire the idea, they failed to appreciate its value and importance, and the hammer remained a mere sketch in Mr. Nasmyth's "scheme-book" till 1842, when, in December of that year, Mr. Nas. myth secured a patent for his invention, and the first steam-hammer was made in accord ance with his plan at the Bridgewater foundry early in 1843; but although considered by some as an improvement upon the old " helves" hitherto used for forging purposes, it was,very far from being a perfect or even a. marketable tool. The hammer was worked by means of an ordinary slide-valve • and a long lever, requiring great labor and constant attention in order to give the blow required ; so that souse contrivance was necessary, capable of adjustment, in order to have complete command over the power of the blow, and that, the instant the blow was struck, the block should rise again, so 'that not only no loss of time should ensue, but that the heat in the mass of iron on the anvil might not be reduced or carried off by the cold face of the block. Time peculiar difficulty of securing a true automatic arrangement will be seen when it is con sidered that the instant of percussion must vary with almost every blow that is strek; for the piece on the anvil becomes thinner and thinner by each succeeding blow, and in flat bars a blow is first given on the flat side, and then on the edge, the difference in the fall of the hammer in the two cases being oftentimes several inches; and further, that the hammer must be under perfect control at all times.
Mr. Nasmyth, after many and protracted trials, failed to produce the motion re quired, and, as a consequence, the whole hammer scheme was on the point of being abandoned. In this dilemma, and during Mr. Nasmyth's absence from the works, his partner, Mr. Gaskell, applied to their engineering manager, Mr. Robert Wilson, who afterward became managing partner and successor to Mr. Nasmyth, to endeavor to sotto the problem which had hitherto baffled the skill of Mr. Nasymth. Mr. Wilson took the matter in hand, and in little more than a week, a motion was invented and attached to a hammer upon which former experiments had been made, and was at once found to answer most admirably every condition required. Under the influence of this very beautiful mechanical motion every variety of blow could be given, from the gentlest tap to the heaviest blow within the compass of the hammer, and that, too, perfectly 'self-acting in every respect, the long lever and the hard work before referred to being now entirely banished. By simply altering the position of the tappet lever by means of two screws, a blow of the exact force required could be produced and continued so long as steam was supplied. So completely was the hammer now under control, that it be came a favorite amusement to place a wine-glass containing an egg upon the anvil, and let the block descend upon it with its quick motion; and so nice was its adjustment, and so delicate its mechanism, that the great block, weighing perhaps several tons, could be heard playing tap, tap, upon the egg without even cracking the shell, when, at a signal to the man in charge, down would come the great mass, and the egg and glass would be apparently, as Walter Savage Landor has it, " blasted into space." On
Aug. 18. 1843, the first hammer was &livered to Messrs. Bird, Dawson, and Hardy of the Low Moor iron works, near Bradford, Yorkshire, and gave such satisfac tion, that orders for this remarkable tool began to flow in from all parts of the country. The hammer remained in this condition, with the exception of a few minor details, from 1843 to 1853, when Mr. Wilson (who in the interim had removed to the Law Moor iron-works) invented, patented, and applied to the hammers at Low Moor and elsewhere what is called the "circular balanced valve." The Praetkal Mechanic's Journal for 1855, vol. viii., p. 174, in an article on this invention, says: " The wonders of Mr. Nasmyth's invention, the have just received new luster at the hands of Mr. Wilson, to whom belongs a large portion of the credit attaching to the early_ prac tical development of the beautiful automatic action of this invaluable tool. The special feature which Mr. Wilson has introduced is his balanced-pressure cylindrical valve. sev eral modifications of which we noticed iu our pages of .June and July last year. Ham mers divested of all self-acting apparatus whatever, and fitted merely with a band geared valve of this kind, exhibit an immensely improved action, enabling the workman to obtain the exact kind of blow he wants under all circumstances. This adjustment of the hammering force is attained just as effectually as with the simple hand-hammer of the smith, one stroke giving perhaps a mere touching tap, and the next a blow of the highest intensity." In July, 1856, Mr. Wilson returned to the Bridgewater foundry as managing ' in the firm of James Nasmyth and company, and in September following obtained a plvz tent for a balanced slide-valve, and at once arranged to apply his invention to all hammers subsequently to be made there, which arrangement continues in operation to the present time. Ills balanced slide-valve, by a most ingenious arrangement, allows the valve, as it to float in an atmosphere of steam pressing equally upon it on every side. en tirely doing away with all superincumbent pressure upon the valve, no matter what the pressure in the Luger may be. The great advantage of this invention will be apparent when it is stated that hammers are now made of such a size, that, if the valve were not balanced, a small steam engine would be required to move it.
In June, 1861, Mr. Wilson patented and introduced another very important im provement, popularly known as the double-acting hand-gear motion. By this arrange. meat. the steam is admitted as before to raise the piston, and when it has attained the required elevation, and at the very moment when about to descend, by slightly in creasing the travel of the hand-lever (more than when working single-actingy, the steam. is admitted into the cylinder above the piston, which accelerates and increases the in tensity of the falling blow and the consequent capacity of the hammer; so much so, that that which had hitherto been described as a five-ton hammer is by this double-acti.in arrangement increased to at least a 1.2} or 15 ton one.
In 1862, Mr. Wilson designed and constructed a small hammer suitable for tilting steel, fitted with the balance-valve, double acting, and with an entirely new self acting motion (much less complicated than the original one) capable of strking fire hundred blows per minute. There are many patents for this kind of hammer, which is now very largely used in the forging of steel.
One of the hugest suam-hammers yet constructed is at Perm (a town in the n.e. of Russia), and is used for the manufacture of large cast-steel guns. It is a 50-ton ham. mer, made double-acting in the way above mentioned, so as to be equal to a 100-ton single-acting one. Its anvil-block is the largest casting ever made, weighing con siderably more than 500 tons. It was cast in its place, but upside down, engines being erected to turn it over when finished. The metal was melted in 14 furnaces, for which the blast was provided by three large blowing-engines, all three being especially fitted up for the purpose. It was several months before the casting was cool enough to bo uncovered and turned over.