I A N O F O R T E atmospheric changes by compensating tubes and plates of the same metals, guaranteeing their stability by a cross batoning of stout wooden bars and a metal bar across the wrest-plank. Allen, being simply a tuner, had not the full practical knowledge for carrying out the idea. He had to ally himself with Stodarts foreman, Thorn; and Allen and Thorn patented the invention in January 1820. The firm of Stodart at once acquired the patent. We have now arrived at an important epoch in pianoforte construction, the abolition, at least in England and France, of the wooden construction in favour of a combined construction of iron and wood, the former material gradually asserting pre eminence. Allen s design is shown in fig. 30. The long bars shown in the dia gram are really tubes fixed at one end only; those of iron lie over the iron or steel wire, while those of brass lie over the brass wire, the metal plates to which they are attached being in the same correspondence. At once a great advance was made in the possibility of using heavier strings than could be stretched before, without danger to the durability of the case and frame. The next step was in 1821 to a fixed iron string-plate, the in vention of one of Broad- woods workmen, Samuel Herve, which was in the first instance applied to one of the square pianos of that firm. The great advantage in the fixe< plate was a more solid counterpoise to the drawing or tension of the strings and the abolition of their undue length behind the bridge, a reduction which Isaac Carter 1 had tried some years before, but unsuccessfully, to accomplish with a plate of wood. So generally was attention now given to improved methods of resistance that it has not been found possible to determine who first practically introduced those long iron or steel resistance bars which are so familiar a feature in modern grand pianos. They were experimented on as substitutes for the wooden bracing by Joseph Smith in 1798; but to James Broadwood belongs the credit of trying them first above the sound-board in the treble part of the scale as long ago as 1808, and again in 1818 ; he did not succeed, however, in fixing them properly. The introduction of fixed resist ance bars is really due to observation of Allen s compen sating tubes, which were, at the same time, resisting. Sebastian and Pierre Erard seem to have been first in the field in 1823 with a complete system of nine resistance bars from treble to bass, with a simple mode of fastening them through the sound-board to the wooden beams beneath, but, although these bars appear in their patent of 1824, which chiefly concerned their repetition action, the Erards did not either in France or England claim them as of original invention, nor is there any string-plate combined 1 Sometime foreman to the pianoforte maker Mott, who attracted much attention by a piano with sosteneute effect, produced by a roller and silk attachments in 1817. But a sostenente piano, how- ever perfect, is no longer a true piano such as Beethoven and Chopin wi ote for. FIG. 30. Allen s Compensating Grand Piano, 1820. The first complete metal framing system applied over the strings. with them in their patent. James Broadwood, by his patent of 1827, claimed the combination of string-plate and resistance bars, which was clearly the completion of the wood and metal instrument, differing from Allen s in the nature of the resistance being fixed. Broadwood however, left the bass bars out, but added a fourth bar in the middle to the three in the treble he had previously used. It must be borne in mind that it was the trebles that gave way in the old wooden construction before the tenor and bass of the instrument. But the weight of the stringing was always increasing, and a heavy close overspinning of the bass strings had become general. The resistance bars were increased to five, six, seven, eight, and, as we have seen, even nine, according to the ideas of the different English and French makers who used them in their pursuit of stability. The next important addition to the grand piano in order of time was the harmonic bar of Pieire Erard, introduced in 1838. This was a gun-metal bar of alter nate pressing and drawing power by means of screws which were tapped into the wrest-plank immediately above the treble bearings ; making that part of the instrument nearly immovable, this favoured the production of higher harmonics to the treble notes, recognized in what we com monly call "ring." A similar bar, subsequently extended by Broadwood across the entire wrest-plank, was to prevent any tendency in the wrest-plank to rise, from the combined upward drawing of the strings. A method of fastening the strings on the string-plate depending upon friction, and thus dispensing with "eyes," was a contribution of the Collards, who had retained James Stewart, who had been in America with Chickering, and was a man of considerable inventive power. This invention was intro duced in 1827. Between 1847 and 1849 Mr Henry Fowler Broadwood, son of James, and grandson of John Broadwood, and also great grandson of Shudi (Tschudi), in vented a grand piano forte to depend prac tically upon iron, in which, to avoid the conspicuous inequali ties caused by the breaking of the scale with resistance bars, there should be no bar parallel to the strings except a bass bar, w T hile another flanged resistance bar, as an entirely novel feature, crossed over the strings from the bass corner of the wrest-plank to a point upon the string-plate where the greatest accumu lation of tension strain was found. Mr Broadwood has I.- IG not continued, with out some compro mise, this extreme renunciation of ordinary resistance means. Since the Great Exhibition of 1851 he has employed an ordinary straight bar in the middle of his concert grand scale, his smaller grands having frequently two such as well as the long bass bar. From 1862 he has covered his wrest-plank with a thick plate of iron into 31. Broadwood s Iron Grand Piano, 1884. Complete iron frame with diagonal resistance
bar.