the wooden wrestplank or pinblock, the great length of the pin and clinging of the wood producing sufficient friction to counteract the pull of the string. The wrestpin-piece was introduced by the firm in the grand pianos exhibited in 1862, and years have proved the efficiency of the invention. This is the successful completion of the iron framing identified with the third of Mr. Broadwood's name, in direct descent an improver of the pianoforte.
Returning to the action, we have seen the steps first taken by Sebastien Erard towards the attainment of double escapement, whereby power is regained over the hammer before the key returns to its equilibrium. He had grown old before the full accomplishment of his idea, and his famous 'Repetition action' was patented in London in 1821 (Patent No. 4631) by Pierre Erard, his nephew. The action is shown in this diagram, which we will describe as far as possible in uutechnioal language.
Fig. 17.
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c is the key; d is a pilot, centred at dd to give the blow, by means of a carrier, e, holding the hopper, g, which delivers the blow to the hammer, o, by the thrust of the hopper, which escapes by forward movement after contact with a projection from the hammer covered with leather, answering to the notch of the English action. This escapement is controlled at x; a double spring, ii, pushes up a hinged lever, ee, the rise of which is checked at pp, and causes the second or double escapement; a little stirrup at the shoulder of the hammer, known as the 'repetition,' pressing down ee at the point, and by this depression permitting g to go back into its place, and be ready for a second blow, before the key has been materially raised. The check, p, is in this action not behind the hammer, but before it, fixed into the carrier, a, which also, as the key is put down, brings down the under damper.
Although at once adopted by Hummel and other pianists of note, including Liszt, then a boy, Erard's action was slow to obtain recognition. It did not gain a satisfactory position until Thalberg, after 1830, had identified his admirable playing with its specialities. In 1835 Pierre Erard obtained an extension of his patent on the ground of the loss sustained in working it. Then 'repetition' became the pianoforte-maker's dominant idea in this country and elsewhere, each according to his knowledge and ability contriving a repetition action to call his own, though generally a modification of an existing one. Names that have come prominently forward in connection with these experiments, are Blüthner in Germany, Pleyel and Kriegelstein in Paris, Southwell the younger, Ramsay and Kind (under Broadwood's patronage at different times) Collard, Hopkinson, and Brinsmead in London. Other repetition actions are the simplified copies of Erard's used by Herz in Paris and by Steinway in New York, the latter lately adopted by Bechstein of Berlin, in place of Kriegelstein's.
Beyond the broad summary of inventions in instrument and action which we have sketched, it is impracticable in our space to go farther into detail; it would moreover be a task of great difficulty, owing to the multiplicity of facts needing to be sifted, and the fact that a writer on this subject must always be influenced by education in taste and use. We may however be permitted to refer to the services of James Stewart (particularly in connection with Messrs. Collard's pianos) and to Henry Pape of Paris, who has tried more ingenious experiments in pianofortes than any other maker, although the majority of them are of doubtful utility. It is to him that we owe the use of felt for hammers (much improved, however, by Mr. H. F. Broadwood, who first substituted sheep's wool for Pape's rabbit's hair). William Stodart invented a continuous bridge for upward bearing in 1822; and the 'harmonic bar' in the treble, as a bar of alternating pressure has been called, from the peculiar timbre obtained by its use,[1] was the invention of Pierre Erard about 1838, according to Dr. Paul. The main object of this bar was to consolidate the wrestplank in the treble, a screw tapped into the plank and drawing it upwards alternating with a screw tapped in the bar pressing it downwards. In 1843 Mr. A. Bord of Paris invented a different bar independent of the wrestplank, which served as a bridge of upward bearing and abolished the treble wrestplank bridge. From its simplicity and cheapness this has found favour, with some modifications, in Germany (where it is known as the Capo
- ↑ In the original application of this invention a third screw pressed upon the bridge.
