Mozart's own grand piano, preserved at Salzburg, and the two grand pianos (the latest dated 179o) by Huhn of Berlin, preserved at Berlin and Charlottenburg, follow Stein in all particulars. These instruments have three unisons upwards, and the muting movement known as celeste, which no doubt Stein had also. The wrest-plank is not inverted; nor is there any imitation of Cristo fori. Stein's instrument was accepted as a model in Berlin as well as Vienna, to which city his business was transferred in 1794 by his daughter Nanette, known as an accomplished pianist and friend of Beethoven, who at that time used Stein's pianos. Streicher, a pianist, who married Nanette, further improved the we can refer as to the introduction of the latter instrument into England. He tells us without giving the exact date that the first hammer harpsichord that came to England was made by an Eng lish monk at Rome, a Father Wood, for an English gentleman, Samuel Crisp of Chesington ; the tone of this instrument was su perior to that produced by quills, with the advantage of piano and forte expression so that, although the touch and mechanism were imperfect, yet in a slow movement like the "Dead March" in Saul it excited wonder and delight. Fulke Greville afterwards bought this instrument for ioo guineas, and it remained unique in England for several years, until Plenius, the inventor of the lyrichord, made a pianoforte in imitation of it. In this instrument the touch was better, but the tone was inferior. Plenius produced his lyrichord, a sostenente harpsichord, in 1745, and Mason imported a piano forte ten years later. Burney further tells us that the arrival in London of J. C. Bach in 1759 was the motive for several of the second-rate harpsichord makers trying to make pianofortes, but with no particular success. Of these Americus Backers (d. 1776), said to be a Dutchman, appears to have gained the first place. He was afterwards the inventor of the so-called English action, based upon Cristofori's, and may have made the instrument referred to in an old play-bill of Covent Garden in Messrs. Broadwoods' possession, dated May 16, 1767, which has the following an nouncement : "End of Act I. Miss Brickler will sing a favourite song from Judith, accompanied by Mr. Dibdin on a new instrument call'd Piano Forte." Backers's "Original Forte Piano" was played at the Thatched House in St. James's Street, London, in 1773. Ponsicchi has found a Backers grand piano at Pistoria, dated that year.
The escapement lever is suggested by Cristofori's first action, to which Backers added a contrivance for regulating it by means of a button and screw (see fig. 18). The check is from Cristo fori's second action. John Broadwood and Robert Stodart were friends, Stodart having been Broadwood's pupil; and they were the assistants of Backers in the installation of his invention. On his deathbed he commended it to Broadwood's care, but Stodart appears to have been the first to advance it—Broadwood being probably held back by his partnership with his brother-in-law, the son of Shudi, in the harpsichord business. (The elder Shudi had died in 1773.) Stodart soon made a considerable reputation with his "grand" pianofortes, a designation he was the first to give them. In Stodart's grand piano we first find an adaptation from
the lyrichord of Plenius, of steel arches between the wrest-plank and belly-rail, bridging the gap up which the hammers rise. These are not found in any contemporary German instruments, but may have been part of Backers's. Zumpe's small square piano had met with great success ; he was soon enabled to retire, and his imitators, who were legion, continued his model with its band stops for the dampers and sourdine, with little change but that which straightened the keys from the divergences inherited from the clavichord.
John Broadwood took this domestic instrument in hand to improve it, and in the year 178o succeeded in entirely recon structing it. He transferred the wrest-plank and pins from the right-hand side, as in the clavichord, to the back of the case, an was solved by dividing the sound-board bridge, the lower half of which was advanced to carry the bass strings, which were still of brass. Even the first attempts to equalize the tension and im prove the striking-place were successful in improving the tone greatly. To please Dussek, Broadwood in 1791 carried his five octave, F to F, keyboard, by adding keys upwards, to five and a half octaves, F to C. In 1794 the additional bass half octave to C, which Shudi had first introduced in his double harpsichords, was given to the piano.
The first square piano made in France is said to have been con structed in 1776 by Sebastian Erard, a young Alsatian. In 1786 he came to England and founded the London manufactory of harps and pianofortes bearing his name. Erard took out his first patent for a "repetition" action in 18°8. He did not, however, succeed in producing his famous repetition or double escapement action until 1821 ; it was then patented by his nephew Pierre Er improvement universally adopted after his patent, No. 1379 of 1783, expired. In this patent we first find the soft and sustaining pedals, since universally accepted, but at first in grand pianofortes only. John Geib patented (No. 1571 of 1786) the hopper with two separate escapements, one of which was soon adopted in the "grasshopper" of the square piano, it is believed by Geib himself ; and Petzold, a Paris maker, appears to have taken later to the escapement effected upon the key.
To return to John Broadwood—having launched his recon structed square piano, he next turned his attention to the grand piano to continue the improvement of it from the point where Backers had left it. He called in the aid of professed men of sci ence—Tiberius Cavallo, who in 1788 published his calculations of the tension, and Dr. Gray, of the British Museum. The problem ard. When the patent expired in England in 1835 it had proved a loss from the difficulties of carrying out the invention. This in duced the House of Lords to grant an extension of the patent.
Erard invented in 18°8 an upward bearing to the wrest-plank bridge, by means of agraffes or studs of metal, through holes in which the strings are made to pass, bearing against the upper side. A long brass bridge on this principle was introduced by William Stodart in 1822. A pressure-bar bearing of later introduction is claimed for the French maker, Bord.