Up to 1760, all pianos had been built in the shape of the modern grand, horizontal or up right; but, between 1760-65, Johann Zumpe, a former workman in Shudi's establishment, in troduced the English square piano. The action was sufficient, although almost rudimentary, and contained what was called the cold man's head,° a metal pin with a leather knob on the top to raise the hammer, and the damper raised by a simple jack. The compass was five octaves from F-'. Zumpe's success was imme diate. The instruments sold rapidly, and the form increased in popularity. Other makers started establishments, and in the last decade of the century, London became the centre of the world's pianoforte trade, with not less than 30 square piano-making establishments, English and German, in active operation.
Between 1780 and 1790, John Broadwood recognized the fact that when the string was struck at a certain point, it yielded a fuller tone. He therefore, adjusted the hammers so as to obtain this result, and also transferred the wrest-plank to the back of the case, and intro duced the two pedals—one to raise all of the dampers, and the other to soften the tones by dropping a piece of cloth over the strings. The change m the place of the wrest-plank enabled him to reduce the inordinate length of the un used wire, and also to straighten the keys, which had been hitherto left more or less twisted, as in the clavichord, but in connection with the crank damper, he did not get beyond the "old man's head° device that lifted the ham mer, and the merit of introducing in the square piano the "hopper° — a jack with a string work ing in a notch forming the front part of a lever, technically known as the "under-hammer° —belongs to John Geib, who took out a patent for the improvement in 1786, and first ap plied it to the square pianos he made for Long man and Broderip, music publishers in Cheap side.
Fig. 6 shows the Broadwood grand piano action, commonly known as the "English direct lever action,° in which the key (k) on being depressed raises the hopper (h) which strikes in the notch (n) cut in the butt of the ham mer (d), the play of the hopper against the notch determining the velocity of the hammer and the individuality of the player's touch; (w) is the wire hopper check; (s) the screw that regulates the lever to determine the distance of the hopper motion; (a) is the hammer-head, and (c) the check which is raised when the key is depressed and arrests the hammer in its fall. It is the first simple contrivance for repetition, that is, for repeating the blow of the hammer before it returns to its original position or eqmpose. The key not only raises the hopper and check, but also the damper, so as to allow the string forming the note to continue the vibration, and the escapement when raised with out impact as depends upon that space between the hammer and the strings, to allow the ham mer to clear them under a blow either soft or loud, and thus prevent the strings stifling the vibration before it has had time to become a musical note. This action was invented about
1772, and was further developed and perfected by Broadwood, with the assistance of Backus and Stodart, until it became the best single ) escapement action.
About 1777 the German manufacturers pro duced another kind of escapement, which was considered favorably by prominent pianists for many years. It was invented by Stein, a pupil of Silbermann, but was carried to its highest state of perfection under the joint efforts of his daughter Nannette and son-in-law, Andreas Streicher, about 1794. Fig. 7 shows the con struction of this action: (k) is the key, (h) the hopper, (s) the hopper spring, (1) the standard in which the hammer butt (d) is centred, (b) the set-off button, (c) the check and (g) the damper. This action differs from the Cristofori (English) action, in that the hammer is directly attached to the rear end of the key itself, in stead of being fixed to a lever independent of the key. This arrangement caused a change of axis of the hammer when the key was struck, thus giving the extreme lightness of touch which enabled easier execution and brilliant playing, although less capable than the English of producing its tone varieties. Up to 1777 the French imported their pianos chiefly from Eng land, when Erard (Erhardt), a German piano maker, produced the first piano made in France. Having been driven to London by the Revolu tion, he familiarized himself with the English methods, and incorporated the English prin ciples in his first instrument. Subsequently he adopted the Stein principle, and afterward de veloped his own action, illustrated by Fig. 8, in which, when the key (k) is depressed, the lever (1) is raised by the pilot (p), and the hopper (h) escapes forward when it has de livered its blow to the roller (r) beneath the hammer fork (f). Similar to the notch of the English action, the roller transmits to the ham mer the player's intention and individuality. A prolongation of the hopper forms the escape ment lever (e) which controls the set-off from the strings by the screw and button (s). The wire hopper spring (b) maintains the hopper in position, and together with the hammer-head (d) and the check (c), completes the single escapement action. The repetition or second escapement is obtained by the roller resting upon the hinged repetition lever (t) which rises when the wire spring (q) is bent by the depression of the key, the rise of the lever be ing controlled by the screw (w), which acts on the point of the lever.