Bartolommeo Cristofori was a Paduan harpsichord maker, who was invited by Prince Ferdinand dei Medici to Florence, to take charge of the large collection of musical instruments the Prince possessed. At Florence he produced the invention of the pianoforte, in which he was assisted and encouraged by this high-minded, richly-cultivated, and very musical prince. Scipione Maffei tells us that in 1709 Cristofori had completed four of the new instruments, three of them being of the usual harpsichord form, and one of another form, which he leaves undescribed. It is interesting to suppose that Handel may have tried one or more of these four instruments during the stay he made at Florence in 1708. But it is not likely that he was at all impressed with the potentialities of the invention any more than John Sebastian Bach was in after years when he tried the pianofortes of Silbermann. The sketch of Cristofori's action in Maffei's essay, from which I have had a working model accurately made, shows that in the first instruments the action was not complete, and it may not have been perfected when Prince Ferdinand died in 1713. But there are Cristofori grand pianos preserved at Florence, dated respectively 1720 and 1726, in which an improved construction of action is found, and of this I also exhibit a model. There is much difference between the two. In the second, Cristofori had obtained his escapement with an undivided key, reconciling his depth of touch, or keyfall, with that of the contemporary harpsichord, by driving the escapement lever through the key. He had contrived means for regulating the escapement distance, and had also invented the last essential of a good pianoforte action, the check. I will explain what is meant by escapement and check. When, by a key being put down, the hammer is impelled toward the strings, it is necessary for their sustained vibration that, after impact, the hammer should rebound or escape; or it would, as pianoforte makers say, "block," damping the strings at the moment they should sound. A dulcimer player gains his elastic blow by the free movement of the wrist. To gain a similarly elastic blow mechanically in his first action, Cristofori cut a notch in the butt of his hammer from which the escapement lever, "linguetta mobile" as he called it--"hopper," as we call it--being centered at the base, moved forward, when the key was put down, to the extent of its radius, and after the delivery of the blow returned to its resting place by the pressure of a spring. The first action gave the blow with more direct force than the second, which had the notch upon what is called the underhammer, but was defective in the absence of any means to regulate the distance of the "go-off," or "escapement" from the string. In the second action, a small check before the hopper is intended to regulate it, but does so imperfectly. The pianoforte had to wait for fifty years for satisfactory regulation of the escapement.