belonging to strings of the same name between metal plates which were bevelled to make them lighter. Thus the neck could be curved at pleasure, and its solidity being assured, the proportions of the strings could be more accurately established. About 1782 they doubled the pedals and connected mechanism, and thus constructed the first double-action harp. The pedals were arranged in two rows, and the tuning of the open strings was changed to the scale of C♭ instead of E♭, as in the single-action harps. But it does not appear that the Cousineaus made many double action harps; they were still too imperfect; and the Revolution must have closed their business, for we hear no more of them.
We now arrive at the perfecting of the harp by that great mechanician Sebastian Erard, whose merit it was to leave this instrument as complete as the Cremona school of luthiers left the violin. His earliest essays to improve the harp date about 1786, and were confined to the single action. He worked upon a new principle, the fork mechanism, and in his harps which were finished about 1789, the arrangement of it was chiefly internal; the studs that shorten the strings alone performing their functions externally. He patented in London in 1794 a fork mechanism external to the plate. He made a double-action harp in 1801, patenting it in 1809, but it was not until 1810 that he produced the culmination of his beautiful contrivance, which has since been the model for all harp makers. In this harp, as in the single action one, Erard maintained seven pedals only, and simply augmented the extent of movement of the cranks and tringles (or levers) acted upon by the pillar-rods, to give successively a portion of revolution to the disks from which the studs project; the first movement of the pedal serving to shorten strings of the same name, to produce the first half tone, the second movement of the pedal for the second half tone, the contrivance being so ingenious that the position of the upper disk—the second to move but the first to act upon the strings—is not changed when the lower disk completes its movement of revolution and acts upon the strings also.
The drawing represents 3 sections of the neck of Erard's double action harp, and shows the position of the forks and external levers, (1) when the strings are open, (2) when stopped for the first half tone, and (3) when stopped for the second. Two strings are shewn for each pitch.
It is not necessary to keep the foot upon a pedal, as it may be fixed in a notch and set free when not required; spiral springs with two arms fixed beneath the pedestal accelerate the return of the pedals. Unlike the weighty expedient of the Cousineaus, there are but two brass plates which form the comb concealing the greater part of the action. Lastly, Erard made the convex body bearing the soundboard of one piece, doing away with the old lute-like plan of building it up with staves.
As already stated, the double-action harp is tuned in C♭. By taking successively the seven pedals for the half-tone transposition, it can be played in G♭, D♭, A♭, E♭, B♭, F, and C♮. By the next action of the pedals, completing the rise of the whole tone, the harp is set successively in G, D, A, E, B, F♯, and C♯. The minor scales can only be set in their descending form, the ascending requiring change of pedals. Changes by transposition constitute a formidable difficulty in playing keyed instruments through the altered fingering required. On the harp passages may be repeated in any key with fingering absolutely the same. The complication of scale fingering, so troublesome to pianoforte playing, is with the harp practically unknown.
The harmonics of the harp are frequently used by solo players, and 'the sonorousness of these mysterious notes when used in combination with flutes and clarinets in the medium' called forth the admiration of Berlioz. ('Modern Instrumentation,' Novello 1858.)
In describing the Double-action Harp of Sebastian Erard, the writer has been much helped by a report, read before the French Institute in 1815, and lent to him by Mr. George Bruzaud.[App. p.668 "Add the following notice of an innovation in harp manufacture:—The difficulties attending performance of the harp, the constant tuning necessitated by the use of catgut strings, and the absence of any means of damping the sounds, have induced M. Dietz, of Brussels, to invent a harp-like instrument with a chromatic keyboard, which he has named the Claviharp. It has been introduced into England through the advocacy of Mr. W. H. Cummings, but the introduction (1888) is too recent to admit of a just comparison being made between this instrument and the ordinary double-action harp. It is sufficient to say that the action of the Claviharp is highly ingenious, the strings being excited mechanically much in the same way as the strings of the harp are excited by the player's fingers. There are two pedals—one being like the pianoforte damper pedal and the other producing the harmonics of the octave. The Claviharp is of pleasing appearance."]
[ A. J. H. ]