There were reasons which induced Mr. Broadwood to somewhat modify and improve this framing, but with the retention of its leading feature, the diagonal bar, which was found to be of supreme importance in bearing the tension where it is most concentrated. From 1852, his concert grands have had, in all, one bass bar, one diagonal bar, a middle bar with arch beneath, and the treble cheek bar. The middle bar is the only one directly crossing the scale, and breaking it. It is strengthened by feathered ribs, and is fastened by screws to the wooden brace below. The three bars and diagonal bar, which is also feathered, abut firmly on the string plate, which is fastened down to the wooden framing by screws. Since 1862, the wooden wrest-plank has been covered with a plate of iron, the iron screw-pin plate bent at a right angle in front. The wrest-pins are screwed into this plate, and again in the wood below. The agraffes, which take the upward bearings of the strings, are firmly screwed into this plate. The long harmonic bar of gun metal lies immediately above the agraffes, and crossing the wrest-plank in its entire width, serves to keep it, at the bearing line, in position.
This construction is the farthest advance of the English pianoforte.
FIG. 2.--WILLIAM ALLEN.
Almost simultaneously with it has arisen a new development in America, which, beginning with Conrad Meyer, about 1833, has been advanced by the Chickerings and Steinways to the well known American and German grand pianoforte of the present day. It was perfected in America about in 1859, and has been taken up since by the Germans almost universally, and with very little alteration. Two distinct principles have been developed and combined--the iron framing in a single casting, and the cross or overstringing. I will deal with the last first, because it originated in England and was the invention of Theobald Boehm, the famous improver of the flute. In Grove's "Dictionary," I have given an approximate date to his overstringing as 1835, but reference to Boehm's correspondence with Mr. Walter Broadwood shows me that 1831 was really the time, and that Boehm employed Gerock and Wolf, of 79 Cornhill, London, musical instrument makers, to carry out his experiment. Gerock being opposed to an oblique direction of the strings and hammers, Boehm found a more willing coadjutor in Wolf. As far as I can learn, a piccolo, a cabinet, and a square piano were thus made overstrung. Boehm's argument was that a diagonal was longer within a square than a vertical, which, as he said, every schoolboy knew.
The first overstrung grand pianos seen in London were made by Lichtenthal, of St. Petersburg; not so much for tone as for symmetry of the case; two instruments so made were among the curiosities of the Great Exhibition of 1851. Some years before this, Henry Pape had made experiments in cross stringing, with the intention to economize space. His ideas were adopted and continued by the London maker, Tomkisson, who acquired Pape's rights for this country. The iron framing in a single casting is a distinctly American invention, but proceeding, like the overstringing, from a German by birth. The iron casting for a square piano of the American Alpheus Babcock, may have suggested Meyer's invention; it was, however, Conrad Meyer, who, in Philadelphia, and in 1833, first made a real iron frame square pianoforte. The gradual improvement upon Meyer's invention, during the next quarter of a century, are first due to the Chickerings and then the Steinways. The former overstrung an iron frame square, the latter overstrung an iron frame grand, the culmination of this special make since of general American and German adoption. It will be seen that, in the American make, the number of tension bars has not been reduced, but a diagonal support has, to a certain extent, been accepted and adopted.
The sound-board bridges are much further apart than obtains with the English grand, or with the Anglo-French Erard. The advocates of the American principle point out the advantages of a more open scale, and more equal pressure on the sound-board. They likewise claim, as a gain, a greater tension. I have no quite accurate information as to what the sum of the tension may be of an American grand piano. One of Broadwood's, twenty years ago, had a strain of sixteen and one-half tons; the strain has somewhat increased since then. The remarkable improvement in wiredrawing which has been made in Birmingham, Vienna, and Nuremberg, of late years, has rendered these high tensions of far easier attainment than they would have been earlier in the century.
For me the great drawback to one unbroken casting is in the vibratory ring inseparable from any metal system that has no resting places to break the uniform reverberation proceeding from metal. We have already seen how readily the strings take up vibrations which are only pure when, as secondary vibrations, they arise by reversion from the sound-board. If vibration arises from imperfectly elastic wood, we hear a dull wooden thud; if it comes from metal, partials of the strings are re-enforced that should be left undeveloped, which give a false ring to the tone, and an after ring that blurs legato playing, and nullifies the staccato. I do not pose as the obstinate advocate of parallel stringing, although I believe that, so far, it is the most logical and the best; the best, because the left hand division of the instrument is free from a preponderance of dissonant high partials, and we hear the light and shade, as well as the cantabile of that part, better than by any overstrung scale that I have yet met with.
I will not, I say, offer a final judgment, because there may come a possible improvement of the overstrung or double diagonal scale, if that scale is persisted in, and inventive power is brought to bear upon it, as valuable as that which has carried the idea thus far.