homePianoforte-makers in England


DETTMER George William
in London


Patent of 1827 : "DETTMER, William, of Upper Marylebone-street, London, pianofortemaker; for improvements in pianofortes. August 30, 1827." The Repertory of Patent Inventions: And Other Discoveries and Improvements ..., 1846, p. 118

"To William Dettmer, of Upper Mary-le-bone Street, Fitzroy Square, in the county of Middlesex, pianoforte maker, for his invention of certain improvements on pianofortes.—[Sealed 30th August 1827-]

The object of the Patentee in adapting this invention to piano fortes, is to enable the instrument, after having been properly tuned, to be brought into unison with other instruments of a different pitch, by raising or lowering the tone of all its strings by a simple operation, instead of the trouble of tuning each string separately.

The plan applies both to grand piano fortes and Square pianofortes, and whether horizontal or upright, and consists in adapting to the ordinary constructions of instruments, a series of tension bars or rods, with adjustments which are to extend across the instrument, and to be connected to the block in which the pins that hold the strings are fixed, the blocks being moveable for a short distance, not more than a quarter of an inch, but confined by the tension bars.

The general construction of the pianoforte, as to the keys and movements and the arrangement of the strings, the blocks for the hitch pins and for the rest pins, being the same as in other piano fortes, the novelty consists in attaching the ends of a series of metal bars or rods to the hitch pin blocks, and connecting the reverse ends of the same bars to the rest pin block; these bars being enabled to elongate or contract by means of adjusting screws.

Supposing each of the strings of the instrument to have been drawn up by the tuning key to the required note, that is properly tuned, but that when so tuned the whole should be found to be too flat or too sharp to play in concord with other instruments in a concert, by simply moving the adjusting screws of the tension bars, the blocks to which the strings are attached, will be brought nearer together to flatten the tone, or farther apart to sharpen it, as may be required, without deranging the tone or notes of the individual strings.

The Patentee says that both the blocks on which the strings are hitched, and that in which the rest pins are set, may be made to slide, but he prefers that the rest pin block only should move, and this may be done by passing the adjusting screws through the block into the tension bar, when by turning the screws, the block will be moved a short distance, and the tension of all the strings will thereby be increased or relaxed.

The same effect may be produced by means of wedges or levers, or some other contrivances, in place of the screws, but that which has been described is preferred.— [Inrolled in the Inrolment Office, February, 1828.]" The London Journal of Arts and Sciences, 1831, p. 329-331

Patent of 1827 : "W. Dettmer, of Upper Marylebone-street, London ; for improvements on piano-fortes." The Annual Register of World Events: A Review of the Year, Volume 69, 1828, p. 534


Patent of 1831 : "On W. Dettmer's Patent Piano Forte And Harmonic Temperament.
To the Editor of the London Journal of Arts.

Sir, — As a lover of music, I am induced to request the favour of your inserting a few observations upon the above subjects in your valuable publication. The deficiency of all musical instruments, with fixed notes, to express the true sounds of the diatonic scale, especially in modulating from one key to another, has been universally observed, and generally complained of by practical musicians. In respect of wind instruments, such as trumpets, clarionets, flutes, &c. the uneven intonation produced by the almost unmanageable variation of theimpetus and weight of Vol. VH.—Second Series.

I wind given by the performer, adds greatly to the obvious inherent defect of these instruments; but in keyed manual instruments having a regular blast of wind, such as the organ, the separate notes of which can be tuned through its octaves upon a system of harmonic temperament according to the skill and inclination of a practised operator, the defects of fixed notes may be nearly obviated.

The piano forte and similar keyed instruments having fixed sounds, capable of being separately tuned, so as to exhibit an equal temperament throughout all its octaves, may (as well as the organ with twelve semi-tones or keys in each octave) be sufficiently well tuned for the practical purposes of the most delicate ear.

I have carefully attended to the effects of Mr. Loeschman's, and of other attempts to remedy the supposed defects of the scale of twelve semi-tones, without the least reference to the difficulty of execution, or the great cost of introducing additional tones, and am satisfied that upon a good system of tuning, there is produced a more agreeable sensation to the mind by the admixture of the major and minor concords upon a twelve-keyed instrument, than can be effected by increasing the number of the tones or keys, so as to represent all the actual sharps and flats of the scale.

All the instruments I have heard, with a large additional number of tones in the octave, are monotonous; the several keys and all the chords minor as well as major being equally harmonious, there is produced a fatiguing dullness of expression; the modulation from one key to another is perfectly insipid.

However good the supposed improvements may be in theory, practical musicians have not supported them, and after years of trial from Lord Stanhope's time, they have only served to elucidate the theorems of the philosopher.

It will be obvious from the foregoing observations, that the great advantage of the organ and piano forte over other instruments, having twelve fixed sounds to express all the note, that is rather all the natural flats and sharps that occur in the octave is, that the several sounds (viz. the pipes and strings giving the twelve semi-tones) can be separately and individually tuned, so as to form a combined system of temperament, producing the most pleasing effect to the ear.

If that adjustment or temperament is altered so as to become unequal through the several octaves, the instrument ceases to be in good tune, although many of the chords taken may not be harsh to the ear, many others will become insufferable.

Now the supposed improvement in Mr. Dettmer's patent, which is described as enabling the piano forte, "after having been properly tuned to be brought into unison with other instruments of a different pitch, by raising or lowering the tone of all its strings by a simple operation, instead of the trouble of tuning each string separately," is, in my humble judgment, any thing but an advantage, so far as the evenness of the adjustment or temperament throughout the instrument is concerned.

The patent is I believe worked by Mr. Tomkisson, the piano forte maker, of Dean-street; at least I have there seen several instruments precisely answering the description of Mr. Dettmer's improvement. I have examined the effect of altering the tension of the wires" by simply moving the adjusting screws of the tension bars," by which means the blocks carrying the pegs are brought into a new position.

The whole body of the strings is thus made sharper or flatter as may be required; and I candidly acknowledge, that this alteration of the general pitch of the instrument is a great accommodation to singers who understand little of music, and cannot alter their pitch so as to sing a piece in a different key to that written, or to others who are so highly finished in the art, and well gifted with accompanying hauteur, that they will not alter their pitch to the instrument, and expect (as Madame Catalani did) that an entire band should rather accompany their sweet voices in a different key to that in which the music is written, than accommodate their "song divine" to the pitch of the band.

Mr. Dettmer's improvement is also an accommodation to accompanying instruments, with fixed tones, which are themselves worse tuned than the piano after its new patent adjustment; and I will acknowledge that the instrument after such adjustment, is not altogether out of tune, when any note is merely sounded with its octave.

But the temperament of the instrument is altered in its several distinct octaves, and the adjustment of such equal temperament no longer continues the same throughout the entire scale of the instrument. This is a defect which may be remedied by the making of separate moving blocks to the several octaves.

It is therefore evident, that the defect of unequal temperament is inherent in Mr. Dettmer's moveable block, for it gives an equal or nearly an equal tension or relaxation of the strings throughout the instrument, although the bass strings are three to six times longer than a treble octave.

By this operation, not only is the tension of strings altered unequally throughout the several octaves, but the same length is added or substracted to or from the longest and the shortest strings, to the evident disarrangement of the previous adjustment of the temperament in tuning.

I trust these few observations may prove conducive to the amelioration of Mr. Dettmer's ingenious invention, and not be unacceptable to such readers of your Journal as may feel interested in improvements connected with the delightful science of music.

I am, Gentlemen, Yours, &c, F. L. S. Isleworth, April, 1831." The London journal of arts and sciences (and repertory of patent inventions ..., William Newton, 1831, p. 57-61

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