AN ENHARMONIC ORGAN.*
BY GENERAL T. PERRONET THOMPSON, M.P.
[* Manufacturers, Messrs. Robson, 101, St. Martin's-Lane.]
To the Editors of the Mechanics' Magazine.
GENTLEMEN, - No more of prelude wil be introduced, than appears necessary for explaining the objects of the mechanism to be described.
It is fast approaching to being a generally admitted truth, that singer, to the extent the cultivation of their ear admits, sing what the ancients intended by enharmonically ; - that is, make the harmonious or just intervals of the musical scale, first from one sound, which is called singing in one key, and then in a multiplicity of keys, by making the same intervals over again de novo, beginning from one of the previously established sounds. The effect of which is to light sometimes on the same sounds as before, but often on different. The system which minces up these differences into twelve sounds which shall serve all purposes, is denominated temperament. The "Sol-fa Associations" have done much towards progress. The violists are behind the singers, but in time they will, perhaps, take the same course.
The foundations of musical relation are within ken, to the same extent as of optical. That shortening a string by the half produces what from the place it finally holds in the musical scale is called the Octave ; by the third part, the Fifth ; by the fourth part, the Fourth ; by the fifth part, the Major Third ; by the sixth part, the Minor Third ; by three-eighths, the Minor Sixth ; by two-fifths, the Major Sixth ; - is as good evidence that the simplicity of these proportions, or the coincidences of the vibrations arising out of them, are at the bottom of what we call harmony, as that a distinct image on the retina or membrane of the eye is at the foundation of vision. We may be unable to tell why these consequences follow ; but that they do follow, is what there is no room left to doubt.
The sounds names are what are called the Consonances ; from their agreeable effect when sounded along with the first or key-note. If they were only one or two, there might be doubt whether simplicity of proportion was the foundsation of their peculiar quality ; but when they are upwards of half-a-dozen, there can be none. And the next thing is to divide the large equal intervals left at each end of the scale, in a manner which shall form concords with some or other of the Consonances previously determined. The ready way to which, is to divide into a Minor and a Major Second at one end, and by analogy a Major and Minor Seventh at the other. The sounds so made are called the Dissonances.
And here starts to light the fact which the reformers mainly trust for the solution of difficulties, - that the Dissonances are double, or have two forms differing by the interval called a Comma, which, through the object of the temperera is to make light of it, is eleven times what the tuners recognize as sensible to the ear. And it will be plain to an arithmetical eye, that these two forms make concords with the Consonances alternately, - that is to say, the grave form with the Fourth and Sixths, and the acute with the Fifth and Thirds. If therefore all these are distinguished by being the one set black and the other white (as done upon the instrument), a useful aid will be established. The Major Seventh and Minor Second would also be capable of a second form ; but as these would make no concord with any of the Consonances, they are never wanted, and therefore may be omitted ; a great relief. Add to which, that when the Minor series is on hand, for reasons it would be tedious to go into, no form of the Major Second but the acute is wanted ; another great relief. So that there is no occasion ever to look out for more than one of the extraordinary or unusual sounds ; to wit, the grave Major Second in the Major series, and the acute Minor Seventh when the Minor series is in hand. The completeness of the analogy, to the minutest point, between the sounds in the Major and Minor series, and the manner in which they occur at equal intervals with alternation of belonging to the Major or Minor, from the central division each way, are objects for the curious observer.
All this was of easy calculation, and the question was of the mechanism by which it could be reduced with tolerable facility to practive. And here the difficulty may be reduced to the Major Second and Minor sevenths having each two manuals, as may be seen by inspection of the finger-boards for the three leading keys. In this the small manuals having resemblance to the keys of a flute, may be put out of view, as having reference solely to the addition[] keys which can be executed with the[] help. Mersenne, the great musical philos[]pher of the seventeenth century, has [] drawing of a finger-board with 32 manua[] in the octave ; but it does not appear [] have occurred to him to divide the soun[] among more finger-boards than one.
Front View of the FINGER-BOARDS, of a Scale of One Fourth.
[Profile, showing the heights of the different kinds of manuals. Sich as differ only in colour, are of the same height.]
Undermost board contains Keys of C\, F\, G/, Bb\ Major, Bb/ Major, Eb/ Major, Ab Major, D/ Minor ; and by having convertivle pipes for Gb\ and Gb/, Cb\ and Cb/, the Keys of Db\ Major, Gb\ Major, Bb\ Minor, Bb/ Minor, Eb/ Minor. Middle board, Keys of E\, B/, G/ Major, D/ Major, C\ Major, and (with help from the uppermost board) A\, C#\, G#/. Uppermost board, the Keys of D\, A\, F\ Major, Bb\ Major, G\, and (with help from the middle board) B\, E\\, and F#\. The colours are expressed here as in heraldry. The means of distinction by the blind, are also represented.
Here follows the description of the sounds, &c., in one octave. A line over [under] any number figures indicates a recurring decimal.
| Places in Primitive Key C\. | Boards in which found | Names. | Indices. | Measures, in decimals. | ||
| Key-note | C | E | D* | ¶C\ | 0 | 1. |
| C | C/ | 1 | .987654320 | |||
| D | C#\\ | 2 | .972 | |||
| E | D | ¶C#\ | 3 | .96 | ||
| E | C#/ | 4 | .9481481 | |||
| Minor Second | C | ¶Db\ | 5 | .9373 | ||
| C | Db/ | 6 | .925925 | |||
| 7 | ||||||
| Grave Maj. 2nd | C* | E | D | ¶D\ | 8 | .9 |
| Acute Maj. 2nd | C* | E* | ¶D/ | 9 | .888 | |
| 10 | ||||||
| E | D#\ | 11 | .864 | |||
| E | D#/ | 12 | .8533 | |||
| C | D | Eb\ | 13 | .84375 | ||
| Minor Third | C | ¶Eb/ | 14 | .833 | ||
| 15 | ||||||
| D* | ¶E\\ | 16 | .81 | |||
| Major Third | C | E | D | ¶E\\ | 17 | .8 |
| E | E/ | 18 | .790123456 | |||
| 19 | ||||||
D | E# | 20 | .768 | |||
| 21 | ||||||
| Fourth | C | E | D | ¶F\ | 22 | .75 |
| C | F/ | 23 | .740740 | |||
| 24 | ||||||
| E* | D | ¶F#\ | 25 | .72 | ||
| Tritone | C | E | F#/ | 26 | .711 | |
| C|| | ¶Gb\ | 27 | .703125 | |||
| C|| | Gb/ | 28 | .6914 | |||
| E | Fx | 29 | .68266 | |||
| C | D | ¶G\ | 30 | .675 | ||
| Fifth | C | E | D | ¶G/ | 31 | .666 |
| 32 | ||||||
| D | G#\ | 33 | .648 | |||
| E | D | ¶G/ | 34 | .64 | ||
| 35 | ||||||
| Minor Sixth | C | ¶Ab | 36 | .625 | ||
| 37 | ||||||
| D | A\\ | 38 | .6075 | |||
| Major Sixth | C | E | D | ¶A\ | 39 | .6 |
| C | E | A/ | 40 | .592592 | ||
| 41 | ||||||
| E | A#\ | 42 | .576 | |||
| E | A#/ | 43 | .5688 | |||
| Grave Min. 7th | C | D | Bb\ | 44 | .5625 | |
| Acute Min. 7th | C* | Bb/ | 45 | .555 | ||
| 46 | ||||||
| D | ¶B\ | 47 | .54 | |||
| Major Seventh | C | E | D | ¶B/ | 48 | .533 |
| C|| | Cb\ | 49 | .52134375 | |||
| C|| | Cb/ | 50 | .520822 | |||
| E | B# | 51 | .512 | |||
| D | C\\ | 52 | .50625 | |||
| Octave | C | E | D* | C\ | 53 or 0 | .5 |
| ¶ Keys. | * Quarrill. | Flutal. | Button. | || By Convertible Pipe. |
In the machinery may be included the Regulator for correcting the effects of changes of temperature, consisting of bars before the mouths of the pipes, each octave forming a distinct frame capable of being raised or depressed in succession ; and a Monochord tuned by weight, presenting all the various sounds, and with the opportunity of applying the method of means, producing the same kind of ease as a magnifying glass in the case of visible objects where accuracy is desired. The Swell is divided into two at Middle c\, each part working separately ; and there is a Concussion-box to prevent quivering. The pipes at present consist only on an Open Diapason, from CC\ in the bass to f/ in alto ; the external dimensions of the instrument benig 11 1/4 feet by 5, and 8 feet 5 1/2 inches high. But on another opportunity it would be proposed to add a second Open Diapason, a fac-simile of the other, on the same regulator, and a Dulciana with a regulator of its worn. It is conjectured that in this state the instrument, under the title of "Enharmonic Stop," would be capable of taking the place of the choir and swell organs in a cathedral, and at a diminished cost. Such an instrument would not be a very expensive addition to a theatrical or other orchestra, and might be an acquisition to Choral Societies, Glee Clubs, and Musical Associations in general. References with any furhter objects, may be made to a shilling pamphlet under the title of Just Intonation, published by Effingham Wilson, 11, Royal Exchange.
On the question of ultimate facility, it would be injustice to omit the following. An advertisement headed "Enharmonic Organ" was inserted in the Times of June 23, 1856, in which, after a description of the instrument, were the words "A pupil wanted ; if blind preferred ; pupil should be able to play psalm-tunes, and tell the existing key ; in which case six lessons deemed sufficient." A young lady of 19, blind from birth, Miss E. S. Northcote, since Organist of St. Anne and St. Agnes, St. Martin's-le-Grand, whose portrait appears in the pamphlet mentioned, presented herself the next day, and after brief instructions sat down to the instrument. She was familiar with the greatest part of the current ecclesiastical music, and had accustomed herself to being the subject in any key that was desired. Being free from the terrors impressed by sight, she played in the three principal keys on their respective boards with nearly the saem ease as on an ordinary instrument ; the difficulties being limited to occasional demand for the unusual form of a Dissonance, which she readily connected with the Consonance to which it owed its rise. Doubts were felt whether it would be agreable to her to be asked to classify the sounds under the denominations of white and black ; but on the inquiry being made through her attendant, wonder was expressed that there should have been any hesitation, and she was soon able to correct the teacher if an error was made in the colour of a note. As shown in the Plate, means were taken for rendering tangible the differences among the coloured notes ; but she never had recourse to them. Advancing from one key to another with exemplary energy and patience, after literally only six lessons, and without having the advantage of having the instrument to practise on between, she gave two performances of sacred musics by advertisement in the Times of 17th July following. It was plain that, after an acquaintance with leading principles, she went mainly by the ear, changing from one manual to another when wrong, as a performer on the violin would amend a faulty fingering. She showed a delight in difficulties, nothing pleasing her so much as playing on two boards at once with two hands ; which, as the boards were not alike, was something like playing two games at chess. The evidence of practicability (which was all that was claimed in the advertisement) was undeniable.
I am, Gentlemen, yours, &c.
T. PERRONET THOMPSON.
Elliot Vale, Blackheath, March 10, 1858.