require this critical hint from the master to remind beginners that under the term "Great Organ" is still often allowed a suitable omission of certain reeds and "screamers," and that a but partial use of groups of stops in accordance with the character of the piece to be played is not excluded. (See also Combinations of Stops.)

H.

Harmonia Etheria. See Harmonica.

Harmonica, a very tender 8-ft. string-tone stop of narrow scale, intonated between Æolina and Salicional, is a delicate solo voice usually placed on the third manual in large organs (Frankfort-on-the-Main, Ulm, Leipsic, Lucerne). In Frankfort-on-the-Oder it occurs under the name Flöte-Harmonica, 8 ft., and in Canterbury under that of Harmonica Flute, 4 ft. It combines splendidly with Bourdonecho. It must not be confounded with Physharmonica (q.v.), nor with the mixtures Progressio Harmonica (Lübeck, Grafenrheinfeld, Merseburg) and Harmonia Ætheria (ex. Echo Organ of the cathedral organ, Riga, and Nicolaikirche, Leipsic), both of which are arranged as particularly delicate mixtures on the upper manuals. (See Reed Stops for the so-called chemical Harmonica, so important for acoustical experiments on the generation of tone in organ pipes.)

Harmonica Bass. An exceedingly delicate, softly stringtoned, 16-ft. wooden pedal stop, corresponding in strength to the softly voiced Salicet-Bass, or 16-ft. Salicional (q.v.), on the pedals. As solo or in combination with 16-ft.

Sub-Bass (q.v.) it is specially suitable for the accompaniment of soft passages. A fine specimen is that, for instance, in the Catholic Church at Berne.

Harmonica Flute. See Harmonica.

Harmonic Flute, Flûte Harmonique, is, briefly, an overblowing Flute of the nature of our Flauto Traverso, very frequently arranged as 4-ft. stop (q.v.), in which case it is called Flûte Traversière Harmonique. On account of its over-blowing, it is also frequently called Flûte Octaviante, Trompette Harmonique, Flageolet Harmonique, etc. It will be seen from the arrangement of French organs of what value the French consider these Jeux Harmoniques, based upon the utilization of harmonic tones. The Jeux Harmoniques frequently represent one-sixth of all the stops. Further scientific notes on the subject, in which special attention is given to French organ-building, are to be found on p. 75 and the following of Adrien de la Fage's "Report to the Société des Beaux-Arts, Paris." In that most magnificent organ for Sydney, now in course of building at W. Hill and Son's works, London, the largest ever built for any English colony, the Harmonic Flutes and Trumpets are ingeniously incorporated in the tremendous army of 126 speaking stops. This English organ will certainly be one of the most remarkable, both as regards tone and mechanical requirements. (See also Trombone.)

Friedrich Ladegast, builder of the Nicolai organ, Leipsic, writes on the subject of the harmonic tones of pipes (Töpfer, vol. ii. § 619): “It is known that these tones have a power and fullness which can never be obtained by ordinary pipes speaking in the foundation tone only. The air column of such pipes as give harmonic tones is divided into two, three, four, or more vibrating sections. The tone

D

improves in quality, and may be strengthened without becoming shrill, and the whole stop receives uniformity." This reminds me also of the apparatus which Dienel found in the workshops of Cavaillé-Coll, and which he described in the Urania for 1878, No. 12. This apparatus demonstrates the effect of harmonics on the foundation tone, and gives a clear list of the names of harmonic tones, the number of sound-waves per second, and the metrical length of the waves. Compare König's apparatus, described by Pietro Blaserna of Rome on p. 211, Fig. 36, which is based on the principle of Helmholtz's resonators. By means of his eight resonators, each of which acts through an elastic membrane on easily affected gas-flames, it may be proved (1) that all musical instruments have harmonic tones, and (2) which these harmonic tones are. (See also Tone Colour.) Harmonic Trumpet. See Harmonic Flute.

Harmonics. See Harmonic Flute, Geigenprincipal, Tone Colour, Mixture, Octave, and Quint.

Harmonium. See Physharmonica.
Hautbois. See Oboe.

Hohlflöte (hollow-tone flute). An open, wide-scale wood stop of a round, rather colourless fluty tone, generally as 2-ft., 4-ft., and 8-ft. tone on the manuals, and arranged as Quint stop, labelled Quintflute, Hohlquint (hollow quint), of 51-ft., 2-ft., and 13-ft. tone. It occurs also as 1-ft. Sifflöte and as 16-ft. Grosshohlflöte. As a particularly rare specimen I found this stop in Ulm Münster as a 2-ft. pedal stop, where, combined with other stops on the upper pedal, it gives, without need of any coupler, a power of expression belonging almost exclusively to the manuals. To explain the term upper pedal," I must say that at Ulm, as well as in the church of St. Paul, Frankfort-on-the-Main,

in the Marienkirche, Lübeck, and in the Stiftskirche, Stuttgart, there are two pedals placed one above the other (like the manuals) instead of the customary single pedal. This arrangement has been superseded by the present convenient composition and combination pedals. Hohlflöte with Gamba give a felicitous, somewhat horn-like combination.

Horn. An 8-ft. reed, intonated between Bassoon and Trumpet (Sydney), frequently resembling the English Horn (q.v.).

I.

Intonation. (From the Latin intonare, to resound, or, in a transitive sense, to cause to sound.) Intonation (the real art in organ-building, unfortunately so often treated as a minor consideration, and also paid as such) is a term which occurs frequently in this work in the articles both on Flues and on Reeds, and which I will therefore endeavour to define by a very few words. The intonation of an organ is one of the most important operations, because the tone (in the proper sense of the word) of the instrument depends upon it. The whole instrument may be very well built, the pipes may be of very good material and very accurately executed, and yet one may not be able to call the organ very excellent, if the effect of each single tone, as well as of the general tone, does not correspond with the faultlessness of the rest of the work. The result of a masterly intonation is: (1) the correct character for each species of pipe; (2) an easy and ready speech. Töpfer (vol. i. § 1160) expresses himself happily: "It is

generally much more difficult to combine good speech with good tone, than to separate them; it is, therefore, easier to obtain a good tone if one is satisfied with slower articulation." Gamba and Salicional, for instance, offer an eloquent proof of the progress made in articulation and intonation generally. (See Frein Harmonique.) (3) The possibility of giving the pipe a colouring of tone suitable to its character and denomination (see, for instance, Trumpet, Flauto Traverso, Oboe); (4) the careful equalizing, in all registers, of the degree of sound to suit the building; and (5) the proper temperament (see Octave), and thoroughly complete tuning of the organ, which should more correctly come under the head of tuning. (See also Tone Colour and Reed Stops.)

J.

Jeux de Fonds. See Shut-off Valve.

Jubal Flute. (Called after Jubal, the father of music in the Old Testament, Genesis iv.) A double-lipped powerful Flute, sounding open and bright, similar to the Double Flute, which is also double-lipped. I found this stop on the first manual in St. Paul's Church, Frankfort-on-theMain; and, labelled Double Flute (q.v.), as 8-ft. stopseldom as 4-ft. or 2-ft. stop-on some of Weigle's instruments. As already remarked with regard to the Double Flute, the Jubal Flute has an enlivening effect, if combined with a fine string-tone stop.