Page:Encyclopædia Britannica, Ninth Edition, v. 17.djvu/896

Rh 830 ORGAN of the figures such as 16, 8, 4, on the stop -handles, will frequently suffice as a key to the complexities of a foreign organ. Manuals. Each of the manuals, or rows of keys, of an organ con stitutes a separate organ, which is more or less complete in itself. The names of the different manuals or organs are (treat organ, swell organ, choir organ, and solo organ, The fifth manual, where it occurs, is the echo organ. The above is the usual order in point of development and frequency of occurrence, although the solo is sometimes preferred to the choir organ, The great organ is in a certain sense the principal department of the organ. It may be regarded as formed by a completely developed series of those funda mental stops which constitute the solid basis of the tone of the instrument. If an instrument be constructed with only a single manual this necessarily assumes, in general, the characteristics of a great organ. The great organ is called &quot;grande orgue&quot; in French, and first manual or &quot;haupt- werk &quot; in German. It is proposed to describe the principal organ-stops under the heads of the manuals to which they belong. The enumeration will not be exhaustive, but will include all the usual types. Great The great organ commences generally with stops of orgau. 16-foot length or tone in large instruments. In some cases a 32-foot sounding stop is introduced, but this cannot be said to be a proper characteristic of the great organ. The foundation tone is of 8 feet ; the stops of higher pitch serve to add brilliancy ; those of 1 6 feet, which sound the octave below the normal pitch, serve to add gravity and weight to the tone. Sixteen -foot stops are commonly spoken of as &quot;doubles,&quot; their conventional length being twice that of stops of normal pitch. The 16-foot stops are the 16 double open diapason, and the 16 bourdon or double stopped diapason, to which, in very large instruments, there may be added a 16 double trumpet. The double open diapason on the great organ consists usually of metal pipes, having moderate &quot; scale &quot; or transverse dimensions. These are of the same general character as the pipes of the ordinary open diapason, though they are made somewhat less powerful. In the better instruments of the second class as to size this stop alone would probably be regarded as representing suitably and sufficiently the class of doubles on the great organ, It gives great body to the general tone, and appears de cidedly preferable to the bourdon, which frequently takes its place, The 16 double dulciana may be regarded as a variation of the double open diapason. It is sometimes used where the full effect of a double open is not considered desirable. It possesses the light and not full tone of the dulciana. It does not appear to be peculiarly suitable for the purposes of a double. The 16 bourdon or double stopped diapason, when used on the great organ, is made of rather small scale and light tone. It gives great body to a large great organ, and affords interesting combinations with other stops, such as the 4-foot flute. It is used either alone in smaller organs of the second class or in addition to a double open in larger instruments. The notes are produced from wooden pipes of rectangular section, stopped at the end, and having half the conventional length, The 16 double trumpet is a trumpet (large reed stop) sounding the octave below the normal pitch. It is used generally in instruments of the largest size, but is some what more common in Germany, It is useful in giving a massive character to the tone of the full great organ, which is otherwise apt to become disagreeable on account of the great development of stops of a piercing character. If, however, the double trumpet is rough in tone, it is apt to communicate to the whole a corresponding impression. The judicious balancing of such elements as the double trumpet and the piercing stops such as mixtures is one of the principal features of a good German great organ. We now proceed to the 8-foot stops (the reeds come at Great the end according to ordinary usage). An ordinary great organ organ may contain 8 stopped diapason, 8 open diapason 8 feet- (one or more), 8 gamba, and 8 hohlflote. The 8 stopped diapason on the great organ is usually of wood, of mode rate scale, and some considerable fulness of tone. The actual lengths are about half the conventional lengths. These pipes are sometimes made of metal. Few stops admit of more variety and individuality in their quality of tone than the stopped diapason ; but too frequently the great organ stopped diapason fails to attract attention on its merits, being regarded simply as an inconsiderable por tion of the foundation tone. If there is any one stop which in itself represents the organ as a whole it is the open diapason. The pipes of this stop are the typical metal pipes which have always been characteristic of the appearance of the organ. A single open diapason stop is capable of being used as an organ of sufficient power for many purposes, though of course without variety. The pipes of this stop are called &quot; principal &quot; in German, this appellation apparently corre sponding to the fact that they are the true and original organ-pipes. The English appellation of &quot; diapason &quot; has been taken to mean that these are the normal pipes which run through the whole compass. This, however, does not appear to be the actual derivation of the term ; originally it is technically applied to the organ-builder s rule, which gives the dimensions of pipes ; and it appears that the application to the stop followed on this meaning. The scales, character, and voicing of the open diapason vary with fashion, and are different in different countries. We may distinguish three principal types. The old English diapasons of the days before the introduction of pedal organs into England were characterized by a rich sweet tone, and were not very powerful. They were generally voiced on a light wind, having a pressure equivalent to that of a column of water of from 2 to 2| inches. The scale was in some cases very large, as in Green s two open diapasons in the old organ at St George s, Windsor ; in these the wind was light and the tone very soft, In other cases the scale was smaller and the voicing bolder, as in Father Smith s original diapasons in St Paul s Cathedral, But on the whole the old English diapasons presented a lovely quality of tone. English travellers of those days, accustomed to these diapasons, usually found foreign organs harsh, noisy, and uninterest ing. And there are many still in England who, while recognizing the necessity of a firmer diapason tone in view of the introduction of the heavy pedal bass, and the corresponding strengthening of the upper departments of the organ tone, lament the disappearance of the old diapason tone. However, it is possible with care to obtain diapasons presenting the sweet characteristics of the old English tone, combined with sufficient fulness and power to form a sound general foundation. And there can be no doubt that this should be one of the chief points to be kept in view in organ design. The German diapason was of an entirely different character from the English. The heavy bass of the pedals has been an essential characteristic of the German organ for at least two or three centuries, or, as it is said, for four. The development of the piercing stops of high pitch was equally general. Thus foundation work of comparatively great power was required to maintain the balance of tone ; the ordinary German diapason was very loud, and we may almost say coarse, in its tone when compared with the old English diapason. The German