Organ

Turning to the reeds we see the same rule of balance and ex pansion working itself out. As soon as an organ is large enough to contain either a tuba or Great trumpets i6ft., 8ft. and 4ft., there enters inevitably a heavy-pressure Pedal trombone, ophicleide or bombarde i6ft. Any further increase of powerful reed tone on the manuals is met by enlisting the aid of the Pedal contra (bombarde) 32ft., the clarion or octave (trombone) 8ft. and occasionally the octave clarion 4ft. A well equipped Pedal Organ would also have one or two lighter reeds such as cor anglais, clarinet, waldhorn and bassoon, "borrowed" from the manuals.

Windchest.

If we may regard all intermediary mechanisms which join the fingers of the organist with the sounding of the pipes as links in a chain, the first "link" claiming our attention is the windchest.

Now, a windchest has this double function: on the one hand it carries the pipes themselves ; on the other it contains within it an apparatus for distributing wind to these pipes. (Each chest carries not more than nine stops.) In shape it is a box of thick pine about 8ft. long X 91in. deep, divided into as many longitudi nal compartments as there are stops to be accommodated. Over its top surface (called the "table") are the "upperboards" on which the pipes stand. Over the upper boards and raised about 41" above them are the rackboards which keep the pipes in an upright position. Fig. 2 shows a form of windchest, which has already enjoyed a wide vogue in the United States having been largely popularized by the Skinner Organ Co., of Boston, Mass. For the sake of simplicity it has been thought desirable to indicate one key action and one stop action only—e.g., tenor F. and open diapason; but the reader must imagine the same mechanism multi plied to the extent of II stops X 6i times. The raison d'etre of all windchests is the same—to enable the pipes to sound when the pallets below them have collapsed and have allowed the wind to flow through the orifices commanded by the pallets. This point is stressed, because it should be stated that what has been described is known as a modern "sliderless" chest (for the obsolescent "slider" windchest, see the Bibliography).

Relay Machine.

After the itself comes the relay machine, which may be looked upon as the next link in our "chain." This serves to keep the key channels charged with pres sure-wind, or to open the same to the atmosphere when the keys are pressed; also it is the place where the pneumatic portion of the "chain" joins the electric, and one motive force is substituted for another. Its component elements are as illustrated.

To each of the longitudinal stop channels in the windchest is attached an exactly similar apparatus; so that henceforward both key and stop "chains" continue in the form of electric wires from the magnets as shown in the illustration. These wires may be regarded as the third link in the "chain." Console.—At the other end of the "chain" is the console or composite keyboard at which the organist sits. Here the "chain" terminates in the outward and visible keys, stop-knobs and other accessories, used by the player to control the organ. In the United States scarcely two builders work to the same plan of console, and as a result hardly two consoles are alike. Fig. 4 shows a typical English model of dignified and not unprogressive design. This would consist of 2-5 manuals according to the number of sec tional organs, and a radiating-concave pedal clavier lying about 31 inches under the surface of the lowest manual. By English convention the Choir manual is the lowest, the Great the next, the Swell the third, the Solo (or Orchestral) the fourth, and the Echo (or Bombarde) the topmost. The stop-knobs are shown pro jecting from the jambs to right and left of the console. On the face of each knob is engraved the name of the particular stop and its approximate pitch-length in terms of feet—e.g., clarinet 8ft , twelfth, 2ift., Bourdon i6ft.—so that a moderate knowledge of technical nomenclature combined with the habit of seizing the meaning of such figures on the stop handles will be found to suffice as a key to the complexities of all consoles. The stop-knobs controlling the various sectional organs are, of course, grouped together systematically so as to avoid any confusion, and in a 5-manual organ would be disposed thus : Left Jamb. Right Jamb.

Swell Organ. Great Organ.

Solo (or Or Organ. Pedal Organ.

Bombarde (or Echo) Organ. Choir Organ.

Over the top manual are ranged the ivory tilting-tablets, which operate the couplers. These provide for the coupling of almost any one clavier to another, at unison (8ft.) pitch, and also at sub-unison (i6ft.) and octave (4ft.). Moreover, any manual except the Great may be duplicated on itself at sub-octave and octave pitches. Sometimes too there is a "unison silent" coupler which cuts out the 8ft. pitch of every stop drawn on the manual in question. Only the Great Organ remains constant, except as against the Pedal to which all manuals can be coupled.