Broken pedal straps are the most frequent annoyance. In all modern organs there is a panel above the pedals which will come out and admit the mechanic to the bellows, straps, springs, etc.; but in some old instruments the case is made solid, in which case the workman must do his work from the bottom, turning the organ down so as to get at it. Pedal straps are easily put on; generally with screws at either end. If the pedal squeaks examine the springs or oil and change their position slightly. Examine the pulleys over which the straps work and oil or rub them on the outside with soap. Broken pedal hinges may be duplicated by any blacksmith; the ordinary hinges, such as can be bought at hardware stores, are sometimes substituted, but they rarely answer the purpose as well as the regular pedal hinge. The leather flaps over the holes in the exhausters sometimes get too tight by shrinkage so that they will not let the air escape readily, and consequently the pedals come up slowly, often making it difficult to keep the instrument sufficiently supplied with power. Simply stretch the leather flaps, being careful not to pull the tacks loose or tear the leather.
Sympathetic Vibrations.
Organs, like pianos, are subject to sympathetic vibrations. A reed fitting loosely in the reed chamber will sometimes buzz when sounded. A bit of paper under the back end of the reed will stop it. Any loose material about the instrument may cause trouble of this kind. Trace up the cause and the remedy will suggest itself.
A buzzing sound may be caused by a reed's being too tight in the reed chamber, causing the tongue to vibrate against the sides of the brass body. In some rare cases, not being firmly riveted, the tongue will move to one side, causing the same trouble. Care and pains must be taken in working with reeds, but when in this condition they must be repaired. Tap the rivet lightly with a hammer and try it; if it still does not sound clear, catch the butt of the reed (riveted end) with a pair of parallel pliers, and turn it toward the center until, when vibrating, it clears the jaws.
Tuning.
The method of tuning the organ is very simple. To flatten the tone of a reed, scrape the tongue near the butt or rivet, making it thinner at that point, which will cause it to vibrate at a slower rate. To sharpen the tone, scrape it at the point, thereby lightening the vibrating end, which will cause a more rapid rate of vibration. When a reed has been scraped or filed so thin at the point that it will bear no more scraping, it can sometimes be sharpened by bending it up and down a few times, which has a tendency to put temper in the metal. Some reeds are curved at the point purposely to secure a certain voice. Do not interfere with the proper curvature when tuning. In tuning organs, the same system and general instruction given for piano tuning will apply; however, it is rarely, if ever, necessary to give an organ as thorough tuning as you would a piano. It is a very tedious job where you have to draw each reed, apply the proper method, insert it and try the result, thus cutting and trying each one perhaps several times before getting the desired result. In factories devices are used which render the operation very much easier.
One thing you should know is, that organs are not tempered as finely as pianos, nor is there the pains taken to secure perfect unisons. In fact, you can hardly find a perfect unison in an organ of modern make, much less, a correct temperament. Finding a tone that is so far out as to be very disagreeable, adjust it between the octave below and the octave above, try it in the proper chords and equalize it in the best possible way; but it is not often you will be able to tune it to absolute precision with its octaves. It is thought by many that a slight deviation from correct unisons, sufficient to give a series of waves, gives the organ a more mellow voice and consequently a more musical (?) tone; and while we do not agree with any such proposition, it makes the tuner's work less exacting.
We feel that an apology is in order for not giving illustrations of the action of the organ, but if the student will study this lesson in connection with the instrument itself, we believe he will have no trouble in learning all about its mechanical action and its demands upon the tuner.
QUESTIONS ON LESSON XVI.
- Name the musical advantages possessed by the organ which are absent in the piano.
- Name the musical advantages possessed by the piano which are absent in the organ.
- Describe the mechanical operations taking place in the organ when a key is being sounded.
- State what you would do to flatten the tone of a reed and give reasons.
- State what you would do to sharpen the tone of a reed and give reasons.