or some foreign substance being in the hole round the wire.  The bushing cloth in the hole may be in such condition as to retard the free passage of the damper wire, in which case the wire may be heated with a match and run up and down a few times through the hole, which will free it.  The damper may not fall readily on account of a sluggish joint in the flange.  Work it back and forth as far as it will go a few times; if necessary, take it off the damper rail and look for the cause of the trouble.

Damper flanges get loose on the damper rail and work to one side, causing defective damping and rattling.  See that they are all tight, and in their places.

Damper lifter buttons sometimes hold the damper off the string.  See that the top button falls so low that the damper lever does not touch it when the key is released.  This is accomplished by altering the lower button.  Examine the damper felts to see if they are moth-eaten, or have become hardened or in any way impaired.  Notice the adjustment of the shade; that it is not too low or too high.  The purpose of the shade is to prevent the damper levers from flying up; but it should be high enough so that the levers do not touch it when the key is depressed gently.

Defective damping is one of the most annoying conditions, and when one is employed to regulate a piano thoroughly and put it in order, he should see that no key is left in which this occurs.  Strike each key and immediately let it up to see if it stops the sound quickly, or, in other words, damps perfectly; if it does not, find the cause and regulate until satisfactory.

8. The grand action being, in principle, practically the same as that of the square and the upright, containing the same mechanism as is found in those actions, it is needless to give special instructions concerning it; as the previous work has given the pupil a thorough knowledge of the requirements of all actions, their common faults, and proper methods of regulating to bring about satisfactory results.  Let us merely remark:  Study thoroughly the behavior of every component part of each action that comes under your observation; understand what each part is for, why it is there, and how it works or should work properly to fill its office.  Then regulate and try for results.  If you have natural mechanical genius, a little experience will prepare you to do all regulating and repairing with skill and quickness.

MISCELLANEOUS REPAIRS.

A few miscellaneous difficulties, common to all styles of actions, are occasionally met with and need to be rectified.

1. Broken Hammer Shank.—­Glue the ends, lay a nicely fitting piece of wood, well coated with glue, on each side and wrap with binding wire.  If it is broken off up so close to the hammer as not to permit this, drill a hole through the hammer head in line with the center of the shank, with a small-sized screwdriver such as watchmakers use, and run the wire through this and around the shank, drawing it firm; glue as before; when dry it will be as strong as ever.  When the shank is broken off close to the butt, the same treatment will sometimes answer, but the strain here is so much greater that it is sometimes necessary to put in a new shank.  In fact, it is always better to do so.