5. Give the purpose of the regulating button, and its proper
adjustment.




LESSON VI.

~REGULATING AND REPAIRING.--(Continued.)~

THE SQUARE ACTION.


1. _The key_ in the square piano is subject to the same troubles as
that of the upright, and requires the same treatment. However, the
keys being much longer are more liable to cause trouble by warping.

2. _Bottom or Key Rocker_.--Unlike in the upright action, the jack is
attached directly to the bottom; but, lowering or raising the bottom
has the same effect in both cases. The screws regulating the height of
the jack can be gotten at with a proper screwdriver. If you have to
take out the key in order to regulate the bottom, first take
particular notice of the conditions in respect to the operation of the
jack on the hammer. Work the key slowly, to discover if there is lost
motion. Decide which way the bottom must go and how far, so that you
will not have to remove and replace the key more than once or twice
to adjust it. In taking out the key, remove the board which is set
edgewise over the keys immediately back of where the fingers strike,
by taking out the screw at each end. Lift the hammer with the finger