Final Inspection.—­Always test every key on the piano, or especially those of the middle five octaves, for bad unisons.  Upon finding one, search for the string that has stood in tune, by testing each string of the unison with its octave.  This being done, simply bring the other to it.  Go over the whole key-board, striking octaves, and correct any that might offend.  One extremely bad tone or octave may disparage your reputation, when in reality your work merits commendation.

Loose Pins.—­You will occasionally find pianos in which the tuning pins have become so loose that they will not resist the pull of the strings.  If many of them are in this condition it is better, before you begin to tune, to take a hammer of considerable weight and drive them a little.  Commence at one end of the row of pins and aim to strike all the pins with the same force.  Those which are tight enough will not yield to the blow, while those which are loose may require two or three blows to tighten them sufficiently.  This defect is generally found in very old squares or cheap uprights wherein the pin-block is of poor material or defective in manufacture or in pianos which have been abused.

Split Bridges.—­Even in pianos of the highest grade, we sometimes find a string sounding as if there was a pin or some metallic substance bearing against it.  In such cases, find the string and examine the place where it crosses the bridge.  You will often find the bridge split at that point or the bridge-pin, having yielded to the pressure of the string, vibrates against the next pin, giving rise to the singing effect.  You can do little if anything toward repairing a split bridge.  You may, however, stop the singing by inserting the point of your screw-driver between the close pins and pressing them apart.  This will generally stop the difficulty for the time being at least.

Strings crossing the bridge near a split will not stand in tune well, and will, perhaps, have to be gone over two or three times.  The same may be said of a broken metal plate.  Many old squares have broken plates; generally found near the overstrung bass, or within the first octave of the treble.  All the tuner can do is to apprise the owner of the defect and inform her that it will not stand well at this point, as the intense strain is thrown largely upon the wooden frame, which will have a tendency to yield gradually to it.

Stringing.—­Strings break while the tuner is drawing them up, sometimes because he does not pull them gradually, gives them an abrupt turn or draws them too far above the pitch at which they are intended to stand.  More often, however, they break from being rusty at the point where they pass over the bridge or around the tuning pin.  The best instruction concerning putting on new strings is, follow appearances.  Make the string you put on look just like those on the instrument.  In most modern pianos the string is wound with three coils around the pin.