The over-strung bass usually has but two strings to a unison and only one mute is needed.  In the extreme low or contra-bass, pianos have but one string, in tuning which the mute is discarded.  Set the mute as indicated by the figures 1, 2, 3, etc., in the diagram below, always tuning the string farthest to the right by its octave above; then move the mute to its next place and tune the left string by the right.  Here, again, you tune two strings every time you reset your mute.  The I’s represent bass strings.

9    8    7    6    5    4    3    2    1
I   I   I   I   I   I   I   II   II   II   II   II   II   II   II   II
C  C[#] D   D[#]  E    F   F[#]  G   G[#]  A   A[#]  B  C
Contra-Bass.                               Bass.                         Treble.

SETTING THE MUTES IN THE SQUARE PIANO.

In setting the temperament in the square piano, simply mute the string farthest to the left and tune the one to the right until the temperament is finished, then set the mutes in the bass the same as in the upright.  In tuning the treble, if the piano has three strings, the same system is used as has been described for the upright.  When the piano has but two strings to a unison, as is usually the case, employ the system described for the bass of the upright, but reversed, as you are proceeding to the right instead of to the left.

Remove the shade before beginning to tune a square piano, and if necessary, lay the dampers back and trace the strings to their pins so as to mark them.  Certain pins are marked to guide the tuner in placing his hammer.  The way we have always marked them is as follows: 

Mark both pins of each pair of C strings with white crayon.  Mark only one pin of each pair of G’s.  Knowing the intervals of the other keys from the marked ones, you can easily calculate correctly, upon which pin to set your hammer to tune any string desired.  For instance, if you are striking D[#], next above middle C, you calculate that, as D[#] is the third chromatic interval from middle C, you are to set the hammer on one or the other of the pins belonging to the third pair to the right of the pair marked as middle C. B would be first pair to the left, F[#] would be first pair to the left of the marked G, and so on.  It is usually necessary to mark only those pairs near the middle of the piano, but we advise the beginner to mark throughout the scale, as by so doing he may avoid breaking a string occasionally by pulling on some other than the one he is sounding.  This will occur in your early practice if you do not use caution.  And for safety, some tuners always mark throughout.

QUESTIONS ON LESSON XI.

    1.  By what means is the tuner enabled to make the strings draw
    through the bridges and equalize the tension throughout their
    entire length?

    2.  State conditions that may result from a tuning pin’s not being
    properly set.