ans of any
variety.

The direction in which the plectra of each row of jacks should be
pointing is not known. Two clavicytheria having two registers of strings
and a single row of double tongue jacks have been examined by the
author. Each of these jacks has two plectra, one pointing to the right
and one to the left. Turning these jacks around does not alter the order
of direction. The plectra nearest the keyboard points the same way
whether the jack is upside down or not. In the clavicytherium at the
Smithsonian Institution the plectra nearest the keyboard points to the
player's left. In a clavicytherium at the Boston Museum of Fine Arts the
opposite is true. Probably both arrangements were used in harpsichords
also.

String Lengths and Pitch Standards

The vibrating lengths of the strings of the polygonal virginal and of
the Ridolfi harpsichord can be roughly determined from the drawings. For
purposes of comparison, a tabulation of the vibrating lengths (in
inches) of the _C_ strings on both instruments follows:

_Polygonal _Harpsichord_
virginal_
c''' 6-5/8 5-1/16
c'' (pitch C) 12-15/16 10
c' (middle C) 25-9/16 20-1/2
c 43-5/16 42-1/16
C/E 50-5/6 61-1/4

The lengths shown for the harpsichord represent the shorter of the two
strings with which each key is provided.

In order to produce a uniform tone color throughout the compass of a
stringed instrument, it is necessary, among other things, to have the
tension of all the strings reasonably uniform. In the treble this is
accomplished by varying the string lengths. Since the length of a
vibrating string is inversely proportional to its frequency, each string
is made about half as long as the string an octave below, two thirds as
long as the string a fifth below, etc. This principle cannot be carried
all the way into the bass since the lowest strings would be
inconveniently long, so somewhere below middle _C_ the strings are
gradually shortened and the diameters of the wires are increased in
compensation.

As the above comparison shows, the string lengths are approximately
doubled at each descending octave down to _c'_ on the virginal and _c_
on the harpsichord. The shape of the case allows the harpsichord to have
longer bass strings than the virginal; between _c'_ and _c_ the string
length is doubled in th