5593. MUSIC, Keeping time.—
Monsieur Renaudin's invention for determining the true
time of the musical movements, Largo, Adagio,
&c. * * * has been examined by the
[Paris] Academy of Music, who are so well
satisfied of its utility, that they have ordered
all music which shall be printed here, in future,
to have the movements numbered in
correspondence with this plexi-chronometer.
* * * The instrument is useful, but still it
may be greatly simplified. I got him to make
me one, and having fixed a pendulum vibrating
seconds, I tried by that the vibrations of
his pendulum, according to the several movements.
I find the pendulum regulated to
| Largo |
vibrates |
52 |
times
in a
minute |
| Adagio |
60 |
| Andante |
70 |
| Allegro |
95 |
| Presto |
135 |
Every one, therefore, may make a chronometer adapted to his instrument. For a harpsichord,
the following occurs to me: In the
wall of your chamber, over the instrument,
drive five little brads, as 1, 2, 3, 4, 5, in the
following manner. Take a string with a bob
to it, of such length, as that hung on No. 1,
it shall vibrate fifty-two times in a minute.
Then proceed by trial to drive number No. 2,
at such a distance, that drawing the loop of
the string to that, the part remaining between
1 and the bob, shall vibrate sixty times in a
minute. Fix the third for seventy vibrations,
&c.; the chord always hanging over No. 1,
as the centre of vibration. A person, playing
on the violin, may fix this on his music stand.
A pendulum, thrown into vibration, will continue
in motion long enough to give you the
time of your piece.—
To Francis Hopkinson. Washington ed. i, 504.
(P.
1786)
