METRONOME, from μέτρον, measure, and νόμος, rule,
a pendulum which marks the times of music by the slow-
ness or quickness of its oscillations. An instrument of
this kind was contrived in France in 1698, and several
others followed; but the one which has obtained the pre-
ference was constructed in 1812 by the celebrated mechani-
cian J. N. Maelzel, inventor of the panharmonicon, the
automaton-trumpeter, &c., and who died in America in
August 1838, aged sixty-six. The invention of the me-
chanical principle of this metronome was publicly and suc-
cessfully claimed by Winkel of Amsterdam; it being
proved that Maelzel had contrived only the scale of num-
bers applied to the pendulum. The mechanism consists of
a vertical rod of steel, which is made to oscillate by clock-
work, and of which the oscillations are rendered slower or
quicker by means of a weight that slides up and down upon
the rod. A scale of numbers, from 50 to 160, but with
omissions, e.g., 50, 52, 54, &c., is placed behind the rod or
pendulum; 50 representing the greatest degree of slow-
ness, and 160 the greatest degree of quickness of the oscil-
lations in one minute of time. The number 60 will thus
represent 60 seconds, and all the other numbers, from 50
to 160, so many fractional parts of a minute; the minute
being the integer to which all these subdivisions must be
referred. The sliding-weight is raised or lowered upon the
rod, so that the oscillations of the pendulum may corres-
pond with this or that number indicated upon the scale;
each audible beat or tick of the pendulum forming a frac-
tional part of the minute, but not the two beats produced
by the pendulum's motion from one side to the other. The
musical notes used in manuscript or printed music, along
with the numbers of the metronome scale, to indicate the
time of a piece of music, are in general a quaver for
an adagio movement, a crotchet for an andante, a minim
for an allegro, a semibreve for a presto. For example:
adagio, Maelzel's metronome . It is very desirable
that composers should always affix metronome numbers to
their compositions. In the latest metronomes the scale
ranges from 40 to 208. (See MOVEMENT.) (G. F. G.)