I use a bow longer by two inches than the ordinary standard. A powerful,
heavy bow is required for four–string passages and many _tours de
force_. The bow, while elastic, should be extremely stiff, so that if
dropped upon the strings the rebounds are very rapid. It should have
weight to give force to these rebounds, as in many passages the weight
of the hand cannot be applied to assist the bow; as in the tremolo,
arpeggio, and staccato volante. In this last example the bow is thrown
upon the strings and runs its length in a series of little rebounds,
neither the fingers nor wrist having anything to do with the result. In
order to graduate, as it were, the different colors of sound, we favor
certain overtones by causing the hair to act at greater or less
distances from the bridge. The nearer we approach the bridge the more
the upper overtones, and the nearer the neck the more the lower
overtones will be favored. In the first instance, the resulting tone
resembles that of the trumpet; and in the second, that of the horn and
clarinet. With a heavy bow, in forte passages, only slight assistance is
needed from the hand. The wrist is not cramped or stiffened in producing
the pressure. In piano passages, the little finger should partially
sustain the weight, and the stick should be inclined toward the neck, so
that only part of the hairs act upon the strings.
The great stiffness and elasticity of the heavy bow gives a freer,
clearer tone than can be produced by one of a lighter and more sluggish
nature.
The length of the bow is two feet, six inches; the length of the hair
two feet, four inches. The number of hairs is about one hundred and
sixty. Half of the hairs are put in one way, the other half the other.
It is known that the hairs, as seen when magnified, have little sawlike
teeth running in one direction. By thus dividing the hairs, they present
the same friction on either the up or down stroke. The best hair is from
Normandy. It should be round and even, and not flat in places.