Kathleen Schlesinger, 1911 Encyclopædia Britannica (1911)
“ With use, the scales of the epithelium wear off, and then no matter how much rosin is applied, the bow fails to elicit musical sounds—it is then “played out” and must be re-haired. The organic construction of horsehair makes it necessary, in hairing the bow, to lay the hairs in opposite directions, so that the up and down strokes may be equal and a pure and even tone obtained. ”
