Note 4 — OSCAR BIE
E. E. (Ernest Edward) Kellett translation
This passage is the only one in Shakespeare where the slightest inaccuracy or looseness in the use of a technical word is to be noticed. The word “jacks” is here used carelessly, meaning the “keys,” over which of course the fingers walk, and which leap up to kiss the inward of the hand. The actual “jacks” are inside the instrument.