Quarter-tones (Gr. diesis), in Music, were the subject of much discussion among the ancient Greeks, but they were used on the lyre for an occasional “grace-note.” Aristoxenos says “no voice could sing three of them in succession, neither can the singer sing less than the quarter-tone correctly, nor the hearer judge of it.” (Consult Chappell’s Hist. of Music.)

Fig. 568. Royal Arms of England, temp. Edward III., quartered with the fleur-de-lys of France.

Quartering, Her. Marshalling two or more coats of arms in the different quarters of the same shield. (Fig. [568].)

Quartet, Quartetto, It. A piece of music for four performers, each of whose parts is obligato, i. e. essential to the music.

Quartile. In Astronomy, distant from each other 90 degrees, or a quarter of a circle.

Quasillum (dimin. of Qualus, q.v.) was a small basket in which the quantity of wool was measured, which was assigned to a slave to spin in a day’s work.

Fig. 569. Quatrefoil.

Quatrefoil. An ornament in pointed architecture consisting of four foils. The term is likewise applied to a rosace formed of four divisions, which figures frequently in the upper part of pointed windows.