1911 Encyclopædia Britannica/Rowel

ROWEL (from O. Fr. rouel or roel, dim. of roue, Lat. rota, wheel), the name of the small revolving wheel or disk with radiating points forming the termination of a rider’s spur. The earliest rowels probably did not revolve but were fixed. They appear on monuments of the 13th century, as in the great seal of Henry III. of England, but the older “prick” spurs remained the standard form till the 14th century (see Spur). In veterinary science, the word is used of a small disk of leather or other material used as a seton.