Abstract: The invention relates to apparatus wherein loom harnesses are operated by cams driven intermittently by respective drives rather than by cams fixed on a driven shaft. The harnesses are illustrated as being lowered by cams against yieldable resilient means tending to raise the harnesses, and the cams as being aligned with treadles carried longitudinally of the loom. Co-acting means are also provided for connecting respective chain drives at predetermined intervals to bearing members, rotatable on a fixed shaft, which carry cams fixed thereto as well as chain carrying sprockets rotatable thereon. The method contemplates operating the harnesses by timing the steps of rotating each cam in a predetermined sequence, and exerting a yielding force upon each cam tending to resist further rotation after the cam has turned on the fixed shaft through a predetermined arc.