An International Correspondence Schools-style instruction paper (Serial 491, Section 56) explaining the construction and operation of the plain power loom, as used for cotton weaving in the early 1900s. It covers the three primary motions (shedding by cams, picking with the cone pick, beating up with the lay) and the auxiliary motions: let-offs (Bartlett and Morton), take-up, filling stop-motion, brake, temples, shuttle protector and loose reed. It ends with practical notes on loom drive, power requirements and calculations for take-up change gears and loom production. Illustrated with line drawings of mechanisms and cam constructions.