A woman attends the high speed warping machines at the Pepperell Mills, Biddeford, circa 1925. The yarn is being taken from the small spindles and wound onto the giant spool directly in front of the woman, which was called a beam. Warping was one of the final steps in producing yarn, which would then be woven into cloth. Warp is the name for the threads that run vertically (length-wise) in cotton fabric.