Spinning frame stolen from) another inventor called Thomas Highs. With the help of other local craftsmen the team produced the spinning frame, which produced a stronger thread than the spinning jenny produced by James Hargreaves. The frame employed the draw rollers invented by Lewis Paul to stretch, or attenuate, the yarn. The roller spinning process starts with a thick 'string' of loose fibres called a "roving", which is passed between three pairs of rollers, each pair rotating slightly faster than the previous one. In this way it is reduced in thickness and increased in length before a strengthening twist is added by
Cotton-spinning machinery rival machine, the throstle frame or ring frame was a continuous process, where the roving was drawn twisted and wrapped in one action. The spinning mule became self-acting (automatic) in 1830s. The mule was the most common spinning machine from 1790 until about 1900, but was still used for fine yarns until the 1960s. A cotton mill in 1890 would contain over 60 mules, each with 1320 spindles. Between the years 1824 and 1830 Richard Roberts invented a mechanism that rendered all parts of the mule self-acting, regulating the rotation of the spindles during the inward run of the carriage.