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
Spinning mule end. In the 1920s much attention was given to this problem. Mules had used this mixture since the 1880s, and cotton mules ran faster and hotter than the other mules, and needed more frequent oiling. The solution was to make it a statutory requirement to only use vegetable oil or white mineral oils, which were believed to be non-carcinogens. By then cotton mules had been superseded by the ring frame and the industry was contracting, so it was never established whether these measures were effective. Spinning mule The spinning mule is a machine used to spin cotton and other fibres.