"The spinning mule is a machine used to spin cotton and other fibres. They were used extensively from the late 18th to the early 20th century. Mules were worked in pairs by a minder, with the help of two boys: the little piecer and the big or side piecer. The carriage carried up to 1,320 spindles and could be 150 feet long, and would move forward and back a distance of 5 feet four times a minute. The mule was the most common spinning machine from 1790 until about 1900 and was still used for fine yarns until the early 1980s." (Wikipedia)