through the holes, and are thus removed from the rotating cotton by the metal plate, before they fall into a collecting pot. On the other side of the first cylinder, there's a second cylinder, also rotating, with brushes attached. This second cylinder wipes the cotton from the first, and deposits it into the collecting bucket. The seed is reused for planting or is sent to an oil mill to be further processed into cottonseed oil and cottonseed meal. The lint cleaners again use saws and grid bars, this time to separate immature seeds and any remaining foreign matter from the fibers. The bale press then compresses the cotton into bales for storage and shipping. Modern gins can process up to 15 tonnes (33,000 lb) of cotton per hour. History A single-roller cotton gin came into use in India by the 5th century. An improvement invented in India was the two-roller gin, known as the "churka", "charki", or "wooden-worm-worked roller". Early cotton gins The earliest versions of the cotton gin consisted of a single roller made of iron or wood and a flat piece of stone or wood. The earliest evidence of the cotton gin is found in the fifth century, in the form of Buddhist paintings depicting a single-roller gin in the Ajanta Caves in western India. These early gins were difficult to use and required a great deal of skill. A narrow single roller was necessary to expel the seeds from the cotton without crushing the seeds. The design was similar to that of a mealing stone, which was used to grind grain. The early history of the cotton gin is ambiguous, because archeologists likely mistook the cotton gin's parts for other tools. Medieval India Between the 12th and 14th centuries, dual-roller gins appeared in India and China. The Indian version of the dual-roller gin was prevalent throughout the Mediterranean cotton trade by the 16th century. This mechanical device was, in some areas, driven by water power. The worm gear roller gin, which was invented in the Indian subcontinent during the early Delhi Sultanate era of the 13th to 14th centuries, came into use in the Mughal Empire sometime around the 16th century, and is still used in the Indian subcontinent through to the present day. Another innovation, the incorporation of the crank handle in the cotton gin, first appeared sometime during the late Delhi Sultanate or the early