What changes might you observe in a rock as it is weathered

It may get smaller, it may change shape, and it may also change color

A cotton gin is a machine that quickly and easily separates cotton fibers from their seeds, allowing for much greater productivity than manual cotton separation.[2] The fibers are then processed into various cotton goods such as linens, while any undamaged cotton is used largely for textiles including clothing. Seeds may be used to grow more cotton or to produce cottonseed oil.

Although simple handheld roller gins had been used in India and other countries since at earliest 500 AD,[3] the first modern mechanical cotton gin was created by American inventor Eli Whitney in 1793 and patented in 1794. However, the Indian worm-gear roller gin, invented some time around the sixteenth century,[4] has, according to Lakwete, remained virtually unchanged up to the present time. Whitney's gin used a combination of a wire screen and small wire hooks to pull the cotton through, while brushes continuously removed the loose cotton lint to prevent jams. It revolutionized the cotton industry in the United States, but also led to the growth of slavery in the American South as the demand for cotton workers rapidly increased. The invention has thus been identified as an inadvertent contributing factor to the outbreak of the American Civil War.[5] Modern automated cotton gins use multiple powered cleaning cylinders and saws, and offer far higher productivity than their hand-powered forebears. [6]