around 1800,two kinds of cotton were grown in the unitid states.one was called upland.The other Sea Island.
Sea Island seeds were loose and smooth . They could be removed from the cotton with a plain roller frame. this worked something like an old-style clothes wringer. it was called a cotton "gin"or engine.
upland cotton had green seeds. These stuck tight to the fibers. Eli Whitney built his cotton gin to pick these seeds out.His gin had a set of disks with sawteeth.the teeth grabbed the cotton
the slots let the fibers through,but not the seeds