This is cotton gin from the colonial history. In 1794, U.S.-born inventor Eli Whitney patented the cotton gin, a machine that revolutionized the production of cotton. Mostly by greatly speeding up the process of removing seeds from cotton fiber. For his work, he is credited as a pioneer of American manufacturing.
In Bill Gates’ vision of the classrooms of the future, students are grouped according to skill set. One cluster huddles around a computer terminal, playing an educational game or working on a simulator. Another works with a human teacher getting direct instruction, while another gets a digital lesson delivered from their teacher’s avatar.