Increased mechanization of industry and improvements to worker efficiency, increased the productivity of factories while undercutting the need for skilled labor. Mechanical innovations such as batch and continuous processing began to become much more prominent in factories. This mechanization made some factories an assemblage of unskilled laborers performing simple and repetitive tasks under the direction of skilled foremen and engineers. In some cases, the advancement of such mechanization substituted for low-skilled workers altogether. Both the number of unskilled and skilled workers increased, as their wage rates grew Engineering colleges were established to feed the enormous demand for expertise. Together with rapid growth of small business, a new middle class was rapidly growing, especially in northern cities.