Which of the following are not raw materials that were important in the Second Industrial Revolution? Think carefully - make sure you understand what is/is not a "raw material." #ThatsSoRaw Merchant ships, telegraph electricity, steel mills, air brakes, knuckle couplers on the railroads. Rubber, oil, food, and copper (metals) Water power, harbors, rivers. Coal, iron, oil, copper rubber, palm oil, cotton tea, coffee, and food stuffs.