Sarehole Mill is the last surviving mill of the 50 water mills that existed in Birmingham at one time. Sarehole has been used not only for corn grinding but also for metal trades such as sharpening tools, wire drawing and metal rolling. Until the late 19th century, many industrial workplaces were powered by water wheels. Waterpower was used in the processing of wool, iron, needles, silk and cotton in factories around the country. Many of Birmingham's water mills were used for industrial work. The names of roads and districts are evidence of this, for example, Thimble Mill Road, Pebble Mill, Hay Mills.