these moorland mills held their own for more than half a century against their big-town rivals, many finding a niche for themselves, as mainline competition increased, by developing as cotton-waste spinners. this involved recycling the inner core of yarn cops, which had been stiffened in manufacture by the application of starch paste to avoid the need for separate wooden bobbins. during the cotton famine caused by the american civil war these waste mills actually experienced a boom.