Flour-milling represents one of the most highly mechanized and organized industries of modern times. The basic principles on which the processes of milling are founded are, of course, far from new. Corn was being ground on handstones or querns as far back as six thousand years ago. In the most modern mills the whole system, from the arrival of the grain at the mill to the delivery of the flour and meal in bags, is completely mechanized, and it is said that the only scope for further mechanization lies in more complete automatic control, though this is already far advanced. The location of the industry is governed primarily by transport costs, first in respect of supplies, and, secondly, of markets. Flour-milling is a processing industry rather than a manufacturing industry, and the cost of the raw material contributes about three-quarters of the value of the finished product.