The war was responsible for great changes in the system of purchasing food from overseas. Formerly practically all food was obtained through private channels and was financed through the ordinary machinery of international trade. World-famed markets were established in London or the provinces through which vast quantities of food passed for consumption in this country and which also carried on an extensive entrepot trade. The Baltic Exchange, Mincing Lane, the London Commercial Sale Rooms, the General Produce Brokers’ Association of London and many specialized associations concerned with commodities such as tea, coffee, cocoa, sugar or copra helped to make London the centre of the world’s trade in food. The commissions, brokerages and payments for financial services, which were earned in connection with the food import and re-export trades, made an important contribution to Britain’s invisible exports.