That which makes possible the low freight rate of the American railroads is the magnitude of the scale upon which the transportation is conducted. The large cars, with a capacity of from thirty to fifty tons, and the powerful locomotives that draw a score or more of these loaded cars in one train, permit an almost infinitesimal freight charge per pound or per yard that, however, yields by the carload or by the trainload no inconsiderable revenue. For example, the average weight of the carload of food products is about 30,000 pounds. If the freight on such a carload be $300 the rate per pound would be only one cent, and there is scarcely a commodity upon which a freight rate of one cent per pound makes any difference in the retail price. As a matter of fact a carload of food products does not bring to the railroad so much revenue as $300 unless it has been moved from a far region; for instance, from the Dakotas or Texas to New York. Specific complaint in regard to the freight rates of the United States for many years has not, except in a small minority of cases, been based on the ground that they have prevented foodstuffs from finding a market, raw material from reaching places of manufacture, or finished products from distribution. While the difference of a cent or two in the rate of freight may not in the least interfere with the conduct of industry or commerce in the aggregate, such a slight difference, may perhaps determine whether a manufacturer obtain his raw material from this or that source of supply, whether a wholesale dealer obtain his stock from the manufacturer in one, or the manufacturer in another city, whether a retail dealer make his purchases from the wholesale dealer in this city or in that city. That is, for example, the prices of the products at the sources of supply being equal, a difference in the rate of freight may determine whether Cleveland, Ohio, obtain potatoes from Michigan or from upper New York; whether a factory in Louisville obtain coal from the fields of southern Indiana or central Kentucky. A carpenter in Des Moines may perhaps pay a dollar for twenty pounds of nails without knowing or caring what the freight rate may have been, or where they may have come from. A difference, however, of a few cents a hundred pounds in the rate of freight may have led the hardware dealer to have purchased the nails in Chicago or St. Louis or even directly from Pittsburg.