In one way the persistence of locally high rates in the South and West, irrespective of the low charges at competitive points, is defensible on the ground that local business is scanty.[244] The roads cannot live upon it. Their mainstay is the long-distance traffic from important points.[245] On the other hand, where there is no obligation to maintain a distance tariff, of course the road with rich local business enjoys a great advantage in making rates at competitive points. It can practically subsist upon its revenue from its own particular constituency, meeting all its fixed charges thereby; and can afford to cut rates on the competitive tonnage down to the bone. Such a road, quite irrespective of the length of its line, would obviously "control" the rate at competitive points, as against any rival without such a subsidiary and independent source of income.[246] Volume of traffic is another fundamental element in the determination of cost of operation. No matter how short the line or how easy its curves and grades, unless it can handle its tonnage in large bulk it will operate at a disadvantage. Hence a most important factor to be reckoned with, in deciding which of two competing lines is in a commanding position as to rates, is the volume of traffic, both in gross and as susceptible of concentration on either line. In the notable Chattanooga case, for example, although the line from New York to Nashville, passing around to the south by way of Chattanooga, is 212 miles shorter than the lines _via_ Cincinnati or Louisville, the latter, by reason of the density of traffic in trunk line territory, seem to stand at least on an even footing. On the other hand, the enjoyment of the bulk of the tonnage sometimes places its possessor at the mercy of a petty rival. The Fall River water line to New York, carrying an overwhelming preponderance of the business, obviously could not afford to cut rates to prevent the Joy Line from stealing a small portion of the traffic. The same principle holds good in other lines of business. The Standard Oil Company can better afford permanently to concede a small fraction of business to a small independent dealer, so long as he knows his place and refrains from ambition to enlarge, rather than to attempt to drive him out entirely by cutting prices on a huge volume of business. Occasionally independents are shrewd enough to take advantage of this; and so to distribute their business that they shall in no single place menace a powerful rival, and yet comfortably subsist on the gleanings over a wide area.[247] In no single locality are they important enough to exterminate, at the cost of cut rates applied to a large volume of business; and yet in the aggregate they may make quite a fair livelihood. The only difference between the status of a railway and other lines of business in this regard is that the railway may not be quite so free to deploy its forces. Its