A third cause of diversion of traffic is akin to the second; and concerns the practices in pro-rating. Much circuitous transportation is due to the existence of independent transverse lines of railway which may participate in the traffic only on condition that it move by an indirect route. This situation is best described by reference to the following diagram. Let us suppose traffic to be moving by two routes passing through points B and C, and converging on A, which last-named point might be Chicago, St. Louis, New York or any other railroad centre. Cutting these two converging lines of railway, we will suppose a tranverse line passing through B and C. Obviously the proper function of this railway is as a feeder for the through lines, each being entitled to traffic up to the half-way point, D. But over and above serving as a mere branch, this road, desirous of extending its business, has a powerful incentive to extend operations. The longer the tranverse haul, the greater becomes its pro-rating division of the through rate with the main line. Traffic from C is of no profit to the tranverse road so long as it is hauled directly to A. But if hauled from C to the same destination by way of B, the profit may be enhanced in two ways. In the first place the pro-rating distance is greater; and secondly, such traffic from C not being _naturally_ tributary to the main line B A but merely a surplus freight to be added to that already in hand, the main line A B is open to temptation to shrink its usual proportion of the through rate in order to secure the extra business. This same motive may on proper solicitation induce the other main line C A to accept traffic from B and its vicinity. The result is a greatly enhanced profit to the cross line and circuitous carriage of the goods in both directions around two sides of a triangle. Only recently in a case in Texas the Interstate Commerce Commission found that two roads thus converging on a common point were each losing to the other traffic which rightfully was tributary to its own line. In a recent case, ninety-nine per cent. of the business from Chatham to New York was moving over a route 249 miles long, when it might have gone directly only 144 miles, by pro-rating with another road.[288] Our illustrative examples are not fanciful in any degree.[289]