These improvements have not been solely or mainly for the benefit of the carriers, though there is no question that they have been prompted by railway self-interest. The new car of 40 tons capacity is but 20% longer than the old car of 13 tons, which means a great augmentation of the efficiency of the private sidings and tracks of the manufacturers, as well as the side tracks and terminals of the railway. Who would retrace the steps of progress of the last decade or of the last two decades? Yet the project to tie railway earnings to replacement cost, which makes no allowance for the costly steps in such progress, is in reality a project to tie them to their present state of development and to prohibit future progress. Nor can it be forgotten that it is an inviolable law of Nature that that which does not go forward must go backward—nothing can remain stationary. The story of the crude millionaire who wanted to know the value of the "plant" of Oxford University, in order that he might duplicate it, is not inappropriate, and ought to have some significance to those who imagine that replacement cost would tell the story of railway values. Do they imagine, because they are ignorant of them, that a great railway organization carries no traditions of loyalty, of persistence in the face of overwhelming difficulty, of generous recognition of public needs and rights, of courageous adherence to the real interests of its shareholders that inspire its personnel and provide a genuine _esprit du corps_? Do they find no superiority in one organization over another, no systematic economies of method, no especial adaptation to economic needs that has value more genuine than any replaceable element, and is at least equally worthy of compensatory return? TABLE 12.—CLASSIFICATION OF FREIGHT EQUIPMENT ACCORDING TO THE CAPACITY.