for coal, lime, or cement, but does not affect the rates chargeable on high-class freight which seldom goes by water in any event. A railway specially interested in the development of some particular industry, wherever it crosses our hypothetical line, effectively holds down the rate on the product of that business. Junction points with other railways having no such interest may have no influence upon that rate, but may cause modifications in other directions. Another railway being in need of back loads over its line, as the result of a predominant movement, let us say, of beef cattle at certain seasons of the year, may introduce competition in all the tonnage capable of being carried on cattle cars. Such a road holds down the rates on this traffic wherever it happens to cross, but has no effect upon any other rate. Thus it comes about in practice, as the last diagram well illustrates, that the tariff lines cross and recross one another, generally rising with increasing distance, but at all sorts of different times and places. Few generalizations are possible in this connection. Rate making must in a growing country ever be a matter of infinite detail. It is generally true, however, that beyond a certain point the tariff on different grades of commodities will separate more and more widely with increasing distance. For, obviously, after the low-grade goods have reached the maximum which they can bear--and this they tend to do speedily--they must remain practically constant; while those of higher grade continue progressively rising. And for very short distances the rate on the low-grade goods may even exceed that imposed upon higher-class tonnage. The coal rate for a ten-mile haul may exceed that upon some commodity worth twice as much; but for a 200-mile haul the coal rate may be only one-eighth of the rate on the other goods. Long experience on the part of the carriers has, however, enabled them to arrange their tonnage in classes; for each of which the conditions are more or less uniform. By reserving the exceptional traffic for special treatment under commodity rates, a fairly consistent scheme of charges, rising by stages with increasing distance may be evolved.