The relationship is sometimes one of divergency or competition of trades. Where the same service may be supplied by two or more different commodities the trades are related by direct competition. Oil, gas, electricity, as illuminants, are a familiar example of this relationship. Many trades which produce commodities that are similar, but far from identical in character, feel this relationship very closely. The competition between various kinds of food, which with different kinds and degrees of satisfaction may produce the same substantial effects, between fish and meat, between various kinds of vegetables and drinks, enables us to realise something of the intricacy of the relations of this kind. In clothing we have antagonism of interests between the various fabrics which has led to great industrial changes. The most signal example is the rise of cotton, its triumph over woollen clothes by the earlier application of the new machinery, and over silk by the early superiority of its dyeing and printing processes.[115] So in recent years in the conflict among beverages, tea, and in a less measure cocoa, have materially damaged the growth of the coffee industry so far as English consumption is concerned. Where such rivalry exists, an industry may be as powerfully and immediately affected by a force which raises or depresses its competitor as by a force which directly affects itself. § 9. The growth of numerous and strongly-built structural attachments between different trades and markets related to different localities implies the existence of a large system of channels of communication throughout our industrial society. By the increased number and complexity of these channels connecting different markets and businesses, and relating the most distant classes of consumers, we can measure the evolution of the industrial organism. Through these channels flow the currents of modern industrial life, whose pace, length, and regularity contrast with the feeble, short, and spasmodic flow of commerce in earlier times. This advance in functional activity of distribution is thus expressed by Mr. Spencer:--"In early English times the great fairs, annual and other, formed the chief means of distribution, and remained important down to the seventeenth century, when not only villages, but even small towns, devoid of shops, were irregularly supplied by hawkers who had obtained their stocks at these gatherings. Along with increased population, larger industrial centres, and improved channels of communication, local supply became easier; and so frequent markets more and more fulfilled the purpose of infrequent fairs. Afterwards, in chief places and for chief commodities, markets themselves multiplied, becoming in some cases daily. Finally came a constant distribution, such that of some foods there is to each town an influx every morning; and of milk even more than once in the day. The transition from times when the movements of