The advance described implies the introduction of barter. The maker of weaponshas to be paid in such other articles as he agrees to take. Now he will nothabitually exchange for one kind of article. He does not want mats only,or skins, or fishing-gear. He wants all these, and on each occasion willbargain for the particular things he then most needs. What follows? If amongthe members of the tribe there exist any slight differences of skill in themanufacture of these various things the weapon-maker will take from eachone the thing which that one excels in making. But he who has bartered awayhis mats or his fishing-gear, must make other mats or fishing-gear for himself;and in so doing must, in some degree, further develop his aptitude. If suchtransactions are repeated, these specializations may become appreciable.
And whether or not there ensue distinct differentiations of other individualsinto makers of particular articles, it is clear that the one original causeproduces not only the first dual effect, but a number of secondary dual effects,like in kind but minor in degree. This process, of which traces may be seenamong groups of schoolboys, cannot well produce a lasting distribution offunctions in an unsettled tribe; but where there grows up a fixed and multiplyingcommunity, it will become permanent, and increase with each generation. Anaddition to the number of citizens, involving a greater demand for everycommodity, intensifies the functional activity of each specialized personor class; and this renders the specialization more definite where it exists,and establishes it where it is nascent. By increasing the pressure on themeans of subsistence, a larger population again augments these results; sinceevery individual is forced more and more to confine himself to that whichhe can do best, and by which he can gain most. And this industrial progressopens the way for further growth of population, which reacts as before. Underthe same stimuli new occupations arise. Among competing workers, some discoverbetter processes or better materials. The substitution of bronze for stoneentails on him who first makes it a great increase of demand -- so greatan increase that presently all his time is occupied in making the bronzefor the articles he sells, and he is obliged to depute the fashioning ofthese articles to others; so that eventually the making of bronze, thus differentiatedfrom a pre-existing occupation, becomes an occupation by itself. But nowmark the ramified changes which follow this change. Bronze soon replacesstone not only in the articles it was first used for, but in many others;and so affects the manufacture of them. Further, it affects the processeswhich such improved utensils subserve, and the resulting products -- modifiesbuildings, carvings, dress, personal decorations. And all these changes reacton the people-increase their manipulative skill, their intelligence, theircomfort-refine their habits and tastes.
This increasing social heterogeneity that results from the productionof many effects by one cause, cannot of Course be followed out. But leavingthe intermediate phases of social development, let us take an illustrationfrom its passing phase. To trace the effects of steampower, in its manifoldapplications to mining, navigation, and manufactures, would carry us intounmanageable detail. Let us confine ourselves to the latest embodiment ofsteam-power -- the locomotive engine. This, as the proximate cause of ourrailway-system, has changed the face of the country, the course of trade,and the habits of the people. Consider, first, the complicated sets of changesthat precede the making of every railway -- the provisional arrangements,the meetings, the registration, the trial-section, the parliamentary survey,the lithographed plans, the books of reference, the local deposits and notices,the application to Parliament, the passing Standing-Orders Committee, thefirst, second, and third readings: each of which brief heads indicates amultiplicity of transactions, and a further development of sundry occupations,(as those of engineers, surveyors, lithographers, parliamentary agents, share-brokers,)and the creation of sundry others (as those of traffic-takers, reference-makers).
Consider, next, the yet more marked changes implied in railway construction-- the cuttings, embankings, tunnellings, diversions of roads; the buildingof bridges, viaducts, and stations; the laying down of ballast, sleepers,and rails; the making of engines, tenders, carriages, and wagons: which processes,acting upon numerous trades, increase the importation of timber, the quarryingof stone, the manufacture of iron, the mining of coal, the burning of bricks;institute a variety of special manufactures weekly advertised in the RailwayTimes; and call into being some new classes of workers-drivers, stokers,cleaners, plate-layers, signalmen. Then come the changes, more numerous andinvolved still, which railways in action produce on the community at large.
