From what has been said it will be readily seen that transportation and marketing (selling) are a part of the process of production. Transportation can be divided into two classes: primary, transportation upon the public roads; and secondary, transportation on railroads, canals, steamboats and steamships. Marketing is likewise divided into two classes: wholesaling and retailing. The wholesaler buys goods in quantity from the manufacturer and sells them to the jobber who in turn sells them to the retailer. The jobber usually divides the larger purchased quantities into smaller or job lots in any quantity suitable to the retailer. The wholesaler and the jobber may be combined into one individual or firm. The jobber will, usually, not sell directly to the consumer; he sells only to retailers. The retailers frequently have a sort of “gentlemen’s” agreement with the jobber not to buy directly from the producer. This sort of complicated machinery often involves more expense than direct trading. After each of the transactions mentioned there is usually a change of place and a waiting in store. =Grain Exchanges.=--In the grain business there has been developed a great system of selling through commission merchants, that is, the selling agents take commissions on the sales for their remuneration. A limited number of the commission merchants of a particular city organize themselves into incorporated bodies for the purpose of providing themselves with houses and facilities for doing business and establishing rules for the transaction of the same. Such organizations with places of doing business are known as Grain Exchanges or Boards of Trade. The Board of Trade of Chicago, the most noted grain market in the world, was established in 1846. Mr. Vincent of the Omaha Grain Exchange explains the matter as follows:[189] Suppose that a group of twenty-five mule breeders in Missouri came to Omaha to sell several hundred mules, and buyers assemble from several states. The mule dealers find a vacant lot in a convenient locality and secure permission to use it temporarily. It is the mule market, or mule exchange. The buyers and sellers meet and dicker, each trying to secure the best bargain he can. Every purchase or sale is an individual transaction--between one seller and one buyer. The vacant lot or “mule exchange” has nothing to do in the transaction--it occupies no place in the trade. It is simply the location where the traders gather for their own convenience. If the traders hire a clerk to act for all in settling the trades and collecting the money, it is simply because the clerk has the knowledge of a technical nature not possessed by all traders and his employment is a convenience to all concerned. He represents the individual traders and not the mule market.