=395. Decline of the market and fair, and rise of the produce exchange.=—I spoke above of the regularity of modern commerce as one of its distinctive features. The gain in regularity shows itself notably in institutions like the market, the fair, and the exchange. The old system of market-days, under which country people came to town on stated days to display their wares and enable housewives to lay in a supply of provisions, has given place to a steady flow of products through city shops and market halls to the consumers. Fairs have lost their significance in modern countries, because the volume of trade is now so great, and the instruments of trade are so highly developed, that commerce has developed into one permanent fair. The great expositions, which began toward the close of the eighteenth century, but of which the London Exposition of 1851 (Crystal Palace) was the first of world-wide significance, seem to have continued to the present time the principle of periodical recurrence, but a tendency to permanence is to be noted even with respect to them. Many of these expositions have led to the establishment of museums of industry, art, and commerce, and the use of permanent expositions of models and samples has come to be a recognized means of furthering industry and commerce. Finally, the nineteenth century has witnessed the foundation of most of the modern produce exchanges, which have proved indispensable to the rapid development of commerce in the great staples. The experience of Hamburg is significant in this respect. The coffee trade of that port declined after 1882, when Havre adopted the system of dealings in futures, and did not recover until 1887, when Hamburg adopted the system also, and then enjoyed a rapid growth of the trade. These produce exchanges are to be found, with variations in the wares handled and in the system pursued, in all advanced countries. Germany, for instance, offers facilities for the characteristic trade of a produce exchange (including dealings in futures), in the following articles: wheat, rye, maize, oats, rye flour, crude alcohol, rape-seed oil, kerosene, cotton, coffee, raw sugar, granulated sugar, and carded wool.