_Prices of farm products; the crop year._—The actual fluctuations of market prices under the law of supply and demand can be most clearly seen by a careful study in the same definite market during a period of years. For illustration here the staple products of the farm have been chosen, and the markets of Chicago and New York, as most truly representative, have furnished the facts for study. These facts are presented to the eye directly by a series of charts, each of which has been most carefully prepared from official records, and gives within narrow limits a large range of investigation. In every case involving annual crops, it seemed necessary to rearrange statistics so as to cover the actual year affected by the crop in question. September 1 was chosen as the beginning of each year, because that date is nearest the time when the new crop of the season appears in market and directly affects the price of such products in store. All calculations upon live stock have been brought to the same basis, for the reason that the supply of marketable stock is largely dependent upon the supply of feed for stock. It seems very desirable that all statistics in regard to markets and productive industry should be brought to a uniform year. The year given in these charts seemed best to suit the subjects treated. It is possible, however, that for all data convenience would settle upon July 1, the beginning of the fiscal year in the United States, as the best for beginning the universal statistical year. Each chart in the series, of course, requires its particular explanation. The fluctuations of supply and prices for series of years are exhibited in the Charts 4, 5, 6, 8, 9 and 12, and these are explained in detail at the close of the chapter. _Fluctuations with season._—Every product of the farm is known to have conditions favorable or unfavorable from the mere changes of season affecting the prospective supply. Conditions equally dependent upon the seasons have something to do with demand. The result of both combined is worthy of study by farmers and dealers in farm produce, that all may get the full benefit of such knowledge as the study affords. For this purpose, charts showing the annual fluctuations of staple products in the leading markets have been carefully prepared. These may have a greater usefulness than simply to illustrate the law of supply and demand, since it is within the possibility of actual practice to in some degree modify by provident foresight the extremes of fluctuation. It is hoped that the suggestiveness of these charts may help the most enterprising farmers to adjust their practice to conditions of market. Charts Nos. 7, 10, 11 and 13 illustrate the fluctuations as related to seasons.