of sample grades. For consumers, car shortage and other transportation difficulties productive of business stagnation overcome by the opportunity to purchase for future delivery the raw material where ‘short’ sales of product call for protection. Consummation of contracts possible at all times thru the machinery of a market for future delivery at continuous prices, reliable to the fluctuations of a small fraction—one-eighth of one cent per bushel. In conclusion, and by no means least, the facilities offered for thus establishing value in every part of the United States, with no inequality because of geographical location, and so a death knell to the exploiters of producers and consumers because of this knowledge widely disseminated and so easy of understanding.” Footnote 3: The skew curves of supply and demand, as derived by H. L. Moore, in his book on “Economic Cycles,” furnish mathematical proof of this statement so far as corn and oats are concerned. Footnote 4: The chart printed in connection with the chapter, “Pork Exports, the Barometer of Corn Belt Prosperity,” gives forty-four years of profit and loss areas per acre of corn in the twelve north central states, the method used being the ratio method as described in the above. Footnote 5: It may be argued that the price of hogs determines the price of corn, and that the price of corn determines the price of land. This to a large extent may be true, and yet not interfere with the usefulness of the ratio method for purposes of price judging. Footnote 6: The link relative method of finding the normal seasonal variation, as used by Warren M. Persons, in the January, 1919, Review of Economic Statistics, is far more difficult than the method here used, and for our purposes is not worth while. Footnote 7: Warren M. Persons, in a footnote on page 35 of the January, 1919, Review of Economic Statistics, expresses the method of ascertaining percentage departure from the secular trend in mathematical symbols as follows: “Let the original series beginning with January be X_{1}, X_{2}, X_{3}, ... X_{n}, the ordinates of secular trend be O_{1}, O_{2}, O_{3}, ... O_{n}, and the adjusted indices of seasonal variation for twelve months be S_{1}, S_{2}, S_{3}, ... S_{12} per cent, respectively. Then the items for secular trend and seasonal variation are: X_{1} − S_{1}O_{1}/O_{1}, X_{2} − S_{2}O_{2}/O_{2}, X_{3} − S_{3}O_{3}/O_{3}, ... X_{3} − S_{1}O_{13}/O_{13} etc.” Footnote 8: These figures are based on seasonal correction factors as follows: January, 96; February, 100; March, 105; April, 104; May, 101; June, 101; July, 103; August, 101; September, 103; October, 100; November, 94; December, 92. These factors are practically the same as those used on page 84. Footnote 9: