From 1896 to date, heavy hog prices, as compiled by Chas. A. S. McCracken for the Chicago Drovers’ Journal Year Book, have been used. From 1881 to 1895, inclusive, the average of the range of Chicago hog prices, as compiled by the Cincinnati Price Current, has been used. Properly speaking, these prices refer more nearly to average hogs than to heavy hogs. Previous to 1881, prices have been compiled from the Chicago Board of Trade Reports, the grade known as heavy packers and shippers being used so far as possible. * * * * * CORN PRICES AT CHICAGO. No. 2 mixed has been used thruout. From 1880 to 1916, inclusive, the average of the high and low for the month has been taken. Since January, 1917, each day of the month has been averaged. Previous to 1880, averages were taken either weekly or semi-monthly. All figures are derived either from the Howard-Bartels Red Book or the Chicago Board of Trade Reports. The two sources generally agree. * * * * * OATS PRICES AT CHICAGO. Previous to 1876, the grade known as No. 1 was chiefly used. Since 1876, No. 2, Standard or Contract oats has been used. Previous to 1881, averages were taken weekly or semi-monthly. Since 1881, the high and low for the month have been averaged. Previous to 1881, Chicago Board of Trade Reports were used. Since 1881, the Howard-Bartels Red Books have been used, which quote practically the same figures as the Board of Trade. * * * * * WHEAT PRICES AT CHICAGO. Previous to 1883, the grade known as No. 2 Spring was used, weekly or semi-monthly averages being taken from the Chicago Board of Trade Reports. From 1883 to 1903, inclusive, there is a slight confusion in grades, but the No. 2 Spring is used chiefly, averages of high and low for the month being taken from the Howard-Bartels Red Book. From 1904 to 1913, inclusive, prices are based on No. 2 Red and No. 1 Northern, the high of the one and the low of the other being used. From 1914 on, prices are based on No. 2 Red, No. 2 Hard and No. 1 Northern, the highest of the highest-priced grade and the lowest of the lowest-priced grade being averaged. * * * * * LIVE STOCK PRICES AND RECEIPTS.