About this time a remedy was found in the south for leaving the land idle during the nine months between harvesting the corn crop in August, and sowing the turnip crop in the following June, by sowing rye, which was eaten green by the sheep in May, a good preparation for the succeeding winter crop. Turnip cutters were at last being used, and corn and cake crushers soon followed. The seasons from 1838 to 1841 were bad, and must be characterized as a period of dearth, wheat keeping at a good price.[628] That of 1844-5 was remarkable for the first general appearance of the potato disease, not only in these islands but on the continent of Europe.[629] In August, 1846, the worst apprehensions of the failure of the crop were more than realized, and the terrible results in Ireland are well known. In the early part of 1847 there was a fear of scarcity in corn, and the price of wheat rose to 102s. 5d. in spite of an importation of 4,500,000 quarters, but this was largely owing to the absence of any reliable agricultural statistics, which were not furnished till 1866, and the price soon fell.[630] We have now reached the period of free trade, when the Corn Laws, which had protected agriculture more or less effectually for so long, were definitely abandoned. That they had failed to prevent great fluctuations in the price of corn is abundantly evident, it is also equally evident that they kept up the average price; in the ten years from 1837 to 1846, the average price of wheat was 58s. 7d. a quarter, in the seven years from 1848 to 1853, the average price was 48s. 2d.[631] The average imports of wheat and flour for the same period were 2,161,813 and 4,401,000 quarters respectively. But to obtain the real effect of free trade on prices, the prices for the period between 1815 and 1846 must be compared with those between 1846 and the present day, when the fall is enormous. The Act of 1815, which Tooke said had failed to secure any one of the objects aimed at by its promoters, had received two important alterations. In 1828 (9 Geo. IV, c. 60) a duty of 36s. 8d. was imposed when the price was 50s., decreasing to 1s. when it was 73s. In 1843 (5 Vict. c. 14) a duty of 20s. was imposed when the price was 50s., and the duty became 7s. when the price reached 65s.