At the restoration of Charles II the corn laws had practically been unaltered since 1571,[361] when it had been enacted that corn might be exported from certain ports in certain ships at all times when proclamation was not made to the contrary, on a payment of 12d. a quarter on wheat and 8d. a quarter on other grain. Now both export and import were subjected to heavy duties, but these caused such high prices in corn that they were reduced in 1663; yet high duties were again imposed in 1673, which continued until the revolution. Then, owing to good crops and low prices, which brought distress on the landed interest, a new policy was introduced: export duties were abolished and the other extreme resorted to, viz. a bounty on export of 5s. in the quarter as long as the home price did not exceed 48s. At the same time import duties remained high, and this system lasted till 1773. Never had the corn-growers of England been so thoroughly protected, yet, owing to causes over which the legislators had no control, namely bountiful seasons, the prices of wheat for the next seventy years was from 15 to 20 per cent. cheaper than in the previous forty. Modern economists have described this system as one of the worst instances of a class using their legislative power to subsidize themselves at the expense of the community. As a matter of fact it was the firm conviction of the statesmen and economists of the time, that husbandry, being the main industry and prop of England, and the foundation on which the whole political power of the country was based, should receive every encouragement. At all events, in many ways the policy was successful.[362] It encouraged investment in land, and materially assisted the agricultural improvement for which the eighteenth century was noted, the export too employed English shipping, and thus aided industry. Arthur Young said it was the singular felicity of this country to have devised a plan which accomplished the strange paradox of at once lowering the price of corn and encouraging agriculture, for by the system in vogue till 1773 if corn was scarce it was imported, while if there was a glut at home export was assisted so that great fluctuations in price were prevented.[363] It seemed of the utmost importance to men of that time that England should be self-supporting and independent of possible adversaries for the necessaries of life; the wisdom of the policy was never questioned, and was accepted by statesmen of every party.[364] To blame the landowners for adopting what seemed the wisest course to every sensible person is merely an instance of partisan spite.