The free-traders consider the tariff of 1846 to be a conclusive proof the beneficial effect of low duties. They challenge a comparison of the years of its operation, between 1846 and 1857, with any other equal period in the history of the country. Manufacturing, they say, was not forced by a hot-house process to produce high-priced goods for popular consumption, but was gradually encouraged and developed on a healthful and self-sustaining basis, not to be shaken as a reed in the wind by every change in the financial world. Commerce, as they point out, made great advances, and our carrying trade grew so rapidly that in ten years from the day the tariff of 1846 was passed our tonnage exceeded the tonnage of England. The free-traders refer with especial emphasis to what the term the symmetrical development of all the great interests of the country under this liberal tariff. Manufactures were not stimulated at the expense of the commercial interest. Both were developed in harmony, while agriculture, the indispensable basis of all, was never more flourishing. The farmers and planters at no other period of our history were in receipt of such good prices, steadily paid to them in gold coin, for their surplus product, which they could send to the domestic market over our own railways and to the foreign market in our own ships. COMPARISON OF REVENUE SYSTEMS. Assertions as to the progress of manufactures in the period under discussion are denied by the protectionists. While admitting the general correctness of the free-trader's statements as to the prosperous condition of the country, they call attention to the fact that directly after the enactment of the tariff of 1846 the great famine occurred in Ireland, followed in the ensuing years by short crops in Europe. The prosperity which came to the American agriculturist was therefore from causes beyond the sea and not at home,--causes which were transient, indeed almost accidental. Moreover an exceptional condition of affairs existed in the United States in consequence of our large acquisition of territory from Mexico at the close of the war and the subsequent and almost immediate discovery of gold in California. A new and extended field of trade was thus opened in which we had the monopoly, and an enormous surplus of money was speedily created from the products of the rich mines on the Pacific coast. At the same time Europe was in convulsion from the revolutions of 1848, and production was materially hindered over a large part of the Continent. This disturbance had scarcely subsided when three leading nations of Europe, England, France, and Russia, engaged in the wasteful and expensive war of the Crimea. This struggle began in 1853 and ended in 1856, and during those years it increased consumption and decreased production abroad, and totally closed the grain-fields of Russia from any competition with the United States.