The best grey pig iron of American manufacture, superior in strength, and equal in all other respects to the Scotch, is now sold in the New York market at $45 per ton. Good grey iron of the usual character, is worth $35 per ton, and there is no question that forge pig could be obtained by the manufacturer of bar iron, for $25. If it were even to cost $30, it is still cheaper than Staffordshire iron, far less fit for the purpose, can be imported. The Muirkirk iron, so valuable for the casting of machinery, used to cost to import it, at the present rate of duty, $55 and $56. The Bennington furnace commenced the competition with it at this rate, but has been compelled, after driving the Scotch iron from the market, to sell at $45, which is as low as the foreign could be imported at a minimum duty. Taking the cost of forge pig at $25, the price of converting into bars by charcoal, would be, according to the Philadelphia memorial, $18, and the ton of wrought iron ought to cost no more than $43. We however believe that this cost is far underrated, and that even by the aid of rollers in a part of the process, iron of the best quality could not be produced under $50. This is as cheap as merchantable English puddled iron can be imported, paying 25 per cent. duty. But, even if the pig cost $35, and the wrought iron, $60, it is still cheaper than the English iron, worth in that market 10_l._ 10_s._ can be imported; and the latter is the cheapest which can be obtained in that country, suitable for the manufacture of anchors and chain-cables. At the present moment, however, iron cannot be produced so cheaply, for the forges and furnaces may be considered as in a great measure new, and undergoing all the difficulties of new establishments. Capital above all is wanting, from a want of confidence in the success of the enterprize, growing out of a fear of the repeal of the duty, and the recollection of the former catastrophe; and even credit, so essential where capital is deficient, is at a low ebb. Hence, if profit be made, it rather centers in the capitalist who makes the advances, than in the maker. Thus we have known iron in the bloom, sold at $45 per ton; and, when finished for the market by rolling, bring $100. The latter price, however, could not long be maintained, and has descended to $75 and $80, which still leaves the greater part of the profit to the capitalist.