3. It is then taken out, and fused again in the same manner, and afterwards a third time. After the third heat, when the iron has become solid enough to bear beating, it is slightly hammered with a sledge, to free it from the adhering scoria. It is then returned to the furnace; but, being placed out of the reach of the blast, it soon becomes sufficiently compact to bear the _tilt-hammer_. 4. With this instrument, the iron is beaten, until the mass has been considerably extended, when it is cut into several pieces, which, by repeated beating and forging, are extended into bars, as we see them for sale. The tilt-hammer weighs from six to twelve hundred pounds, and is most commonly moved by water power. 5. For manufacturing bar-iron directly from the ore, the furnace is similar in its construction to the one just described, and the operations throughout are very similar. A fire is first made upon the hearth with charcoal; and, when the fuel has become well ignited, a quantity of ore is thrown upon it, and the ore and the fuel are renewed as occasion may require. As the iron melts, and separates from the earthy portions of the ore, it sinks to the bottom of the hearth. The scoria is let off occasionally, through holes made for the purpose. When iron enough has accumulated to make a _loop_, as the mass is called, it is taken out, and forged into bars under the tilt-hammer. 6. This way of making bar-iron is denominated the _method of the Catalan forge_, and is by far the cheapest and most expeditious. It is in general use in all the southern countries of Europe, and it is beginning to be extensively practised in the United States. When a Catalan forge is employed in making _blooms_, it is called a _bloomery_. 7. The blooms are about eighteen inches long, and four in diameter. They are formed under the tilt-hammer, and differ in substance from bar-iron in nothing, except that, having been imperfectly forged, the fibres of the metal are not fully extended, nor firmly united. The blooms are manufactured in the interior of the country, where wood is abundant, and sold by the ton, frequently, in the cities, to be converted into bar or sheet iron. 8. These blooms are converted into bar-iron, by first heating them in an air-furnace, by means of stone coal, and then passing them between chill cast iron rollers. The rollers are filled with grooves, which gradually decrease in size from one side to the other. When the iron has passed through these, the bloom of eighteen inches in length, has become extended to nearly as many feet. The bar thus formed, having been cut into four pieces, the process is finished by welding them together laterally, and again passing them between another set of rollers, by which they are brought to the form in which they are to remain.