The next process is "boiling," which is a modification of "puddling," and is generally used in the best iron-works in this country. The process of puddling was invented by Henry Cort, an Englishman, and patented by him in 1783 and 1784 as a new process for "shingling, welding and manufacturing iron and steel into bars, plates and rods of purer quality and in larger quantity than heretofore, by a more effectual application of fire and machinery." For this invention Cort has been called "the father of the iron-trade of the British nation," and it is estimated that his invention has, during this century, given employment to six millions of persons, and increased the wealth of Great Britain by three thousand millions of dollars. In his experiments for perfecting his process Mr. Cort spent his fortune, and though it proved so valuable, he died poor, having been involved by the government in a lawsuit concerning his patent which beggared him. Six years before his death, the government, as an acknowledgment of their wrong, granted him a yearly pension of a thousand dollars, and at his death this miserly recompense was reduced to his widow to six hundred and twenty-five dollars. [Illustration: ROTARY SQUEEZER.] [Illustration: BOILING-FURNACE.] When iron is simply melted and run into any mould, its texture is granular, and it is so brittle as to be quite unreliable for any use requiring much tensile strength. The process of puddling consisted in stirring the molten iron run out in a puddle, and had the effect of so changing its atomic arrangement as to render the process of rolling it more efficacious. The process of boiling is considered an improvement upon this. The boiling-furnace is an oven heated to an intense heat by a fire urged with a blast. The cast-iron sides are double, and a constant circulation of water is kept passing through the chamber thus made, in order to preserve the structure from fusion by the heat. The inside is lined with fire-brick covered with metallic ore and slag over the bottom and sides, and then, the oven being charged with the pigs of iron, the heat is let on. The pigs melt, and the oven is filled with molten iron. The puddler constantly stirs this mass with a bar let through a hole in the door, until the iron boils up, or "ferments," as it is called. This fermentation is caused by the combustion of a portion of the carbon in the iron, and as soon as the excess of this is consumed, the cinders and slag sink to the bottom of the oven, leaving the semi-fluid mass on the top. Stirring this about, the puddler forms it into balls of such a size as he can conveniently handle, which are taken out and carried on little cars, made to receive them, to "the squeezer." [Illustration: THE ROLLS.]