UNITED STATES PATENT OFFICE. ALEXR. H. EVERETT, OF NEW YORK, N. Y., ASSIGNOR TO AMERICAN CAR PLACE.WHEEL AND RAILWAY CHAIR MANUFACTURING COMPANY, OF SAME 4. IMPROVEMENT IN THE MANUFACTURE of Ron. Specification forming part of Letters Patent No. 4 S,4S3, dated June 27, 1865. To all chon it may concern: and sulphur) and other impurities always pres-- Be it known that I, ALEXANDER. H. Ev ent in iron, with which impurities they com ERETT, of the city of New York, have invented bine, forming a fluid slag. certain new and useful Improvements in the I prefer the mineral cryolite, but am aware Composition and Manufacture of Iron; and I that an artificial compound of the elements do hereby declare the following to be a full, composing this mineral, or a portion of them, clear, and exact description thereof. would produce the same result-as, for in My invention consists in the use of cryolite stance, oxide of aluminium and carbonate of with cast or pig iron or its use with cast or pig soda, or, in fact, any combination of alumina iron and wrought-iron combined, by means of that may be decomposed by carbon at a high which an improved quality of metal is obtained, temperature. increasing its strength and density. There are various modes of applying this in To enable those skilled in the art to use my vention, and the amount of the cryolite used improvement, I will proceed to describe the will require to be varied according to the Salme. amount of impurities in theiron and the quality Where cast-iron alone is used I use only the of metal desired. •. ordinary cupola furnace, simply adding to each The advantages to be derived from the use one hundred pounds of ii on three to five of this improved metal are important and pounds of cryolite, using the precaution be varied. Reliable and official tests prove that fore drawing off to add any of the ordinary metal produced as above described possesses a substances to thicken the slag which are in tensile strength equal to two and one-halftimes common use by foundrymen. that of ordinary anthracite iron; and experi When it is desired to form a combination of ments also show its very remarkable capacity cast and wrought iron I use a common wind for receiving the chill or hardening, and to a furnace, like those employed in the manufac greater depth and in a more perfect manner ture of steel. The proportions employed to than any other known metal. Thus car-wheels constitute a fine tough iron are one hundred of less weight and more strength can be pro pounds cast-iron, twenty pounds wrought-iron, duced with the periphery hardened so as to three pounds of cryolite. Another method is equal steel. The castings for reapers, mow to take twenty pounds of wrought-iron and ers, plows, thrashers, horse-powers, drills, mill any number of pounds of cast-iron not less gearing, and, in fact, every name and style of than twenty pounds and melt them together cast-iron castings which require strength and in a crucible, and when melted add to the re durability, can be reduced in weight and in maining number of pounds of cast-iron, as creased in strength Uy the use of the invention drawn from the ordinary cupola, mixing them herein described and set forth. in the melted state. The addition of cryolite, What I claim as my invention, and wish to which is a mineral substance consisting of secure by Letters Patent, is fluoride of soda and aluminium, produces the 1. The employment of cryolite or its compo following results: First, the carbon in the cast nent elements in the melting of cast-iron, for iron, in combination with the heat of the fur the purpose of refining and strengthening the nace, decomposes the cryolite, reducing the same. aluminium to the metallic state, and thus forms an alloy of iron and aluminium, and a very 2. The employment of cryolite or its compo small portion of the latter adds largely to the nent elements in the melting of cast-iron and strength of the iron; second, the partial re wrought-iron mixed, thereby producing a metal moval of the carbon from the iron, as above, of great strength and fineness. adds largely to the strength of the metal and 3. The use of cryolite as a purifying agent gives it much of the tenacity which character in the melting of irons. izes wrought-iron; third, the action of the sodi ALEXANDER. H. EVERETT, um and fluoric acid, both having a strong af. Witnesses: finity for silica (and the former for phosphorus WM. T. DENNIs, C. W. STAFFORD.