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Corning v. Burden, 56 U.S. (15 How.) 252 (1853) (full-text).

Factual Background[]

The issue was whether Burden's ambiguous claim was properly interpreted as for a process. The patent was ostensibly directed toward a machine for rolling puddle balls in the manufacture of iron. But the lower court had instructed the jury that the patent was for a new method of converting puddle balls to blooms "by continuous pressure and rotation * * * between converging surfaces."

U.S. Supreme Court Proceedings[]

The U.S. Supreme Court held the claim limited to the machine, since, in the Court's mind, a contrary decision would call into question the validity of the claim.[1] In an influential aside on the way to this conclusion, Justice Grier, for a unanimous Court, discussed the patentability of processes:

A process, eo nomine, is not made the subject of a patent in our act of Congress. It is included under the general term "useful art." An art may require one or more processes or machines in order to produce a certain result or manufacture. The term machine includes every mechanical device or combination of mechanical powers and devices to perform some function and produce a certain effect or result. But where the result or effect is produced by chemical action, by the operation or application of some element or power of nature, or of one substance to another, such modes, methods, or operations, are called processes. A new process is usually the result of a discovery; a machine, of invention. The arts of tanning, dyeing, making water-proof cloth, vulcanizing India rubber, smelting ores, and numerous others are usually carried on by processes, as distinguished from machines. One may discover a new and useful improvement in the process of tanning, dyeing, &c., irrespective of any particular form of machinery or mechanical device. And another may invent a labor-saving machine by which this operation or process may be performed, and each may be entitled to his patent. As, for instance, A has discovered that by exposing India rubber to a certain degree of heat, in mixture or connection with certain metallic salts, he can produce a valuable product or manufacture; he is entitled to a patent for his discovery, as a process or improvement in the art, irrespective of any machine or mechanical device. B, on the contrary, may invent a new furnace or stove, or steam apparatus, by which this process may be carried on with much saving of labor, and expense of fuel; and he will be entitled to a patent for his machine, as an improvement in the art. Yet A could not have a patent for a machine, or B for a process; but each would have a patent for the means or method of producing a certain result, or effect, and not for the result or effect produced. It is for the discovery or invention of some practicable method or means of producing a beneficial result or effect, that a patent is granted, and not for the result or effect itself. It is when the term process is used to represent the means or method of producing a result that it is patentable, and it will include all methods or means which are not effected by mechanism or mechanical combinations.[2]


  1. The Court reasoned that the law's requirement for a description of the invention may have been ignored if the patent were interpreted as for a process. 56 U.S. (15 How.) at 269
  2. Id. at 267-68.