A function is that "which a machine is designed to do, as distinguished from the machine itself and from the product of its action or something external to itself ;" Den ning Wire & Fence Co. v. Steel Co., 169 Fed. 793, 95 C. C. A. 259. In Westinghouse v. Power Brake Co., 170 U. S. 537, 18 Sup. Ct. 707, 42 L. Ed. 1136, it was said that the term "function" may not be readily defined, and that it was not advisable that it should be attempted.
While the end or purpose sought to be ac complished by the device is not the subject of a patent, the device or mechanical means by which the desired result is to be secured, is; Knapp v. Morss, 150 U. S. 221, 14 Sup. Ct. 81, 37 L. Ed. 1059. An idea is not pat entable; a patent is valid only for the prac tical application of an idea ; Sickels v. Bor den, 3 Blatch. 535, Fed. Cas. No. 12,832; Rubber-Tip-Pencil Co. v. Howard, 20 Wall. 498, 22 L. Ed. 410. A principle denotes the physical force employed by an invention. It is some natural power or energy which oper ates with uniformity under given circum stances, and may thus be contemplated as obedient to law. It is a necessary factor in every means which produce physical effects, whether such means be natural or artificial; Rob. Pat. § 135.
To be entitled to a patent, a person must have invented and discovered some new and useful art, machine, manufacture, or compo sition of matter, or some new and useful im provement thereof ; and it is not enough that a thing is new, in the sense that in the shape or form in which it is produced, it has not been known, and that it is useful, but it must amount to an invention or discovery; Burt v. Evory, 133 U. S. 349, 10 Sup. Ct. 394, 33 L. Ed. 647.
An invention, to be patentable, must not only be new, but must also be useful. But by this it is not meant that it must be more useful than anything of the kind previously known, but that it is capable of Ise for a beneficial purpose. The word "useful" is also to be understood in contradistinction to "pernicious," Or "frivolous." A contrivance directly and mainly calculated to aid the counterfeiter, the pickpocket, or the assassin, or which would in any way be directly cal culated to be injurious to the morals, the health, or the good order of society, would not be patentable. Neither would a new
contrivance which was of too trivial a char acter to be worthy of serious consideration; Langdon v. De Groot, 1 Paine 203, Fed. Cas. No. 8,059 ; Many v. Jagger, 1 Blatch. 372, Fed. Cas. No. 9,055 ; Parkhurst v. Kinsman, 1 Blatch. 488, Fed. Cas. No. 10,757.
The patent itself is prima facie evidence of utility ; Waterbury Brass Co. v. Miller, 9 Blatch. 77, Fed. Cas. No. 17,254; Bell v. Daniels, 1 Bond 212, Fed. Cas. No. 1,247; and its use by the defendant and others is evidence of utility ; Smith v. Elastic Fabrics Co., 1 Holmes 340, Fed. Cas. No. 13,050.
A mere application of an old device or process to the manufacture of an article is held to constitute only a "double use," and not to be patentable. There must be some new process or machinery used to produce the effect; Brown v. Piper, 91 U. S. 37, 23 L. Ed. 200; Roberts v. Ryer, 91 U. S. 150, 23 L. Ed. 267. See Howe Mach. Co. v. Needle Co., 134 U. S. 388, 10 Sup. Ct. 570, 33 L. Ed. 963; Grant v. Walter, 148 U. S. 547, 13 Sup, Ct. 699, 37 L. Ed. 552. A combination of old elements does not constitute a patentable invention, where they are all found, some in one and some in another of earlier de vices for the same purpose, in which each element performs the same function that it has in the new combination; Busell Trim. mer Co. v. Stevens, 137 U. S. 423, 11 Sup. Ct. 150, 34 L. Ed. 719 ; Knapp v. Morss, 150 U. S. 221, 14 Sup. Ct. 81, 37 L. Ed. 1059.
A mere carrying forward of the original thought, a change only in form, propor tions, or degree, doing the same thing in the same way, by substantially the same means, with better results, is not such an invention as will sustain a patent ; Belding Mfg. Co. v. Corn Planter Co., 152 U. S. 100, 14 Sup. Ct. 492, 38 L. Ed. 370; and some thing more is required to support one than a slight advance over what has preceded it, or mere superiority in workmanship or fin ish; International Tooth Crown Co. v. Gay lord, 140 U. S. 55, 11 Sup. Ct. 716, 35 L. Ed. , 347.
Invention, in the nature of improvements, is the double mental act of discerning, iu ex isting machines, processes or articles, some deficiency,, and pointing out the means of overcoming it; General Electric Co. v. Elec tric Co., 174 Fed. 246, 98 C. C. A. 154.