As to the second requirement, of utility, this does not go so far as to render a preliminary investigation necessary into probable profits or the extent of probable employment of the patented article; but the question is, whether the thing may be applied to some use beneficial to society, as distinguished from an invention which is injurious to the morals, the health, or the good order of society. Provided the invention be not absolutely frivolous or insignificant, it is almost invariably "useful" within the meaning of our patent acts, save so far as it has some tendency positively mischievous and injurious. While the extent to which a patented device has gone into use affords an unsafe criterion of patentability, especially where its popularity was due to no patentable feature, this extent of general use and the displacement of other devices is entitled to weight in a doubtful case, as tending to show utility, and even perhaps novelty, sufficient to uphold a patent.2 So, under like qualification, may the invention of what does more work and at less expense than devices before it furnish an important circumstance for judicial consideration.3

§ 521. No Public Use for Two Years prior to the Claim. But, again, the supposed invention, according to the act of 1870, must not have been known or used by others in this country and not patented or described in this or any foreign country before the alleged discovery or invention, and not in public use or on sale for more than two years prior to the application. That which infringes a patent if later in date,

cisions (1884) appears to be to restrict the right of claiming a patent as for novelty of invention; and doubts are cast upon the validity of many patents which have issued from the Patent Office in years past. But (1895) the latest cases incline to turn the scale in favor of upholding an invention where the article has gone into general use, displacing other analogous devices. Krementz v. Cottle Co., 148 U. S. 556; 148 U. S. 674; 151 U. S. 139; 158 U. S. 68.

66

1 See Story, J., in Bedford v. Hunt, 1 Mas. 302; Curt. Pat. §§ 105, 106; Bright. Fed. Dig. Patents," 2, and cases cited; Abb. Nat. Dig. "Patents," 3. And see Seymour v. Osborne, 11 Wall. 516.

2 Keystone Co. v. Adams, 151 U. S. 139; 141 U. S. 419; 149 U. S. 216.

8 140 U. S. 55; 148 U. S. 482.

+ Supra, § 519. See Curt. Pat. §§ 85-88; Gayler v. Wilder, 10 How. 477.

anticipates it if earlier; and to show that the invention claimed was patented or described in some printed publication earlier is a sufficient defence against an infringement suit.1 Absolute novelty, if estimated with reference to all ages and all countries, would be rarely attainable; for the further we explore into the customs of other nations of ancient or modern times, the more we find that what seems new to us was old to them, and that many of our so-called discoveries consist merely in the revival of some lost art.

§ 522. Patent of a Foreign Invention. - Under certain conditions, a foreign invention may be patented in this country; and no patent shall be declared invalid under our statutes because of any prior patent obtained abroad, provided the same shall not have been introduced into public use in the United States for more than two years prior to the application; though there are certain requirements, besides, as to the expiration of the term of the patent thus applied for.2 A foreign patent or publication describing an invention, unless published anterior to the making of the discovery or invention secured by letters-patent issued by the United States, is no defence.3

§ 523. Abandonment or Public Dedication of One's Invention. It is thus manifest that a public use or sale in this country for more than two years before the patent is applied for may prove fatal to the inventor's claim, whether a prior patent is obtained abroad or not. This is because the law infers a legal abandonment of the invention or discovery after such a lapse of time. There may be an abandonment before application for letters-patent, or an abandonment after the letterspatent have been granted; and in either case the public enjoy the benefits of the discovery, just as though there were no patent laws in existence. An inventor may, and frequently does, allow the use of his invention by individuals for any period not exceeding two years before he puts in his application, and still retain the right to a valid patent; but he

1 Miller v. Eagle Man. Co., 151

U. S. 186; 140 U. S. 481.

2 See Act July 8, 1870, § 25.

8 See Elizabeth v. Pavement Co., 97 U. S. 126.

must be careful not to exceed this period. Nor, under any circumstances, should he do such acts as virtually amount to a general abandonment and free dedication of the invention to the public; for such acts of themselves, if proved, deprive him of his exclusive right to the invention, though the two years have not expired.1

Abandonment after an invention rests on the general equity principle that a claimant will not receive extraordinary aid from the court if he unreasonably delays asking for it, or encourages or acquiesces in any infringement of his rights.2

The alleged prior inventor, in order to intercept one who gets hold of the invention and surreptitiously secures the first patent, must have used reasonable diligence in adapting and perfecting his invention, so as to keep clear of any presumed abandonment on his part. Yet our courts are disposed to favor the true inventor as far as they safely may. And it is well settled that the mere forbearance on an inventor's part to apply for a patent during the progress of experiments, and until he has perfected his invention and tested its value by actual practice, affords no just grounds for any presumption that he has abandoned his invention, and surrendered or dedicated it to the public. Nor will his silence, or open acts or conduct, so far as they have not caused injury to others, be construed to his own detriment under such circumstances.4 Justifiable causes of delay in applying for a patent are fairly considered in such cases.5 But a patentee may claim the whole or only part of his invention; and by claiming only

1 See Curt. Pat. §§ 102, 103, 381399; McClurg v. Kinsland, 1 How. 202; Suffolk Co. v. Hayden, 3 Wall. 315. There may be an abandonment or dedication to the public use, though but one machine be permissively used by one person. Egbert v. Lippmann, 104 U. S. 333. And see Worley v. Tobacco Co., 104 U. S. 340; 140 U. S. 355. Long acquiescence in the grant of a patent to another infers abandonment. 119 U. S. 664.

2 See Curt. Pat. § 440; Abb. Nat. Dig. "Patents," 9.

3 Agawam Co. v. Jordan, 7 Wall. 583.

4 Railroad Company v. Dubois, 12 Wall. 47. An inventor must, however, comply with statutory conditions. He should not unreasonably hold his application pending during a long period of years. 101 U. S. 479. Cf. 98 U. S. 31.

5 122 U. S. 71.

a part he is presumed to have abandoned the residue to the public.1

§ 524. Priority among Conflicting Claimants of a Patent. As to the person entitled to a patent, where there are conflicting claimants, the settled rule is, that whoever first brings a machine to perfection, and makes it capable of useful operation, is the real inventor, and entitled to the patent, although others may previously have had the idea, and made some experiments towards putting it in practice.2 And while it is true that persons employed are entitled to their own independent inventions, as well as their employers, it is also a rule that where the employer has conceived the plan of an invention, and is engaged in experiments to perfect it, no suggestions from an employee, not amounting to a new method or arrangement which in itself is a complete invention, will suffice to deprive the employer of the exclusive property in the perfected improvement.3

§ 525. Proceedings for procuring a Patent. The proceedings requisite in order to obtain a patent are next to be considered. According to our statutes, the inventor or discoverer must make a written application to the Commissioner of Patents, and file what is commonly known among professional men as a specification; or, to use the words of our Patent Act of 1870, "a written description" of the invention or discovery, "and of the manner and process of making, constructing, compounding, and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art or science to which it appertains, or with which it is most nearly connected, to make, construct, compound, and use the same." And it is further provided that, "in case of a machine, he shall explain the principle thereof, and the best mode in which he has contemplated applying that principle, so as to distinguish it from other inventions; and shall particularly point out and distinctly

1 McClain v. Ortmayer, 141 U. S. 419.

2 Agawam Co. v. Jordan, 7 Wall. 583.

government cannot appropriate without compensation a man's property invested in a patent, although the inventor was in the government em

8 Ib. And see 149 U. S. 315. The ploy. 137 U. S. 342.

claim the part, improvement, or combination which he claims as his invention or discovery." This specification and claim is to be signed by the inventor, and attested by two witnesses.1 The applicant likewise furnishes a drawing, specimen, or model, as the case may be, to illustrate his claim; and, finally, he must make oath or affirmation that he does verily believe himself to be the original and first inventor or discoverer of the art, machine, manufacture, composition, or improvement for which he solicits a patent; that he does not know, and does not believe, that the same was ever before known or used; stating, also, of what country he is a citizen.2 So much for the claimant's papers, which, of course, he must not file without paying to government the preliminary fee in advance. But, on his compliance with all these formalities, his claim is taken up and considered at the Patent Office in Washington; and if, on examination, it appears that the claimant is justly entitled to a patent, the Commissioner will issue the letters-patent accordingly; not, however, without requiring him to pay a final fee to government according to law.3 § 526. The Same Subject; Specifications. The preliminaries, then, are simple enough, except as to preparing the specification. Here it is that legal knowledge and scientific aptitude are most severely tested; for a badly drawn specification, such as claims too much, or not enough, or the wrong thing, may defeat the wishes of the inventor altogether, and

1 Act July 8, 1870, § 26. The claim is a statutory requirement, prescribed for the purpose of making the inventor define precisely what his invention is. 134 U. S. 388. Distinct and formal claims are necessary to ascertain the scope of the invention. 148 U. S. 547. The claim is to be construed in connection with the explanation contained in the specification; but specifications and drawings are only explanatory, and cannot be used to enlarge the claim. 141 U. S. 419; 134 U. S. 388. The Commissioner has considerable latitude to correct or require modifica