struction, which may be disturbed by the announcement of a different rule.

3. Where the language of a statute is plain and unambiguous, it is the duty of the court to enforce it according to the obvious meaning of the words, without attempting to change it by adopting a different construction, based upon some supposed policy of congress in regard to the subject of legislation, or upon considerations of injustice or inconvenience arising from the enforcement of the statute according to its terms.

4. The act of July 8, 1870, entitled "An act to revise, consolidate, and amend the statutes relating to patents and copyright" (16 Stat. 198), was not, as finally passed, a mere revision and consolidation, as the language of some of the committee reports in the house would seem to indicate, but, on the contrary, it contained numerous amendments and changes of prior laws, some of them of considerable importance; and hence the former statutes are not to be resorted to as controlling, where changes in phraseology seem to indicate a purpose to change the law.

5. The twenty-fifth section of the patent act of 1870 (16 Stat. 198) having been immediately construed by the patent commissioner according to the ordinary and natural meaning of the words, and having been subsequently reproduced in section 4887 of the Revised Statutes, and never amended, the supreme court will not, after a lapse of 25 years, adopt a different construction.

On a Certificate from the United States Circuit Court of Appeals for the Second Circuit.

This was a bill in equity by the Bate Refrigerating Company against Ferdinand Sulzberger, Samuel Weil, and Frederick Joseph, doing business under the firm name of Scharzchild & Sulzberger, for infringement of letters patent No. 197,314, issued November 20, 1877, to John Bate, for an improvement in processes for preserving meats. The cause was heard in the circuit court on pleas to the bill, and a decree entered dismissing the suit. 56 Fed. 713. Complainant took an appeal to the circuit court of appeals, which court certified to the supreme court the question of issue.

James C. Carter, Charles E. Mitchell, and J. J. Storrow, for appellant. Wheeler H. Peckham, Edmund Wetmore, and Leonard E. Curtis, for appellees. B. F. Lee filed briefs for Chemical Rubber Co. B. H. Briston and W. H. Kenyon filed briefs for Harrison International Tel. Co. Chas. H. Aldrich filed briefs for Milo G. Kellogg.

Mr. Justice HARLAN delivered the opinion of the court.

This case is before us upon a certificate made under the sixth section of the act of March 3, 1891 (26 Stat. 826, c. 517), providing that a circuit court of appeals may, in any case of which it has appellate jurisdiction, certify questions or propositions of law for the proper decision of which it desires the instruction of this court.

On the 1st day of December, 1876, John J. Bate made application to the United States for letters patent for an improvement in processes for preserving meats during storage and transportation.

Pending this application, two foreign patents were granted for the Bate invention.-one, for the term of 14 years, by the British gov

ernment, to William Robert Blake, on a communication from Bate under date of January 29, 1877, which patent was sealed July 13, 1877, and the complete specifications of which were filed July 26, 1877; the other, for the term of 5 years, by the government of the dominion of Canada, to Bate himself, under date of January 9, 1877.

After these foreign patents were issued, namely, on the 20th day of November, 1877, Bate received a patent from the United States, expressed to be for the term of 17 years, and assigned it to the Bate Refrigerating Company, the plaintiff in this suit.

The present suit was brought by that company July 25, 1892, for an injunction against the infringement of the American patent, as well as for an accounting. It was heard in the circuit court on pleas to the bill, and a decree was passed dismissing the suit. From that decree an appeal was taken to the circuit court of appeals.

Both foreign patents for the Bate invention having expired before the expiration of the 17 years specified in the United States patent, the following questions arose in and have been certified by the circuit court of appeals: Whether the invention for which the patent from the United States was issued had been "previously patented in a foreign country," within the meaning of those words in section 4887 of the Revised Statutes; and whether the American patent expired, under the terms of that section, before the expiration of 17 years from its date.

The Revised Statutes of the United States provide that any person inventing or discovering any new and useful art, machine, manufacture, or composition of matter, or any new and useful improvement thereof, "not known or used by others in this country, and not patented or described in any printed publication in this or any foreign country, before his invention or discovery thereof, and not in public use or on sale for more than two years prior to his application, unless the same is proved to have been abandoned," may obtain a patent therefor, which shall contain a grant of the exclusive right for the term of 17 years to make, use, and vend such invention or discovery throughout the United States and the territories thereof, and bear date as of a day not later than six months from the time at which it was passed and allowed, and notice thereof sent to the applicant or his agent. Sections 4884-4886.

*

By section 4887 it is provided that "no person shall be debarred from receiving a patent for his invention or discovery, nor shall any patent be declared invalid, by reason of its having been first patented or caused to be patented in a foreign country, unless the same has been introduced into public use in the United States more than two years prior to the application. But every patent granted for an invention which has been previously patented in a foreign country shall be so limited as to expire at the same time with

the foreign patent, or, if there be more than one, at the same time with the one having the shortest term, and in no case shall it be in force more than seventeen years."

Other sections prescribe what the application for a patent shall contain, the nature of the oath or affirmation to be made by the applicant, and the time within which an application shall be completed and prepared for examination. Sections 4888, 4892, 4894.

The plaintiff insists that an invention patented or caused to be patented in a foreign country before being patented in this country should not be deemed to have been "previously patented in a foreign country," within the meaning of section 4887, unless the foreign patent was granted prior to the application for the American patent.

The defendants contend that the respective dates of the American and foreign patents, and not the date of the American application, determine the question whether an invention patented here has been "previously patented in a foreign country."

Counsel for the respective parties have deemed it necessary to refer very fully to the principal statutes relating to patents for inventions. In our consideration of the case the same method will be pursued, reserving any observations we may make upon the words of particular acts until we shall have given an outline of the history of such legislation by congress as is supposed to bear upon the questions certified.

The first act of congress passed under the authority given by the constitution to promote the progress of science and useful arts by securing for limited times to authors and inventors the exclusive right to their respective writings and discoveries was approved April 10, 1790. 1 Stat. 109, c. 7. The persons to whom, under that act, patents could be issued, were those inventing or discovering any useful art, manufacture, engine, machine, or device, or any improvement therein "not before known or used." The applicant was required, at the time the patent was granted, to deliver to the secretary of state such specification in writing, containing a description of the invention or discovery,-accompanied, when necessary, with drafts or models, and explanations of the thing invented or discovered,-as would distinguish the invention or discovery from other things "before known and used," and enable one skilled in the art or manufacture to make, construct, or use the same, "to the end that the public may have the full benefit thereof after the expiration of the patent term." Sections 1, 2.

The act of February 21, 1793, which took the place of the act of 1790, made no material change, except to restrict the right to a patent to citizens of the United States, and to provide that the invention or discovery sought to be patented should be one "not known or used before the application." 1 Stat. 318, c. 11. In Pennock v. Dialogue, 2

Pet. 1, 19, 21, Mr. Justice Story, speaking for the court, said that the addition made by the act of 1793 of the words "before the application," after the words "not known or used," in the act of 1790, was made ex industria with the intention "to clear away a doubt, and fix the original and deliberate meaning of the legislature," which was that the invention should be one not known or used by the public before the application.

Then came the act of April 17, 1800, which extended the provisions of the act of 1793 to all aliens residing for two years in the United States, and who should make oath or affirmation that the invention, art, or discovery for which a patent was asked had not "been known or used either in this or any foreign country." That act further provided that any patent for an invention, art, or discovery, subsequently found to have been "known or used previous to such application for a patent," should be void. 2 Stat. 37, c. 25.

*The provisions of the act of 1800 were extended by the act of July 13, 1832, to every alien who, at the time of petitioning for a patent, was a resident of this country, and had declared his intention, according to law, of becoming a citizen of the United States. But every patent granted under the latter act was to become void if the patentee failed for one year after its date to introduce into public use in the United States the invention or improvement for which his patent was issued, or in case the invention or improvement should, for any period of six months after such introduction, not continue to be publicly used and applied in the United States, or in case of his failure to become a citizen of the United States at the earliest period within which he could become such citizen. 4 Stat. 577, c. 203.

On the 4th day of July, 1836, congress passed an act entitled "An act to promote the progress of useful arts, and to repeal all acts and parts of acts heretofore made for that purpose." 5 Stat. 117, c. 357.

By the fifth section of that act it was provided that every patent should be for a term of 14 years.

The sixth section described those entitled to receive patents, namely, "any person or persons having discovered or invented any new and useful art, machine, manufacture, or composition of matter, or any new and useful improvement in any art, machine, manufacture, or composition of matter, not known or used by others before his or their discovery or invention thereof, and not, at the time of his application for a patent, in public use or on sale, with his consent or allowance, as the inventor or discoverer."

The seventh section prescribed an examination of the alleged new invention or discovery, and provided: "If, on any such examination, it shall not appear to the commissioner that the same had been invented or discovered by any other person in this coun

try prior to the alleged invention or discovery thereof by the applicant, or that it had been patented or described in any printed publication in this or any foreign country, or had been in public use or on sale with the applicant's consent or allowance prior to the application, if the commissioner shall deem it to be sufficiently useful and important, it shall be his duty to issue a patent therefor. But whenever, on such examination, it shall appear to the commissioner that the applicant was not the original and first inventor or discoverer thereof, or that any part of that which is claimed as new had before been invented or discovered, or patented, or described in any printed publication in use in this or any foreign country, as aforesaid, or that the description is defective and insufficient, he shall notify the applicant thereof, giving him, briefly, such information and references as may be useful in judging of the propriety of renewing his application, or of altering his specification to embrace only that part of the invention or discovery which is new."

The eighth section, after providing for the hearing and decision of opposing claims of priority of right or invention, declared:

"But nothing in this act contained shall be construed to deprive an original and true inventor of the right to a patent for his invention by reason of his having previously taken out letters patent therefor in a foreign country, and the same having been published, at any time within six months next preceding the filing of his specification and drawings. And whenever the applicant shall request it, the patent shall take date from the time of the filing of the specification and drawings, not however exceeding six months prior to the actual issuing of the patent; and on like request, and the payment of the duty herein required, by any applicant, his specification and drawings shall be filed in the secret archives of the office until he shall furnish the model and the patent be issued, not exceeding the term of one year, the applicant being entitled to notice of interfering applications." 5 Stat. 120, c. 357.

We come next to the act of March 3, 1839, entitled "An act in addition to 'An act to promote the progress of the useful arts.'" 5 Stat. 354, c. 88, § 6. By that act it was declared:

"That no person shall be debarred from receiving a patent for any invention or discovery, as provided in the act approved on the fourth day of July, one thousand eight hundred and thirty-six, to which this is additional, by reason of the same having been patented in a foreign country more than six months prior to his application: provided, that the same shall not have been introduced into public and common use in the United States, prior to the application for such patent: and provided, also, that in all cases every such patent shall be limited to the

term of fourteen years from the date or publication of such foreign letters patent."

By the act of March 2, 1861, it was provided that all patents thereafter granted should remain in force "for the term of seventeen years from the date of issue," and all extensions of such patents were prohibited. 12 Stat. 246, c. 88, § 16.

By an act approved June 27, 1866 (14 Stat. 74, c. 140), provision was made for the appointment of three persons, learned in the law, as commissioners, "to revise, simplify, arrange, and consolidate all statutes of the United States, general and permanent in their nature," which should be in force at the time of their final report. They were directed to "bring together all statutes and parts of statutes which, from similarity of subject, ought to be brought together, omitting redundant or obsolete enactments, and making such alterations as may be neces sary to reconcile the contradictions, supply the omissions, and amend the imperfections of the original text; and they shall arrange the same under titles, chapters, and sections, or other suitable divisions and subdivisions, with head-notes briefly expressive of the matter contained in such divisions; also with side-notes, so drawn as to point to the contents of the text, and with references to the original text from which each section is compiled, and to the decisions of the federal courts, explaining or expounding the same, and also to such decisions of the state courts as they may deem expedient; and they shall provide by a temporary index, or other expedient means, for an easy reference to every portion of their report." Upon the comple tion of their work they were to "cause a copy of the same, in print, to be submitted to congress, that the statutes so revised and consolidated may be re-enacted, if congress shall so determine; and at the same time they shall also suggest to congress such contradictions, omissions, and* imperfections as may appear in the original text, with the mode in which they have reconciled, supplied, and amended the same; and they may also designate such statutes or parts of statutes as, in their judgment, ought to be repealed, with their reasons for such repeal." They were authorized to cause their work to be printed in parts as fast as it was ready for the press, and distribute the same to members of congress, and to such other persons, in limited numbers, as they saw fit, for the purpose of obtaining their suggestions. 14 Stat. 74, c. 140, §§ 1-4, incl.

One of the results of that statute was the passage by congress of the act of July 8, 1870, entitled "An act to revise, consolidate, and amend the statutes relating to patents and copyrights." 16 Stat. 198, c. 230. The original bill upon which that act was based was the work of the revisers appointed under the above act of 1866.

The act of 1870 declared, among other things, that every patent should be express

ed for the term of 17 years, and should date as of a day not later than 6 months from the time at which it was passed and allowed. Sections 22, 23.

But the parts of that act which have most to do with the case before us are its twentyfourth and twenty-fifth sections. The twenty-fourth section describes, in the language of section 4886 of the Revised Statutes, as above quoted, those who are entitled to patents. The twenty-fifth section is in these words:

"Section 25. That no person shall be debarred from receiving a patent for his invention or discovery, nor shall any patent be declared invalid, by reason of its having been first patented or caused to be patented in a foreign country: provided, the same shall not have been introduced into public use in the United States for more than two years prior to the application, and that the patent shall expire at the same time with the foreign patent, or, if there be more than one, at the same time with the one having the shortest term; but in no case shall it be in force more than seventeen years." 16 Stat. 198, 201, c. 230.

From this history of acts of congress relating to patents for inventions, it appears:

(1) That in all of them congress had in mind the date of an application for a patent, the date of the filing of specifications, and the date of the patent.

(2) That, under the act of 1836, a patent could not be granted if it appeared that the applicant was not the original and first inventor or discoverer, or that any part of that which was claimed as new had before been invented or discovered, or patented or described in any foreign publication in use in this or any foreign country. Yet an original and true inventor was not to be deprived of a patent for his invention "by reason of his having previously taken out letters patent therefor in a foreign country, and the same having been published at any time within six months next preceding the filing of his specification and drawings."

(3) That, under the act of 1839, an inventor, whose invention had not been introduced into public and common use in the United States prior to the application for a patent, should not be debarred from receiving a patent by reason of his invention "having been patented in a foreign country more than six months prior to his application."

(4) That, under the act of 1870, one whose invention had not been introduced into public use in the United States for more than two years prior to the application for an American patent should not be debarred from receiving a patent by reason of his invention "having been first patented or caused to be patented in a foreign country." -those words not being qualified, as in the act of 1839, by any reference to the date of the application.

(5) That when an American patent was

granted, in conformity with the sixth section of the act of 1839, for an invention "patented in a foreign country more than six months prior to the American application," it expired, in every case, at the end of 14 years "from the date or publication of such foreign letters patent;" and when in conformity with the twenty-fifth section of the act of 1870, a patent was granted for an invention "first patented or caused to be patented in a foreign country," it expired “at the same time with the foreign patent," or, if there were more than one, "at the same time with the one having the shortest term.": (6) That, under the Revised Statutes, while' a patent could not be withheld nor deemed invalid by reason of the invention "having been first patented or caused to be patented in a foreign country, unless the same has been introduced into public use in the United States more than two years prior to the application," yet "every patent granted for an invention previously patented in a foreign country shall be so limited as to expire at the same time" with the one having the shortest term,-in no case to remain in force longer than 17 years.

Notwithstanding the difference in the wording of these statutes, the plaintiff contends that the words in the act of 1870, "first patented or caused to be patented in a foreign country," and the same words, together with the words, "previously patented in a foreign country," in the Revised Statutes, refer to a foreign patent issued prior to the application for the American patent, and do not embrace a foreign patent issued after such application, although issued before the American patent was issued. In other words, the contention is that when the same invention is patented both in this country and abroad, the American patent remains in force for 17 years from its date, if the foreign patent was issued after the application for, although prior to the date of, the American patent.

What was the interpretation placed upon the act of 1870 by the executive branch of the government?

The objects and scope of that act were considered by Mr. Fisher, the commissioner of patents, in several cases, within a few months after the passage of the act of 1870. The decisions of the commissioner derive some importance from the fact that they were rendered while the changes made by the act of 1870 were fresh in the minds of those who, like himself, took special inter est in legislation affecting patent rights.

In Mushet's Case, decided September 19, 1870, the question was as to the extension of letters patent for an improvement in the manufacture of iron and steel, granted May 26, 1857, and antedated September 2, 1856. The commissioner, referring to the twentyfifth section of the act of 1870, said: "When therefore, the statute declares that the patent shall expire at the same time with the

foreign patent, I am very clearly of the opinlon that if, at the expiration of the original term, it appears that the foreign patent has already expired, no prolongation of the term of the American patent can be permitted. This is in accordance with the letter and spirit of the enactment. The intention of congress obviously was to obtain for this country the free use of the inventions of foreigners as soon as they became free abroad. This is indicated by the use of the phrase, 'first patented, or caused to be patented, in a foreign country,' for it was presumable that American citizens would obtain their first patent here, while a foreigner would first patent his invention in his own country. The statute was designed to prevent a foreigner from spending his time and capital in the development of an invention in his own country, and then coming to this to enjoy a further monopoly, when the invention had become free at home. The result of such a course would be that while the foreign country was developing the invention and enjoying its benefits, its use could be interdicted here; while, if the term of the monopoly could be further extended here, the market could be controlled long after the foreign nation was prepared to flood this country with the unpatented products of the patented process. It appears in this case that under the Bessemer patents, assisted by the Mushet process, English manufacturers have been enabled to send to this country 100,000 tons of steel railroad iron, against 10,000 tons manufactured here. If, now, when both patents are free to all English manufacturers, the American manufacturer must pay a royalty for those inventions, he is immediately placed at a disadvantage as compared with his foreign competitor, and this by the act of the patentee, either in neglecting to obtain that extension abroad, for which he sues in this country, or by devoting his time during the original term to the development of the invention abroad to the neglect of the American field." Com. Dec. (1870) 106, 108.

A like ruling was made October 6, 1870, in the Case of Ward, an American inventor. Com. Dec. (1870) 126.

* In Boyer's Case, decided October 25, 1870, which was an application for the extension of letters patent granted November 4, 1856, to one Evans, for an improvement in spading machines, it appears that Evans obtained letters patent in England, dated December 17, 1855, sealed May 27, 1856, and which expired December 17, 1869. The commissioner, referring to section 25 of the act of 1870, said: "In the case of Mushet it was a foreign inventor, and in the case of Ward an American inventor, who were seeking the extension; but in both cases letters patent were first obtained in the foreign country. * * I was and am of the opinion that the policy which congress plainly declares in this section is that if a foreigner obtains a patent in .15s.c.-33

his own country, and permits it to expire there, it shall also expire in this country, so that the right to use the invention without liability to the inventor shall be simultaneous in this and in the most favored foreign nation. Therefore, while I held that the section did not shorten the term of patents already granted, I also held that it did prevent the extension of such patents when the original term expired. It would, I conceive, be a manifest impropriety to grant to a patentee seven additional years of protection, when the fact has been brought home to me that he first patented his invention abroad, and that his foreign patent has expired. Whether the section in question does or does not actually forbid the extension, it so clearly declares that the American patent shall not survive the death of the prior foreign patent that a decent respect for the declared policy of the legislature would determine an officer, while exercising his discretion, to exercise it in accordance with that policy, and not in opposition to it. It is urged, however, that congress intended only to reach the case of the foreign inventor who first patented his invention in his own country, and that they did not intend to put the American inventor, who obtained a patent abroad, in a worse position than if he had obtained no patent at all in a foreign country. It is said, with much force, that if the American patentee had not obtained an English or French patent, the invention would be free in those countries, even during the lifetime of his original patent; and that 2

the fact that it was free there would be no bar to the grant of an extension. This may be true, but we have no means of judging of the intention of congress in this case, except by the language employed in the declaration of their will. The language of the statute is, 'first patented, or caused to be patented, in a foreign country.' This, by its terms, includes American citizens as well as foreigners who first take out a patent abroad. The term 'patented' may well be construed as applying to foreigners obtaining patents in their own country, and the phrase, 'caused to be patented,' to such persons, not citizens of the same country, including Americans, as should cause their inventions to be introduced or patented there. It does not include either foreigners or citizens who first obtain their patents in this country. It was supposed that American inventors would first obtain their patents here, in which case they would not have been within the terms of the section; but if, on the other hand, they choose to obtain patents abroad before doing so in their own country, they were to be placed upon the same platform as the foreign patentee. It is reasonable to suppose that the inventor will follow up his earliest patent with the greatest vigor, and that, other things being equal, he will protect his invention first in that country where he expects to make most use of it. If, therefore, the American inventor chooses to exhibit this preference for a foreign country,