delivered the opinion of the Court.
Three suits were brought in the District Court for Delaware against the respondent as exclusive licensee under three separate patents issued to Francis W. Dunmore and Percival D. Lowell. The bills recite that the inventions were made while the patentees were employed in the radio laboratories of the Bureau of Standards, and are therefore, • in equity, the property of the United States. The prayers are for a declaration that the respondent is a trustee for the Government, and, as such, required to assign to the United States all its right, title and interest in the patents; for an accounting of all moneys received as licensee, and for general relief. The District Court consolidated the cases for trial, and after a hearing dismissed the bills.1 The Court of Appeals for the Third Circuit affirmed the decree.2
The courts-below concurred in findings which are not challenged and, in summary, are:
The Bureau of Standards is a subdivision of the Department of Commerce.3 Its' functions consist' in the.. custody of standards; the comparison of .standards used in scientific investigations, engineering, manufacturing, •' commerce, and educational institutions with those adopted. *183or recognized by the Government; the construction of standards, their multiples or subdivisions; the testing and calibration of standard measuring apparatus; the solution of problems which arise in connection with standards; and the physical properties of materials. In 1915 the Bureau was also charged by Congress with the duty of investigation and standardization of methods and instruments employed in radio communication, for which special appropriations were made.'4 In recent years it has been engaged in' research and testing work of various kinds for the benefit of private industries, other departments of the Govern.ment, and the general public.5
The Bureau is composed of divisions, each charged with a specified field of activity, one of which is the electrical, division. These are further subdivided into- sections. One section of the electrical division is the radio section. In 1921 and 1922 the employees in the laboratory of this section numbered approximately twenty men doing tech-, nical work, and. some draftsmen and mechanics. The twenty were engaged in testing radio apparatus and methods and in radio research work. They were subdivided into ten groups, each group having a chief. The work of each group was defined in outlines by the chief or alternate chief of the section.
Dunmore and Lowell were employed in the radio section and engaged in research and testing in the laboratory. In the outlines of laboratory work the subject of “ airplane radio ” was assigned to the group of which Dunmore was chief and Lowell a member. The subject of “ radio receiving sets ” was assigned to a group of which J. L. Preston was chief, but to which neither Lowell nor Dunmore belonged.
*184In May, 1921, the Air Corps of the Army and the Bureau of Standards entered into an arrangement whereby the latter undertook the prosecution of forty-four research projects for the benefit of the Air Corps. To pay the cost of such work, the Corps transferred and allocated to the Bureau the sum of $267,500. Projects Nos. 37 to 42; inclusive, relating to the use of radio in connection with aircraft, were assigned to the radio section and $25,000 was allocated to pay the cost of the work; Project No. 38 was styled “ visual indicator for radio signals,” 'and suggested the construction of a modification ,o£ what was known as an " Eckhart recorder.” Project No. 42 was styled ".airship bomb control and marine torpedo control.” Both were problems of design merely.
In the summer of 1921 Dunmore, as chief of the group to which “ airplane radio ” problems had been assigned, without further instructions from his superiors, picked out for himself one of these navy problems, that of operating a relay for remote control of bombs on airships and torpedoes in the sea, “ as one of particular interest and having perhaps a rather easy solution, and worked on it.” In September he solved it.
In the midst of aircraft' investigations and numerous routine problems of the section, Dunmore was wrestling in his own mind, impelled thereto solely by his own scientific' curiosity, with the subject of substituting house-lighting alternating current for direct battery current in radio apparatus. He obtained a relay for operating a telegraph instrument which was in no way related to the remote control relay devised for aircraft use. The conception of the application of alternating'current concerned particularly broadcast reception. This idea was eon-' ceived by Dunmore August 3, 1921, and he reduced the invention to practice December 16, 1921. Early in 1922 he advised his superior of his invention and spent ¿ddi*185tional time in perfecting the details. February 27, 1922 he filed an application for a patent.
In the fall of 1921 both Dunmore and Lowell were considering the problem of applying alternating current to broadcast receiving sets. This project was'not involved in or suggested by jthe problems with which the radio section was then dealing and was hot assigned by any superior as a task to be solved by either of these employees. It was independent of their work and voluntarily assumed.
While performing their regular tasks they experimented at the laboratory in devising apparatus-..for operating a radio receiving set by alternating current with the hum' incident thereto eliminated. The invention was completed on December 10,1921. Before _its completion no instructions were received from and no conversations relative to the invention were held by these employees with’ the head of the radio section, or with any superior.
' They also conceived the idea of energizing a dynamic type of loud speaker from an alternating current house-lighting circuit, and reduced the invention to practice on January 25, 1922. March 21, 1922, they filed an application for a “ power amplifier.” The conception embodied in this patent was devised by the patentees without suggestion, instruction, or assignment from any superior.
Dunmore and Lowell were permitted by their chief after the discoveries hád been brought to his attention, to pursue their work in the laboratory and to perfect the' devices embodying their inventions. No one' advised them prior to the filing of applications for patents that they would be expected to assign the patents to the United States or to grant the Government exclusive rights thereunder. "
The respondent concedes’that the United States may practice the inventions without payment of royalty, but asserts that all others are excluded, during the life of the *186patents, from using, them without the respondent’s consent. The petitioner insists that the circumstances require a declaration either that the Government has sole and exclusive property in the inventions, or that they have been dedicated to the public so that .anyone may use them.
First. By Article I, § 8, clause 8 of the Constitution, Congress is given power to promote the progress of science and the useful arts by securing for limited times to inventors the exclusive rights to their respective discoveries. R.S. 4886 as amended (.U.S. Code, Title 35, § 31) is the last of a' series of statutes which since 1793 have implemented the constitutional provision.
Though often so characterized, a patent is not, accurately speaking, a- monopoly, for it is not created by the executive authority at thé expense and to the prejudice of all the community except the grantee of the patent. Seymour v. Osborne, 11 Wall. 516, 533. The term monopoly connotes the giving of an exclusive privilege for buying, selling, working or using a thing which the public freely enjoyed prior to the grant.6 Thus a monopoly/ takes something from the people. An. inventor deprives the public of nothing which it enjoyed before his discovery, but gives something of value to the community by adding to the sum of human knowledge. United States v. Bell Telephone Co., 167 U.S. 224, 239; Paper Bag Patent Case, 210 U.S. 405, 424; Brooks v. Jenkins, 3 McLean 432, 437; Parker v. Haworth, 4 McLean 370, 372; Allen v. Hunter, 6 McLean 303, 305-306; Attorney General v. Rumford Chemical Works, 2 Bann. & Ard. 298, 302. He may keep his invention secret and reap its fruits indefinitely. In consideration of its disclosure and the consequent benefit to the community, the patent is granted. An exclusive enjoyment is guaranteed him for *187seventeen years, but upon the expiration of that period, the knowledge of the invention enufes to the people, who are thus enabled without restriction to practice it and profit by its use. Kendall v. Winsor, 21 How. 322, 327; United States v. Bell Telephone Co., supra, p. 239. To this end the law requires such disclosure to be made in the application for patent that others skilled in the art may understand the invention and how to put it to use.7
A patent is property and title to it can pass only by assignment. If not yet issued, an agreement to assign when issued, if valid as a contract, will be specifically enforced. The respective rights and'obligations of employer and employee, touching an invention conceived by the latter, spring from the contract of employment.
One employed to make an invéntion, who succeeds, during his term of service, in accomplishing that task, is bound to assign to his, employer any patent obtained. The reason is that he has only produced that which he was employed to invent. His invention is the precise subject of the contract of employment. A term of the agreement necessarily is that what he is paid to produce belongs to his paymaster. Standard Parts Co. v. Peck, 264 U.S. 52. On the other hand, if the employment be genéral, albeit it cover a field of labor and effort in .the performance of which the employee conceived the invention for which he obtained a patent, the contract is not so broadly construed as to require an assignment of the patent. Hapgood v. Hewitt, 119 U.S. 226; Dalzell v. Dueber Watch Case Mfg. Co.149 U.S. 315. In the latter case it was said [p. 320]:
“ But a manufacturing corporation, which has employed a skilled workman, for a stated compensation, to take charge of its works, and to devote his time and services to devising and making improvements in articles *188there manufactured, is not entitled to a conveyance of patents obtained for inventions made by him while so employed, in the absence of express agreement to that effect.”
The reluctance of courts to imply or infer an agreement by the employee to assign his patent is due to a recognition of the peculiar nature of the act of invention, which consists neither in finding out the laws of nature, nor in fruitful' reséarch as to the operation of natural laws, but in discovering how those laws may be utilized or applied for some beneficial purpose, by a process, a device or a machine. It is the result of an inventive act, the birth of an idea and its reduction to practice; the product of original thought; a.concept demonstrated to be true by practical application or embodiment in tangible form. Clark Thread Co. v. Willimantic Linen Co., 140 U.S. 481, 489; Symington Co. v. National Castings Co., 250 U.S. 383, 386; Pyrene Mfg. Co. v. Boyce, 292 Fed. 480, 481.
Though.¡the mental concept is embodied or realized in, ,a mechanism or a physical or chemical aggregate, the embodiment is not the invention and is not the subject of a patent. This distinction between the idea arid its application in practice is the basis of the rule that employment merely to design or to construct Or to devise methods of manufacture is not thq same as employment to invent.; Recognition of the nature of the act of invention also defines the limits of the so-called shop-right,, which shortly stated, is that where a servant,. during his hours of employment, working with his master’s materials and appliances, conceives and perfects an invention for which he obtains a patent, he must, accord his master a non-exclusive right to practice the invention. McClurg v. Kingsland, 1 How. 202; Solomons v. United States, 137 U.S. 342; Lane & Bodley Co. v. Locke, 150 U.S. 193. This is ari application of equitable principles. Since the servant uses his master’s time, facilities and materials to attain a *189concrete result, the latter is in equity entitled to use that which embodies his own property and to duplicate it as often as he may find occasion to employ similar appliances in his business. But the employer in such a case has no equity tq demand a conveyance of the invention, whiph is . the original conceptiqn of the employee alone, in which the employer had no part. This remains the property of him who conceived it, together with the right conferred by the patent, to exclude all others than the employer from the accruing benefits. These principles are settled '"V-as respects private employment. —_-.C
. Second. Does the character of the service call for different rules as to the relative rights of the United States and its employees?
The title,of a patentee is subject to no superior right of the Government. The grant of letters patent is not, as in England, a matter of grace or. favor, so that conditions xhay be annexed at the pleasure of the executive. To the laws passed by the Congress, and to them alone, may we look for guidance as to the exteiit and the limitations of the respective rights of the inventor and the public. Attorney General v. Rumford Chemical Works, supra, at pp. 303-4. And this court has held that ,the Constitution evinces no-public policy, which requires the holder of a patent to cede the use or benefit of the invention to the United States, even though the discovery concerns matters which can properly be used only by the Government; as, for example, munition's of war. James v. Campbell, 104 U.S. 356, 358. Hollister v. Benedict Mfg. Co., 113 U.S. 59, 67.
No servant of the United States has by statute been disqualified from applying for and receiving a patent for his invention, save officers and employees of the Patent Office during the period for which they hold their appointments.8 *190This being so, this court has applied the rules enforced as between private employers and their servants'to the relation between the Government and its officers and employees.
United States v. Burns, 12 Wall. 246, was a suit in the Court of Claims by an army officer as assignee of a patent obtained by another such officer for a military fent, to recover royalty under a contract made by the Secretary of War for the use of the tents. The court said, in affirming a judgment for the plaintiff [p. 252]:
“ If an officer in the military service, not specially employed to make experiments with a view to suggest improvements, devisés a new and valuable improvement in arms, tents, or any other kind of war material, he is entitled to the benefit of it, and to letters-patent for the improvement from the United States, equally with any other citizen not engaged in such service; and the government cannot, after the patent is issued, make use of the improvement any more than, a private individual, without' license' of the inventor or making compensation to him.”
In United States v. Palmer, 128 U.S. 262, Palmer, a lieutenant in the army, patented certain improvements in infantry accoutrements. An' army board recommended their use and the Secretary of War confirmed the recommendation. The United States manufactured, and purchased a large number of the articles. Palmer brought suit in the Court of Claims for a sum alleged to be a fair and reasonable royalty. From a judgment for the plaintiff the United States appealed. This court, in affirming, said [p. 270]:
“ It was at one time somewhat doubted 'whether the government might not be entitled to the use and benefit of every patented invention, by analogy to the English law which reserves this right to the crown. But that *191notion ho longer exists. It was ignored in the case of Burns.”
These principles were recognized in later cases involving the relative rights of the Government and its employees in instances where the subject-matter of the patent was useful to the public generally. While these did not involve a claim to an assignment of the patent,: the court reiterated the views earlier announced.
In Solomons v. United States, 137 U.S. 342, 346, it was said:
“ The government has no more power to appropriate a man’s property invested in a patent than it has to take his property invested in real estate; nor does the mere fact that an inventor is at the time of his invention in the employ of the government transfer to it any title to, or interest in it. An employé, performing all the duties assigned to him in his department of service, may exercise his inventive faculties in any direction he chooses, with the assurance that whatever invention.he may thus conceive and perfect is his individual property. There is no difference between the government and any other em-player in this respect.”-
And in Gill v. United States, 160 U.S. 426, 435:
“ There is no doubt whatever of the proposition laid down in Solomons case, that the mere fact that a person is in the employ of the-government does not preclude him from making improvements in the machines with which he is connected, and obtaining patents therefor, as his individual property, and'that in such case the government would have no more right to seize upon and appropriate such property, than any other proprietor would have. ...”
The distinction between an employment to make an invention and a general employment in the course of *192which the servant conceives an invention has been recognized by the executive department of the Government., A lieutenant in the navy patented an anchor while he was on duty in the Bureau of Equipment and Recruiting, which was charged with the duty of furnishing anchors for the navy; he was not while attached to the bureau specially- employed* to make experiments with a view to suggesting improvements to anchors or assigned' the duty of making or improving. The Attorney General advisecl that as the invention did not relate to a matter as to which the lieutenant was specially directed to experiment with a view to suggesting improvements, he was entitled to compensation from the Government for the use of his invention in addition to his salary or pay as a navy officer.9
A similar ruling, was .made with respect to an ensign who obtained a patent for improvements in “ B.L.R. ordnance ” and who offered to sell the improvements, pr the right to use.them, to the Government. It was held that the navy might properly make a contract with him to this .end.10 ' ■ ■ •
The United States is entitled, in the same way and to the same extent as a private employer, to shop-rights, that is, the free and non-exclusive use of "a patent which results from effort of its employee in his working hours and with material belonging to the. Government. ■ Solomons v. United States, supra, pp. 346-7; McAleer v. United States, 150 U.S. 424; Gill v. United States, supra.
The statutes, decisions and administrative, practice negate the existence of a duty binding one in the service of the Government different from the obligation of one in private- employment. .
*193' Third. When the United States filed its bills it recognized the law as heretofore declared; realized that it must like any other employer, if it desired an assignment of the respondent’s rights, prove a contractual obligation on the part of Lowell and Dunmore to .assign the patents to the Government. The averments clearly disclose this. The bill in No. 316 is typical. After reciting that the employees were laboratory apprentice and associate physicist, and laboratory assistant and associate physicist, respectively, and that one of their duties was “ to carry on investigation research and experimentation in such problems relating to radio and wireless as might be assigned to them by their superiors,” it is charged “jin the course of his employment as aforesaid, there was assigned to said Lowell by his superiors in said radio section, for investigation and research, the problem of developing a radio receiving set capable of operation by alternating current. ...”
Thus' the Government understood that respondent could be deprived of rights under the patents only by proof that Dunmore and Lowell were employed to devise the inventions. The findings of the courts below show how far the proofs fell short of sustaining these averments.
The Government is consequently driven to the contention that though the employees were not specifically assigned the task of making the inventions (as in Standard Parts Co. v. Peck, supra), still, as the discoveries were “ within the general field of their research and inventive work,” the United States is entitled to an assignment of the patents. • The courts below expressly found that Dun-more and Lowell did not agree to exercise their inventive faculties in their work, and that invention was not within its scope. In this connection it is to be remembered that the written evidence of their employment does not mention research, much less invention; that never was there *194a. word said to either of them, prior to- their discoveries, concerning invention or patents or their duties or obligations respecting these-matters; that as shown by the records of the patent office, employees of the Bureau of Standards and other departments had, while so employed, received numerous patents and enjoyed the exclusive rights obtained as against all private persons without let or hindrance from the Government.11 In no proper *195sense may it be said that the contract of employment contemplated invention; everything that Dunmore and Lowell knew negatived the theory that they were employed to invent; they knew, on the contrary, that the past and then present practice was that the employees of the Burean were allowed to take patents on their inventions and have the benefits thereby conferred save as to use by the *196United States. .The circumstances preclude the implication of any agreement to assign their inventions or patents.
The record affords even less'basis for inferring a contract on the part of the inventors to refrain from patenting their discoveries than for finding an agreement to assign them.
The bills aver that the inventions and patents are held in trust for the United States, and that the court should so declare. It is claimed that as 'the work of the Bureau, including all that Dunmor'e and Lowell did, was in the public interest, these public servants had dedicated ■ the offspring of their brains to the public, and so held their, patents in "trust for the common weal, represented here in a corporate capacity by the United States. The patentees, we are told, should surrender the patents- for cancellation, and the respondent must also give up its rights under the patents.
The.trust cannot be express. Every fact in the case negatives the existence of one. Nor can'it arise ex maleficio. The employees’ conduct was not fraudulent in any respect. They promptly disclosed their inventions. Their superiors encouraged them to. proceed in perfecting and applying the discoveries. Their note books and reports disclosed the work they were.doing, and there is not a syllable to suggest their use of time or material was clandestine or improper. No word was spoken regarding any claim of title by the Government until after applications for patents were filed. And, as we have seen, no such trust has been spelled out of the relation of master and servant, even in the cases where the employee has perfected his invention by the use of his employer’s time and materials. The case's recognizing the doctrine of shop rights may be said to fix a trust upon the employee in favor of his master as respects the use of the invention *197by the latter, but they do not affect the title to the patent and the exclusive rights conferred by it against the public.
The Government’s position in reality is, and must be, that a public policy, to be declared by á court, forbids one employed by the United States, for scientific research,' to obtain a patent for what he invents, though neither the Constitution nor any statute so declares.'
Where shall the courts set the limits of the doctrine? For, confessedly, it must be limited. The. field of research is as broad as that of science itself. If the petitioner is entitled to-a cancellation of the patents in this-case, would' it be so entitled if the employees had done their work at home, in their own time and with their own appliances and materials? What is to be said of an invention evolved as the result of the solution of a problem in a realm apart from that to which the employee is assigned by his official superiors? We have seen that the Bureau has numerous divisions. It is entirely possible that an employee in one division may make an invention falling within the work of some other diviéion. Indeed this ease presents that exact situation, for the inventions in' question had to do with radio reception, a matter assigned to a group of which Dunmore and Lowell were not members. Did the mere fact of their employment by the Bureau require these employees to cede to the public every device they might conceive?
Is the doctrine to be applied only where the employment is in a bureau devoted to scientific investigation pro bono publico? Unless it is to be so circumscribed, the statements of this court in United States v. Burns, supra, Solomons v. United States, supra, and Gill v. United States, supra, must be held for naught.
Again, what are to be defined as bureaus devoted entirely to scientific research? It is. common knowlédge that many in the Department of Agriculture conduct re*198searches and investigations; that' divisions of the War and Navy Departments do the like; and doubtless there are many other bureaus and sections in various departments of government where employees are set the task of solving problems all of which involve more or less of science. Shall the field of the scientist be distinguished from the art of a skilled mechanic? Is it conceivable that one working on a formula for a drug or an antiseptic in.,the Department of Agriculture stands in a different class from á machinist in an arsenal? Is the distinction to bfe that where the government department is, so to speak, a business department operating a business activity of the government, the employee has the same rights as one in private employment, whereas if his work be for. a bureau interested more particularly in what may be termed scientific research he is upon notice that whatever he invents in the field of activity of the bureau, broadly defined, belongs to the public and is unpatentable? Illustrations of the difficulties which would attend an attempt to define the policy for which the Government contends might be multiplied indefinitely.
The courts ought not to declare any such policy; its formulation belongs solely to the Congress. Will permission to an employee to enjoy patent rights as against all others than the Government tend to the. improvement of the public service by attracting a higher class of employées? Is there in fact greater benefit to the people in a dedication to the public of inventions conceived by officers of government, than in their exploitation under patents by private industry? Should certain classes of invention be treated in one way and other classes differently? These are not legal questions, which courts are-competent to answer. They are practical questions, and the decision as to what will accomplish the greatest good for the inventor, the Government and the public rests *199with the Congress. We should not read into the .patent laws limitations and conditions which the legislature has not expressed.
Fourth. Moreover, we are of opinion Congress has approved a policy at variance with the petitioner’s contentions. This is demonstrated by examination of two statutes, with their legislative history, and the hearings and debates respecting proposed legislation which failed of passage..
Since 1883 there has been in force an act12 which provides:
“ The Secretary of the Interior [now the Secretary of Commerce, Act of February 14, 1903, c. 552,' § 12, 32 Stat. 830] and the Commissioner of Patents are authorized to grant any officer of thé government, except officers and employees of the Patent Office, a patent for any invention of the classes mentioned in section forty eight hundred and eighty six of the Revised Statutes, when such invention is used or to be used in the public service, without the payment of any fee:' Provided, That the applicant in his application shall state that the invention described therein, if patented, may be used by the government or any of its officers or employees in the prosecution of work for the-government, or by any other person in the United States, without the payment to him of any royalty thereon, -which stipulation shall be included 'in the patent.”
This law. was evidently intended to encourage government employees to' obtain patents, by relieving them of the payment of the usual fees. The condition upon which the privilege was accorded is stated as the grant of free use by the government, “ its officers or employees in the prosecution of work for the government, or by.any *200other person m the United States.” For some time the effect of the italicized phrase was a matter of doubt.
In 1910' the Judge Advocate General of the Army rendered an opinion to the effect that one taking a patent pursuant to the act threw his invention “ open to public and private use in. the United States?’13 It was later realized that this view made such a patent a contradiction in terms, for” it secured no exclusive right to anyone. In 1918 the Judge Advocate General gave a well-reasoned opinion14 holding that if the státute were construed to involve a dedication to the public, the so-called patent would at most amount to a publication or prior reference. He concluded that the intent of the act was that the free use of the invention extended only to the Government or those doing work for it. A similar construction was adopted in an opinion of the Attorney General.15 Several federal courts referred to the statute and in dicta indicated disagreement with the views expressed in these later opinions.16
The departments of government were anxious to have the situation cleared, and repeatedly requested that the act be amended. Pursuant to the recommendations of the War Department an amendment was enacted April 30, 1928.17 The.proviso was changed to read:
“ Provided, That the applicant, in his application shall state that the invention described therein, if patented, *201may be manufactured or used by. or for the Government for governmental purposes without the payment to him of any royalty thereon, which stipulation shall’be included in the patent.”
The legislative history of the amendment clearly discloses the purpose to save to the employee his right to exclude the public.18 In the report of the Senate Committee on Patents submitted with the amendment, the object of the bill was said to be the protection of the interests of the Government, primarily by securing patents on inventions made by officers and employees, presently useful in the interest of the national defense or those which may prove useful in the interest of national defense in the future; and secondarily, to encourage the patenting of inventions by officers and employees of the Government with the view to future protection of the Government against suits for infringement of patents. The committee stated that the bill had the approval of the Commissioner of Patents and was introduced at the request of the Secretary of War. Appended to the report is a copy of a letter of the Secretary of War addressed to the committees of both Houses stating that the language of the legislation then- existing was susceptible of two interpretations contrary to each other. The letter quoted the proviso.of the section as it then stood, and continued:
“ It is clear that a literal construction of this proviso would work a dedication to the public of every patent taken out under the act. If the proviso must be construed literally we would have a situation wherein all the patents taken out under the act would be nullified by the *202very terms of the act under which they were granted, for the reason that a patent which does not carry with it the limited monopoly referred to in the Constitution is' in reality not a patent at all. The only value that a patent hás is the right that it extends to the patentee to exclude all others from making, using, or selling the invention for a certain period of years. A patent that is dedicated to the public is virtually the same as a patent that has expired'.”
After referring to the interpretation of the Judge Advocate General and the Attorney General and mentioning that no satisfactory adjudication of the question had been afforded by the courts, the letter went on to state:
“ Because of the ambiguity referred to and the unsettled condition that has arisen therefrom, it has become the policy of the War Department to advise all its personnel who desire to file applications for letters patent, to do so under the general law and pay the required, patent-office fee in each case.”
And added:
“ If the proposed legislation is enacted into law, Government officers and employees may unhesitatingly avail themselves of the benefits of the act with full assurance that in so doing their patentas not dedicated to the public by operation of law. The War Department has been favoring legislation along the lilies of the proposed bill for the past five or six years.”
When the bill .came up for passage in the House a colloquy occurred which clearly disclosed the purpose of the amendment.19 The intent was that a government *203employee who in the course of his employment conceives an invention should afford the Government free use thereof, but should be protected in his right to exclude all others.- If Dunmore.and Lowell, who tendered the Government a non-exclusive license without royalty, and always understood that the Government might use their inventions freely, had proceeded under the act of 1883, they would have retained their rights as against all but -the United States. This is clear from the executive interpretation of the act. But for greater .security they pursued the very course then advised by the law officers of the Government. It would be surprising if they thus lost all rights as patentees; especially so, since Congress has now confirmed the soundness-of the views held by the law officers of the. Government.
*204Until the year 1910 the Court of Claims was without •jurisdiction to award compensation to the owner of a patent for unauthorized use by the United States or,.its agents. Its power extended only to the trial of claims based upon an express or implied contract for such use.20 In that year Congress enlarged the'jurisdiction to embrace the former class of claims.21 'In giving consent to be sued, the restriction was imposed that it should not extend to owners of patents obtained by employees of the Government while in the service. From this it is inferred that Congress recognized no right in such patentees to exclude the public from practicing the invention. But *205an examination of the legislative record completely refutes the contention.
The House Committee in reporting the bill, after referring to the law as laid down in the Solomons case, said: “ The United States in such a case has an implied license to use the patent without compensation, for the reason that the inventor used the time or the money or the material of the United States in perfecting his invention. The use by the United States of such a patented invention without any authority from the owner thereof is a lawful use under existing law, and we have inserted the words ' or lawful right to use the same ’ in order to make it plain that we do not intend to make any change in existing law in this respect, and do not intend to give the owner of such a patent any claim against the United States for its use.” 22 From this it is clear that Congress had no purpose to declare a policy at variance with the decisions of this court.
The executive departments have advocated legislation regulating the taking of patents by government employees and the administration by government agencies of the patents so obtained. In 1919 and 1920 a bill sponsored by the Interior Department was introduced. It provided for the voluntary assignment or license by any government employee, to the Federal Trade Commission, of a patent applied for by him, and the licensing of manufacturers by the Commission, the license fees to be paid into the Treasury and such part of them as the President might deem equitable to be turned over to the patentee.23 In the hearings and reports upon this measure stress was laid not only upon the fact that action by an employee thereunder would be' vólüiltary, but that the inventor would be protected at least to some extent in his private *206right of exclusion. It was recognized that the Government could not compel an assignment, was incapable of taking such assignment or administering the patent, and that it had shop-rights in a patent perfected by the use of government material and in government working time. Nothing contained in the ,bill itself or in the hearings or reports indicates any intent to change the existing and well understood rights of government employees who obtain patents for their inventions made while in the service. The measure failed of passage.
. In 1923 the President sent to the Congress the report of an interdepartmental patents-board created by executive order to study the question of patents within the government service and to recommend regulations establishing a policy to be followed in respect thereof. The report adverted to the fact that in the absence of a contract providing otherwise a patent- taken out by a government employee, and any invention developed by on£ in the public service, is th.e sole property of the inventor. The committee recommended strongly against public-dedication of such an invention, saying that this in effect voids a patent, and, if this were not so, “there is little incentive for anyone to take up a patent and spend time, effort, and money ... on its commercial development without at least some measure of protection against others free to take the patent as developed by him and .compete in its use. In such a case one of the chief objects of the patent law would be defeated.” 24 In full accord is- the statement on behalf of the Department of the Interior in a memorandum furnished with respect to the bill introduced in 1919.25
With respect to a policy of permitting the patentee to take a patent and control it in his own interest (subject, *207of course, to the Government’s right of use, if any) the committee said:
. . it must not be lost sight of that in general it is the constitutional right of every patentee to exploit his patent as he may desire, however expedient it may appear to endeavor to modify this right in the interest of the public when the patentee , is in the Government service.” 26
Concerning a requirement that all patents obtained by government employees be assigned to the United States or its agent, the committee said:.
. . it would, on the one hand, render difficult securing the best sort of technical men for the service and, on the other, would influence technical workers to resign in order to exploit inventions which they might evolve and suppress while still in the service. There has always, been more or less of a tendency for able men in the service to do this, particularly in view of the comparative meagerness of Government salaries; thus the Government has suffered loss among its most capable class of workers.” 27
The committee recommended legislation to create an Interdepartmental Patents Board; and further that the law make it part of the express terms of employment, having the effect of a contract, that any patent application made or patent granted for an invention discovered or developed during the period of government service and incident to the line of official duties, which in the judgment of the board should, in the interest of the national defense, or otherwise in the public interest, be controlled by the Government, should upon demand by the board be assigned by the employee to an agent of the Government. The recommended measures were not adopted.
*208Fifth. Congress has refrained from imposing upon government -servants a contract obligation' of the sort above described. At least one department has attempted to. do so by regulation.28 Since the record in this case discloses that the Bureau of Standards had no such regulation, it is unnecessary to consider whether- the various departments have power to impose such a contract upon employees without authorization by act of Congress. The question is more difficult under our form of government than under that of Great Britain, where such departmental regulations seem to settle the matter.29
All of this legislative history, emphasizes what we have stated — that the courts are incompetent to answer the difficult question whether the patentee is to be allowed ■ his exclusive right or compelled to dedicate his invention to the public. It is suggested that the election rests with the authoritative officers of the Government. Under what power, express or implied, may such officers, by administrative fiat, determine the nature and extent of .rights exercised under a charter granted a patentee pur-, suant to constitutional and legislative provisions? Apart from the fact that express authority is nowhere to be-1 found, the question arises, who are the authoritative officers whose determination shall bind the United States and the patentee? The Government’s position comes to this — that the courts may not reexamine the exercise of an authority by some officer, not named, purporting to deprive the patentee of the rights conferred upon him by law. Nothing would be settled by such a holding, except that the determination of the reciprocal rights and obligations of the Government and its employee as re*209spects inventions are to be adjudicated^ without review, by an unspecified department hea;d or bureau chief. Hitherto both the executive and the legislative branches of the Government have concurred in what we consider the correct view, — that any suchy declaration of policy must come from Congress and that no power to declare it is vested in administrative officers.
The decrees are Affirmed.
59 F. (2d) 381.
See Act of March 3,1901,31 Stat. 1449; Act of February 14, 1903, '§ 4, 32 Stat. 826. '
Act of March 4, 1915, 3S Stat. 1044; Act of May 29, 1920, 41 Stat. 684; Act of March 3, 1921, 41 Stat. 1303.
The fees charged cover merely the cost of the service rendered, as provided in the Act of June 30, 1932, § 312, 47 Stat. 410.
Webster's New International Dictionary: “Monopoly.”
tf.S. Code, Tit. 35, § 33.
R.S. 480; U.S. Code, Tit.'35, § 4.
19 Opinions Attorney-General, 407. -
20 Opinions Attorney-General, 329. And compare Report Judge Advocate General of the Navy, 1901, p. 6; Digest, Opinions Judge Advocate General of the Army, 1912-1930, p. 237; Opinions, Judge Advocate General of the Army, 1918, ,Vol. 2, pp. 529, 988, .1066.
No exhaustive examination of the-official records has been attempted. It is sufficient, however, for present purposes, to call attention to the following instances.
Dr. Frederick A. Kolster was employed in the radio section, Bureau of Standards, from December, 1912, until about March 1, 1921. He applied for the following patents: No. 1,609,366, for radio apparatus, application dated November 26, 1920. No. 1,44J,165, for -radio method and apparatus, application dated January 30, 1919. No. 1,311,654, for radio method and apparatus, application dated March 25, 1916. No. 1,394,560, for apparatus for transmitting radiant energy, application dated November 24, 1916. The Patent Office records show assignments of these patents to Federal Telegraph Company, San Francisco, Cal., of which Dr. Kolster is now president. He testified that these are all subject to a non-exclusive license in the United States to use and practice the same.
Burten McCollum was an employee of the Bureau of Standards between 1911 and 1924. On the dates mentioned he filed the following applications -for patents, which were issued to him. No. 1,035,373, alternating current induction motor, March 11, 1912. No. 1,156,364, induction motor, February 25, 1915. No. 1,226,091, alternating current induction motor, August 2, 1915. No. 1,724,495, method and apparatus for determining the slope of subsurface rock boundaries, October 24, 1923. No. 1,724,720, method and apparatus for studying subsurface contours, October 12 ,1923. The last two inventions were assigned to -McCollum Geological Explorations, Inc., a Delaware corporation.
Herbert B. Brooks, while ah employee of the Bureau between 1912 and 1930, filed, November 1, 1919, an application on which patent No. 1,357,197, for an electric transformer, was issued.
William W. Coblentz, an employee of' the Bureau of Standards from 1913, and still such at the date of the trial, on the dates mentioned, filed applications on which patents issued as follows: No. *1951,418,362, for electrical resistance, September 22, 1920. No. 1,458,165, system of electrical control, September 22,1920. No. 1,450,061, optical method for producing pulsating .electric current, August 6, 1920. No. 1,563,557, optical means for rectifying alternating currents, September 18, 1923. The Patent Office records show that all of these stand in the name of Coblentz, but are subject to a license to the United 'States of America.
August Hund, who was an employee of the Bureau from 1922 to 1927, on the dates mentioned filed applications on which letters patent issued: No. 1,649,828, method of preparing Piezo-electric plates, September 30, 1925. No.-1,688,713, Piezo-eleetric-crystal oscillator system, May 10, 1927. No. 1,688,714, Piezo-electric-erystal apparatus, May 12, 1927.' No. 1,648,689, condenser transmitter, April 10, 1926. All of these patents are shown of record to have been assigned to Wired Radio, Inc., a corporation.
Paul R. Heyl and Lyman J. Briggs, while employees of the Bureau, filed an application January 11, 1922, for patent No. 1,660,751, on inductor compass, and assigned the same to the Aeronautical Instrument Company of Pittsburgh, Pennsylvania.
C. W. Burrows-was an employee of the Bureau of Standards between 1912 and 1919. While such employee he filed applications on the dates mentioned for patents, which were issued: No. 1,322,405, October 4, 1917, method and apparatus for testing magnetizable objects by magnetic leakage; assigned to Magnetic Analysis Corporation, Long Island City, N.Y. No. 1,329,578, relay, March 13, 1918; exclusive license issued to make, use and sell for the field of railway signaling and train control, to Unión Switch & Signal Company, Swissvale, Pa. No. 1,459,970, method of and’ apparatus for testing magnetizable objects, July 25, 191-7; assigned to Magnetic Analysis Corporation, Long Island City, N.Y.
John A. Willoughby; an employee of the Bureau of Standards be-, tween 1918. and 1922, while so employed, on June 26, 1919, applied for arid was granted a patent, No. 1,555,345, for a loop antenna.
ct of March 3, 1883, c. 143, 22 Stat. 625.
See Squier v. American T. & T. Co., 21 F. (2d) 747, 748.
November 30, 1918; Opinions of Judge Advocate General, 1918, Vol. 2, p. 1029.
32 Opinions Attorney General, 145.
See Squier v. American Tel. & Tel. Co., 7 F. (2d) 831, 21 F. (2d) 747; Hazeltine Corporation v. Electric Service Engineering Corp., 18 F. (2d) 662; Hazeltine Corporation v. A. W. Grebe & Co., 21 F. (2d) 643; Selden Co. v. National Aniline & Chemical Co., 48 F. (2d) 270.
45 Stat. 467, 468.
Report No. 871, 70th Cong., 1st Sess., House of Representatives, to accompány H.R. 6103; Report No. 765, 70th Cong., 1st Sess.. Senate, to accompany H.R. 6103; Cong. Rec., House of Representatives, March 19, 1928, 70th Cong., 1st Sess., p. 5013; Cong. Rec., Senate, April 24, 1928, 70th Cong., 1st Sess., p. 7066.
Cong. Rec., 70th Cong., 1st Sess., Vol. 69, Part 5, p. 5013:
“ Mr. LaGuardia. Mr. Speaker, reserving the right to object, is not the provisb too broad? Suppose an employee of the Government invents some improvement which is very valuable, is he compelléd to give the Government free use of it?
" Mr, Vestal [who reported the bill for the Committee and was in charge of it]. If he is employed by the Government and the in*203vention is made while working in his capacity as an agent of the Government. If the head of the bureau certifies this invention will be used by. the Government, then the Government, of course gets it without the payment of any royalty.
“Mr. LaGuardia. The same as a factory rule?
“Mr. Vestal. Fes; but the man who takes put the patent has his commercial rights outside.
“Mr. LaGuardia. Outside of the Government?
“ Mr. Vestal. Yes.
“Mr. LaGuardia. But the custom is, and without this bill, the Government has the right to the use of the improvement without payment if it is invented in.Government time and in Government work.
“ Mr. Vestal. That is correct; and then on top of that, may I say that a number of instances-have occurred where' an employee of the .Government, instead of taking out a patent had some one else take out the patent and the Government has been involved in a number of suits. There is now $600,000,000 worth of such claims in the Court of Claims.”
It will be noted from the last statement of the gentleman in charge of the bill that Congress was concerned with questions of policy in the adoption of the amendment. Thése, as stated above, are questions of business policy and business judgment — what is to the best advantage of the Government and the public. They are not questions as to which the courts ought to invade the province of the Congress.
See Belknap v. Schild, 161 U.S. 10, 16; Eager v. United States, 35 Ct. Cls. 556.
Act of June 25, 1910, 36 Stat. 851: (See Crozier v. Krupp, 224 U.S. 290.)
“ That whenever an invention described in and covered by a patent of the United States shall hereafter be used by the United States without license of the owner thereof or lawful right to use, the same, such owner may recover reasonable compensation for such use by suit in the Court of Claims: Provided, however, That'said Court of Claims shall not entertain a suit or reward [sic] compensation under the provisions of this Act where the claim for compensation is based on the use by the United States of any article heretofore owned, leased, used by, or in the possession of the United States: Provided further', That in any such suit the United States may avail itself of any and all defenses, general or special, which might be pleaded by a defendant in an action for infringement, as set forth in Title Sixty of the Revised Statutes, or otherwise: And provided, further, That the benefits of this Act shall not inure to any patentee, who,' when he makes such claim is in the employment or service of the Government of the United States; or the assignee of any such patentee; nor shall this Act apply to any device discovered or invented by, such employee during the time of his employment or service.”
The Act was amended in respects immaterial to the present question, July 1, 1918, 40 Stat. 705. See William Cramp & Sons Co. v. Curtis Turbine Co., 246 U.S. 28; Richmond Screw Anchor Co. v. United States, 275 U.S. 331, 343. As amended it appears in U.S.C., Tit. 35, § 68.
House Report 1288, 61st Cong., 2d Sess.
S, 5265, 65th Cong. 3d Sess.; S. 3223, 66th Cong., 2d Sess.; H.R. 9932, 66th Cong., 2d Sess.; H.R. 11984, 66th Cong., 3d Sess.
Sen. Dpc. No. 83,- 68th Cong., 1st Sess., p. 3.
Hearings, Senate Patent Committee, 66th Cong., 2d Sess., January 23, 1920, p. 11.
Sen. Doe. No. 83, 68th Cong., 1st Sess., p. 3.
Ibid., p. 4.
See Annual Report, Department of Agriculture, for 1907, p. 775. See Selden Co. v. National Aniline & Chemical Co., 48 F. (2d) 270, 273.
Queen’s Regulations (Addenda 1895, 1st February); Ch. 1, Instructions for Officers in General,' pp. 15-16.
Act of March 3,. 1901, 31 Stat. 1449; Act of .February 14/1903, § 4, 32 Stat. 825, 82(3. For an account -of the origin and development of the Bureau and its predecessor, see Weber, The Bureau of Standards, 1-75.